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Find video protocols related to scientific articles indexed in Pubmed.
Is D-aspartate produced by glutamic-oxaloacetic transaminase-1 like 1 (Got1l1): a putative aspartate racemase?
Amino Acids
PUBLISHED: 07-23-2014
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D-Aspartate is an endogenous free amino acid in the brain, endocrine tissues, and exocrine tissues in mammals, and it plays several physiological roles. In the testis, D-aspartate is detected in elongate spermatids, Leydig cells, and Sertoli cells, and implicated in the synthesis and release of testosterone. In the hippocampus, D-aspartate strongly enhances N-methyl-D-aspartate receptor-dependent long-term potentiation and is involved in learning and memory. The existence of aspartate racemase, a candidate enzyme for D-aspartate production, has been suggested. Recently, mouse glutamic-oxaloacetic transaminase 1-like 1 (Got1l1) has been reported to synthesize substantially D-aspartate from L-aspartate and to be involved in adult neurogenesis. In this study, we investigated the function of Got1l1 in vivo by generating and analyzing Got1l1 knockout (KO) mice. We also examined the enzymatic activity of recombinant Got1l1 in vitro. We found that Got1l1 mRNA is highly expressed in the testis, but it is not detected in the brain and submandibular gland, where D-aspartate is abundant. The D-aspartate contents of wild-type and Got1l1 KO mice were not significantly different in the testis and hippocampus. The recombinant Got1l1 expressed in mammalian cells showed L-aspartate aminotransferase activity, but lacked aspartate racemase activity. These findings suggest that Got1l1 is not the major aspartate racemase and there might be an as yet unknown D-aspartate-synthesizing enzyme.
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IL1RAPL1 knockout mice show spine density decrease, learning deficiency, hyperactivity and reduced anxiety-like behaviours.
Sci Rep
PUBLISHED: 04-29-2014
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IL-1 receptor accessory protein-like 1 (IL1RAPL1) is responsible for nonsyndromic intellectual disability and is associated with autism. IL1RAPL1 mediates excitatory synapse formation through trans-synaptic interaction with PTP?. Here, we showed that the spine density of cortical neurons was significantly reduced in IL1RAPL1 knockout mice. The spatial reference and working memories and remote fear memory were mildly impaired in IL1RAPL1 knockout mice. Furthermore, the behavioural flexibility was slightly reduced in the T-maze test. Interestingly, the performance of IL1RAPL1 knockout mice in the rotarod test was significantly better than that of wild-type mice. Moreover, IL1RAPL1 knockout mice consistently exhibited high locomotor activity in all the tasks examined. In addition, open-space and height anxiety-like behaviours were decreased in IL1RAPL1 knockout mice. These results suggest that IL1RAPL1 ablation resulted in spine density decrease and affected not only learning but also behavioural flexibility, locomotor activity and anxiety.
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A590T mutation in KCNQ1 C-terminal helix D decreases IKs channel trafficking and function but not Yotiao interaction.
J. Mol. Cell. Cardiol.
PUBLISHED: 02-28-2014
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KCNQ1 encodes the ? subunit of the voltage-gated channel that mediates the cardiac slow delayed rectifier K(+) current (IKs). Here, we report a KCNQ1 allele encoding an A590T mutation [KCNQ1(A590T)] found in a 39-year-old female with a mild QT prolongation. A590 is located in the C-terminal ? helical region of KCNQ1 that mediates subunit tetramerization, membrane trafficking, and interaction with Yotiao. This interaction is known to be required for the proper modulation of IKs by cAMP. Since previous studies reported that mutations in the vicinity of A590 impair IKs channel surface expression and function, we examined whether and how the A590T mutation affects the IKs channel. Electrophysiological measurements in HEK-293T cells showed that the A590T mutation caused a reduction in IKs density and a right-shift of the current-voltage relation of channel activation. Immunocytochemical and immunoblot analyses showed the reduced cell surface expression of KCNQ1(A590T) subunit and its rescue by coexpression of the wild-type KCNQ1 [KCNQ1(WT)] subunit. Moreover, KCNQ1(A590T) subunit interacted with Yotiao and had a cAMP-responsiveness comparable to that of KCNQ1(WT) subunit. These findings indicate that the A590 of KCNQ1 subunit plays important roles in the maintenance of channel surface expression and function via a novel mechanism independent of interaction with Yotiao.
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Efficient in vivo depletion of CD8(+) T lymphocytes in common marmosets by novel CD8 monoclonal antibody administration.
Immunol. Lett.
PUBLISHED: 04-16-2013
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In order to directly demonstrate the roles of CD8(+) T lymphocytes in non-human primates, in vivo depletion of the CD8(+) T cells by administration of a CD8-specific monoclonal antibody (mAb) is one of the crucial techniques. Recently, the common marmoset (Callithrix jacchus), which is classified as a New World monkey, has been shown useful as an experimental animal model for various human diseases such as multiple sclerosis, Parkinsons disease and a number of infectious diseases. Here we show that an anti-marmoset CD8 mAb 6F10, which we have recently established, efficiently depletes the marmoset CD8(+) T lymphocytes in vivo, i.e., the administration of 6F10 induces drastic and specific reduction in the ratio of the CD8(+) T cell subset for at least three weeks or longer. Our finding will help understand the pivotal role of CD8(+) T cells in vivo in the control of human diseases.
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Dynamics of cellular immune responses in the acute phase of dengue virus infection.
