Antimicrobial susceptibility surveillance of bacterial isolates recovered in Japan from odontogenic infections in 2013.

We report on the findings of the first antimicrobial susceptibility surveillance study in Japan of isolates recovered from odontogenic infections. Of the 38 facilities where patients representing the 4 groups of odontogenic infections were seen, 102 samples were collected from cases of periodontitis (group 1), 6 samples from pericoronitis (group 2), 84 samples from jaw inflammation (group 3) and 54 samples from phlegmon of the jaw bone area (group 4) for a total of 246 samples. The positivity rates of bacterial growth on culture were 85.3%, 100%, 84% and 88.9%, respectively, for groups 1, 2, 3 and 4. Streptococcus spp. isolation rates according to odontogenic infection group were 22% (group 1), 17.7% (group 3) and 20.7% (group 4). Anaerobic isolation rates were 66.9% (group 1), 71.8% (group 3) and 68.2% (group 4). Drug susceptibility tests were performed on 726 strains excluding 121 strains that were undergrown. The breakdown of the strains subjected to testing was 186 Streptococcus spp., 179 anaerobic gram-positive cocci, 246 Prevotella spp., 27 Porphyromonas spp., and 88 Fusobacterium spp. The isolates were tested against 30 antimicrobial agents. Sensitivities to penicillins and cephems were good except for Prevotella spp. The low sensitivities of Prevotella spp is due to ß-lactamase production. Prevotella strains resistant to macrolides, quinolones, and clindamycin were found. No strains resistant to carbapenems or penems were found among all strains tested. No anaerobic bacterial strain was resistant to metronidazole. Antimicrobial susceptibility testing performed on the S. anginosus group and anaerobic bacteria, which are the major pathogens associated with odontogenic infections, showed low MIC90 values to the penicillins which are the first-line antimicrobial agents for odontogenic infections; however, for Prevotella spp., penicillins combined with ß-lactamase inhibitor showed low MIC90 values.

Long-term culture of human odontoma-derived cells with a Rho kinase inhibitor.

Because of cellular senescence/apoptosis, no effective culture systems are available to maintain replication of cells from odontogenic tumors especially for odontoma, and, thus, the ability to isolate human odontoma-derived cells (hODCs) for functional studies is needed. The current study was undertaken to develop an approach to isolate hODCs and fully characterize the cells in vitro. The hODCs were cultured successfully with a Rho-associated protein kinase inhibitor (Y-27632) for an extended period with stabilized lengths of the telomeres to sustain a similar phenotype/property as the primary tumoral cells. While the hODCs showed stable long-term expansion with expression of major dental epithelial markers including dentin sialophosphoprotein (DSPP) even in the three-dimensional microenvironment, they lack the specific markers for the characteristics of stem cells. Moreover, cells from dental pulp showed significant up-regulation of DSPP when co-cultured with the hODCs, while control fibroblasts with the hODCs did not. Taken together, we propose that the hODCs can be isolated and expanded over the long term with Y-27632 to investigate not only the development of the hODCs but also other types of benign human tumors.

The effects of perioperative oral management on perioperative serum albumin levels in patients treated surgically under general anesthesia: A multicenter retrospective analysis in Japan.

ABSTRACT: The purpose of the present study was to investigate the efficacy of perioperative oral managements (POMs) on perioperative nutritional conditions in patients undergoing surgery with general anesthesia. Medical records were retrospectively reviewed and the effects of POMs were investigated based on a large number of cases using a multicenter analysis. The profile of serum albumin levels was assessed and compared between patients with and without POMs using the multivariate analysis. Seventeen Eleven thousand and one hundred sixty patients (4,873 males and 6,287 females) were reviewed. Of these, 2710 patients (24.3%) had undergone POMs. The results of a multivariate analysis revealed the significant positive effect of POMs on perioperative serum albumin level (change between at admission and discharge, (Estimate: 0.022, standard error: 0.012, P < .0001). Patient gender, age, surgical site, performance status, the American Society of Anesthesiologists (ASA) physical status classification, operation time, amount of blood loss, and serum albumin level at admission were also significant predictors. Adjusted multivariate analysis of the effects of POMs on perioperative change of serum albumin level in all subjects reveled the significance of POMs intervention (estimate: 0.022, standard error: 0.012, P < .0001). These results suggest that POMs exerts significant positive effects on perioperative serum albumin levels in patients underwent surgery under general anesthesia.

