[A persistent shock state with severe lactic acidosis, after increasing biguanaide to a diabetic patient with renal impairment].
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Acidosis, Lactic↗
Biomedical subjects
Yumiko Hosoya
Publications and source records attributed to Yumiko Hosoya.
Membrane potential of rat ventricular myocytes responds to axial stretch in phase, amplitude and speed-dependent manners.
OBJECTIVE: To elucidate the interdependence between the mechanical state of the myocardium and its electrical activity, previous studies have been performed at the cellular level. However, the information to date has been limited by the technical difficulties associated with stretching single myocytes. METHODS: We solved this problem by combining two techniques, namely a carbon fiber technique for stretching rat myocytes with wide ranges of amplitude and speed, and ratiometric measurement of a fluorescent indicator (di8-ANEPPS) for evaluating the membrane potential in the non-contact mode. RESULTS: During systole, stretching caused depolarization that prolonged the action potential duration without affecting the peak amplitude, but the effect was only significant in the late phase. Application of a stretch to quiescent myocytes depolarized the membrane potential in amplitude- and speed-dependent manners, but the response was suppressed by cytochalasin D treatment, suggesting participation of the cytoskeleton in the mechanotransduction mechanism. Finally, ion replacement experiments revealed that although Na+ was the dominant charge carrier for large amplitude stretches, Ca2+ permeation was involved in small amplitude stretches, suggesting amplitude-dependent ion selectivity. CONCLUSIONS: Application of axial stretching to rat ventricular myocytes changed the membrane potential in phase-, amplitude- and speed-dependent manners. Amplitude may also modulate the ion selectivity of stretch-activated channels.
Animals↗
Micro-tensile bond strength of sound and caries-affected primary tooth dentin measured with original designed jig.
To measure the micro-tensile bond strength (MTBS) on sound and caries-affected primary tooth dentin using an original designed jig that was developed for making symmetric and uniformly-sized specimens for the micro-tensile strength testing. The MTBS of dumbbell-shaped specimens and matchstick-shaped specimens were measured. Dumbbell-shaped specimens: The occlusal surfaces of 15 sound primary molars were ground with a water-cooled air turbine using a diamond bur. The adhesive systems and resin-based composites were Clearfil SE Bond and Clearfil AP-X (SE group) and Single Bond and Z250 (SB group). Matchstick-shaped specimens: Sixteen primary molars (5 sound and 11 carious) were used. The occlusal surfaces of sound teeth were ground with a water-cooled air turbine using a diamond bur. Infected dentin was determined by a caries detecting dye solution and removed with a round-shaped steel bur under water-cooling and with a hand instrument. SE was applied. Data was statistically analyzed using ANOVA and Fisher's PLSD at p < 0.05. The MTBSs (MPa) for the dumbbell-shaped specimens were 8.9 +/- 7.0 in the SE group and 10.3 +/- 5.8 in the SB group and that for the matchstick-shaped specimens were 9.0 +/- 6.3 in the sound-SE group and 9.2 +/- 5.8 in the carious-SE group. No significant difference was observed among them.
Bisphenol A-Glycidyl Methacrylate↗
Ultrastructure of intraradicular dentin after irrigation with BioPure MTAD. II. The consequence of obturation with an epoxy resin-based sealer.
In addition to an initial report on the creation of thick demineralized collagen matrices in root dentin that were irrigated with BioPure MTAD or EDTA as final rinses for 5 minutes, this study examined the effect of a 2-minute irrigation time of these final irrigants on the extent of demineralization of intact intraradicular dentin and on interfacial nanoleakage after obturation with AH Plus and gutta-percha using warm vertical compaction. Transmission electron microscopy confirmed that the reduction in irrigation time did not compromise the smear layer removing capacity of these two irrigants when 1.3% NaOCl was employed as the initial rinse. BioPure MTAD created 5 to 6 microm thick demineralized dentin matrices, while 17% EDTA produced 1 to 2 microm thick matrices that were suboptimally infiltrated by the epoxy resin-based sealer, as manifested by the occurrence of silver tracer deposits within the hybrid layers.
Chelating Agents↗
Study of the colors and retention of over-the-counter cosmetic veneers.
