Nicotine-specific and non-specific effects of cigarette smoking on endogenous opioid mechanisms.

PubMed

Nuechterlein, Emily B; Ni, Lisong; Domino, Edward F; Zubieta, Jon-Kar

2016-08-01

This study investigates differences in μ-opioid receptor mediated neurotransmission in healthy controls and overnight-abstinent smokers, and potential effects of the OPRM1 A118G genotype. It also examines the effects of smoking denicotinized (DN) and average nicotine (N) cigarettes on the μ-opioid system. Positron emission tomography with (11)C-carfentanil was used to determine regional brain μ-opioid receptor (MOR) availability (non-displaceable binding potential, BPND) in a sample of 19 male smokers and 22 nonsmoking control subjects. Nonsmokers showed greater MOR BPND than overnight abstinent smokers in the basal ganglia and thalamus. BPND in the basal ganglia was negatively correlated with baseline craving levels and Fagerström scores. Interactions between group and genotype were seen in the nucleus accumbens bilaterally and the amygdala, with G-allele carriers demonstrating lower BPND in these regions, but only among smokers. After smoking the DN cigarette, smokers showed evidence of MOR activation in the thalamus and nucleus accumbens. No additional activation was observed after the N cigarette, with a mean effect of increases in MOR BPND (i.e., deactivation) with respect to the DN cigarette effects in the thalamus and left amygdala. Changes in MOR BPND were related to both Fagerström scores and changes in craving. This study showed that overnight-abstinent smokers have lower concentrations of available MORs than controls, an effect that was related to both craving and the severity of addiction. It also suggests that nicotine non-specific elements of the smoking experience have an important role in regulating MOR-mediated neurotransmission, and in turn modulating withdrawal-induced craving ratings. Copyright © 2016 Elsevier Inc. All rights reserved.

DNA-binding proteins from marine bacteria expand the known sequence diversity of TALE-like repeats

PubMed Central

de Lange, Orlando; Wolf, Christina; Thiel, Philipp; Krüger, Jens; Kleusch, Christian; Kohlbacher, Oliver; Lahaye, Thomas

2015-01-01

Transcription Activator-Like Effectors (TALEs) of Xanthomonas bacteria are programmable DNA binding proteins with unprecedented target specificity. Comparative studies into TALE repeat structure and function are hindered by the limited sequence variation among TALE repeats. More sequence-diverse TALE-like proteins are known from Ralstonia solanacearum (RipTALs) and Burkholderia rhizoxinica (Bats), but RipTAL and Bat repeats are conserved with those of TALEs around the DNA-binding residue. We study two novel marine-organism TALE-like proteins (MOrTL1 and MOrTL2), the first to date of non-terrestrial origin. We have assessed their DNA-binding properties and modelled repeat structures. We found that repeats from these proteins mediate sequence specific DNA binding conforming to the TALE code, despite low sequence similarity to TALE repeats, and with novel residues around the BSR. However, MOrTL1 repeats show greater sequence discriminating power than MOrTL2 repeats. Sequence alignments show that there are only three residues conserved between repeats of all TALE-like proteins including the two new additions. This conserved motif could prove useful as an identifier for future TALE-likes. Additionally, comparing MOrTL repeats with those of other TALE-likes suggests a common evolutionary origin for the TALEs, RipTALs and Bats. PMID:26481363

Synthesis and evaluation of 4-substituted piperidines and piperazines as balanced affinity μ opioid receptor (MOR) agonist/δ opioid receptor (DOR) antagonist ligands.

PubMed

Bender, Aaron M; Clark, Mary J; Agius, Michael P; Traynor, John R; Mosberg, Henry I

2014-01-15

In this letter, we describe a series of 4-substituted piperidine and piperazine compounds based on tetrahydroquinoline 1, a compound that shows balanced, low nanomolar binding affinity for the mu opioid receptor (MOR) and the delta opioid receptor (DOR). We have shown that by changing the length and flexibility profile of the side chain in this position, binding affinity is improved at both receptors by a significant degree. Furthermore, several of the compounds described herein display good efficacy at MOR, while simultaneously displaying DOR antagonism. The MOR agonist/DOR antagonist has shown promise in the reduction of negative side effects displayed by selective MOR agonists, namely the development of dependence and tolerance. Copyright © 2013 Elsevier Ltd. All rights reserved.