The number of microvascular complications is associated with an increased risk for severity of periodontitis in type 2 diabetes patients: Results of a multicenter hospital-based cross-sectional study.

AIMS/INTRODUCTION: To explore the relationships between periodontitis and microvascular complications as well as glycemic control in type 2 diabetes patients. MATERIALS AND METHODS: This multicenter, hospital-based, cross-sectional study included 620 patients with type 2 diabetes. We compared the prevalence and severity of periodontitis between patients with ≥1 microvascular complication and those without microvascular complications. We also compared the prevalence and severity of periodontitis among patients with different degrees of glycemic control. RESULTS: After adjusting for confounding factors, multiple logistic regression analysis showed that the severity of periodontitis was significantly associated with the number of microvascular complications (odds ratio 1.3, 95% confidence interval 1.1-1.6), glycated hemoglobin ≥8.0% (64 mmol/mol; odds ratio 1.6; 95% confidence interval 1.1-2.3), and older age (≥50 years; odds ratio 1.7; 95% confidence interval 1.1-2.6). However, the prevalence of periodontitis was not significantly associated with the number of microvascular complications, but was associated with male sex, high glycated hemoglobin (≥8.0% [64 mmol/mol]), older age (≥40 years), longer duration of diabetes (≥15 years) and fewer teeth (≤25). Furthermore, propensity score matching for age, sex, diabetes duration and glycated hemoglobin showed that the incidence of severe periodontitis was significantly higher among patients with microvascular complications than among those without microvascular complications (P < 0.05). CONCLUSIONS: The number of microvascular complications is a risk factor for more severe periodontitis in patients with type 2 diabetes, whereas poor glycemic control is a risk factor for increased prevalence and severity of periodontitis.

Elevation of galectin-9 as an inflammatory response in the periodontal ligament cells exposed to Porphylomonas gingivalis lipopolysaccharide in vitro and in vivo.

Considerable evidence suggests that periodontal disease not only is caused by bacterial infection but also is associated with host susceptibility. Using in-house cDNA microarray analysis, we attempted to identify gene expression changes in human periodontal ligament (PDL)-derived cells with and without treatment with lipopolysaccharide (LPS) extracted from Porphylomonas gingivalis (P. gingivalis LPS). Of the five up-regulated genes in the PDLs treated with P. gingivalis LPS, galectin-9, which was reported to have eosinophil chemoattraction, was selected for further analyses. By semiquantitative reverse transcriptase-polymerase chain reaction (sqRT-PCR), real-time quantitative RT-PCR, and Western blot analyses, elevated galectin-9 gene expression was detected in LPS-treated PDL-derived cells. Consequently, it was confirmed that the LPS enhances the expression level of galectin-9 mRNA and protein in a time-dependent manner together with interleukin-8. In addition, strong immunoreaction for galectin-9 was detected in the PDL consisting of the periodontal pocket of a patient with severe periodontal disease. Furthermore, significant up-regulation of galectin-9 mRNA expression was detected in the mRNA from PDLs of patients with periodontal disease when compared with healthy donors (P < 0.05). These results suggest that galectin-9 expression is associated with inflammatory reactions in the PDL.

Expression of caveolin-1 and its correlation with cisplatin sensitivity in oral squamous cell carcinoma.

PURPOSE: Cisplatin (CDDP) is widely used for chemotherapy of oral squamous cell carcinoma (OSCC). However, the mechanism of resistance to CDDP is unclear. Recently, caveolin-1 was identified as being associated with both metastasis and multidrug resistance. In the present study, we showed that caveolin-1 expression is significantly related to chemosensitivity in OSCC. METHODS: We established a CDDP-resistant cell line, H-1R, from the parental OSCC cell line, H-1. Caveolin-1 expression was determined by reverse transcriptase-polymerase chain reaction (RT-PCR) in both cell lines. We analyzed expression of caveolin-1 in 30 OSCC biopsy specimens and investigated the relationship between expression of caveolin-1 and patients' clinicopathological parameters and chemotherapeutic responses. RESULTS: The 3-(3,4-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay indicated that H-1R has a ten-times greater resistance to CDDP than H-1 has. The level of caveolin-1 expression in H-1R was significantly decreased in comparison with that in H-1 by real-time RT-PCR analysis. Positive caveolin-1 immunostaining correlated positively with a complete response (16/20, 80.0%). However, negative immunostaining was found in 6/7 (85.7%) cases with no response. Positive immunohistochemical staining of caveolin-1 correlated positively with chemosensitivity to CDDP-based combination chemotherapy (P=0.02). CONCLUSIONS: These results suggest that overexpression of the caveolin-1 gene may provide novel diagnostic markers associated with CDDP sensitivity in OSCC.

