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Biomedical subjects

A Ehara

Publications and source records attributed to A Ehara.

At least 19 recordsLinked to original sources
PubMed2004

Effects of cyclosporin-A-induced immunosuppression on periapical lesions in rats.

Cyclosporin A (CsA) might induce immune response alterations in periapical lesions and modify bone remodeling. This study determined the changes that occur in the periapical lesions of rats during CsA administration and after CsA withdrawal. After the induction of periapical lesions, the animals were treated with CsA (0-20 mg/kg/day) for 4 wks. Lesion volumes were measured by computed tomography. Histological observations and immunohistochemical evaluations were performed with anti-CD3 and anti-CD25 antibodies. CsA administration reduced lesion volumes, and the lesions significantly expanded after CsA withdrawal. CsA inhibited the proliferation and activation of T-cells at lesion sites. The effects of CsA on T-cells were dose-dependent up to 10 mg/kg/day, after which no significant difference was evident. These results suggest that CsA inhibits periapical destruction by interfering with T-cell function in periapical lesions.

Alveolar Process↗
PubMed2001

Degree of conversion of composites measured by DTA and FTIR.

OBJECTIVE: Differential thermal analysis (DTA) using a split fiber optic light source has been reported to be a convenient method of measuring the degree of conversion (DC) of light-activated composites. The purpose of this study was to compare the results by DTA and Fourier transformation infrared spectroscopy (FTIR), and evaluate the usefulness of the DTA method. METHODS: Experimental 2,2-bis[4-(3-methacryloyloxy-2-hydroxypropoxy)phenyl]propane-based composites containing SiO2 filler and various amounts of triethyleneglycol dimethacrylate (TEGDMA) were prepared, and the DC of each composite was determined by DTA or FTIR with 60s irradiation. The DC of three proprietary composites containing hybrid filler or prepolymerized resin filler were also measured by both methods with 20 or 60s irradiation. The results were analyzed by ANOVA and Fisher's protected least significant difference test. RESULTS: By both DTA and FTIR, the DC of experimental composites increased as the proportion of TEGDMA increased, although DTA showed 3-10% greater values (p<0.05) than FTIR. For proprietary composites that contain hybrid filler, the values by DTA were not significantly different from those by FTIR at 20s exposure. Longer irradiation time resulted in greater DC (p<0.05) for both methods, and DTA showed 5-7% greater values than FTIR. However, the DC of the composite containing prepolymerized resin filler was 30% less by FTIR than by DTA, possibly due to the influence of unpolymerized species in the filler. SIGNIFICANCE: The DC values determined by DTA and FTIR showed good agreement for most materials including model composites. In addition, DTA may be more useful than FTIR to measure the DC of composites containing prepolymerized resin filler.

Analysis of Variance↗
PubMed2001

Control of hydroxyapatite crystallinity by mechanical grinding method.

Crystallinity of hydroxyapatite reflecting crystal size and crystal elastic strain was controlled by the mechanical grinding (MG) technique using a set of container and balls made of SUS304 stainless steel or agate. Variation in the crystallinity through MG was monitored by the XRD method and represented by the broadening of the diffraction peak. Effect of changes in crystallite size and strain on the crystallinity was also examined using the Hall-plot method. Crystallinity rapidly decreased with milling time. Significant crystallographic diffraction peaks disappeared and a broad diffraction around 2theta=32 degrees was observed after MG for 72 h. The broadening was dominantly due to an increase in crystal strain in addition to fine crystallite size. Contamination from the container and balls during MG was more suppressed using agate than SUS304 stainless steel. The recovery process of crystallinity during heating between 300 degrees C and 1200 degrees C was examined focusing on the decrease in residual elastic strain. Low crystallinity was maintained at annealing temperatures below 800 degrees C but lattice defects were recovered above 1000 degrees C.

Journal Article↗
PubMed2000

Time-course changes of eosinophil counts in premature infants: no effects of medical manipulation, except erythropoietin treatment, on eosinophilia.

