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Search Results: 1 - 10 of 536 matches for " Kazutaka Kasai "
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TNF-α and RANKL facilitates the development of orthodontically-induced inflammatory root resorption  [PDF]
Tadashi Kojima, Masaru Yamaguchi, Tomokazu Yoshino, Mami Shimizu, Kunihiko Yamada, Takemi Goseki, Kazutaka Kasai
Open Journal of Stomatology (OJST) , 2013, DOI: 10.4236/ojst.2013.39A008
Abstract:

Background: The objective of this study was to determine the levels of tumor necrosis factor-alpha (TNF-α) and receptor activator of NF-kB ligand (RANKL) in the gingival crevicular fluid (GCF) in patients with severe root resorption after orthodontic treatment. Materials and Methods: Ten patients who had been receiving orthodontic treatment (5-control subjects and 5-severe root resorption subjects) participated in this study. GCF was collected from all patients. Subjects with severe root resorption (>1/3 of the original root length) were identified. Control group subjects with no loss of the root structure undergoing orthodontic treatment were also identified. The GCF was collected non-invasively from the mesial and distal sides of each of the upper central and lateral incisors using filter paper strips. The eluted GCF was used for a Western blot analysis with Antibodies against TNF-α and soluble RANKL (sRANKL). Ten male 6-week-old Wistar rats were subjected to orthodontic force of 50 g to induce a mesially tipping movement of the upper first molars for 7 days. The expression levels of TNF-α and RANKL proteins were determined in periodontal ligament (PDL) by immunohistochemical analysis. Results: The Western blot analysis showed that the TNF-α and sRANKL expressions were significantly higher in the severe root resorption group than in the control group. In the experimental tooth movement in vivo, resorption lacunae with multinucleated cells were observed in 50 g group. The immunoreactivity for TNF-α and RANKL was detected in PDL tissue subjected to the orthodontic force on day 7. Conclusion: These results suggest that

Immunohistochemical Localization of Versican, Link Protein and Hyaluronic Acid Binding Protein in the Human Periodontal Ligament  [PDF]
Tadahiko Utsunomiya, Aki Otsuka, Rei Sato, Masaru Yamaguchi, Kazutaka Kasai, Hirotsugu Yamamoto, Kayo Kuyama
Open Journal of Stomatology (OJST) , 2014, DOI: 10.4236/ojst.2014.49060
Abstract: The purpose of the present study was to histopathologically and immunohistochemically investigate the distribution of proteoglycans in human periodontal ligament (PDL). Specimens from osteotomy and tooth extraction having healthy PDL were studied. Histologically, PDL consisted of fibrous tissues, involving a compact arrangement area and edematous or myxoid area. Immuno-histochemically, versican binding region (12C5), versican link protein (8A4) and biotinylated hyaluronic acid binding protein (B-HABP) were distributed in PDL. In addition, positive immunore-activity for 12C5 and 8A4 was stronger in the compact arrangement area than in the edematous or myxoid area. Reactivity for B-HABP was stronger in the edematous or myxoid area than in the compact fibrous area. These results suggest that versican and link protein are associated with fibrous tissues, whereas hyaluronic acid is related to the formation of edematous and/or myxoid tissue in human PDL. These substances may play a role in periodontal homeostasis by protecting against mechanical stress.
External apical root resorption and the release of interleukin-6 in the gingival crevucular fluid induced by a self-ligating system  [PDF]
Ryoko Kawashima-Ichinomiya, Masaru Yamaguchi, Yasuhiro Tanimoto, Masaki Asano, Kunihiko Yamada, Ryo Nakajima, Shoji Fujita, Kazutaka Kasai
Open Journal of Stomatology (OJST) , 2012, DOI: 10.4236/ojst.2012.22021
Abstract: The aim of this study was to investigate the amount of external apical root resorption (EARR) and the release of interleukin (IL)-6 in the gingival crevicular fluid (GCF) in subjects treated with a low-force low-friction system. Sixty patients were assigned to two groups of thirty patients for each: one group received treatment with self-ligating brackets and the other with conventional ligated edgewise brackets. All patients were treated with extraction of the maxillary first premolars. The EARR of the maxillary central incisors was evaluated on the periapical radiographs and cephalograms, taken before and after orthodontic treatment. The GCF was also collected non-invasively from the mesial and distal sides of central incisors by using filter paper strips before and after orthodontic treatment. Enzyme-linked immunosorbent assay (ELISA) kits were used to determine the IL-6 levels in the GCF samples. A significant difference was found in the amount of EARR between the patients with self-ligating brackets and conventional brackets. The mean amount of EARR was significantly lower for self-ligating brackets than conventional brackets (p < 0.05). The GCF levels of IL-6 for the patients with self-ligating brackets appliance were significantly lower than for those with the conventional brackets (p < 0.05). These results show that the mean amount of EARR and the GCF levels of IL-6 were significantly lower in the patients treated using low-force low-friction appliances than conventional brackets. Therefore, self-ligating brackets may be a useful system for reducing inflammation and EARR.