Arch. Virol.
PUBLISHED: 02-05-2013
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In this study, we examined the dynamics of cellular immune responses in the acute phase of dengue virus (DENV) infection in a marmoset model. Here, we found that DENV infection in marmosets greatly induced responses of CD4/CD8 central memory T and NKT cells. Interestingly, the strength of the immune response was greater in animals infected with a dengue fever strain than in those infected with a dengue hemorrhagic fever strain of DENV. In contrast, when animals were re-challenged with the same DENV strain used for primary infection, the neutralizing antibody induced appeared to play a critical role in sterilizing inhibition against viral replication, resulting in strong but delayed responses of CD4/CD8 central memory T and NKT cells. The results in this study may help to better understand the dynamics of cellular and humoral immune responses in the control of DENV infection.
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IL1RAPL1 associated with mental retardation and autism regulates the formation and stabilization of glutamatergic synapses of cortical neurons through RhoA signaling pathway.
PLoS ONE
PUBLISHED: 01-01-2013
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Interleukin-1 receptor accessory protein-like 1 (IL1RAPL1) is associated with X-linked mental retardation and autism spectrum disorder. We found that IL1RAPL1 regulates synapse formation of cortical neurons. To investigate how IL1RAPL1 controls synapse formation, we here screened IL1RAPL1-interacting proteins by affinity chromatography and mass spectroscopy. IL1RAPL1 interacted with Mcf2-like (Mcf2l), a Rho guanine nucleotide exchange factor, through the cytoplasmic Toll/IL-1 receptor domain. Knockdown of endogenous Mcf2l and treatment with an inhibitor of Rho-associated protein kinase (ROCK), the downstream kinase of RhoA, suppressed IL1RAPL1-induced excitatory synapse formation of cortical neurons. Furthermore, we found that the expression of IL1RAPL1 affected the turnover of AMPA receptor subunits. Insertion of GluA1-containing AMPA receptors to the cell surface was decreased, whereas that of AMPA receptors composed of GluA2/3 was enhanced. Mcf2l knockdown and ROCK inhibitor treatment diminished the IL1RAPL1-induced changes of AMPA receptor subunit insertions. Our results suggest that Mcf2l-RhoA-ROCK signaling pathway mediates IL1RAPL1-dependent formation and stabilization of glutamatergic synapses of cortical neurons.
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Predisposition for borderline personality disorder with comorbid major depression is associated with that for polycystic ovary syndrome in female Japanese population.
Neuropsychiatr Dis Treat
PUBLISHED: 11-01-2011
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Polycystic ovary syndrome (PCOS) is a common lifestyle-related endocrinopathy in women of reproductive age and is associated with several mental health problems. We examined the genotypic distributions of IRS-1 Gly972Arg and CYP11B2 -344T/C, which were previously described as influencing PCOS, and assayed the serum levels of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-?), in a set of female patients with borderline personality disorder (BPD) with comorbid major depressive disorder (MDD) (n = 50) and age-matched control subjects (n = 100), to investigate the predisposition for BPD with MDD. The results showed that the patients were more frequently IRS-1 972Arg variant allele carriers (P = 0.013; OR 6.68; 95% CI = 1.30-34.43) and homozygous for the CYP11B2 -344C variant allele (P = 0.022; OR = 3.32; 95% CI = 1.18-9.35) than the control subjects. The IL-6 level was significantly higher in the patients than in the controls (P < 0.0001). There was no significant difference in the serum TNF-? level between patients with BPD with MDD and the healthy comparison group (P = 0.5273). In conclusion, the predisposition for BPD with MDD is associated with that for PCOS, in the female Japanese population. An elevated serum IL-6 level is considered to be a possible biomarker of BPD with MDD.
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Long-Term Persistent GBV-B Infection and Development of a Chronic and Progressive Hepatitis C-Like Disease in Marmosets.
Front Microbiol
PUBLISHED: 10-21-2011
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It has been shown that infection of GB virus B (GBV-B), which is closely related to hepatitis C virus, develops acute self-resolving hepatitis in tamarins. In this study we sought to examine longitudinally the dynamics of viral and immunological status following GBV-B infection of marmosets and tamarins. Surprisingly, two of four marmosets but not tamarins experimentally challenged with GBV-B developed long-term chronic infection with fluctuated viremia, recurrent increase of alanine aminotransferase and plateaued titers of the antiviral antibodies, which was comparable to chronic hepatitis C in humans. Moreover, one of the chronically infected marmosets developed an acute exacerbation of chronic hepatitis as revealed by biochemical, histological, and immunopathological analyses. Of note, periodical analyses of the viral genomes in these marmosets indicated frequent and selective non-synonymous mutations, suggesting efficient evasion of the virus from antiviral immune pressure. These results demonstrated for the first time that GBV-B could induce chronic hepatitis C-like disease in marmosets and that the outcome of the viral infection and disease progression may depend on the differences between species and individuals.
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IL-1 receptor accessory protein-like 1 associated with mental retardation and autism mediates synapse formation by trans-synaptic interaction with protein tyrosine phosphatase ?.
