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Search Results: 1 - 10 of 190 matches for " Ayano Katagiri "
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Satellite glial cell P2Y12 receptor in the trigeminal ganglion is involved in lingual neuropathic pain mechanisms in rats
Ayano Katagiri, Masamichi Shinoda, Kuniya Honda, Akira Toyofuku, Barry J Sessle, Koichi Iwata
Molecular Pain , 2012, DOI: 10.1186/1744-8069-8-23
Abstract: The head-withdrawal reflex thresholds to mechanical and heat stimulation of the lateral tongue were significantly decreased in LNC-rats compared to sham-rats. These nocifensive effects were apparent on day 1 after LNC and lasted for 17 days. On days 3, 9, 15 and 21 after LNC, the mean relative number of TG neurons encircled with GFAP-immunoreactive (IR) cells significantly increased in the ophthalmic, maxillary and mandibular branch regions of TG. On day 3 after LNC, P2Y12R expression occurred in GFAP-IR cells but not neuronal nuclei (NeuN)-IR cells (i.e. neurons) in TG. After 3 days of successive administration of the P2Y12R antagonist MRS2395 into TG in LNC-rats, the mean relative number of TG neurons encircled with GFAP-IR cells was significantly decreased coincident with a significant reversal of the lowered head-withdrawal reflex thresholds to mechanical and heat stimulation of the tongue compared to vehicle-injected rats. Furthermore, after 3 days of successive administration of the P2YR agonist 2-MeSADP into the TG in na?ve rats, the mean relative number of TG neurons encircled with GFAP-IR cells was significantly increased and head-withdrawal reflex thresholds to mechanical and heat stimulation of the tongue were significantly decreased in a dose-dependent manner compared to vehicle-injected rats.The present findings provide the first evidence that the activation of P2Y12R in SGCs of TG following lingual nerve injury is involved in the enhancement of TG neuron activity and nocifensive reflex behavior, resulting in neuropathic pain in the tongue.Neuropathic pain occurs and persists in a heterogeneous group of etiologically different diseases involving a peripheral nerve lesion or dysfunction of the peripheral or central nervous system. Neuropathic pain is relatively common and frequently resistant to clinical treatment [1].Injury to trigeminal nerve branches is known to cause neuropathic pain in the orofacial region [2,3]. The lingual nerve, a branch of the t
The Aggregation of Bentonite Using Poly(N-isopropylacrylamide) as a Flocculant  [PDF]
Ayano Nakamura, Kenji Murakami
Journal of Materials Science and Chemical Engineering (MSCE) , 2018, DOI: 10.4236/msce.2018.64011
Abstract: Sedimentation tests of bentonite suspension were carried out by adding various concentrations of poly(N-isopropylacrylamide) (PNIPAM) with different molecular weights as flocculant below and above lower critical solution temperature (LCST). Also, the effect of PNIPAM on aggregation of bentonite was investigated by sedimentation rate, turbidity of supernatant. Additionally, XRD patterns and SEM photographs were measured in order to consider aggregation mechanism of PNIPAM. The sedimentation rate and turbidity for the PNIPAM with large molecular weight or PNIPAM solution of high concentration above LCST were faster and clearer than those with small molecular weight or low concentration. From XRD patterns, the peak of bentonite sediment with PNIPAM shifted to the low-angle side, suggesting that a part of PNIPAM chain entered between bentonite layers. Furthermore, it was confirmed by SEM photographs that PNIPAM covered bentonite surface after sedimentation test. It was indicated that PNIPAM adsorbs on the bentonite surface and aggregates each bentonite particle above LCST. From these results, PNIPAM works as a flocculant and the PNIPAM with large molecular weight has a good ability.