Establishment and gene analysis of a cisplatin-resistant cell line, Sa-3R, derived from oral squamous cell carcinoma.

Cisplatin (CDDP) is widely used for chemotherapy of many malignancies, especially of oral squamous cell carcinoma (SCC). However, because the mechanism of resistance to CDDP is unclear, we established a CDDP-resistant cell line, Sa-3R, from a CDDP-sensitive cell line, Sa-3, which was derived from moderately differentiated SCC of the lower gingiva. The 3-(3,4-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide assay indicated that Sa-3R has 7.5-fold greater resistance to CDDP than Sa-3. Comparing gene expression levels in the cell lines using an in-house cDNA microarray, which represented 2,201 oral disease origin genes, many differentially expressed genes were identified. The ATP-binding cassette transporter genes (MDR-1, MRP-1, and MRP-2), and FANCONI, GRP58, FLJ12089, and SPINT-2 were up-regulated, whereas FOSL1, MRPS27, and PGK-1 were down-regulated. These results were confirmed by semiquantitative reverse transcriptase-polymerase chain reaction. The Sa-3/Sa-3R cell lines could be useful to identify the candidates responsible for the mechanism of CDDP-resistance and the up- or down-regulated genes identified by the gene expression profiles in the Sa-3R cell line may be, in part, associated with the mechanism.

Establishment and characterization of a cisplatin-resistant oral squamous cell carcinoma cell line, H-1R.

Cisplatin (CDDP) is a widely used potent chemotherapeutic agent for many malignancies. However, the mechanism of resistance to CDDP remains unclear. To investigate the molecular mechanism, we established a CDDP-resistant cell line (H-1R) from a CDDP-sensitive cell line (H-1) which was derived from moderately differentiated squamous cell carcinoma of the lower gingiva. The 3-(3,4-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) assay indicated that H-1R had a 10-fold greater resistance to CDDP than H-1. When we compared gene expression levels in the cell lines using an in-house cDNA microarray, which represented 2,201 genes originating from normal oral tissue, primary oral cancer, and oral cancer cell lines, 12 genes showing elevated mRNA expression in H-1R compared with H-1 were identified. Among them, the up-regulated expression of ATP-binding cassette transporter genes (MDR1, MRP1, and MRP2), CD55, and PGK1 and down-regulated expression of Caveolin 1 were further confirmed by semiquantitative reverse transcriptase-polymerase chain reaction (PCR) or real-time PCR. Our results suggest that H-1 and H-1R cell lines could be useful for elucidating the candidate genes responsible for CDDP resistance, including the genes found in this study.

Interleukin-1 receptor antagonist (IL1RN) is associated with suppression of early carcinogenic events in human oral malignancies.

Inflammatory abnormalities have been implicated in the pathogenesis of various human diseases, including cancer. Interleukin-1 receptor antagonist (IL1RN) is a potent anti-inflammatory molecule that modulates the biological activity of the proinflammatory cytokine, interleukin-1. The aim of this study was to examine the expression of IL1RN in oral squamous cell carcinomas (OSCCs), and to determine its clinical significance. Expression levels of IL1RN in matched normal and tumor specimens from 39 OSCCs were evaluated using real-time quantitative polymerase chain reaction methods, and immunohistochemical analysis. Protein expression of IL1RN was also examined in 18 oral premalignant lesions (OPLs). Expression of IL1RN mRNA was significantly downregulated in OSCCs compared with normal tissues. Decreased expression of IL1RN protein was also observed in OPLs and OSCCs. The IL1RN expression level was lower in the OPL cases with severe dysplasia compared to those with mild/moderate dysplasia. Significantly downregulated IL1RN expression was observed in all OSCC lesion sites examined when compared with the matched normal tissues. However, the decreased level of IL1RN expression did not correspond with tumor progression. Noteworthy, IL1RN expression was higher in the advanced OSCC cases (T3/T4) compared to early cases (T1/T2). Among OSCC samples, relatively higher IL1RN expression was associated with active tumor development in the OSCCs occurring in the buccal mucosa, oral floor, fauces and gingiva, but not the tongue. These data suggest that IL1RN may exhibit opposing characteristics in oral malignancies depending on the stage of cancer development, suppressing early carcinogenic events, yet promoting tumor development in some lesion sites. Thus, IL1RN could represent a reliable biomarker for the early diagnosis of OSCCs. Furthermore, IL1RN may possess unknown and complex functions in the developed OSCC.