Functional Characteristics of the Naked Mole Rat μ-Opioid Receptor

PubMed Central

Roth, Clarisse A.

2013-01-01

While humans and most animals respond to µ-opioid receptor (MOR) agonists with analgesia and decreased aggression, in the naked mole rat (NMR) opioids induce hyperalgesia and severe aggression. Single nucleotide polymorphisms in the human mu-opioid receptor gene (OPRM1) can underlie altered behavioral responses to opioids. Therefore, we hypothesized that the primary structure of the NMR MOR may differ from other species. Sequencing of the NMR oprm1 revealed strong homology to other mammals, but exposed three unique amino acids that might affect receptor-ligand interactions. The NMR and rat oprm1 sequences were cloned into mammalian expression vectors and transfected into HEK293 cells. Radioligand binding and 3'-5'-cyclic adenosine monophosphate (cAMP) enzyme immunoassays were used to compare opioid binding and opioid-mediated cAMP inhibition. At normalized opioid receptor protein levels we detected significantly lower [3H]DAMGO binding to NMR compared to rat MOR, but no significant difference in DAMGO-induced cAMP inhibition. Strong DAMGO-induced MOR internalization was detectable using radioligand binding and confocal imaging in HEK293 cells expressing rat or NMR receptor, while morphine showed weak or no effects. In summary, we found minor functional differences between rat and NMR MOR suggesting that other differences e.g. in anatomical distribution of MOR underlie the NMR's extreme reaction to opioids. PMID:24312175

Roles of the µ-opioid receptor and its related signaling pathways in the pathogenesis of premenstrual syndrome liver-qi stagnation

PubMed Central

Song, Chunhong; Xue, Ling

2017-01-01

The present study aimed to investigate the roles of the µ-opioid receptor (MOR) and its related signaling pathways in the pathogenesis of premenstrual syndrome (PMS) liver-qi stagnation, along with the therapeutic effects of the Shu-Yu capsule in treating the condition. A PMS liver-qi stagnation rat model was established using a chronic restraint stress method. The protein expression level of MOR within rat hippocampal tissue was detected via western blot analysis and cyclic adenosine monophosphate (cAMP) levels within the supernatant of a rat hippocampal cell culture were determined by ELISA. The western blot analysis indicated that the hippocampal expression level of MOR was significantly elevated in the PMS liver-qi stagnation model group. However, subsequent treatment with a Shu-Yu capsule was found to significantly decrease the level of MOR expression. In addition, in vitro experiments were performed, whereby primary hippocampal neurons were treated with model rat serum. It was observed that the level of MOR expression was significantly elevated, while brain-derived neurotrophic factor (BDNF) and cAMP levels in the culture supernatant were significantly decreased. These effects were reversed by treatment with serum from the Shu-Yu capsule-treated rats. Furthermore, when treated with the MOR activator DAMGO, the following were significantly decreased in the primary neurons: Phosphorylation levels of cAMP response element binding protein and extracellular signal-regulated protein kinases (ERK); BDNF expression; and cAMP content in the culture supernatant. These effects were reversed in primary neurons treated with DAMGO and Shu-Yu-containing rat serum. Collectively, the data suggest that increased MOR expression and activation of the cAMP/ERK signaling pathway in the hippocampus may be involved in the pathogenesis of PMS liver-qi stagnation. Furthermore, the efficacy of the Shu-Yu capsule in treating the condition may be via its regulation of MOR receptor signaling. PMID:28587388

DNA-binding proteins from marine bacteria expand the known sequence diversity of TALE-like repeats.