J. Neurosci.
PUBLISHED: 09-24-2011
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Mental retardation (MR) and autism are highly heterogeneous neurodevelopmental disorders. IL-1-receptor accessory protein-like 1 (IL1RAPL1) is responsible for nonsyndromic MR and is associated with autism. Thus, the elucidation of the functional role of IL1RAPL1 will contribute to our understanding of the pathogenesis of these mental disorders. Here, we showed that knockdown of endogenous IL1RAPL1 in cultured cortical neurons suppressed the accumulation of punctate staining signals for active zone protein Bassoon and decreased the number of dendritic protrusions. Consistently, the expression of IL1RAPL1 in cultured neurons stimulated the accumulation of Bassoon and spinogenesis. The extracellular domain (ECD) of IL1RAPL1 was required and sufficient for the presynaptic differentiation-inducing activity, while both the ECD and cytoplasmic domain were essential for the spinogenic activity. Notably, the synaptogenic activity of IL1RAPL1 was specific for excitatory synapses. Furthermore, we identified presynaptic protein tyrosine phosphatase (PTP) ? as a major IL1RAPL1-ECD interacting protein by affinity chromatography. IL1RAPL1 interacted selectively with certain forms of PTP? splice variants carrying mini-exon peptides in Ig-like domains. The synaptogenic activity of IL1RAPL1 was abolished in primary neurons from PTP? knock-out mice. IL1RAPL1 showed robust synaptogenic activity in vivo when transfected into the cortical neurons of wild-type mice but not in PTP? knock-out mice. These results suggest that IL1RAPL1 mediates synapse formation through trans-synaptic interaction with PTP?. Our findings raise an intriguing possibility that the impairment of synapse formation may underlie certain forms of MR and autism as a common pathogenic pathway shared by these mental disorders.
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Protein tyrosine phosphatase ? regulates the synapse number of zebrafish olfactory sensory neurons.
J. Neurochem.
PUBLISHED: 08-29-2011
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The formation and refinement of synaptic connections are key steps of neural development to establish elaborate brain networks. To investigate the functional role of protein tyrosine phosphatase (PTP) ?, we employed an olfactory sensory neuron (OSN)-specific gene manipulation system in combination with in vivo imaging of transparent zebrafish embryos. Knockdown of PTP? enhanced the accumulation of synaptic vesicles in the axon terminals of OSNs. The exaggerated accumulation of synaptic vesicles was restored to the normal level by the OSN-specific expression of PTP?, indicating that presynaptic PTP? is responsible for the regulation of synaptic vesicle accumulation. Consistently, transient expression of a dominant-negative form of PTP? in OSNs enhanced the accumulation of synaptic vesicles. The exaggerated accumulation of synaptic vesicles was reproduced in transgenic zebrafish lines carrying an OSN-specific expression vector of the dominant-negative PTP?. By electron microscopic analysis of the transgenic line, we found the significant increase of the number of OSN-mitral cell synapses in the central zone of the olfactory bulb. The density of docked vesicles at the active zone was also increased significantly. Our results suggest that presynaptic PTP? controls the number of OSN-mitral cell synapses by suppressing their excessive increase.
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CD16(+) natural killer cells play a limited role against primary dengue virus infection in tamarins.
Arch. Virol.
PUBLISHED: 07-29-2011
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CD16 is a major molecule expressed on NK cells. To directly assess the role of natural killer (NK) cells in dengue virus (DENV) infection in vivo, CD16 antibody-treated tamarins were inoculated with a DENV-2 strain. This resulted in the transient depletion of CD16(+) NK cells, whereas no significant effects on the overall levels or kinetics of plasma viral loads and antiviral antibodies were observed in the treated monkeys when compared to control monkeys. It remains elusive whether the CD16(-) NK subpopulation could play an important role in the control of primary DENV infection.
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Common marmoset (Callithrix jacchus) as a primate model of dengue virus infection: development of high levels of viraemia and demonstration of protective immunity.
J. Gen. Virol.
PUBLISHED: 06-22-2011
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Dengue virus (DENV) causes a wide range of illnesses in humans: dengue fever (DF), dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Animal models that constantly develop high levels of viraemia are required for the development of protective and preventive measures. Common marmosets (Callithrix jacchus) demonstrated high levels of viraemia after inoculation with clinical isolates of four serotypes of DENV; in particular, over 10(6) genome copies ml(-1) after inoculation with DENV-2. Non-structural protein 1 and DENV-specific IgM and IgG antibodies were consistently detected. The DENV-2 genome was detected in lymphoid organs including the lymph nodes, spleen and thymus, and also in non-lymphoid organs. DENV antigen was detected by immunohistochemistry in the liver and spleen from inoculated marmosets. Four marmosets were reinoculated with DENV-2 at 33 weeks after primary inoculation with DENV-2. The DENV-2 genome was not detected in any of these marmosets, indicating protection from a secondary infection. The results indicate that common marmosets are highly sensitive to DENV infection, and suggest that marmosets could be a reliable primate model for the evaluation of candidate vaccines.
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Selective intraarterial chemoradiation therapy for oropharyngeal carcinoma with high-dose cisplatin.
Jpn J Radiol
PUBLISHED: 04-12-2011
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Cisplatin has shown a high tumor response rate among head and neck carcinomas, and the tumor response is related to the cisplatin dosage. The purpose of this study was to evaluate the efficacy and toxicity of selective intraarterial chemoradiation therapy for oropharyngeal carcinomas with high-dose cisplatin.
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Sentinel node biopsy for oral and laryngopharyngeal squamous cell carcinoma: a retrospective study of 177 patients in Japan.
