Biomedical subjects

Masayoshi Fukushima

Publications and source records attributed to Masayoshi Fukushima.

5 recordsLinked to original sources

PubMed2007

Combination of non-viral connexin 43 gene therapy and docetaxel inhibits the growth of human prostate cancer in mice.

Docetaxel (DTX) is used for the treatment of advanced hormone refractory prostate cancer. Connexin 43 (Cx43) is a tumor suppressor gene, and transfection of the Cx43 gene increases sensitivity to several chemotherapeutic agents. The objective of this study was to evaluate the effectiveness of combination therapy of Cx43-expressing plasmid DNA (pCMV-Cx43) and DTX both in vitro and in vivo using a non-viral vector in human prostate cancer PC-3 cells. Transfection of pCMV-Cx43 into the cells neither inhibited tumor growth nor increased gap junctional intercellular communication; however, combination therapy of pCMV-Cx43 and DTX significantly inhibited cell growth. Forced expression of Cx43 in the cells induced apoptotic cells by down-regulation of Bcl-2 expression and significantly more up-regulation of caspase-3 activity than either treatment alone. The combination of repeated intratumoral injection of pCMV-Cx43 (10 microg/tumor) with non-viral vector and a single intravenous injection of DTX (15 mg/kg) was compared with a repeated injection of Cx43 alone and a single injection of DTX alone on PC-3 tumor xenografts. Significant antitumoral effects were observed in mice receiving combined treatment, compared with DTX alone. The data presented here provide a rational strategy for treating patients with advanced hormone refractory prostate cancer.

Animals↗

PubMed2006

Evaluation of a new fluoride-releasing one-step adhesive.

In this study, a newly developed S-PRG (surface pre-reacted glass-ionomer) filler-containing one-step adhesive, called SI (SI-IB551, Prototype), was evaluated regarding its fluoride release behavior. As a result, fluoride ion distribution in the tooth structures and acid resistance of cavity margins were also evaluated. In addition, Absolute (a fluoride-releasing one-step adhesive; AB) was evaluated in comparison to G-Bond (a non-fluoride-releasing one-step adhesive; GB) which was used as a negative control. Concentration of fluoride released was measured using a fluoride ion selective electrode after immersion of each material in distilled water. Fluoride distribution in tooth-adhesive interfacial areas was examined with EPMA following cavity preparation in human premolars and having treated resin restorations with each material. To evaluate acid resistance, restored specimens were immersed in an acetic acid buffer (0.2 M, pH 4.5) for 12 hours and then the cavity margins were observed using scanning electron microscopy. Amounts of fluoride released from AB and SI were significantly greater than that from GB. Further, significant differences in fluoride release were detected between AB and SI. A layer of increased fluoride density was clearly detected at the enamel- and dentin-SI interfaces. In terms of acid resistance, an acid resistance zone was also formed adjacent to the tooth-adhesive interface of AB and SI specimens. However, in GB specimen, acid resistance zone was not observed. These findings suggested that one-step adhesives displayed a favorable fluoride release property, thereby contributing positively to inhibition of recurrent caries.

Acrylic Resins↗

PubMed2005

Enamel micro-cracks produced around restorations with flowable composites.

In this study, enamel micro-cracks produced around flowable composite restorations were observed using a stereomicroscope and a scanning confocal laser microscope (SCLM). The effects of polymerization shrinkage, mobility of composite and polishing period after filling on the incidence of marginal enamel micro-cracks were examined. Enamel micro-cracks were observed on all of the composite restorations when the restoration was polished immediately after filling. Enamel micro-cracks distributed approximately parallel to the cavity margin and located 0.01-0.3 mm from the restored cavity margin. The occurrence of enamel micro-cracks was higher in conventional hybrid composite restorations than in flowable composites, and when polished 15 minutes after filling (as compared to 24 hours after filling).

Analysis of Variance↗

PubMed2004

Cariology in Japanese dental schools.

AIM: The aim of this study was to evaluate the teaching of cariology in Japanese dental schools. DESIGN: Postal questionnaires were sent to all Japanese dental schools. PARTICIPANTS: Twenty-five of the 29 Japanese dental schools (response rate: 86%). RESULTS: The results were in many areas similar to those reported from North America. The non-surgical approach to the management of primary caries predominated, but no schools used bacteriological tests in caries diagnosis and only one school recommended antibacterial treatment. Four of the 25 responding schools advocated the treatment of primary enamel lesions by surgical intervention while three awaited operative intervention until the lesions had reached the middle third of the dentine. Recommendation of fluoride treatment was less common than in North America. The use of electronic devices to diagnose occlusal caries lesions was more common than in North America, but 'explorer catch' was the most frequently used method to diagnose primary and secondary caries in dental schools in both regions. CONCLUSION: Research in cariology over the years has led to altered views on how and when to treat caries lesions. The interpretation of research findings and the transfer of knowledge by teachers in dental schools have an impact on the practice of operative dentistry, but the diversity in the teaching of cariology indicates that the interpretation and implementation of modern principles in the treatment of caries differ quite markedly in Japanese dental schools.

Curriculum↗

PubMed2004

An ultrastructural analysis of the prototype single-step adhesive applied on enamel and dentin surfaces.

A new type of self-etching agent, the single-step adhesive, was developed. The purpose of this study was to investigate the difference in the ultrastructural features of enamel and dentin surfaces following application of the prototype single-step adhesive (EXM618, 3M, MN, USA). Extracted caries-free human premolars were used in this study. Occlusal enamels of teeth--to be used as cut surface specimens--were removed perpendicular to the long axis of the specimens. The mesial and distal surfaces of these teeth, on the other hand, were used as uncut surface specimens in the test. In addition, Mega Bond (Kuraray Medical Inc., Tokyo, Japan) and Xeno CFII Bond (Dentsply Sankin, Tokyo, Japan) were used as controls. After covering half of the tooth surfaces with nail varnish (for control), the other half of each surface was treated with one of the three test adhesives--EXM618, Mega Bond, or Xeno CFII Bond--according to the manufacturer's recommendations. Conditioned enamel and dentin surfaces (i.e., decalcified depth and rugged surface) were observed with a scanning confocal laser microscope (SCLM 1100, Olympus, Tokyo, Japan; henceforth abbreviated as SCLM). Based on the findings of this study, the prototype single-step adhesive EXM618 appears to be suitable for use in dental clinics.

Acid Etching, Dental↗