PubMed

de Lange, Orlando; Wolf, Christina; Thiel, Philipp; Krüger, Jens; Kleusch, Christian; Kohlbacher, Oliver; Lahaye, Thomas

2015-11-16

Transcription Activator-Like Effectors (TALEs) of Xanthomonas bacteria are programmable DNA binding proteins with unprecedented target specificity. Comparative studies into TALE repeat structure and function are hindered by the limited sequence variation among TALE repeats. More sequence-diverse TALE-like proteins are known from Ralstonia solanacearum (RipTALs) and Burkholderia rhizoxinica (Bats), but RipTAL and Bat repeats are conserved with those of TALEs around the DNA-binding residue. We study two novel marine-organism TALE-like proteins (MOrTL1 and MOrTL2), the first to date of non-terrestrial origin. We have assessed their DNA-binding properties and modelled repeat structures. We found that repeats from these proteins mediate sequence specific DNA binding conforming to the TALE code, despite low sequence similarity to TALE repeats, and with novel residues around the BSR. However, MOrTL1 repeats show greater sequence discriminating power than MOrTL2 repeats. Sequence alignments show that there are only three residues conserved between repeats of all TALE-like proteins including the two new additions. This conserved motif could prove useful as an identifier for future TALE-likes. Additionally, comparing MOrTL repeats with those of other TALE-likes suggests a common evolutionary origin for the TALEs, RipTALs and Bats. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Evidence of the neuron-restrictive silencer factor (NRSF) interaction with Sp3 and its synergic repression to the mu opioid receptor (MOR) gene

PubMed Central

Kim, Chun Sung; Choi, Hack Sun; Hwang, Cheol Kyu; Song, Kyu Young; Lee, Byung-Kwon; Law, Ping-Yee; Wei, Li-Na; Loh, Horace H.

2006-01-01

Previously, we reported that the neuron-restrictive silencer element (NRSE) of mu opioid receptor (MOR) functions as a critical regulator to repress the MOR transcription in specific neuronal cells, depending on neuron-restriction silence factor (NRSF) expression levels [C.S.Kim, C.K.Hwang, H.S.Choi, K.Y.Song, P.Y.Law, L.N.Wei and H.H.Loh (2004) J. Biol. Chem., 279, 46464–46473]. Herein, we identify a conserved GC sequence next to NRSE region in the mouse MOR gene. The inhibition of Sp family factors binding to this GC box by mithramycin A led to a significant increase in the endogenous MOR transcription. In the co-immunoprecipitation experiment, NRSF interacted with the full-length Sp3 factor, but not with Sp1 or two short Sp3 isoforms. The sequence specific and functional binding by Sp3 at this GC box was confirmed by in vitro gel-shift assays using either in vitro translated proteins or nuclear extract, and by in vivo chromatin immunoprecipitation assays. Transient transfection assays showed that Sp3-binding site of the MOR gene is a functionally synergic repressor element with NRSE in NS20Y cells, but not in the NRSF negative PC12 cells. The results suggest that the synergic interaction between NRSF and Sp3 is required to negatively regulate MOR gene transcription and that transcription of MOR gene would be governed by the context of available transcription factors rather than by a master regulator. PMID:17130167

Synthetic Studies of Neoclerodane Diterpenes from Salvia divinorum: Identification of a Potent and Centrally Acting μ Opioid Analgesic with Reduced Abuse Liability.

PubMed

Crowley, Rachel Saylor; Riley, Andrew P; Sherwood, Alexander M; Groer, Chad E; Shivaperumal, Nirajmohan; Biscaia, Miguel; Paton, Kelly; Schneider, Sebastian; Provasi, Davide; Kivell, Bronwyn M; Filizola, Marta; Prisinzano, Thomas E