Maxillary Swelling as the First Evidence of Multiple Myeloma.

Multiple myeloma is a malignant neoplasm of plasma cells characterized by proliferation of a single clone of abnormal immunoglobulin-secreting plasma cells. Since the amount of hemopoietic bone marrow is decreased in the maxilla, oral manifestations of multiple myeloma are less common in the maxilla than in the mandible. We report the case of 33-year-old Japanese man who presented with a mass in the right maxillary alveolar region. Computed tomography and magnetic resonance images showed a soft tissue mass in the right maxilla eroding the anterior and lateral walls of the maxillary sinus and extending into the buccal space. The biopsy results, imaging, and laboratory investigations led to the diagnosis of multiple myeloma. This case report suggests that oral surgeons and dentists should properly address oral manifestations as first indications of multiple myeloma.

Expression and regulation of the gene for arginase I in mouse salivary glands: requirement of CCAAT/enhancer-binding protein alpha for the expression in the parotid gland.

Arginase in salivary glands is potentially involved in the synthesis of proline, glutamate, and polyamines that play specific physiological roles in the glands, and also in depletion of arginine in the oral cavity to protect teeth from microorganisms. We detected protein and mRNA for the type I isoform of arginase in mouse salivary glands. Enzymes of the arginine-biosynthetic pathway were also detected. Immunohistochemical analysis revealed that arginase I was enriched in the striated duct, and was also present in the acinus, demilune and granulated duct. Mice with targeted disruption of the gene for C/EBPalpha, which is a transcription factor essential for expression of the arginase I gene in the liver, showed dramatically reduced immunoreactivity for arginase I in the parotid gland but not in the submandibular and sublingual glands. Therefore, C/EBPalpha is specifically required for expression of the arginase I gene in the parotid gland.

Relationship between the number of remaining teeth and physical activity in community-dwelling elderly.

The relationship between oral health and general health in the elderly has been much studied. However, further studies focussing on the influence of oral health on the quality of life (QOL) among the elderly are required. The goal of this study was to evaluate the relationship between oral health and physical or cultural activities. Subjects were 101 community-dwelling elderly persons who were functionally independent (mean age 70.3). Oral health status was evaluated according to the number of remaining teeth and the number of functional teeth. Physical and cultural activities were evaluated from self-reported information. The relationship between oral health and physical or cultural activities was examined by logistic regression analysis. About 60% of subjects took part in cultural activities, and less than half actively exercised (leisure sports, 33.6%; travel, 42.6%). Persons with 20 or more remaining teeth were more active in leisure sports (Odds ratio (OR)=4.86, 95% confidence interval (CI)=1.34, 17.38) and travel (OR=5.42, 95% CI=1.63, 18.08) than those with fewer than 20 remaining teeth. These results suggest that the number of remaining teeth is associated with physical activity in elderly persons.

Relationship between oral motor dysfunction and oral bacteria in bedridden elderly.

OBJECTIVE: The purpose of this study was to analyze the relationship between oral bacterial colonization and oral motor dysfunction. STUDY DESIGN: Oral motor dysfunction (swallowing and speech disorders) and detection of oral bacterial species from dental plaque in 55 elderly persons who had remained hospitalized for more than 3 months were investigated and statistically analyzed. RESULTS: The detection rates of methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Streptococcus agalactiae, and Stenotrophomonas maltophilia were significantly higher in subjects with than in those without a swallowing disorder. A similar result was found with regard to the presence of a speech disorder. About half of subjects who had oral motor dysfunction and hypoalbuminemia had colonization by MRSA and/or Pseudomonas aeruginosa. CONCLUSION: These results suggest that the combination of oral motor dysfunction and hypoalbminemia elevated the risk of opportunistic microorganisms colonization in the oral cavity of elderly patients hospitalized over the long term.

Epithelioid myoepithelioma of the hard palate.