In order to determine the factors responsible for eosinophilia during the neonatal period, we counted the eosinophils of premature infants every week and compared the medical profiles of infants with eosinophil counts above the 95th percentile and those below that percentile during the course of study. Medical treatments such as mechanical ventilation, antibiotics administration and intravenous catheterization had no significant effects on the increase of eosinophils. Furthermore, the incidence of eosinophil counts above the 95th percentile was not different between breast-fed and formula-fed infants. The infants treated with erythropoietin had greater eosinophil counts than those with no treatment. It is probable that medical manipulation using foreign bodies such as intratracheal tube, intravenous catheter, antibiotics and artificial formula had no significant effects on the increase of eosinophil counts, except for exogenous erythropoietin.

Disease Progression↗
PubMed2000

Are high barometric pressure, low humidity and diurnal change of temperature related to the onset of asthmatic symptoms?

BACKGROUND: Meteorologic factors play a role in the expression of asthmatic symptoms; however, there are controversies about the causal relationship between meteorologic factors and asthma. The relationship between meteorologic parameters and emergency admissions for asthmatic symptoms in this hospital were analyzed. METHODS: A total of 205 patients (130 boys and 75 girls, 0.1-16.6 years of age) who were admitted to Hakodate Chuo General Hospital for asthmatic symptoms between 1 January and 31 December 1997 were submitted to our study. We divided a total of 365 days into two groups of days with and without any admissions. Meteorologic factors for the days with admissions and 1-3 days before hospitalization were compared with those of the days of no admissions. Statistical analysis was done with the Mann-Whitney U-test. RESULTS: On the days with admissions and 1 day before hospitalizations, barometric pressure was higher and relative humidity lower than on days with no admissions. The diurnal difference between maximum and minimum temperature for days 1 day before days with admissions was larger than that for 1 day before days with no admissions. CONCLUSIONS: It is thought that change in barometric pressure, relative humidity and temperature had some influence on the worsening of asthmatic symptoms.

Asthma↗
PubMed2000

Age-dependent expression of abdominal symptoms in patients with Yersinia enterocolitica infection.

BACKGROUND: The aim of the present study was to determine the relationship between the expression of abdominal symptoms and the age of patients with Yersinia enterocolitica infections. METHODS: Twenty-four patients with positive fecal cultures of Yersinia enterocolitica participated in the present study. The abdominal symptoms were taken from medical records. Statistical analysis was performed by Mann-Whitney U-test. RESULTS: Patients with diarrhea were younger than those without diarrhea (P = 0.014). Older children had abdominal pain or irritability more frequently than younger children (P = 0.004). CONCLUSIONS: In Yersinia enterocolitica infections, younger children are predisposed to diarrhea and older children are predisposed to abdominal pain.

Abdominal Pain↗
PubMed2000

Antibacterial activities and release kinetics of a newly developed recoverable controlled agent-release system.

We attempted to develop a resin with a recoverable antibacterial activity based on the desorption/adsorption of a cationic bactericide by the ion-exchange mechanism. The aims of this study were to investigate the release kinetics of the agent and the antibacterial activity of this newly designed resin system. An experimental resin was prepared by the addition of methacrylic acid as a cation-exchanger and a cationic antibacterial agent, cetylpyridinium chloride (CPC), to triethyleneglycol dimethacrylate. The amount of CPC desorbed from the experimental resin into buffer solutions at pH 4-8 was measured. The adsorption of CPC to control resin and re-adsorption of CPC to the experimental resin, which had once desorbed the agent, were also determined. The antibacterial activity of experimental resin against Streptococcus mutans was evaluated, and the relationship between bacterial acid production and antibacterial effect was assessed. The experimental resin desorbed CPC at pH < or = 6, and the amount of agent desorbed increased with increasing acidity. The control resin adsorbed CPC when immersed in CPC aqueous solution at a rate determined by the concentration of the agent and immersion time. The experimental resin, once desorbed CPC, could re-adsorb the bactericide by being exposed to a solution of the agent. Less plaque formed on the experimental resin, and the growth and survival of S. mutans was inhibited in the condition in which acid was produced. These results demonstrate that the resin system proposed was able to desorb and re-adsorb the cationic bactericide by an ion-exchange mechanism and could show an inhibitory effect on S. mutans growth and plaque formation.

Adsorption↗
PubMed1999

Post-irradiation polymerization of composites containing bis-GMA and TEGDMA.