The purpose of this study was to observe the tooth colors and retention of a cosmetic veneer Fiche Pearl On containing shellac and five experimental formulations containing benzoin gum and ethyl cellulose. Tooth color was measured with a spectrophotometer before and after application of the veneers to the buccal or labial surface of experimental teeth. Through both in vitro and in vivo studies, the retention rates of veneers were assessed. In terms of color difference (deltaE*ab) between before and after veneer application, it ranged from 4.3 (Fiche Pearl On) to 15.0 (experimental formulation White Plus). In terms of retention rate, in vitro test found the retention rate of experimental formulation White Plus was significantly higher than that of Fiche Pearl On. In in vivo test where subjects were permitted to drink water and tea, it was found that the retention rate after two hours ranged from 94.0 to 98.5%. In conclusion, teeth applied with the experimental cosmetic veneer formulations showed better color and retention than teeth with Fiche.
Analysis of Variance↗
Influence of tooth-polishing pastes and sealants on DIAGNOdent values.
OBJECTIVE: The purpose of this study was to investigate the influence of tooth-polishing pastes and sealants on values obtained with a caries diagnostic system based on detection of caries-associated fluorescence (DIAGNOdent, KaVo). METHOD AND MATERIALS: Ten tooth-polishing pastes and four dentifrices were measured alone, and it was shown that products containing pumice gave high DIAGNOdent values. The deepest occlusal pits of 20 extracted sound premolars (12 unsealed teeth, 8 sealed teeth) were measured before polishing, after rotating-brush polishing with pumice-containing tooth-polishing paste, and after final rotating-brush polishing with water in this in vitro study. In the clinical phase, the deepest occlusal pits of 21 molars and 2 premolars that clinically required application of sealant were measured before polishing, after rotating-brush polishing with one of two pumice-containing tooth-polishing pastes, and after sealant application. All measurements were done five times, and the average values were obtained. Data were statistically analyzed using analysis of variance subsequent to Fisher's protected, least significant difference. RESULTS: Clinical study showed that the value after polishing with either of the two polishing pastes was significantly higher than the value before polishing. Both in vitro and clinical studies showed that the value was increased by pumice-containing paste polishing and rotating-brush polishing with water after paste polishing could not recover the value to the level before paste polishing. Sealant treatment in the clinical study significantly decreased DIAGNOdent values, and the values after sealant application were lower than the values before polishing. CONCLUSION: Polishing pastes and sealants used in this study could interfere with DIAGNOdent values.
Analysis of Variance↗
Effects of diamond bur particle size on dentin bond strength.
PURPOSE: To evaluate the influence of particle size of originally designed diamond burs on resin adhesion to sound young human permanent dentin. METHODS: The buccal surfaces of 105 premolars were used. Six test groups were prepared. The adhesive systems and resin-based composites used for Groups 1-3 were Clearfil SE Bond (SE) and Clearfil AP-X, and for Groups 4-6, Single Bond (SB) and Z250. Flat dentin surfaces were finely ground with 25 microm particle size IW-G5 diamond bur (IW-G5, Groups 1 and 4), 50 microm particle size IW-G4 diamond bur (IW-G4, Groups 2 and 5), or 600-grit SiC paper (#600, Groups 3 and 6). The microstructure of the prepared dentin, SE primed or SB etched dentin, and resin-dentin interfaces of each group (3 teeth/group) were studied using SEM. Shear bond strengths (SBS) in MPa were tested (10 teeth/group), and the failed surfaces were observed using SEM. Data was statistically analyzed using ANOVA and Fisher's PLSD at P < 0.05. RESULTS: The dentin ground with the IW-G5 or IW-G4 bur was rougher than the dentin ground with the 600-grit SiC paper. The mean SBS (MPa) for Groups 1-6 were: 32.3 +/- 5.0, 27.6 +/- 6.4, 21.3 +/- 3.6, 5.9 +/- 2.9, 6.5 +/- 3.1 and 5.3 +/- 2.0. The SBS of Groups 1-3 (SE groups) were significantly higher than those of Groups 4-6 (SB groups). The SBS of Group 1 (IW-G5, SE group) was significantly higher than those of Groups 2 (IW-G4, SE group) and 3 (#600, SE group), and the SBS of Group 2 was significantly higher than that of Group 3. There was no significant difference for SBS among Groups 4, 5 and 6. Fracture mode after SBS test mainly showed mixed fracture (adhesive and cohesive resin fracture) for the SE groups, and adhesive fracture for the SB groups.
Analysis of Variance↗
Microleakage and sealant penetration using a vibrating probe.