Involvement of peripheral ionotropic glutamate receptors in orofacial thermal hyperalgesia in rats
Kuniya Honda, Noboru Noma, Masamichi Shinoda, Makiko Miyamoto, Ayano Katagiri, Daiju Kita, Ming-Gang Liu, Barry J Sessle, Masafumi Yasuda, Koichi Iwata
Molecular Pain , 2011, DOI: 10.1186/1744-8069-7-75
Abstract: Glu application to the tongue or whisker pad skin caused an enhancement of head-withdrawal reflex and extracellular signal-regulated kinase (ERK) phosphorylation in Vc-C2 neurons. Head-withdrawal reflex and ERK phosphorylation were also enhanced following cold stimulation of the tongue but not whisker pad skin in Glu-injected rats, and the head-withdrawal reflex and ERK phosphorylation were enhanced following heat stimulation of the tongue or whisker pad skin. The enhanced head-withdrawal reflex and ERK phosphorylation after heat stimulation of the tongue or whisker pad skin, and those following cold stimulation of the tongue but not whisker pad skin were suppressed following ionotropic glutamate receptor antagonists administration into the tongue or whisker pad skin. Furthermore, intrathecal administration of MEK1/2 inhibitor PD98059 caused significant suppression of enhanced head-withdrawal reflex in Glu-injected rats, heat head-withdrawal reflex in the rats with Glu injection into the tongue or whisker pad skin and cold head-withdrawal reflex in the rats with Glu injection into the tongue.The present findings suggest that peripheral Glu receptor mechanisms may contribute to cold hyperalgesia in the tongue but not in the facial skin, and also contribute to heat hyperalgesia in the tongue and facial skin, and that the mitogen-activated protein kinase cascade in Vc-C2 neurons may be involved in these Glu-evoked hyperalgesic effects.It is well known from human psychophysical studies that thermal and mechanical sensitivity of the tongue is different from that of the facial skin [1-4]. Cold and heat sensory thresholds are significantly higher in the tongue compared to the facial skin. The pain threshold is also higher in tongue compared to the facial skin. Previous histological studies have also reported that cutaneous tissues are covered by orthokeratinized tissues, whereas mucosal membranes are covered by parakeratinized tissues, and mucosal surfaces are highly moist
Involvement of ERK Phosphorylation of Trigeminal Spinal Subnucleus Caudalis Neurons in Thermal Hypersensitivity in Rats with Infraorbital Nerve Injury
Ikuko Suzuki, Yoshiyuki Tsuboi, Masamichi Shinoda, Kazuo Shibuta, Kuniya Honda, Ayano Katagiri, Masaaki Kiyomoto, Barry J. Sessle, Shingo Matsuura, Kinuyo Ohara, Kentaro Urata, Koichi Iwata
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0057278
Abstract: To evaluate the involvement of the mitogen-activated protein kinase (MAPK) cascade in orofacial neuropathic pain mechanisms, this study assessed nocifensive behavior evoked by mechanical or thermal stimulation of the whisker pad skin, phosphorylation of extracellular signal-regulated kinase (ERK) in trigeminal spinal subnucleus caudalis (Vc) neurons, and Vc neuronal responses to mechanical or thermal stimulation of the whisker pad skin in rats with the chronic constriction nerve injury of the infraorbital nerve (ION-CCI). The mechanical and thermal nocifensive behavior was significantly enhanced on the side ipsilateral to the ION-CCI compared to the contralateral whisker pad or sham rats. ION-CCI rats had an increased number of phosphorylated ERK immunoreactive (pERK-IR) cells which also manifested NeuN-IR but not GFAP-IR and Iba1-IR, and were significantly more in ION-CCI rats compared with sham rats following noxious but not non-noxious mechanical stimulation. After intrathecal administration of the MEK1 inhibitor PD98059 in ION-CCI rats, the number of pERK-IR cells after noxious stimulation and the enhanced thermal nocifensive behavior but not the mechanical nocifensive behavior were significantly reduced in ION-CCI rats. The enhanced background activities, afterdischarges and responses of wide dynamic range neurons to noxious mechanical and thermal stimulation in ION-CCI rats were significantly depressed following i.t. administration of PD98059, whereas responses to non-noxious mechanical and thermal stimulation were not altered. The present findings suggest that pERK-IR neurons in the Vc play a pivotal role in the development of thermal hypersensitivity in the face following trigeminal nerve injury.