Auris Nasus Larynx
PUBLISHED: 03-07-2011
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Sentinel node (SN) biopsy in the head and neck region has not been widely used in Japan, except at a few facilities. However, almost all these facilities perform preoperative localization and intraoperative diagnosis by frozen section analysis of SN to select patients who must undergo neck dissection in a one-stage procedure. The objective of this study was to determine the actual status of SN biopsy at those facilities in Japan that have actively conducted this procedure, and to elucidate the usefulness and drawbacks of this technique in head and neck cancer.
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Differential interactions of cerebellin precursor protein (Cbln) subtypes and neurexin variants for synapse formation of cortical neurons.
Biochem. Biophys. Res. Commun.
PUBLISHED: 02-15-2011
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Trans-synaptic interaction of postsynaptic glutamate receptor ?2 and presynaptic neurexins (NRXNs) through cerebellin precursor protein (Cbln) 1 mediates synapse formation in the cerebellum [T. Uemura, S.J. Lee, M. Yasumura, T. Takeuchi, T. Yoshida, M. Ra, R. Taguchi, K. Sakimura, M. Mishina, Cell 141 (2010) 1068-1079]. This finding raises a question whether other Cbln family members interact with NRXNs to regulate synapse formation in the forebrain. Here, we showed that Cbln1 and Cbln2 induced presynaptic differentiation of cultured cortical neurons, while Cbln4 exhibited little activity. When compared with neuroligin 1, Cbln1 and Cbln2 induced preferentially inhibitory presynaptic differentiation rather than excitatory one in cortical cultures. The synaptogenic activities of Cbln1 and Cbln2 were suppressed by the addition of the extracellular domain of NRXN1? to the cortical neuron cultures. Consistently, Cbln1 and Cbln2 showed robust binding activities to NRXN1? and three ?-NRXNs, while only weak interactions were observed between Cbln4 and NRXNs. The interactions of Cbln1, Cbln2 and Cbln4 were selective for NRXN variants containing splice segment (S) 4. Affinities for NRXNs estimated by surface plasmon resonance analysis were variable among Cbln subtypes. Cbln1 showed higher affinities to NRXNs than Cbln2, while the binding ability of Cbln4 was much lower than those of Cbln1 and Cbln2. The affinities of Cbln1 and Cbln2 were comparable between NRXN1? and NRXN1?, but those for NRXN2? and NRXN3? were lower. These results suggest that Cbln subtypes exert synaptogenic activities in cortical neurons by differentially interacting with NRXN variants containing S4.
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Identification and characterization of a novel zebrafish semaphorin.
Neurosci. Lett.
PUBLISHED: 08-31-2010
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The semaphorin gene family contains numerous secreted and transmembrane proteins. Some of them function as the repulsive and attractive axon guidance molecules during development. Herein, we report the cloning and characterization of a novel member of zebrafish semaphorin gene, semaphorin 6E (sema6E). Sema6E is expressed predominantly in the nervous system during embryogenesis. Results also show that Sema6E binds Plexin-A1, but not other Plexins. Sema6E chemorepels not only dorsal root ganglion axons but also sympathetic axons. Therefore, Sema6E might utilize Plexin-A1 as a receptor to repel axons of the specific types during development.
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Improved capacity of a monkey-tropic HIV-1 derivative to replicate in cynomolgus monkeys with minimal modifications.
Microbes Infect.
PUBLISHED: 07-31-2010
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Human immunodeficiency virus type 1 (HIV-1) hardly replicates in Old World monkeys. Recently, a mutant HIV-1 clone, NL-DT5R, in which a small part of gag and the entire vif gene are replaced with SIVmac239-derived ones, was shown to be able to replicate in pigtail monkeys but not in rhesus monkeys (RM). In the present study, we found that a modified monkey-tropic HIV-1 (HIV-1mt), MN4-5S, acquired the ability to replicate efficiently in cynomolgus monkeys as compared with the NL-DT5R, while neither NL-DT5R nor MN4-5S replicated in RM cells. These results suggest that multiple determinants may be involved in the restriction of HIV-1 replication in macaques, depending on the species of macaques. The new HIV-1mt clone will be useful for studying molecular mechanisms by which anti-viral host factors regulate HIV-1 replication in macaques.
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Trans-synaptic interaction of GluRdelta2 and Neurexin through Cbln1 mediates synapse formation in the cerebellum.
Cell
PUBLISHED: 03-10-2010
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Elucidation of molecular mechanisms that regulate synapse formation is required for the understanding of neural wiring, higher brain functions, and mental disorders. Despite the wealth of in vitro information, fundamental questions about how glutamatergic synapses are formed in the mammalian brain remain unanswered. Glutamate receptor (GluR) delta2 is essential for cerebellar synapse formation in vivo. Here, we show that the N-terminal domain (NTD) of GluRdelta2 interacts with presynaptic neurexins (NRXNs) through cerebellin 1 precursor protein (Cbln1). The synaptogenic activity of GluRdelta2 is abolished in cerebellar primary cultures from Cbln1 knockout mice and is restored by recombinant Cbln1. Knockdown of NRXNs in cerebellar granule cells also hinders the synaptogenic activity of GluRdelta2. Both the NTD of GluRdelta2 and the extracellular domain of NRXN1beta suppressed the synaptogenic activity of Cbln1 in cerebellar primary cultures and in vivo. These results suggest that GluRdelta2 mediates cerebellar synapse formation by interacting with presynaptic NRXNs through Cbln1.
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Assessment of damage to cerebral white matter fiber in the subacute phase after carbon monoxide poisoning using fractional anisotropy in diffusion tensor imaging.