Mini-Implants in the Anchorage Armamentarium: New Paradigms in the Orthodontics
Masaru Yamaguchi,Toshihiro Inami,Ko Ito,Kazutaka Kasai,Yasuhiro Tanimoto
International Journal of Biomaterials , 2012, DOI: 10.1155/2012/394121
Abstract: Paradigms have started to shift in the orthodontic world since the introduction of mini-implants in the anchorage armamentarium. Various forms of skeletal anchorage, including miniscrews and miniplates, have been reported in the literature. Recently, great emphasis has been placed on the miniscrew type of temporary anchorage device (TAD). These devices are small, are implanted with a relatively simple surgical procedure, and increase the potential for better orthodontic results. Therefore, miniscrews not only free orthodontists from anchorage-demanding cases, but they also enable clinicians to have good control over tooth movement in 3 dimensions. The miniplate type also produces significant improvements in treatment outcomes and has widened the spectrum of orthodontics. The purpose of this paper is to update clinicians on the current concepts and versatile uses and clinical applications of skeletal anchorage in orthodontics. 1. Introduction The goal of orthodontic treatment is to improve the patient’s life through enhancement of dentofacial functions and esthetics. Anchorage, defined as a resistance to unwanted tooth movement [1], is a prerequisite for the orthodontic treatment of dental and skeletal malocclusions [2, 3]. Controlling anchorage helps to avoid undesirable tooth movements. However, even a small reactive force can cause undesirable movements; it is important to have absolute anchorage to avoid them [4, 5]. Absolute or infinite anchorage is defined as no movement of the anchorage unit (zero anchorage loss) as a consequence to the reaction forces applied to move teeth [1]. Such an anchorage can only be obtained by using ankylosed teeth or dental implants as anchors, both relying on bone to inhibit movement [6]. Anchorage provided by devices, such as implants or miniscrew implants fixed to bone, may be obtained by enhancing the support to the reactive unit (indirect anchorage) or by fixing the anchor units (direct anchorage), thus facilitating skeletal anchorage. Orthodontic anchorage is an important factor in obtaining good treatment results. Stable anchorage is a pre-requisite for orthodontic treatment with fixed appliances. Traditional appliances for reinforcement of anchorage have included headgear and intraoral elastics. The inclusion of implants for skeletal anchorage can move a tooth without the use of headgear and intraoral elastics. Skeletal anchorage with temporary anchorage devices (TADs) has been widely incorporated into orthodontic treatment for expanding the boundary of tooth movement without patient compliance [7–10]. TAD
Essential Role of NMDA Receptor Channel ε4 Subunit (GluN2D) in the Effects of Phencyclidine, but Not Methamphetamine
Yoko Hagino,Shinya Kasai,Wenhua Han,Hideko Yamamoto,Toshitaka Nabeshima,Masayoshi Mishina,Kazutaka Ikeda
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0013722
Abstract: Phencyclidine (PCP), a noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist, increases locomotor activity in rodents and causes schizophrenia-like symptoms in humans. Although activation of the dopamine (DA) pathway is hypothesized to mediate these effects of PCP, the precise mechanisms by which PCP induces its effects remain to be elucidated. The present study investigated the effect of PCP on extracellular levels of DA (DAex) in the striatum and prefrontal cortex (PFC) using in vivo microdialysis in mice lacking the NMDA receptor channel ε1 or ε4 subunit (GluRε1 [GluN2A] or GluRε4 [GluN2D]) and locomotor activity. PCP significantly increased DAex in wildtype and GluRε1 knockout mice, but not in GluRε4 knockout mice, in the striatum and PFC. Acute and repeated administration of PCP did not increase locomotor activity in GluRε4 knockout mice. The present results suggest that PCP enhances dopaminergic transmission and increases locomotor activity by acting at GluRε4.