Mechanisms Underlying Ectopic Persistent Tooth-Pulp Pain following Pulpal Inflammation
Shingo Matsuura, Kohei Shimizu, Masamichi Shinoda, Kinuyo Ohara, Bunnai Ogiso, Kuniya Honda, Ayano Katagiri, Barry J. Sessle, Kentaro Urata, Koichi Iwata
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0052840
Abstract: In order to clarify the peripheral mechanisms of ectopic persistent pain in a tooth pulp following pulpal inflammation of an adjacent tooth, masseter muscle activity, phosphorylated extracellular signal-regulated protein kinase (pERK) and TRPV1 immunohistochemistries and satellite cell activation using glial fibrillary acidic protein (GFAP) immunohistochemistry in the trigeminal ganglion (TG) were studied in the rats with molar tooth-pulp inflammation. And, Fluorogold (FG) and DiI were also used in a neuronal tracing study to analyze if some TG neurons innervate more than one tooth pulp. Complete Freund’s adjuvant (CFA) or saline was applied into the upper first molar tooth pulp (M1) in pentobarbital-anesthetized rats, and capsaicin was applied into the upper second molar tooth pulp (M2) on day 3 after the CFA or saline application. Mean EMG activity elicited in the masseter muscle by capsaicin application to M2 was significantly larger in M1 CFA-applied rats compared with M1 vehicle-applied rats. The mean number of pERK-immunoreactive (IR) TG cells was significantly larger in M1 CFA-applied rats compared with M1 vehicle-applied rats. Application of the satellite cell inhibitor fluorocitrate (FC) into TG caused a significant depression of capsaicin-induced masseter muscle activity and a significant reduction of satellite cell activation. The number of TRPV1-IR TG cells innervating M2 was significantly larger in M1 CFA-applied rats compared with M1 vehicle-applied rats, and that was decreased following FC injection into TG. Furthermore, 6% of TG neurons innervating M1 and/or M2 innervated both M1 and M2. These findings suggest that satellite cell activation following tooth pulp inflammation and innervation of multiple tooth pulps by single TG neurons may be involved in the enhancement of the activity of TG neurons innervating adjacent non-inflamed teeth that also show enhancement of TRPV1 expression in TG neurons, resulting in the ectopic persistent tooth-pulp pain following pulpal inflammation of adjacent teeth.
Cognitive Control and Brain Network Dynamics during Word Generation Tasks Predicted Using a Novel Event-Related Deep Brain Activity Method  [PDF]
Emiko Imai, Yoshitada Katagiri
Journal of Behavioral and Brain Science (JBBS) , 2018, DOI: 10.4236/jbbs.2018.82006
Abstract: There is a growing interest in the diagnosis and treatment of patients with dementia and cognitive impairment at an early stage. Recent imaging studies have explored neural mechanisms underlying cognitive dysfunction based on brain network architecture and functioning. The dorsal anterior cingulate cortex (dACC) is thought to regulate large-scale intrinsic brain networks, and plays a primary role in cognitive processing with the anterior insular cortex (aIC), thus providing salience functions. Although neural mechanisms have been elucidated at the connectivity level by imaging studies, their understanding at the activity level still remains unclear because of limited time-based resolution of conventional imaging techniques. In this study, we investigated temporal activity of the dACC during word (verb) generation tasks based on our newly developed event-related deep brain activity (ER-DBA) method using occipital electroencephalogram (EEG) alpha-2 powers with a time resolution of a few hundred milliseconds. The dACC exhibited dip-like temporal waveforms indicating deactivation in an initial stage of each trial when appropriate verbs were successfully generated. By contrast, monotonous increase was observed for incorrect responses and a decrease was detected for no responses. The dip depth was correlated with the percentage of success. Additionally, the dip depth linearly increased with increasing slow component of the DBA index at rest across all subjects. These findings suggest that dACC deactivation is essential for cognitive processing, whereas its activation is required for goal-oriented behavioral outputs, such as cued speech. Such dACC functioning, represented by the dip depth, is supported by the activity of the upper brainstem region including monoaminergic neural systems.
The accuracy of clinical malaria case reporting at primary health care facilities in Honiara, Solomon Islands
Ayano Kunimitsu
Malaria Journal , 2009, DOI: 10.1186/1475-2875-8-80