Neuroradiology
PUBLISHED: 01-12-2010
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Chronic neuropsychiatric symptoms after carbon monoxide (CO) poisoning are caused by demyelination of cerebral white matter fibers. We examined whether diffusion tensor imaging can sensitively represent damage to fibers of the centrum semiovale in the subacute phase after CO intoxication.
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Study of the outcome of suicide attempts: characteristics of hospitalization in a psychiatric ward group, critical care center group, and non-hospitalized group.
BMC Psychiatry
PUBLISHED: 01-12-2010
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The allocation of outcome of suicide attempters is extremely important in emergency situations. Following categorization of suicidal attempters who visited the emergency room by outcome, we aimed to identify the characteristics and potential needs of each group.
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DNA methyltransferases 1, 3a, and 3b overexpression and clinical significance in gastroenteropancreatic neuroendocrine tumors.
Hum. Pathol.
PUBLISHED: 01-05-2010
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The alteration of DNA methylation is one of the most common epigenetic changes in human cancers. Three genes, namely, DNA methyltransferase 1, 3a, and 3b, which code for DNA methyltransferases that affect promoter methylation status, are thought to play an important role in the development of cancers and may be good anticancer therapy targets. The methylation of tumor suppressor genes has been reported in gastroenteropancreatic neuroendocrine tumors; however, there have been no studies about DNA methyltransferase protein expression and its clinical significance in gastroenteropancreatic neuroendocrine tumors. In this study, the expression of DNA methyltransferase 1, 3a, and 3b was studied in 63 gastroenteropancreatic neuroendocrine tumors by immunohistochemistry. The expression of DNA methyltransferase 1, 3a, and 3b was frequently detected in gastroenteropancreatic neuroendocrine tumors (87%, 81%, and 75%, respectively). The DNA methyltransferase 3a expression level was significantly higher in poorly differentiated neuroendocrine carcinomas than in well-differentiated neuroendocrine tumors or well-differentiated neuroendocrine carcinomas (P < .01 and P < .05, respectively). The expression of DNA methyltransferase 1, 3a, and 3b showed significantly higher levels in stage IV tumors than in stage I or II tumors. In addition, the expression levels of DNA methyltransferase 1, 3a, and 3b were positively correlated with the MIB-1 labeling index in gastroenteropancreatic neuroendocrine tumors (R = 0.293, P = .019; R = 0.457, P = .001; and R = 0.249, P = .049; respectively). In addition, the expression levels and positive immunostaining frequencies of DNA methyltransferase 3a and 3b were significantly lower in midgut neuroendocrine tumors than in foregut or hindgut neuroendocrine tumors. Our findings suggest that the overexpression of DNA methyltransferase 1, 3a, and 3b is related to tumorigenesis and the progression of gastroenteropancreatic neuroendocrine tumors.
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The C-terminus of interferon gamma receptor beta chain (IFNgammaR2) has antiapoptotic activity as a Bax inhibitor.
Cancer Biol. Ther.
PUBLISHED: 09-20-2009
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Bax is a pro-apoptotic protein that mediates intrinsic cell-death signaling. Using a yeast-based functional screening approach, we identified interferon gamma receptor beta chain (IFNgammaR2) as a new Bax suppressor. IFNgammaR2 is a component of the IFNgamma receptor complex along with the IFNgammaR alpha chain (IFNgammaR1). Upon IFNgamma binding, a conformational change in the receptor complex occurs that activates the Jak2/STAT1 signaling cascade. We found that the C-terminal region (amino acids 296-337) of IFNgammaR2 (IFNgammaR2(296-337)) contains a novel Bax inhibitory domain. This portion does not contain the Jak2-binding domain; therefore, the antiapoptotic function of IFNgammaR2 is independent of JAK/STAT signaling. IFNgammaR2(296-337) rescued human cells from apoptosis induced by overexpression of Bax but not Bak. Overexpression of IFNgammaR2 (wild type and IFNgammaR2(296-337)) rescued cells from etoposide and staurosporine, which are known to induce Bax-mediated cell death. Interestingly, IFNgammaR2 inhibited apoptosis induced by the BH3-only protein Bim-EL, suggesting that IFNgammaR2 inhibits Bax activation through a BH3-only protein. Bax and IFNgammaR2 were co-immunoprecipitated from cell lysates prepared from HEK293 and DAMI cells. Furthermore, direct binding of purified recombinant proteins of Bax and IFNgammaR2 was also confirmed. Addition of recombinant Bcl-2 protein to cell lysates significantly reduced the interaction of IFNgammaR2 and Bax, suggesting that Bcl-2 and IFNgammaR2 bind a similar domain of Bax. We found that the C-terminal fragment (cytoplasmic domain) of IFNgammaR2 is expressed in human cancer cell lines of megakaryocytic cancer (DAMI), breast cancer (MDA-MD-468), and prostate cancer (PC3 cells). The presence of the C-terminal fragment of IFNgammaR2 may confer on cancer cells resistance to apoptotic stresses. Our discovery of the anti-Bax activity of the cytoplasmic domain of IFNgammaR2 may shed new light on the mechanism of how cell death is controlled by IFNgamma and Bax.
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Regulation of synaptic vesicle accumulation and axon terminal remodeling during synapse formation by distinct Ca signaling.
