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Biomedical subjects

A Manabe

Publications and source records attributed to A Manabe.

At least 127 records · Page 7Linked to original sources

Umbilical artery blood flow velocity waveforms in pregnancy complicated by diabetes mellitus.

Umbilical artery blood velocity waveforms were recorded by a pulsed Doppler system in the third trimester of pregnancy in 16 diabetic women (12 class B, 1 class C, 3 class D) and the waveforms were analysed for resistance index (RI = peak systolic velocity minus end diastolic velocity/peak systolic velocity). There was no significant correlation between the RI values and either serum glucose (r = 0.385) or fructosamine levels (r = 0.380). However, the RI values were raised in two cases with serum glucose levels of over 300 mg/dl. With a fall in serum glucose levels, the RI values returned to the normal range. No abnormal umbilical artery velocity waveforms were found when the serum glucose level was below 200 mg/dl.

Blood Flow Velocity↗

The optimum combination of dentin bonding systems.

The efficacy of dentin bonding systems composed of a commercial or an experimental dentin cleanser, a dentin primer, and an intermediate resin was examined by measurement of the wall-to-wall polymerization contraction gap. Light-activated composites in a cylindrical dentin cavity were prepared in exposed dentin of the proximal surface of the extracted human premolar. The combination of a dentin cleanser of neutralized 0.5 mol/L EDTA, a dentin primer of 35% hydroxyethyl methacrylate (HEMA) or 35% HEMA containing 5% glutaraldehyde and a commercial intermediate resin (Clearfil New Bond, Kuraray Co., Osaka, Japan; Pyrofil Light Bond, Sankin Co., Osaka, Japan) was effective in compensating for the contraction stress of a light-activated composite and for obtaining marginal integrity between the composite and the dentin cavity wall.

Composite Resins↗

Bonding efficacy of erythritol methacrylate solutions as dentin primers.

The bonding efficacy of aqueous solutions of two kinds of erythritol methacrylates as dentin primers was examined by measurement of the polymerization contraction gap of a light-activated resin composite in a cylindrical dentin cavity and the tensile bond strength of the composite to the flat dentin surface. The dentin surface was cleaned with neutralized 0.5 mol/L EDTA and pre-treated with a meso-erythritol or penta-erythritol methacrylate solution, followed by application of a commercial dentin bonding agent (Clearfil New Bond) and a resin composite. Among the tested primers, a 40% meso-erythritol methacrylate solution was shown to be the most effective because, in contrast to the other primers, contraction gap formation by the composite was prevented in all tested specimens.

Composite Resins↗

Effect of water sorption and thermal stress on cavity adaptation of dental composites.

The effect of water sorption of composite and thermal stress on the marginal adaptation to the dentin cavity wall was evaluated by measurement of the gap width between composite fillings and the dentin cavity wall. The wall of a cylindrical dentin cavity prepared in the proximal surface of extracted human molars was cleaned with neutralized 0.5 M EDTA and pre-treated with one of three experimental dentin primers [35% hydroxyethyl methacrylate (HEMA), 35% HEMA containing 5% glutaraldehyde, and 35% glyceryl methacrylate]. A light-activated composite (Silux, 3M Co., St. Paul, MN) was used to fill the cavity after application of a bonding agent (Clearfil New Bond, Kuraray Co., Osaka, Japan). The marginal gap width was measured after the specimens were immersed in water and thermal-cycled. The initial contraction gap of the tested bonding systems was closed completely by the water sorption of the composite for six hours, and such a marginal adaptation was not interrupted by 60 thermal cycles between 10 and 45 degrees C. Among the dentin primers tested, only the 35% aqueous solution of glyceryl methacrylate mediated gap-free fillings in all specimens.

Composite Resins↗

Morphological changes of rabbit skin by application of dentin primer.

The side effects of dentin primer applications on soft tissue were examined pathologically. Of the 4 experimental dentin primers tested, dimethylaminoethyl methacrylate (DMAEM) and glutaraldehyde (GLU) caused irritation to the skin of rabbits whereas hydroxyethyl methacrylate (HEMA) and glyceryl methacrylate (GM) caused only insignificant changes in the substrate. It was concluded that an aqueous solution of GM can be used clinically because of its low irritation to skin and high bonding efficacy, as previously reported, though possible irritation to pulp tissues should perhaps still be investigated. The mechanisms of irritation to operator fingertips caused by repeated direct contact with dentin primers containing HEMA remain unknown.

Animals↗

Investigation of self-etching dentin primers.

In order to simplify the dentin bonding procedures by combining the dentin cleansing and dentin primer steps, we investigated the efficacy of the four acidic monomers--monomethacryloxyethyl succinate (MES), dimethacryloxyethyl phosphate (DMEP), tertiary butylacrylamide sulfonic acid (TBAS), and 4-methacryloxyethyl trimellitic anhydride (4-META), diluted in 35% hydroxyethyl methacrylate (HEMA) solution--by measuring the maximum contraction gap of the visible-light-curing composite (Silux 3M, St. Paul, MN, USA) in the cylindrical dentin cavity mediated by the bonding agent (Clearfil New Bond, Kuraray Co., Osaka, Japan). More than five of the ten specimens which were pre-treated with an aqueous mixture of 35% HEMA and four functional monomers at the concentrations of 0.1 M, 0.2 M, and 0.3 M showed a complete marginal adaptation, and this result was the same as in the control group in which the cavities were cleansed and pre-treated with 0.5 M EDTA and 35% HEMA, respectively. Moreover, the procedures were simpler. Therefore, these four monomers are considered to be effective as self-etching primers.