Abstract: All medical records for outpatients in 2007, handwritten by nurses, were collected from local clinics in Honiara, the capital of the Solomon Islands. The all-monthly clinical malaria cases were then recalculated. The corresponding monthly data in official statistics were provided by the government. Next, in order to estimate any data discrepancy, the ratio of the cases recorded at clinics to the cases reported to the government was determined on the monthly basis. Finally, the associations between the monthly discrepancy and other variables were evaluated by a multiple regression analysis.The mean data discrepancy between the records of clinics and government statistics was 21.2% (n = 96). Significant associations were observed between the discrepancy and the average number of patients (coefficient: 0.05, 95%CI: 0.31, 0.07), illegible handwriting (coefficient: 0.09, 95%CI: 0.04, 0.15), the use of tally sheets (coefficient:-0.38, 95%CI: -0.54, -0.22), and the clinic level (coefficient:-0.48, 95%CI:-0.89,-0.06).The findings of this study demonstrate the huge data discrepancy between the records of clinics and government statistics in regard to clinical malaria case reporting. Moreover, the high numbers of patients, illegible writing, the disuse of tally sheets, and insufficient resources at some clinics are likely to be related to the increase in the discrepancy. The clinical malaria case reporting at the local clinic level therefore urgently needs improvement, in order to achieve both better malaria surveillance and to also eventually eliminate this disease in the Solomon Islands.Malaria case reporting at primary health care facilities, which constitute the baseline data of the surveillance, is currently being carried out in most countries and the collected epidemiological information is submitted to the World Health Organization (WHO) [1]. Malaria reporting from national surveillance systems, however, varies in quality and reporting completeness [1,2]. The inadequat
Sigma Functions for Telescopic Curves
Takanori Ayano
Mathematics , 2012,
Abstract: In this paper, we consider the sigma functions for algebraic curves expressed by a canonical form using a finite sequence $(a_1,...,a_t)$ of positive integers whose greatest common divisor is equal to one (Miura [13]). The idea is to express a non-singular algebraic curve by affine equations of $t$ variables whose orders at infinity are $(a_1,...,a_t)$. We construct a symplectic basis of the first cohomology group and the sigma functions for telescopic curves, i.e., the curves such that the number of defining equations is exactly $t-1$ in the Miura canonical form. The largest class of curves for which such construction has been obtained thus far is $(n,s)$-curves ([3][15]), which are telescopic because they are expressed in the Miura canonical form with $t=2$, $a_1=n$, and $a_2=s$, and the number of defining equations is one.
Rates of convergence for nearest neighbor estimators with the smoother regression function
Takanori Ayano
Statistics , 2011, DOI: 10.1587/transinf.E94.D.2244
Abstract: In regression analysis one wants to estimate the regression function from a data. In this paper we consider the rate of convergence for the nearest neighbor estimator in case that the regression function is $(p,C)$-smooth. It is an open problem whether the optimal rate can be achieved by some nearest neighbor estimator in case that $p$ is on (1,1.5]. We solve the problem affirmatively. This is the main result of this paper. Throughout this paper, we assume that the data is independent and identically distributed and as an error criterion we use the expected $L_2$ error.
Involvement of AMPA Receptor GluR2 and GluR3 Trafficking in Trigeminal Spinal Subnucleus Caudalis and C1/C2 Neurons in Acute-Facial Inflammatory Pain
Makiko Miyamoto, Yoshiyuki Tsuboi, Kuniya Honda, Masayuki Kobayashi, Kogo Takamiya, Richard L. Huganir, Masahiro Kondo, Masamichi Shinoda, Barry J. Sessle, Ayano Katagiri, Daiju Kita, Ikuko Suzuki, Yoshiyuki Oi, Koichi Iwata
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0044055
Abstract: To evaluate the involvement of trafficking of alpha-amino-3-hydroxy-5-methyl-4-isoxazo?lepropionicacid receptor (AMPAR) GluR2 and GluR3 subunits in an acute inflammatory orofacial pain, we analyzed nocifensive behavior, phosphorylated extracellular signal-regulated kinase (pERK) and Fos expression in Vi/Vc, Vc and C1/C2 in GluR2 delta7 knock-in (KI), GluR3 delta7 KI mice and wild-type mice. We also studied Vc neuronal activity to address the hypothesis that trafficking of GluR2 and GluR3 subunits plays an important role in Vi/Vc, Vc and C1/C2 neuronal activity associated with orofacial inflammation in these mice. Late nocifensive behavior was significantly depressed in GluR2 delta7 KI and GluR3 delta7 KI mice. In addition, the number of pERK-immunoreactive (IR) cells was significantly decreased bilaterally in the Vi/Vc, Vc and C1/C2 in GluR2 delta7 KI and GluR3 delta7 KI mice compared to wild-type mice at 40 min after formalin injection, and was also significantly smaller in GluR3 delta7 KI compared to GluR2 delta7 KI mice. The number of Fos protein-IR cells in the ipsilateral Vi/Vc, Vc and C1/C2 was also significantly smaller in GluR2 delta7 KI and GluR3 delta7 KI mice compared to wild-type mice 40 min after formalin injection. Nociceptive neurons functionally identified as wide dynamic range neurons in the Vc, where pERK- and Fos protein-IR cell expression was prominent, showed significantly lower spontaneous activity in GluR2 delta7 KI and GluR3 delta7 KI mice than wild-type mice following formalin injection. These findings suggest that GluR2 and GluR3 trafficking is involved in the enhancement of Vi/Vc, Vc and C1/C2 nociceptive neuronal excitabilities at 16–60 min following formalin injection, resulting in orofacial inflammatory pain.
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