J. Neurochem.
PUBLISHED: 07-27-2009
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The synaptic vesicle accumulation and subsequent morphological remodeling of axon terminals are characteristic features of presynaptic differentiation of zebrafish olfactory sensory neurons. The synaptic vesicle accumulation and axon terminal remodeling are regulated by protein kinase A and calcineurin signaling, respectively. To investigate upstream signals of presynaptic differentiation, we focused on Ca(2+) signaling as Ca(2+)/calmodulin is required for the activation of both calcineurin and some adenylyl cyclases. We here showed that application of Ca(2+)/calmodulin inhibitor or olfactory sensory neuron-specific expression of calmodulin inhibitory peptide suppressed both synaptic vesicle accumulation and axon terminal remodeling. Thus, the trigger of presynaptic differentiation could be Ca(2+) release from intracellular stores or Ca(2+) influx. Application of a phospholipase C inhibitor or olfactory sensory neuron-specific expression of inositol 1,4,5-trisphosphate (IP(3)) 5-phosphatase suppressed synaptic vesicle accumulation, but not morphological remodeling. In contrast, application of a voltage-gated Ca(2+) channel blocker or expression of Kir2.1 inward rectifying potassium channel prevented the morphological remodeling. We also provided evidence that IP(3) signaling acted upstream of protein kinase A signaling. Our results suggest that IP(3)-mediated Ca(2+)/calmodulin signaling stimulates synaptic vesicle accumulation and subsequent neuronal activity-dependent Ca(2+)/calmodulin signaling induces the morphological remodeling of axon terminals.
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Ciprofloxacin suppresses Cyp3a in mouse liver by reducing lithocholic acid-producing intestinal flora.
Drug Metab. Pharmacokinet.
PUBLISHED: 07-03-2009
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Ciprofloxacin (CPX), a new quinolone antibiotic, is reported to reduce CYP3A expression in the liver when administered to rats. The present study investigates whether the reduction in intestinal flora is involved in this reduction of CYP3A. While hepatic Cyp3a11 expression and triazolam metabolic activity were significantly reduced by CPX treatment of SPF mice, no significant changes were seen by CPX treatment of germ-free (GF) mice. Lithocholic acid (LCA)-producing bacteria in the feces as well as hepatic level of taurine conjugate of LCA were significantly reduced in CPX-treated SPF mice. Cyp3a11 expression in GF mice was significantly elevated when treated with LCA, known as an activator of fernesoid X receptor and pregnane X receptor. These results indicate that antibiotics such as CPX, having antimicrobial spectrums against LCA-producing bacteria, possibly cause decrease in LCA in the liver, resulting in lower CYP3A expression. The intestinal flora is reported to be altered also by stress, disease and age etc. The findings of the present study suggest that these changes in intestinal flora may modify CYP expression and contribute to individual differences in pharmacokinetics.
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[Clinical photodynamic diagnosis and therapy efficiency in oropharyngeal cancer].
Nippon Jibiinkoka Gakkai Kaiho
PUBLISHED: 06-13-2009
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We studied photodynamic diagnosis (PDD) and therapy (PDT) applicability using NPe6 in with oropharyngeal cancer patients.
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Antibiotics suppress Cyp3a in the mouse liver by reducing lithocholic acid-producing intestinal flora.
Yakugaku Zasshi
PUBLISHED: 05-08-2009
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We previously demonstrated that ciprofloxacin (CPX), a new quinolone antibiotic, suppresses Cyp3a in the mouse liver by reducing the hepatic level of lithocholic acid (LCA) produced by intestinal flora. The present study investigated the possibility that other antibiotics with antibacterial activity against LCA-producing bacteria also cause a decrease in the LCA level in the liver, leading to reduced expression of Cyp3a11. While the mRNA expression of Cyp3a11 in the liver was significantly reduced when SPF mice were administered antibiotics such as ampicillin, CPX, levofloxacin, or a combination of vancomycin and imipenem, no significant changes were observed after antibiotic treatment of GF mice lacking intestinal flora. LCA-producing bacteria in the feces as well as the hepatic level of the taurine conjugate of LCA were significantly reduced in the antibiotic-treated SPF mice, suggesting that the decrease in Cyp3a11 expression can be attributed to the reduction in LCA-producing intestinal flora following antibiotic administration. These results suggest that the administration of antibiotics with activity against LCA-producing bacteria can also cause a decrease in the LCA level in humans, which may lower CYP3A4 expression. The intestinal flora are reported to be altered not only by drugs, such as antibiotics, but also by stress, disease, and age. The findings of the present study suggest that these changes in intestinal flora could modify CYP expression and contribute to the individual differences in pharmacokinetics.
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Characterization of arytenoid vertical displacement in unilateral vocal fold paralysis by three-dimensional computed tomography.
Eur Arch Otorhinolaryngol
PUBLISHED: 05-06-2009
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The paralyzed arytenoid is not immobile and is subjected to passive movement during phonation. If anatomical changes during inspiration and phonation are compared by three-dimensional computed tomography (3D CT), it is possible to observe vertical movement of the paralyzed arytenoid. Our aim was to use 3D CT to examine the characteristics of 3D arytenoid movement in unilateral vocal fold paralysis (UVFP). This is a prospective study. A total of 61 patients (18 females and 43 males) with UVFP who had undergone 3D CT imaging between April 2005 and January 2007 were included. Cricoid and arytenoid cartilage was imaged by 3D CT. We detected the movements of the paralyzed side when comparing inspiration and phonation. The degree of cranial displacement of the paralyzed arytenoids was classified into three grades (I for mild to III for severe). The mean flow rate (MFR) was calculated for each grade. By comparing the MFR of each grade with the normal control group, we determined whether cases would worsen according to grade. Passive gliding movement of the paralyzed arytenoids was found in 90.7% of cases. In all cases, the paralyzed arytenoids were displaced cranially compared to the unaffected side. MFR worsened significantly as the grade became more severe. We believe that the passive gliding movements observed when comparing inspiration and phonation are characteristic of paralysis. Even in mild cases, the paralyzed arytenoids are passively displaced cranially during phonation, and the degree of this displacement is one indicator that can be used to evaluate the severity of UVFP.
