Biomedical subjects

Maiko Oshikawa

Publications and source records attributed to Maiko Oshikawa.

5 recordsLinked to original sources

PubMed2004

Gene expression in the developing rat mandible: a gene array study.

To analyse the molecular events that occur in the developing mandible, gene arrays containing probes for 1176 known genes were used. Total RNA was extracted from the mandibles of 1- and 6-day-old rats. Radiolabeled probes were then synthesised and used to probe the DNA arrays. Of the 1176 genes examined, 306 were detectable, and the latter were analyzed by bioinformatics algorithms. K-means clustering grouped 72 genes into Up, 56 genes into Down and 178 genes into NO change. A large number of genes related to cell receptors (by ligands) were grouped into the Down cluster. Gene array technology appears to be a useful tool for studying the complex process of mandibular development.

Animals↗

PubMed2004

Relationship between Porphyromonas gingivalis, Epstein-Barr virus infection and reactivation in periodontitis.

The aim of this study was to assess the relationship-between Porphyromonas gingivalis, Epstein-Barr virus (EBV) infection and reactivation in periodontitis using real-time PCR. The mean proportion of P. gingivalis cells to total bacterial cells in the saliva from EBV-positive periodontitis patients was significantly higher than that in saliva from EBV-negative patients. An EBV-positive B-cell line was used to determine whether P. gingivalis sonicate induced reactivation of EBV, using real-time PCR to measure the virus genome in the culture medium. A significant increase in EBV numbers was observed after the stimulation with P. gingivalis sonicate. These findings suggest that the interaction between EBV and P. gingivalis is bi-directional, with EBV reactivation suppressing host defenses and permitting overgrowth of P. gingivalis, and P. gingivalis having the potential to induce EBV reactivation.

Adult↗

PubMed2004

Differential gene induction in macrophage-like human cells by two types of Porphyromonas gingivalis: a microarray study.

Several studies have provided clinical evidence that FimA clonal variation may contribute to the periodontopathogenicity of Porphyromonas gingivalis (P.g.). We studied the gene expression profiling of the macrophage-like human cell line U937 after infection of two types of P.g. (fimA type I; Pg-I and fimA type II; Pg-II) using microarray. Of 1088 genes examined, 394 genes were detectable. Bioinformatics algorithms were used to analyze the detectable genes. Hierarchical clustering analysis showed that gene expression patterns of Pg-II and the control (no infection) were grouped together. K-means clustering grouped 79 genes into Pg-II dominance and 88 genes into Pg-I dominance. A large number of genes related to cell signaling, extracellular communication proteins, cell receptors (by ligands), protein turnover and cell adhesion receptors/proteins were grouped into clusters of Pg-I dominance. Our results indicate that compared with Pg-I, Pg-II induces a low host response as measured by its weak induction of gene expression.

Bacteroidaceae Infections↗

PubMed2003

Detection of Streptococcus anginosus and 8-hydroxydeoxyguanosine in saliva.

Several studies have demonstrated a close association between Streptococcus (S.) anginosus infection and head and neck cancer. Accumulation of 8-hydroxy-deoxyguanosine (8-OHdG), which may result from the continuous generation of reactive oxygen species associated with chronic inflammation, has been reported in human preneoplastic lesions and in cancerous tissues. The purpose of the present investigation was to assess the salivary levels of S. anginosus and 8-OHdG in patients with periodontitis. Salivary levels of S. anginosus were measured by real-time PCR. S. anginosus was detected in 28 out of 38 (73.7%) of subjects. The 8-OHdG level was significantly higher in patients positive for S. anginosus than in patients negative for the bacterium. A significant decrease in S. anginosus and 8-OHdG levels was observed after initial periodontal treatment. Our findings indicate that, although the levels of S. anginosus are relatively low, there is a correlation between the salivary level of S. anginosus and 8-OHdG, and that periodontal treatment can decrease the levels of these hazard factors.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed2002

Effects of ipriflavone on bone augmentation within a titanium cap in rabbit calvaria.

Ipriflavone (7-isopropoxyisoflavone, IP), a drug used in the treatment of osteoporosis, may promote bone formation during bone remodeling. IP has been shown to accelerate both the activity of, and formation of mineralized nodules by a human osteosarcoma cell line at an early stage. However, the direct effects of IP on bone augmentation have not been investigated. The purpose of this study was to determine whether IP induces bone augmentation within a titanium cap in rabbit calvaria at an early stage. Five adult male Japanese white rabbits were used. One cap (test site) was packed with IP in a collagen gel, and the other (control site) was packed with the collagen gel alone. After the one- and three-month healing periods, we measured the newly generated tissue and bone within the titanium caps. The amount of newly generated tissue within the titanium caps of the control sites was higher than the tests sites after one month and three months. However, the percentage of newly generated bone/bone marrow in the newly generated tissue at the test sites was higher than for the control sites after one month and three months. These results suggest that IP affects the quality of bone augmentation at an early stage.

Animals↗