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Osaka, Japan

Osaka Dental University is a private university in Hirakata, Osaka, Japan. The predecessor of the school was founded in 1911, and it was chartered as a university in 1947. There is a hospital associated with the university located near Temmabashi Station in Chūō-ku, Osaka. Wikipedia.

Sawai H.,Osaka Dental University
Leukemia Research

Caspase-independent programmed necrotic cell death (necroptosis) has recently been described. Previously described models of necroptosis required 16. h or more of induction, which made the interpretation of findings somewhat difficult. In human monocytic leukemia cell line U937 necroptosis could be induced within 6. h by combination of TNF and Z-VAD-fmk. Here we show that the reduction in intracellular ATP levels may not be the sole determinant of necroptosis, and that necroptosis is associated with the loss of mitochondrial membrane potential, but not the activation of Bak/Bax or calcineurin. © 2014 Elsevier Ltd. Source

Takeuchi H.,University of Louisville | Hirano T.,University of Louisville | Whitmore S.E.,University of Louisville | Morisaki I.,Osaka Dental University | And 2 more authors.
PLoS Pathogens

Porphyromonas gingivalis is a major pathogen in severe and chronic manifestations of periodontal disease, which is one of the most common infections of humans. A central feature of P. gingivalis pathogenicity is dysregulation of innate immunity at the gingival epithelial interface, including suppression of IL-8 production by epithelial cells. NF-κB is a transcriptional regulator that controls important aspects of innate immune responses, and NF-κB RelA/p65 homodimers regulate transcription of IL8. Phosphorylation of the NF-κB p65 subunit protein on the serine 536 residue affects nuclear translocation and transcription of target genes. Here we show that SerB, a haloacid dehalogenase (HAD) family serine phosphatase secreted by P. gingivalis, is produced intracellularly and can specifically dephosphorylate S536 of p65 in gingival epithelial cells. A P. gingivalis mutant lacking SerB was impaired in dephosphorylation of p65 S536, and ectopically expressed SerB bound to p65 and co-localized with p65 in the cytoplasm. Ectopic expression of SerB also resulted in dephosphorylation of p65 with reduced nuclear translocation in TNF-α-stimulated epithelial cells. In contrast, the p105/50 subunit of NF-κB was unaffected by SerB. Co-expression of a constitutively active p65 mutant (S536D) relieved inhibition of nuclear translocation. Both the activity of the IL8 promoter and production of IL-8 were diminished by SerB. Deletion and truncation mutants of SerB lacking the HAD-family enzyme motifs of SerB were unable to dephosphorylate p65, inhibit nuclear translocation or abrogate IL8 transcription. Specific dephosphorylation of NF-κB p65 S536 by SerB, and consequent inhibition of nuclear translocation, provides the molecular basis for a bacterial strategy to manipulate host inflammatory pathways and repress innate immunity at mucosal surfaces. © 2013 Takeuchi et al. Source

Periodontal disease as a biofilm infectious disease is considered. Periodontal disease-associated bacteria formed biofilm in periodontal pockets or on the surface of cementum. Planktonic bacteria from biofilm invade into periodontal tissues and lead to inflammation and destruction of tissues directly and indirectly by eliciting the host defense mechanism. Supragingival dental plaques (biofilm) are easily removed by professional mechanical tooth cleaning, while subgingival dental plaques and bacteria invading into periodontal tissues are difficult to remove. Therefore, the development of a method for periodontal disease based on the concept that regards periodontal disease as a biofilm infectious disease is needed. Hereby, I report the effect of antibiotics on an in vitro biofilm model of periodontal disease and the systemic administration of azithromycin for early-onset (aggressive) periodontitis like a treatment resistant periodontitis. © 2010 The Japanese Pharmacological Society. Source

Ishizuka T.,Osaka Dental University | Yamatodani A.,Osaka University
Frontiers in Systems Neuroscience

Feeding behavior is regulated by a complex interplay of many endogenous substances, such as peptides and neurotransmitters in the central nervous system. Histamine is a neurotransmitter which expresses an anorectic effect on food intake via histamine H 1 receptors. The histaminergic system exists downstream of leptin, a satiety factor secreted from white adipose tissue. Because direct stimulation of the histaminergic system by histamine H 3-inverse agonists or antagonists can normalize the obese phenotype in which animal models with exogenous leptin resistance, which resembles human obesity, the potential roles of histamine H 3 receptors as a therapeutic target now draw attention. Histaminergic activity is enhanced during feeding, and an oral somatic sensation is thought to affect histaminergic activity while blood glucose levels do not. In addition, gustatory information can modulate histaminergic activity by two mechanisms: by physiological excitation of the chorda tympani nerve, one of the taste nerves and by emotions elicited by taste perception, i.e., taste palatability. Particularly, aversive and hazardous taste stimuli tonically facilitate histaminergic activity, suggesting that the histaminergic system is involved in the response to harmful stimuli. Together with recent findings, it is postulated that the histaminergic system responds to both mechanical and chemical sensory input from the oral cavity during feeding and is exerted as a part of the danger response system. © 2012 Ishizuka and Yamatodani. Source

To compare the effects of 60 Gy/10 fractions (twice a day) with those of 54 Gy/9 fractions in high-dose-rate interstitial brachytherapy (HDR-ISBT) for early tongue cancer, we performed a matched-pair analysis of patients with early tongue cancer (T1-2N0M0), who were treated with 60 or 54 Gy of radiation between 1996 and 2004. Seventeen patients treated with 54 Gy and 34 matched-pair patients treated with 60 Gy were extracted and analyzed. Local recurrence occurred in two patients in the 54-Gy arm and five patients in the 60-Gy arm. The 2-year local control rates were 88% for both the 54-Gy arm and 60-Gy arm (not significant). The 2-year overall survival rates were 88% in the 60-Gy arm and 82% in the 54-Gy arm. Two-year actuarial complication-free rates were 91% in the 60-Gy arm and 83% in the 54-Gy arm (not significant), respectively. There was no significant association between the total dose and local control rate and late complications. The outcome of 54 Gy/ 9 fractions was similar to that of 60 Gy/ 10 fractions in patients with early tongue cancer. Source

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