2016-12-22

Opioids are widely used to treat millions suffering from pain, but their analgesic utility is limited due to associated side effects. Herein we report the development and evaluation of a chemical probe exhibiting analgesia and reduced opioid-induced side effects. This compound, kurkinorin (5), is a potent and selective μ-opioid receptor (MOR) agonist (EC 50 = 1.2 nM, >8000 μ/κ selectivity). 5 is a biased activator of MOR-induced G-protein signaling over β-arrestin-2 recruitment. Metadynamics simulations of 5's binding to a MOR crystal structure suggest energetically preferred binding modes that differ from crystallographic ligands. In vivo studies with 5 demonstrate centrally mediated antinociception, significantly reduced rewarding effects, tolerance, and sedation. We propose that this novel MOR agonist may represent a valuable tool in distinguishing the pathways involved in MOR-induced analgesia from its side effects.

It still hurts: altered opioid activity in the brain during social rejection and acceptance in major depressive disorder

PubMed Central

Hsu, David T; Sanford, Benjamin J; Meyers, Kortni K; Love, Tiffany M; Hazlett, Kathleen E; Walker, Sara J; Mickey, Brian J; Koeppe, Robert A; Langenecker, Scott A; Zubieta, Jon-Kar

2015-01-01

The μ-opioid receptor (MOR) system, well known for dampening physical pain, is also hypothesized to dampen “social pain.” We used positron emission tomography scanning with the selective MOR radioligand [11C]carfentanil to test the hypothesis that MOR system activation in response to social rejection and acceptance is altered in medication-free patients diagnosed with current major depressive disorder (MDD, n = 17) compared to healthy controls (HCs, n = 18). During rejection, MDD patients showed reduced MOR activation (e.g., reduced endogenous opioid release) in brain regions regulating stress, mood, and motivation, and slower emotional recovery compared to HCs. During acceptance, only HCs showed increased social motivation, which was positively correlated with MOR activation in the nucleus accumbens, a reward structure. Abnormal MOR function in MDD may hinder emotional recovery from negative social interactions and decrease pleasure derived from positive interactions. Both effects may reinforce depression, trigger relapse, and contribute to poor treatment outcomes. PMID:25600108

Knockdown of ventral tegmental area mu-opioid receptors in rats prevents effects of social defeat stress: Implications for amphetamine cross-sensitization, social avoidance, weight regulation and expression of brain-derived neurotrophic factor

PubMed Central

Johnston, Caitlin E.; Herschel, Daniel; Lasek, Amy W.; Hammer, Ronald P.; Nikulina, Ella M.

2014-01-01

Social defeat stress causes social avoidance and long-lasting cross-sensitization to psychostimulants, both of which are associated with increased brain-derived neurotrophic factor (BDNF) expression in the ventral tegmental area (VTA). Moreover, social stress upregulates VTA mu-opioid receptor (MOR) mRNA. In the VTA, MOR activation inhibits GABA neurons to disinhibit VTA dopamine neurons, thus providing a role for VTA MORs in the regulation of psychostimulant sensitization. The present study determined the effect of lentivirus-mediated MOR knockdown in the VTA on the consequences of intermittent social defeat stress, a salient and profound stressor in humans and rodents. Social stress exposure induced social avoidance and attenuated weight gain in animals with non-manipulated VTA MORs, but both these effects were prevented by VTA MOR knockdown. Rats with non-manipulated VTA MOR expression exhibited cross-sensitization to amphetamine challenge (1.0 mg/kg, i.p.), evidenced by a significant augmentation of locomotion. By contrast, knockdown of VTA MORs prevented stress-induced cross-sensitization without blunting the locomotor-activating effects of amphetamine. At the time point corresponding to amphetamine challenge, immunohistochemical analysis was performed to examine the effect of stress on VTA BDNF expression. Prior stress exposure increased VTA BDNF expression in rats with non-manipulated VTA MOR expression, while VTA MOR knockdown prevented stress-induced expression of VTA BDNF. Taken together, these results suggest that upregulation of VTA MOR is necessary for the behavioral and biochemical changes induced by social defeat stress. Elucidating VTA MOR regulation of stress effects on the mesolimbic system may provide new therapeutic targets for treating stress-induced vulnerability to substance abuse. PMID:25446676

Opiate antagonist prevents μ- and δ-opiate receptor dimerization to facilitate ability of agonist to control ethanol-altered natural killer cell functions and mammary tumor growth.

