Nishie M.,Kyushu University |
Nagao J.-I.,Fukuoka Dental College |
Sonomoto K.,Kyushu University
Biocontrol Science | Year: 2012
Bacteriocins are ribosomally synthesized antibacterial peptides produced by bacteria that inhibit the growth of similar or closely related bacterial strains. A number of bacteriocins from a wide variety of bacteria have been discovered, and their diverse structures have been reported. Growing evidence suggests that bacteriocins have diverse structures, modes of action, mechanisms of biosynthesis and self-immunity, and gene regulation. Bacteriocins are considered as an attractive compound in food and pharmaceutical industries to prevent food spoilage and pathogenic bacterial growth. Furthermore, elucidation of their biosynthesis has led to the use of bacteriocin-controlled gene-expression systems and the biosynthetic enzymes of lantibiotics, a class of bacteriocins, as tools to design novel peptides. In this review, we summarize and discuss currently known information on bacteriocins produced by Gram-positive bacteria and their applications.
Islam M.R.,Kyushu University |
Nagao J.-I.,Fukuoka Dental College |
Zendo T.,Kyushu University |
Sonomoto K.,Kyushu University
Biochemical Society Transactions | Year: 2012
Lantibiotics are ribosomally synthesized antimicrobial peptides that commonly target the cell wall precursor lipid II during their antimicrobial mechanism and exert their inhibitory activity by (i) inhibition of cell wall biosynthesis, and (ii) stable pore formation in the target membrane. Type-A(I) (i.e. nisin) and two-component (i.e. lacticin 3147) lantibiotics initially interact with lipid II to stabilize the complex, which then proceeds to inhibit cell wall biosynthesis and pore formation. Type-A(II) (i.e. nukacin ISK-1) and type-B (i.e. mersacidin) lantibiotics also use lipid II as a docking molecule, but can only inhibit cell wall biosynthesis without forming pores. In the present paper, we review the antimicrobial mechanism of different types of lantibiotics, their current progress and future prospect. ©The Authors Journal compilation ©2012 Biochemical Society.
Ojima M.,Osaka University |
Hanioka T.,Fukuoka Dental College
Tobacco Induced Diseases | Year: 2010
Many epidemiological evidences have proven the association between smoking and periodontal disease. The causality can be further established by linking findings of traditional epidemiological studies with the developments in molecular techniques that occurred in the last decade. The present article reviews recent studies that address the effect of smoking on molecular and genetic factors in periodontal disease. Most findings support the fact that tobacco smoking modulates destruction of the periodontium through different pathways: microcirculatory and host immune systems, connective tissue, and bone metabolism. Although smokers experience an increased burden of inflammatory responses to microbial challenges compared to non-smokers, understanding the association between smoking and periodontal diseases involves substantial problems with respect to accuracy of measurements, and particularly, sampling of many subjects. It remains unclear whether genetic susceptibility to periodontal disease is influenced by exposure to smoking or the effect of smoking on periodontal disease is influenced by genetic susceptibility. Employment of molecular techniques may play a key role in further elucidation of mechanisms linking smoking and periodontal destruction, the direct relationship as environmental factors and indirect relationship through genetic factors. © 2010 Ojima and Hanioka; licensee BioMed Central Ltd.