OBJECTIVE: This study was conducted to evaluate the effect of the amount of TEGDMA on post-irradiation polymerization of bis-GMA based composites. METHODS: Four experimental composites containing bis-GMA and TEGDMA at the ratios (w/w) of 75/25, 70/30, 67/33, and 50/50 were prepared. The degree of conversion of each composite was measured by Fourier transformation infrared spectroscopy immediately after being cured and after 24 h of storage, and the post-irradiation polymerization was determined. In addition, the change in respective amounts of residual bis-GMA and TEGDMA in cured specimens over 24 h was determined by high performance liquid chromatography. Data were analyzed by means of ANOVA, followed by a Fisher's PLSD test at a significance level of 0.05. RESULTS: At both stages of as-cured and after 24 h-sotrage, the composites containing greater amounts of TEGDMA showed a greater degree of conversion. The amount of post-irradiation polymerization decreased as the content of the incorporated TEGDMA increased. The reduction in the amount of TEGDMA remaining unreacted during post-irradiation polymerization also decreased as the content of TEGDMA increased, while the amount of unreacted bis-GMA showed almost constant values. SIGNIFICANCE: An increase in the amount of TEGDMA-incorporation in bis-GMA based composites resulted in less post-irradiation polymerization. As the change in the amount of residual unreacted TEGDMA in cured specimens showed the same trend as the results of the post-irradiation polymerization. TEGDMA is considered to be the main contributor to post-irradiation polymerization of bis-GMA based composites.

Analysis of Variance↗
PubMed1998

Antibacterial activity of dentine primer containing MDPB after curing.

OBJECTIVES: A monomer methacryloyloxydodecylpyridinium bromide (MDPB) has antibacterial activity before polymerization. Furthermore, the antibacterial agent is immobilized by the polymerization of MDPB and the resin-based material incorporating MDPB is able to show an antibacterial effect even after being cured. The purpose of this study was to investigate the antibacterial effect of a dentine primer containing MDPB after curing. METHODS: The inhibitory effect of a cured MDPB-containing primer on the growth of Streptococcus mutans, Actinomyces viscosus and Lactobacillus casei was determined by the agar-disc method. The bactericidal activity of cured primer during a 1-h contact period was assessed using S. mutans, and the elution of unpolymerized MDPB was measured with high performance liquid chromatography. RESULTS: Cured MDPB-containing primer showed an inhibitory effect on the growth of all species which were in contact with the specimen surface, and displayed a little bactericidal effect on S. mutans without releasing any unpolymerized antibacterial components. CONCLUSION: Incorporation of antibacterial monomer MDPB into dentine primer is beneficial for providing antibacterial activity after curing.

Actinomyces viscosus↗
PubMed1994

A case of Fanconi syndrome whose origin was suspected to be cystinosis.

We report a case of 6 year old girl with Fanconi syndrome the origin of which was suspected to be cystinosis. Pathological findings of a renal biopsy showed needle-like materials in the epithelial cells but the cystine content of the white blood cells was normal. Although excessive urinary loss of growth hormone was detected, the height and weight of the patient was normal. Urinary loss of growth hormone did not cause growth retardation in this case.

Body Height↗
PubMed1991

Structural basis of electrophoretic variants of rat alpha-fetoprotein.

The molecular basis for electrophoretic variations of rat alpha-fetoprotein was studied. Stepwise deglycosylations of proteins and radiolabeling of the sugars indicated that the number of such chains per molecule is two and one for the slow and fast variants, respectively.

Amidohydrolases↗
PubMed1991

[Electrophoretic variants of rat alpha-fetoprotein].

It has been well documented that rat AFP is separated into two discrete fractions electrophoretically and by ion exchange chromatography and it is generally accepted that the two forms of AFP, "Slow" and "Fast" variants, have different charges and molecular sizes. In this paper, the molecular basis of electrophoretic variants of rat alpha-fetoprotein (AFP) was studied. Carbohydrate-free rat AFP was electrophoretically homogeneous. Stepwise conversion of molecular sizes by deglycosylation with glycopeptidase F and the specific activities of the variants of which sugar chains were radiolabelled suggest that "Slow" and "Fast" variants have two and one sugar chains per molecule, respectively.

Amidohydrolases↗