Acid Etching, Dental↗

Dentin surface roughness vs. bond strength of dentin adhesives.

The effects of differently prepared dentin surfaces on the bond strength mediated by five dentin adhesive/composite resin systems were investigated: Clearfil new bond/Clearfil Ray, Gluma/Lumifor, Scotchbond/Silux, Scotchbond 2/Valux, and Tenure/Silux. Bonding surfaces were produced either by wet-grinding of human teeth on SiC paper, grits 180, 240, 320, 400, 600, and 4000, respectively, or by cutting them with dental preparation instruments. The surfaces of the dentin were analyzed by a profilometer. Tensile bond strengths (TBS) were determined two min after light activation of the restorative systems. In spite of greatly different effective areas for bonding, ANOVA showed no significant differences on the 5% level between the TBS means of one material system recorded for the different dentin preparations. It was concluded that the dentin roughness produced by preparation has no significant influence on early bond strengths of bonding composite resin systems.

Dental Bonding↗

Cerebral artery blood flow velocity waveforms in normal and small for dates fetuses.

Middle cerebral artery (MCA) blood flow velocity waveforms were recorded by a pulsed Doppler system in normal and small for dates (SFD) fetuses. Eighty four normal growth fetuses and 15 SFD fetuses were studied between the 28th and 40th gestational week. The flow velocity waveforms were analysed to determine the resistance index (RI = peak systolic velocity minus end diastolic velocity/peak systolic velocity). The results obtained were as follows: 1. The mean values of RI in the MCA had a peak of 0.802 +/- 0.049 at 32-33 gestational weeks and decreased gradually to a level of 0.686 +/- 0.087 at 40 gestational weeks. 2. In 8 asymmetrical SFD fetuses, the RI values for the MCA were below the normal range (mean -1.5 SD) in 6 cases and normal in 2 cases. 3. The RI values for MCA in all 7 symmetrical SFD fetuses were in the normal range.

Blood Flow Velocity↗

Efficacy of glyceryl methacrylate as a dentin primer.

The efficacy of pretreatment on the dentin surface with an aqueous solution of glyceryl methacrylate (GM) was examined by measuring the wall-to-wall polymerization contraction of a light activated composite in a cylindrical dentin cavity, and by measuring the tensile bond strength to a flat dentin surface. All of the tested dentin surfaces were cleaned with neutralized 0.5 M EDTA and treated with experimental primers, followed by a marketed dentin bonding agent and composite. The contraction gap formation of the composite was completely prevented by the application of the GM solution at concentrations of 25 and 35% in water. In contrast, half of the specimens treated with 35% HEMA and 35% HEMA containing 5% glutaraldehyde showed gap formation. Furthermore, a considerably high tensile bond strength of more than 18MPa was observed in the above described dentin bonding system.

Dental Bonding↗

zero.1-T human fat/water separation by SIDAC.

High-resolution human fat/water separated images were obtained in 17 min at a static magnetic field strength as low as 0.1 T. The sequence used was based on SIDAC (spectroscopic imaging by dephasing amplitude changing), which employs a stepwise changing dephase gradient for the separation of spectral and spatial information of magnetic spins.

Adipose Tissue↗

[Effects of phenol and related compounds on erythrocytes and hepatocytes from rats and dipalmitoyl phosphatidylcholine-liposomes].

The effects of phenol, guaiacol and m-cresol on erythrocytes, hepatocytes, dipalmitoyl phosphatidylcholine (DPPC)-liposomes and surface tension were studied at various concentrations. Phenol at 10 mM caused a slight inhibition of hypotonic hemolysis in rat erythrocytes. Guaiacol at 4 and 10 mM and m-cresol at 0.6 to 10 mM caused a significant inhibition of hypotonic hemolysis. In the enzyme leakage from isolated rat hepatocytes, phenol at 0.001 to 0.4 mM and 2 to 10 mM, guaiacol at 2 to 10 mM and m-cresol at 0.001 to 4 mM caused an inhibition in GOT leakage. The leakage of GPT from hepatocytes was inhibited by phenol at 0.4 to 10 mM, guaiacol at 2 to 10 mM, and m-cresol at 0.001 to 4 mM. m-Cresol at 10 mM caused increases in GOT and GPT leakage. The inhibition of phenol and m-cresol on the LDH leakage in hepatocytes were observed at a concentration of 0.001 mM and 0.1 to 1 mM, respectively. Guaiacol or m-cresol at 10 mM caused an increase in LDH leakage. Phase-transition temperature of DPPC-liposomes was depressed by phenol and m-cresol at 1 to 10 mM and by guaiacol at 5 and 10 mM. Guaiacol at 1 and 10 mM and m-cresol at 10 mM caused a depression of surface tension, but phenol caused no change in surface tension. The order of effects on erythrocyte, hepatocyte and DPPC-liposome membranes was m-cresol greater than phenol greater than or equal to guaiacol. In the present study, phenol and its related compound showed a positive correlation between their effects on various membranes and germicidal effects as evaluated by the phenol coefficient, but the effects were not related to a depression of surface tension.

1,2-Dipalmitoylphosphatidylcholine↗