Nogami K.,Fukuoka Dental College
Journal of Oral and Maxillofacial Surgery | Year: 2015
Purpose The aim of this study was to evaluate the relative effectiveness of stellate ganglion blockade (SGB) versus xenon light irradiation (XLI) for the treatment of neurosensory deficits resulting from orthognathic surgery as determined by a comparison of prospective measurements of electrical current perception thresholds (CPTs) and ranged CPTs (R-CPTs). Materials and Methods CPT and R-CPT in the mental foramen area were measured during electrical stimulation at 98 different sites on the body in patients who had undergone orthognathic surgery. After surgery, patients were assigned to the SGB group or the XLI group. CPT and R-CPT of the 2 groups were measured at stimulation frequencies of 2,000, 250, and 5 Hz before surgery, 1 week after surgery, and after 10 treatment sessions. Furthermore, the influence of surgical factors, such as genioplasty and a surgically exposed inferior alveolar nerve (IAN), was examined in the 2 groups. Results Patients' CPT and R-CPT values indicated a considerable amount of sensory disturbance in most cases after surgery. The change in magnitude of all CPT and R-CPT values for the SGB group decreased considerably compared with that for the XLI group after treatment. There was no correlation between CPT or R-CPT values and surgical factors (eg, genioplasty and exposure of the IAN). Conclusion SGB of the IAN could be an effective method for treating neurosensory deficits after orthognathic surgery on the IAN. © 2015 American Association of Oral and Maxillofacial Surgeons.
Kawaguchi M.,Fukuoka Dental College
International journal of nanomedicine | Year: 2011
Carbon nanotubes act as a photon antenna that serves as an effective "molecular heater" around the near-infrared (NIR) region. This exothermic generation can be used as a possible heating source for hyperthermia therapy. The current study reports the dispersible and exothermic properties with NIR irradiation for single-walled carbon nanotubes (SWNTs) treated with a strong acid (acid-treated SWNTs), and the SWNTs further functionalized with double-stranded DNA (DNA-functionalized SWNTs: DNA-SWNTs). DNA-SWNTs significantly improved the dispersibility of SWNTs when compared with the acid-treated SWNTs. The binding ratio of the acid-treated SWNT and DNA was calculated to be 3.1 (DNA/SWNTs) from the phosphorous content in the DNA-SWNT. This interaction of the SWNTs and DNA would contribute to the stable dispersion of the DNA-SWNTs in a culture medium. With NIR irradiation by a halogen lamp light source, the acid-treated SWNTs and the DNA-SWNTs showed strong heat evolution in vitro (in a culture medium) and in vivo (in the subcutaneous tissue of a mouse) condition without any invasive effect on the non-SWNT area. The results of this study suggested that the functionalization with DNA was an efficient approach to improve the dispersibility of SWNTs in body fluids, and the DNA-SWNT would be a promising source for photo-induced exothermic generation.
Shimizu H.,Fukuoka Dental College
The European journal of prosthodontics and restorative dentistry | Year: 2011
The purpose of the present study was to determine an effective surface preparation for the bonding of a gingival shade composite resin to a denture base resin. The flat surfaces of a heat-processed denture base resin were prepared in various ways. A highly filled gingival shade composite resin was applied and polymerized. Shear testing was performed in a universal testing machine, and the maximum fracture load values were determined. The application of chemically activated 4-META resin using the brush-dip technique was an effective surface preparation for the bonding of a gingival shade composite resin to a denture base resin.
Ohkubo T.,Fukuoka Dental College |
Yamazaki J.,Fukuoka Dental College
International Journal of Oncology | Year: 2012
T-type voltage-gated Ca 2+ channels have unique electrophysiological properties, suitable for generating Ca 2+ oscillations and waves and thus controlling the proliferation of various tumor cells. In the present study, we investigated the role of Ca v3.1, a candidate tumor suppressor gene, in neoplastic processes, and compared the differences between Ca v3.1 with Ca v3.2 channels. While the overexpression of a full-length Ca v3.1 clone suppressed cell proliferation, the knockdown of the Ca v3.1 gene by siRNA, or treatment with ProTx-I, a relatively selective inhibitor for Cav3.1, promoted the cell proliferation of MCF-7 cells (a human breast adenocarcinoma cell line). Although Ca v3.1 and Ca v3.2 channels possess comparable biophysical properties and are often co-expressed in various tissues, gene knockdown or the overexpression of Ca v3.2 channels exhibited no effect on cell proliferation. Using immunocytochemical co-staining, the Cav3.1 channels were specifically visualized in the plasma membranes of apoptotic cells, identified by Annexin V and terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL) assays and nuclear condensation. On the contrary, Ca v3.2 channels were expressed at the membrane of large portions of cells, with no likely relation to Ca v3.1 expression or apoptosis. An apoptosis assay revealed that the overexpression of the Ca v3.1 clone caused an increase in the number of apoptotic cells. Furthermore, Ca v3.1 knockdown blocked cyclophosphamide-induced apoptosis. These results suggest that Ca v3.1 channels may contribute to the repression of tumor proliferation and the promotion of apoptosis mediated via Ca v3.1-specific Ca 2+ influx.