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Non-human primate surrogate model of hepatitis C virus infection.
Microbiol. Immunol.
PUBLISHED: 01-24-2009
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More than 170 million people worldwide are chronically infected by HCV, which is the causative agent of chronic hepatitis C, cirrhosis, and finally liver cancer. Although animal models of viral hepatitis are a prerequisite for the evaluation of antiviral and vaccine efficacy, the restricted host range of HCV has hampered the development of a suitable small animal model of HCV infection. Use of the chimpanzee, the only animal known to be susceptible to HCV infection, is limited by ethical and financial restrictions. In this regard GBV-B, being closely related to HCV, appears to be a promising non-human surrogate model for the study of HCV infection. This review describes the characteristic of GBV-B infection of New World monkeys, and discusses current issues concerning the GBV-B model and its future directions.
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[Treatment experience of the metastatic renal cell carcinomas to the head and neck region in our department].
Nippon Jibiinkoka Gakkai Kaiho
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Renal cell carcinoma is the most common cancer known for multiple metastasis, but the frequency of metastasis to the head and neck region is low. We report two cases of metastatic renal cell carcinoma to the head and neck region. The case 1 is a 79 year-old man with renal cell carcinoma treatment six years later. Metastasize to the larynx was found by the chief complaint of hoarseness. After treatment, no recurrence was shown for two years. The case 2 is a 61 year-old woman with renal cell carcinoma treatment two years later. Metastasize to the thyroid was found by the chief complaint of neck discomfort. After treatment, no recurrence was shown for two years and six months. These two cases obtained good control after surgical treatment. Since renal cell carcinoma often metastasized even after a long after treatment, it needs to follow progress over a long time. The possibility of metastasis is considered and a positive biopsy is required. The first choice of medical treatment is excision of a metastatic focus.
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Molecular mechanism of parallel fiber-Purkinje cell synapse formation.
Front Neural Circuits
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The cerebellum receives two excitatory afferents, the climbing fiber (CF) and the mossy fiber-parallel fiber (PF) pathway, both converging onto Purkinje cells (PCs) that are the sole neurons sending outputs from the cerebellar cortex. Glutamate receptor ?2 (GluR?2) is expressed selectively in cerebellar PCs and localized exclusively at the PF-PC synapses. We found that a significant number of PC spines lack synaptic contacts with PF terminals and some of residual PF-PC synapses show mismatching between pre- and postsynaptic specializations in conventional and conditional GluR?2 knockout mice. Studies with mutant mice revealed that in addition to PF-PC synapse formation, GluR?2 is essential for synaptic plasticity, motor learning, and the restriction of CF territory. GluR?2 regulates synapse formation through the amino-terminal domain, while the control of synaptic plasticity, motor learning, and CF territory is mediated through the carboxyl-terminal domain. Thus, GluR?2 is the molecule that bridges synapse formation and motor learning. We found that the trans-synaptic interaction of postsynaptic GluR?2 and presynaptic neurexins (NRXNs) through cerebellin 1 (Cbln1) mediates PF-PC synapse formation. The synaptogenic triad is composed of one molecule of tetrameric GluR?2, two molecules of hexameric Cbln1 and four molecules of monomeric NRXN. Thus, GluR?2 triggers synapse formation by clustering four NRXNs. These findings provide a molecular insight into the mechanism of synapse formation in the brain.
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Allele frequency of antiretroviral host factor TRIMCyp in wild-caught cynomolgus macaques (Macaca fascicularis).
Front Microbiol
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A recent study showed that the frequency of an antiretroviral factor TRIM5 gene-derived isoform, TRIMCyp, in cynomolgus macaques (Macaca fascicularis) varies widely according to the particular habitat examined. However, whether the findings actually reflect the prevalence of TRIMCyp in wild cynomolgus macaques is still uncertain because the previous data were obtained with captive monkeys in breeding and rearing facilities. Here, we characterized the TRIM5 gene in cynomolgus macaques captured in the wild, and found that the frequency of the TRIMCyp allele was comparable to those in captive monkeys. This suggests that the previous results with captive monkeys do indeed reflect the natural allele frequency and that breeding and rearing facilities may not affect the frequency of TRIM5 alleles. Interestingly, the prevalence of a minor haplotype of TRIMCyp in wild macaques from the Philippines was significantly lower than in captive ones, suggesting that it is advantageous for wild monkeys to possess the major haplotype of TRIMCyp. Overall, our results add to our understanding of the geographic and genetic prevalence of cynomolgus macaque TRIMCyp.
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Epidemiological study of zoonoses derived from humans in captive chimpanzees.