PubMed

Sarkar, Dipak K; Sengupta, Amitabha; Zhang, Changqing; Boyadjieva, Nadka; Murugan, Sengottuvelan

2012-05-11

In the natural killer (NK) cells, δ-opiate receptor (DOR) and μ-opioid receptor (MOR) interact in a feedback manner to regulate cytolytic function with an unknown mechanism. Using RNK16 cells, a rat NK cell line, we show that MOR and DOR monomer and dimer proteins existed in these cells and that chronic treatment with a receptor antagonist reduced protein levels of the targeted receptor but increased levels of opposing receptor monomer and homodimer. The opposing receptor-enhancing effects of MOR and DOR antagonists were abolished following receptor gene knockdown by siRNA. Ethanol treatment increased MOR and DOR heterodimers while it decreased the cellular levels of MOR and DOR monomers and homodimers. The opioid receptor homodimerization was associated with an increased receptor binding, and heterodimerization was associated with a decreased receptor binding and the production of cytotoxic factors. Similarly, in vivo, opioid receptor dimerization, ligand binding of receptors, and cell function in immune cells were promoted by chronic treatment with an opiate antagonist but suppressed by chronic ethanol feeding. Additionally, a combined treatment of an MOR antagonist and a DOR agonist was able to reverse the immune suppressive effect of ethanol and reduce the growth and progression of mammary tumors in rats. These data identify a role of receptor dimerization in the mechanism of DOR and MOR feedback interaction in NK cells, and they further elucidate the potential for the use of a combined opioid antagonist and agonist therapy for the treatment of immune incompetence and cancer and alcohol-related diseases.

How Oliceridine (TRV-130) Binds and Stabilizes a μ-Opioid Receptor Conformational State That Selectively Triggers G Protein Signaling Pathways.

PubMed

Schneider, Sebastian; Provasi, Davide; Filizola, Marta

2016-11-22

Substantial attention has recently been devoted to G protein-biased agonism of the μ-opioid receptor (MOR) as an ideal new mechanism for the design of analgesics devoid of serious side effects. However, designing opioids with appropriate efficacy and bias is challenging because it requires an understanding of the ligand binding process and of the allosteric modulation of the receptor. Here, we investigated these phenomena for TRV-130, a G protein-biased MOR small-molecule agonist that has been shown to exert analgesia with less respiratory depression and constipation than morphine and that is currently being evaluated in human clinical trials for acute pain management. Specifically, we carried out multimicrosecond, all-atom molecular dynamics (MD) simulations of the binding of this ligand to the activated MOR crystal structure. Analysis of >50 μs of these MD simulations provides insights into the energetically preferred binding pathway of TRV-130 and its stable pose at the orthosteric binding site of MOR. Information transfer from the TRV-130 binding pocket to the intracellular region of the receptor was also analyzed, and was compared to a similar analysis carried out on the receptor bound to the classical unbiased agonist morphine. Taken together, these studies lead to a series of testable hypotheses of ligand-receptor interactions that are expected to inform the structure-based design of improved opioid analgesics.

Positive transcriptional regulation of the human micro opioid receptor gene by poly(ADP-ribose) polymerase-1 and increase of its DNA binding affinity based on polymorphism of G-172 -> T.