PURPOSE: To evaluate the effect of a vibrating probe on sealant penetration into pits and fissures. METHODS: Thirty-six extracted human third molars were used. The occlusal surface of each molar was cleaned with a rubber cup and pumice slurry. Scotchbond Etchant (35% phosphoric acid gel) was applied to the occlusal fissures of each molar for 20 seconds. Fissures were then sealed as follows: Group 1: Concise Light Cured White Sealant was applied without vibration; Group 2: same as in Group 1 but with vibration; Group 3: Single Bond Adhesive was applied, then Concise Light Cured White Sealant was applied without vibration; Group 4: same as in Group 3, but sealant was applied with vibration; Group 5: Concise Light Cured White Sealant was applied without vibration, then Z-100 composite was burnished over the sealant and light-cured; Group 6: same as in Group 5, but sealant was applied with vibration. Microvibe vibrating probe was used for sealant vibration. After 24-hour immersion in 2% basic fuchsin dye solution, specimens were sectioned, and dye and sealant penetration were scored using a stereomicroscope and color slides. Selected sectioned samples were observed under the SEM. RESULTS: No statistically significant differences between the groups were observed for either dye or sealant penetration scores. In all groups, sealant penetration was more influenced by the shape, depth and residual debris of fissures than by the use of a vibrating probe.
Acid Etching, Dental↗
Bonding efficacy of single-step self-etch systems to sound primary and permanent tooth dentin.
Currently, there is little information regarding the bonding efficacy of single-step self-etch systems to primary tooth dentin. This study examined the microtensile bond strength of single-step self-etch systems (Clearfil tri-S Bond and One-Up Bond F Plus) to sound primary and permanent tooth dentin. Adhesives were applied to flat samples of primary and permanent tooth dentin, and resin composites were bonded according to the manufacturers' instructions. After 24 hours of storage in distilled water at 37 degrees C, hour glass-shaped specimens were produced. They were subjected to microtensile testing at a crosshead speed of 1.0 mm/minute. The results were analyzed using 2-way analysis of variance (ANOVA) followed by the Tukey HSD post-hoc test (alpha=0.05). Field-emission scanning electron microscopy (FE-SEM) observations of the adhesive-treated dentin surfaces and the resin/dentin interface were also conducted. The bond strengths of primary tooth dentin were significantly lower than that of permanent tooth dentin for both self-etch systems: 44.7 +/- 10.4 versus 54.3 +/- 9.0 MPa for Clearfil tri-S Bond and 40.6 +/- 9.9 versus 50.0 +/- 8.7 MPa for One-Up Bond F Plus (p<0.001). There was no statistically significant interaction between the type of adhesive system and the dentin substrate (p=0.957). Although there was no statistically significant difference in the mean values among the different adhesive systems (p=0.094), there was a statistically significant difference in mean values among the different dentin substrates (p<0.001), which were lower for primary tooth dentin than for permanent tooth dentin. The failure modes were also independent of the type of dentin but dependent on the adhesive systems, an equal distribution among the 3 types of failure for Clearfil tri-S Bond and cohesive failures in adhesives for One-Up Bond F Plus. FE-SEM observations of dentin to which adhesive had been applied revealed that the smear layer had been removed and the collagen fibers exposed. Though the bond strengths to primary tooth dentin were lower than to permanent tooth dentin, excellent adaptation of the single-step self-etch systems to both dentin substrates was observed by FE-SEM. Further studies are required to determine the long-term clinical performance of these adhesive systems when applied to primary tooth dentin.
Adhesives↗
Colorimetric values of esthetic stainless steel crowns.
OBJECTIVES: The colorimetric values of two different kinds of esthetic stainless steel crowns were measured and compared with the colorimetric values of primary anterior teeth in Japanese children. METHOD AND MATERIALS: The colorimetric values of resin composite-faced stainless steel crowns (Kinder Krown) and epoxy-coated stainless steel crowns (White Steel Crown) were measured with a color difference meter. The Commission Internationale de Eclairage L*, a*, b*, and delta E*ab values and Munsell value, chroma, and hue were calculated. The data were compared with previously reported colorimetric values of Japanese primary anterior teeth measured with the same color difference meter used in this study. RESULTS: Compared to Japanese primary anterior teeth, Kinder Krown Pedo I and Pedo II showed much higher L* values and lower hue; on the other hand, White Steel Crown showed much higher L*, a*, b* values, much higher value and chroma, and much lower hue. CONCLUSION: Color analysis revealed that the colors of the White Steel Crown and Kinder Krown Pedo I were substantially different from the color of Japanese primary anterior teeth. The color difference between Pedo II crowns and Japanese primary anterior teeth was relatively high, but the color of Pedo II might be acceptable for clinical use.
Algorithms↗