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Biomedical subjects

Naoyuki Sugano

Publications and source records attributed to Naoyuki Sugano.

7 recordsLinked to original sources

Periodic exacerbation of gingival inflammation during the menstrual cycle.

Sex hormones are believed to be a risk factor for periodontitis because of their ability to proliferate specific periodontal microorganisms and affect host immunologic response. In this case report, gingival redness and swelling occurred during the menstrual cycle, although the patient maintained good oral hygiene during periodontal treatment. Medical history revealed that exacerbation of gingival inflammation corresponded to the menstrual cycle and occurred during the ovulation period, when estrogen levels are high. Mean bleeding index of the ovulation period (18.9%) showed higher levels than that during the menstrual phase (5.3%). This case indicates that frequent and effective maintenance should be provided while considering the influence of the menstrual cycle, as sex hormones may be involved in exacerbating gingival inflammation.

Adult↗

A marker of oxidative stress in saliva: association with periodontally-involved teeth of a hopeless prognosis.

The aim of this study was to determine the association between levels of a marker of oxidative stress, 8-hydroxydeoxyguanosine (8-OHdG), in saliva and the presence of teeth with a hopeless prognosis as a result of advanced periodontitis. Thirty-four periodontitis patients were divided into two groups based on the presence or absence of periodontally-involved teeth of hopeless prognosis. Salivary levels of 8-OHdG in those with were significantly higher than in subjects without periodontally-involved teeth of hopeless prognosis (4.78 +/- 0.14 ng/ml and 2.35 +/- 0.18 ng/ml, respectively). We also evaluated 8-OHdG levels in gingival crevicular fluid (GCF) of teeth with advanced periodontal destruction (mean probing depth = 7.2). In this case, 8-OHdG was detected only from those periodontally-involved teeth of hopeless prognosis, and only in some cases (8 out of 18 samples). These data suggest that periodontally-involved teeth of hopeless prognosis are a major source of salivary 8-OHdG. Measurement of salivary 8-OHdG levels may prove to be useful in identifying patients with teeth of hopeless prognosis.

8-Hydroxy-2'-Deoxyguanosine↗

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↗

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↗

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↗

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↗

New biomarker evidence of oxidative DNA damage in whole saliva from clinically healthy and periodontally diseased individuals.

BACKGROUND: There is an increasing body of evidence implicating reactive oxygen species in the pathogenesis of periodontal tissue destruction. 8-Hydroxy-deoxyguanosine (8-OHdG) is one of the most commonly used markers to evaluate oxidative damage in a number of disorders including chronic inflammatory diseases. The aim of the present study was to evaluate 8-OHdG levels in whole saliva of patients with periodontitis and to assess the changes after initial treatment. METHODS: Saliva samples were collected from 78 patients with untreated periodontitis and 17 healthy control subjects. Clinical parameters and levels of 8-OHdG were assessed first to establish a baseline and again after initial periodontal treatment from 15 patients. 8-OHdG levels were determined by enzyme-linked immunosorbent assay. RESULTS: The mean value of 8-OHdG in the saliva of periodontally diseased subjects, 4.28 +/- 0.10 ng/ml, was significantly higher (P<0.01) than that of clinically healthy subjects (1.56 +/- 0.10 ng/ml). A significant decrease in salivary 8-OHdG was observed after therapy (P<0.01). CONCLUSION: In the present study, we evaluated for the first time 8-OHdG levels in whole saliva of patients with periodontitis and assessed changes after initial periodontal treatment. Our study indicated that 8-OHdG levels in saliva appear to reflect the status of periodontal health.

8-Hydroxy-2'-Deoxyguanosine↗