Kajiya H.,Fukuoka Dental College
Advances in Experimental Medicine and Biology | Year: 2012
Calcium (Ca 2+) signaling controls multiple cellular functions and is regulated by the release of Ca 2+ from internal stores and its entry from the extracellular fluid. Ca 2+ signals in osteoclasts are essential for diverse cellular functions including differentiation, bone resorption and gene transcription. Recent studies have highlighted the importance of intracellular Ca 2+ signaling for osteoclast differentiation. Receptor activator of NF-κB ligand (RANKL) signaling induces oscillatory changes in intracellular Ca 2+ concentrations, resulting in Ca 2+/calcineurin-dependent dephosphorylation and activation of nuclear factor of activated T cells c1 (NFATc1), which translocates to the nucleus and induces osteoclast-specific gene transcription to allow differentiation of osteoclasts. Recently, some reports indicated that RANKL-induced Ca 2+ oscillation involved not only repetitive intracellular Ca 2+ release from inositol 1, 4, 5-triphosphate channels in Ca 2+ store sites, but also via store-operated Ca 2+ entry and Ca 2+ entry via transient receptor potential V channels during osteoclast differentiation. Ca 2+-regulatory cytokines and elevation of extracellular Ca 2+ concentrations have been shown to increase intracellular Ca 2+ concentrations ([Ca 2+] i) in mature osteoclasts, regulating diverse cellular functions. RANKL-induced [Ca 2+] i increase has been reported to inhibit cell motility and the resorption of cytoskeletal structures in mature osteoclasts, resulting in suppression of bone-resorption activity. In conclusion, Ca 2+ signaling activates differentiation in osteoclast precursors but suppresses resorption in mature osteoclasts. This chapter focuses on the roles of long-term Ca 2+ oscillations in differentiation and of short-term Ca 2+ increase in osteoclastic bone resorption activity. © 2012 Springer Science+Business Media B.V.
Shimada K.,Fukuoka Dental College
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012
An associative classification method for incomplete database is proposed based on an evolutionary rule extraction method. The method can extract class association rules directly from the database including missing values and build an associative classifier. Instances including missing values are classified by the classifier. In addition, an evolving associative classifier is proposed. The proposed method evolves the classifier using the labeled instances by itself as acquired information. The performance of the classification was evaluated using artificial incomplete data set. The results showed that the proposed evolving associative classifier has a potential to expand the target data for classification through its evolutionary process and gather useful information itself. © 2012 Springer-Verlag.
Ikebe T.,Fukuoka Dental College
Oral Science International | Year: 2013
Since the first article about bisphosphonate-related osteonecrosis of the jaw (BRONJ) was published in 2003, clinical and basic research for BRONJ has continued worldwide to understand this novel disease. Several organizations have proposed the definition, diagnostic criteria, risk factors, and treatment strategy for BRONJ. Recently, some new drugs used for cancer patients such as bevacizumab and sunitinib have also been reported to be involved in osteonecrosis of the jaw (ONJ). Because ONJ appears to be initially derived from osteoclast inhibition, a new category of diseases named as " drug-related osteoclastic disease of the jaw" may be assumed. Considering the accumulated knowledge related to BRONJ, including osteoclast biology, bisphosphonate pharmacology, animal experiments, and clinicopathological findings, a perspective of BRONJ from the pathophysiological viewpoint is proposed in this review. © 2012 Japanese Stomatological Society.