Inhibitory Role of Inducible cAMP Early Repressor (ICER) in Methamphetamine-Induced Locomotor Sensitization
Wenhua Han, Yukio Takamatsu, Hideko Yamamoto, Shinya Kasai, Shogo Endo, Tomoaki Shirao, Nobuhiko Kojima, Kazutaka Ikeda
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0021637
Abstract: Background The inducible cyclic adenosine monophosphate (cAMP) early repressor (ICER) is highly expressed in the central nervous system and functions as a repressor of cAMP response element-binding protein (CREB) transcription. The present study sought to clarify the role of ICER in the effects of methamphetamine (METH). Methods and Findings We tested METH-induced locomotor sensitization in wildtype mice, ICER knockout mice, and ICER I-overexpressing mice. Both ICER wildtype mice and knockout mice displayed increased locomotor activity after continuous injections of METH. However, ICER knockout mice displayed a tendency toward higher locomotor activity compared with wildtype mice, although no significant difference was observed between the two genotypes. Moreover, compared with wildtype mice, ICER I-overexpressing mice displayed a significant decrease in METH-induced locomotor sensitization. Furthermore, Western blot analysis and quantitative real-time reverse transcription polymerase chain reaction demonstrated that ICER overexpression abolished the METH-induced increase in CREB expression and repressed cocaine- and amphetamine-regulated transcript (CART) and prodynorphin (Pdyn) expression in mice. The decreased CART and Pdyn mRNA expression levels in vivo may underlie the inhibitory role of ICER in METH-induced locomotor sensitization. Conclusions Our data suggest that ICER plays an inhibitory role in METH-induced locomotor sensitization.
Factors that Affect Intravenous Patient-Controlled Analgesia for Postoperative Pain Following Orthognathic Surgery for Mandibular Prognathism
Yoshinori Aoki, Kaori Yoshida, Daisuke Nishizawa, Shinya Kasai, Tatsuya Ichinohe, Kazutaka Ikeda, Ken-ichi Fukuda
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0098548
Abstract: The predictors of postoperative pain and analgesic consumption were previously found to include preoperative pain, anxiety, age, type of surgery, and genotype, but remaining unclear was whether intraoperative factors could predict postoperative pain. In the present study, we investigated the time-course of fentanyl consumption using intravenous patient-controlled analgesia records from patients who underwent orthognathic surgery for mandibular prognathism and analyzed the influence of anesthesia methods and surgical methods together with sex on the time course. A significant difference in the time course of fentanyl administration was found (P<0.001). No significant difference in the time course of fentanyl administration was found between males and females (P = 0.653), with no interaction between time course and sex (P = 0.567). No significant difference in the time course of fentanyl administration was found among anesthesia methods, such as fentanyl induction followed by fentanyl maintenance, fentanyl induction followed by remifentanil maintenance, and remifentanil induction followed by remifentanil maintenance (P = 0.512), but an interaction between time course and anesthesia method was observed (P = 0.004). A significant difference in the time course of fentanyl administration was found between surgical methods, such as bilateral mandibular sagittal split ramus osteotomy (BSSRO) and BSSRO combined with Le Fort I osteotomy (bimaxillary; P = 0.008), with no interaction between time course and surgical method (P = 0.535). Total postoperative 24 h consumption associated with the bimaxillary procedure was significantly higher than with BSSRO (P = 0.008). The present results indicate that administration patterns and total 24 h consumption were different among the three groups of anesthesia methods and between the two groups of surgical methods, respectively. Although more research on patient-controlled analgesia patterns and consumption is necessary, the present study will contribute to adequately relieving individual patients from postoperative pain.
Association between Genetic Polymorphisms in Cav2.3 (R-type) Ca2+ Channels and Fentanyl Sensitivity in Patients Undergoing Painful Cosmetic Surgery
Soichiro Ide, Daisuke Nishizawa, Ken-ichi Fukuda, Shinya Kasai, Junko Hasegawa, Masakazu Hayashida, Masabumi Minami, Kazutaka Ikeda
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0070694
Abstract: Individual differences in the sensitivity to fentanyl, a widely used opioid analgesic, lead to different proper doses of fentanyl, which can hamper effective pain treatment. Voltage-activated Ca2+ channels (VACCs) play a crucial role in the nervous system by controlling membrane excitability and calcium signaling. Cav2.3 (R-type) VACCs have been especially thought to play critical roles in pain pathways and the analgesic effects of opioids. However, unknown is whether single-nucleotide polymorphisms (SNPs) of the human CACNA1E (calcium channel, voltage-dependent, R type, alpha 1E subunit) gene that encodes Cav2.3 VACCs influence the analgesic effects of opioids. Thus, the present study examined associations between fentanyl sensitivity and SNPs in the human CACNA1E gene in 355 Japanese patients who underwent painful orofacial cosmetic surgery, including bone dissection. We first conducted linkage disequilibrium (LD) analyses of 223 SNPs in a region that contains the CACNA1E gene using genomic samples from 100 patients, and a total of 13 LD blocks with 42 Tag SNPs were observed within and around the CACNA1E gene region. In the preliminary study using the same 100 genomic samples, only the rs3845446 A/G SNP was significantly associated with perioperative fentanyl use among these 42 Tag SNPs. In a confirmatory study using the other 255 genomic samples, this SNP was also significantly associated with perioperative fentanyl use. Thus, we further analyzed associations between genotypes of this SNP and all of the clinical data using a total of 355 samples. The rs3845446 A/G SNP was associated with intraoperative fentanyl use, 24 h postoperative fentanyl requirements, and perioperative fentanyl use. Subjects who carried the minor G allele required significantly less fentanyl for pain control compared with subjects who did not carry this allele. Although further validation is needed, the present findings show the possibility of the involvement of CACNA1E gene polymorphisms in fentanyl sensitivity.