Primates
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Emerging infectious diseases (EIDs) in wildlife are major threats both to human health and to biodiversity conservation. An estimated 71.8 % of zoonotic EID events are caused by pathogens in wildlife and the incidence of such diseases is increasing significantly in humans. In addition, human diseases are starting to infect wildlife, especially non-human primates. The chimpanzee is an endangered species that is threatened by human activity such as deforestation, poaching, and human disease transmission. Recently, several respiratory disease outbreaks that are suspected of having been transmitted by humans have been reported in wild chimpanzees. Therefore, we need to study zoonotic pathogens that can threaten captive chimpanzees in primate research institutes. Serological surveillance is one of several methods used to reveal infection history. We examined serum from 14 captive chimpanzees in Japanese primate research institutes for antibodies against 62 human pathogens and 1 chimpanzee-borne infectious disease. Antibodies tested positive against 29 pathogens at high or low prevalence in the chimpanzees. These results suggest that the proportions of human-borne infections may reflect the chimpanzees history, management system in the institute, or regional epidemics. Furthermore, captive chimpanzees are highly susceptible to human pathogens, and their induced antibodies reveal not only their history of infection, but also the possibility of protection against human pathogens.
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Changes in hematological and serum biochemical parameters in common marmosets (Callithrix jacchus) after inoculation with dengue virus.
J. Med. Primatol.
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Marmosets are susceptible to dengue virus (DENV) infection. However, blood parameter data and clinical signs of DENV-infected marmosets are limited.
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GluR?2 assembles four neurexins into trans-synaptic triad to trigger synapse formation.
J. Neurosci.
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Elucidation of molecular mechanisms of synapse formation is a prerequisite for the understanding of neural wiring, higher brain functions, and mental disorders. The trans-synaptic interaction of postsynaptic glutamate receptor ?2 (GluR?2) and presynaptic neurexins (NRXNs) through cerebellin precursor protein 1 (Cbln1) mediates synapse formation in vivo in the cerebellum. Here, we asked how the trans-synaptic triad induces synapse formation. Native GluR?2 existed as a tetramer in the membrane, whereas the N-terminal domain (NTD) of GluR?2 formed a stable homodimer. When incubated with cultured mouse cerebellar granule cells (GCs), dimeric GluR?2-NTD and Cbln1 exerted little effect on the accumulation of punctate immunostaining signals for Bassoon and vesicular glutamate transporter 1 in GC axons. However, tetramerized GluR?2-NTD stimulated the accumulation of these presynaptic proteins in the axons. Analysis of Cbln1 mutants suggested that the binding sites of GluR?2 and NRXN1? on Cbln1 are differential. Furthermore, there was no competition in the binding to Cbln1 between GluR?2-NTD and the extracellular domain (ECD) of NRXN1?. Thus, GluR?2 and Cbln1 interacted with each other rather independently of Cbln1-NRXN1? interaction and vice versa. Gel filtration and isothermal titration calorimetry analyses consistently showed that dimeric GluR?2-NTD and hexameric Cbln1 assembled in the 1:1 ratio, whereas hexameric Cbln1 and the laminin-neurexin-sex hormone-binding globulin domain of NRXN1?-ECD assembled in the 1:2 ratio. Thus, the synaptogenic triad is assembled from tetrameric GluR?2, hexameric Cbln1, and monomeric NRXN in the ratio of 1:2:4. These results suggest that GluR?2 triggers synapse formation by clustering four NRXNs through triad formation.
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Diagnosis of congenital cervical cysts using carcinoembryonic antigen levels in cyst fluid.
Auris Nasus Larynx
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To investigate whether carcinoembryonic antigen (CEA) levels in the fluid of median or lateral cervical cysts can improve diagnosis.
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Interleukin-1 receptor accessory protein organizes neuronal synaptogenesis as a cell adhesion molecule.
J. Neurosci.
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Interleukin-1 receptor accessory protein (IL-1RAcP) is the essential component of receptor complexes mediating immune responses to interleukin-1 family cytokines. IL-1RAcP in the brain exists in two isoforms, IL-1RAcP and IL-1RAcPb, differing only in the C-terminal region. Here, we found robust synaptogenic activities of IL-1RAcP in cultured cortical neurons. Knockdown of IL-1RAcP isoforms in cultured cortical neurons suppressed synapse formation as indicated by decreases of active zone protein Bassoon puncta and dendritic protrusions. IL-1RAcP recovered the accumulation of presynaptic Bassoon puncta, while IL-1RAcPb rescued both Bassoon puncta and dendritic protrusions. Consistently, the expression of IL-1RAcP in cortical neurons enhances the accumulation of Bassoon puncta and that of IL-1RAcPb stimulated both Bassoon puncta accumulation and spinogenesis. IL-1RAcP interacted with protein tyrosine phosphatase (PTP) ? through the extracellular domain. Mini-exon peptides in the Ig-like domains of PTP? splice variants were critical for their efficient binding to IL-1RAcP. The synaptogenic activities of IL-1RAcP isoforms were diminished in cortical neurons from PTP? knock-out mice. Correspondingly, PTP? required IL-1RAcPb to induce postsynaptic differentiation. Thus, IL-1RAcPb bidirectionally regulated synapse formation of cortical neurons. Furthermore, the spine densities of cortical and hippocampal pyramidal neurons were reduced in IL-1RAcP knock-out mice lacking both isoforms. These results suggest that IL-1RAcP isoforms function as trans-synaptic cell adhesion molecules in the brain and organize synapse formation. Thus, IL-1RAcP represents an interesting molecular link between immune systems and synapse formation in the brain.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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