BACKGROUND: Myoepithelioma, a generally benign tumor comprised of myoepithelial cells, is an uncommon salivary gland tumor. Among four morphologic variants of myoepithelioma, epithelioid type has not been reported in the oral and maxillofacial region. CASE REPORT: A 61-year-old man first noticed the mass 3 years previously. The oral examination revealed a firm, non-tender, and well-circumscribed mass in the middle of the hard palate. A magnetic resonance imaging scan showed a well-circumscribed mass with low signal intensity (T(1)-weighted image) or increased signal intensity (T(2)-weighted image). DISCUSSION: Immunohistochemically, the tumor cells in the present case reacted to the epithelial (CK HMW and CAM5.2) and the mesenchymal (vimentin) markers. However, myoepithelial markers (S-100 protein, α-smooth muscle actin, glial fibrillary acidic protein, and calponin), except p63, were not expressed in the tumor cells. These results indicated that the epithelial myoepithelioma cells differentiated into epithelial cells rather than myoepithelial cells. We believe that epithelioid myoepithelioma of the palate is a distinctive subtype of myoepithelioma that should be included in the differential diagnosis of tumors of the palate.

Gibberellic acid induces α-amylase expression in adipose-derived stem cells.

Salivary α-amylase is the most important enzyme for oral digestion of dietary starch. Therefore, regeneration of the salivary glands via a tissue engineering approach is clearly required for patients with salivary gland dysfunction. Early during seed germination, the embryo synthesizes gibberellic acid (GA3), a plant hormone that activates the synthesis and secretion of α-amylase. The purpose of this study was to explore an approach for differentiation of stem cells into salivary glands using GA3. We isolated adipose-derived stem cells (ASCs), which are positive for mesenchymal stem cell markers (CD73, CD90 and CD105) and possess pluripotency to osteoblasts, adipocytes and neural cells, from human buccal fat pads, which are a readily available source for dentists and oral surgeons. In addition, we investigated the cytotoxicity of GA3 for human ASCs. GA3 neither affects cell morphology nor cell viability in a dose- or time-dependent manner. ASCs were incubated with GA3 to assess mRNA and protein expression of α-amylase by reverse transcriptase-polymerase chain reaction and western blot analyses. α-amylase mRNA expression on 21 days after treatment with GA3 (1 mM) was seven times greater than that in resting condition (Day 0). While we did not detect α-amylase bands on Day 0, α-amylase protein was detectable 7 days after treatment with GA3, reaching a maximal level on Day 21. Our results indicated that GA3 can increase cellular α-amylase expression and that our induction method would be useful for therapeutic application for salivary gland regeneration.

GLUT1 is highly expressed in cementoblasts but not in osteoblasts.

Cementum is a specialized mineralized tissue covering root surface of the tooth. Although the tissue's composition resembles bone, there are distinct structural and functional differences between the two mineralized tissues. In this study, the genes that are differentially expressed in putative cementoblasts (human cementum-derived cells [HCDCs]) compared with preosteoblastic cells (human bone marrow stromal cells [BMSCs]) were screened by two independent microarray systems, and some of the selected genes were further analyzed by quantitative real-time RT-PCR. The gene encoding glucose transporter 1 [GLUT1], which showed the greatest difference between the two groups by the latter analysis, was subjected to further analyses. High levels of the GLUT1 protein in HCDCs, but not in BMSCs, were detected by Western blotting and immunocytochemistry. Furthermore, intense immunoreactivities for GLUT1 were observed in cementoblasts and cementocytes but not in osteoblasts or osteocytes in human periodontal tissues. These results indicate that GLUT1 may play a role in cementogenesis and could serve as a biomarker to differentiate between cells of cementoblastic and osteoblastic lineage.

Contribution of body habitus and craniofacial characteristics to segmental closing pressures of the passive pharynx in patients with sleep-disordered breathing.

Obesity and craniofacial abnormalities may contribute to the pathogenesis of obstructive sleep apnea. The purpose of this study was to evaluate the influence of body habitus and craniofacial characteristics on types of pharyngeal closure. The types of pharyngeal closure were determined by endoscopic evaluations of closing pressures of the passive pharynx in 54 paralyzed and anesthetized patients with sleep-disordered breathing (SDB). Assessment of craniofacial characteristics of the SDB patients and 24 normal subjects were made by lateral cephalometry. As compared with normal subjects, SDB patients demonstrated receded mandibles and long lower faces with downward mandible development. SDB patients with positive closing pressures at both the velopharynx and oropharynx (VP + OP group) demonstrated smaller maxillas and mandibles than those with positive closing pressures at the velopharynx only (VP-only group). Obesity was more prominent in the VP-only group than in the VP + OP group. Our results suggest that obesity and craniofacial abnormalities contribute synergistically to increases in collapsibility of the passive pharyngeal airway in patients with SDB. Furthermore, the relative contribution of obesity and craniofacial anomaly appears to determine the type of pharyngeal closure in SDB.