Association between KCNJ6 (GIRK2) Gene Polymorphisms and Postoperative Analgesic Requirements after Major Abdominal Surgery
Daisuke Nishizawa, Makoto Nagashima, Ryoji Katoh, Yasuo Satoh, Megumi Tagami, Shinya Kasai, Yasukazu Ogai, Wenhua Han, Junko Hasegawa, Naohito Shimoyama, Ichiro Sora, Masakazu Hayashida, Kazutaka Ikeda
PLOS ONE , 2009, DOI: 10.1371/journal.pone.0007060
Abstract: Opioids are commonly used as effective analgesics for the treatment of acute and chronic pain. However, considerable individual differences have been widely observed in sensitivity to opioid analgesics. We focused on a G-protein-activated inwardly rectifying potassium (GIRK) channel subunit, GIRK2, that is an important molecule in opioid transmission. In our initial polymorphism search, a total of nine single-nucleotide polymorphisms (SNPs) were identified in the whole exon, 5′-flanking, and exon-intron boundary regions of the KCNJ6 gene encoding GIRK2. Among them, G-1250A and A1032G were selected as representative SNPs for further association studies. In an association study of 129 subjects who underwent major open abdominal surgery, the A/A genotype in the A1032G SNP and -1250G/1032A haplotype were significantly associated with increased postoperative analgesic requirements compared with other genotypes and haplotypes. The total dose (mean±SEM) of rescue analgesics converted to equivalent oral morphine doses was 20.45±9.27 mg, 10.84±2.24 mg, and 13.07±2.39 mg for the A/A, A/G, and G/G genotypes in the A1032G SNP, respectively. Additionally, KCNJ6 gene expression levels in the 1032A/A subjects were significantly decreased compared with the 1032A/G and 1032G/G subjects in a real-time quantitative PCR analysis using human brain tissues, suggesting that the 1032A/A subjects required more analgesics because of lower KCNJ6 gene expression levels and consequently insufficient analgesic effects. The results indicate that the A1032G SNP and G-1250A/A1032G haplotype could serve as markers that predict increased analgesic requirements. Our findings will provide valuable information for achieving satisfactory pain control and open new avenues for personalized pain treatment.
Linking better shiftwork arrangements with safety and health management systems
Kogi,Kazutaka;
Revista de Saúde Pública , 2004, DOI: 10.1590/S0034-89102004000700011
Abstract: objective: various support measures useful for promoting joint change approaches to the improvement of both shiftworking arrangements and safety and health management systems were reviewed. a particular focus was placed on enterprise-level risk reduction measures linking working hours and management systems. methods: voluntary industry-based guidelines on night and shift work for department stores and the chemical, automobile and electrical equipment industries were examined. survey results that had led to the compilation of practicable measures to be included in these guidelines were also examined. the common support measures were then compared with ergonomic checkpoints for plant maintenance work involving irregular nightshifts. on the basis of this analysis, a new night and shift work checklist was designed. results: both the guidelines and the plant maintenance work checkpoints were found to commonly cover multiple issues including work schedules and various job-related risks. this close link between shiftwork arrangements and risk management was important as shiftworkers in these industries considered teamwork and welfare services to be essential for managing risks associated with night and shift work. four areas found suitable for participatory improvement by managers and workers were work schedules, ergonomic work tasks, work environment and training. the checklist designed to facilitate participatory change processes covered all these areas. conclusions: the checklist developed to describe feasible workplace actions was suitable for integration with comprehensive safety and health management systems and offered valuable opportunities for improving working time arrangements and job content together.
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