PubMed

Ono, Takeshi; Kaneda, Toshio; Muto, Akihiro; Yoshida, Tadashi

2009-07-24

Micro opioid receptor (MOR) agonists such as morphine are applied widely in clinical practice as pain therapy. The effects of morphine through MOR, such as analgesia and development of tolerance and dependence, are influenced by individual specificity. Recently, we analyzed single nucleotide polymorphisms on the human MOR gene to investigate the factors that contribute to individual specificity. In process of single nucleotide polymorphisms analysis, we found that specific nuclear proteins bound to G(-172) --> T region in exon 1 in MOR gene, and its affinity to DNA was increased by base substitution from G(-172) to T(-172). The isolated protein was identified by mass spectrometry and was confirmed by Western blotting to be poly(ADP-ribose) polymerase-1 (PARP-1). The overexpressed PARP-1 bound to G(-172) --> T and enhanced the transcription of reporter vectors containing G(-172) and T(-172). Furthermore, PARP-1 inhibitor (benzamide) decreased PARP-1 binding to G(-172) --> T without affecting mRNA or protein expression level of PARP-1 and down-regulated the subsequent MOR gene expression in SH-SY5Y cells. Moreover, we found that tumor necrosis factor-alpha enhanced MOR gene expression as well as increased PARP-1 binding to the G(-172) --> T region and G(-172) --> T-dependent transcription in SH-SY5Y cells. These effects were also inhibited by benzamide. In this study, our data suggest that PARP-1 positively regulates MOR gene transcription via G(-172) --> T, which might influence individual specificity in therapeutic opioid effects.

Transcription factor REST negatively influences the protein kinase C-dependent up-regulation of human mu-opioid receptor gene transcription.

PubMed

Bedini, Andrea; Baiula, Monica; Carbonari, Gioia; Spampinato, Santi

2010-01-01

Mu-opioid receptor expression increases during neurogenesis, regulates the survival of maturing neurons and is implicated in ischemia-induced neuronal death. The repressor element 1 silencing transcription factor (REST), a regulator of a subset of genes in differentiating and post-mitotic neurons, is involved in its transcriptional repression. Extracellular signaling molecules and mechanisms that control the human mu-opioid receptor (hMOR) gene transcription are not clearly understood. We examined the role of protein kinase C (PKC) on hMOR transcription in a model of neuronal cells and in the context of the potential influence of REST. In native SH-SY5Y neuroblastoma cells, PKC activation with phorbol 12-myristate 13-acetate (PMA, 16 nM, 24h) down-regulated hMOR transcription and concomitantly elevated the REST binding activity to repressor element 1 of the hMOR promoter. In contrast, PMA activated hMOR gene transcription when REST expression was knocked down by an antisense strategy or by retinoic acid-induced cell differentiation. PMA acts through a PKC-dependent pathway requiring downstream MAP kinases and the transcription factor AP-1. In a series of hMOR-luciferase promoter/reporter constructs transfected into SH-SY5Y cells and PC12 cells, PMA up-regulated hMOR transcription in PC12 cells lacking REST, and in SH-SY5Y cells either transfected with constructs deficient in the REST DNA binding element or when REST was down-regulated in retinoic acid-differentiated cells. These findings help explain how hMOR transcription is regulated and may clarify its contribution to epigenetic modifications and reprogramming of differentiated neuronal cells exposed to PKC-activating agents. Copyright 2009 Elsevier Ltd. All rights reserved.

Blunted Endogenous Opioid Release Following an Oral Amphetamine Challenge in Pathological Gamblers

PubMed Central

Mick, Inge; Myers, Jim; Ramos, Anna C; Stokes, Paul R A; Erritzoe, David; Colasanti, Alessandro; Gunn, Roger N; Rabiner, Eugenii A; Searle, Graham E; Waldman, Adam D; Parkin, Mark C; Brailsford, Alan D; Galduróz, José C F; Bowden-Jones, Henrietta; Clark, Luke; Nutt, David J; Lingford-Hughes, Anne R

2016-01-01

Pathological gambling is a psychiatric disorder and the first recognized behavioral addiction, with similarities to substance use disorders but without the confounding effects of drug-related brain changes. Pathophysiology within the opioid receptor system is increasingly recognized in substance dependence, with higher mu-opioid receptor (MOR) availability reported in alcohol, cocaine and opiate addiction. Impulsivity, a risk factor across the addictions, has also been found to be associated with higher MOR availability. The aim of this study was to characterize baseline MOR availability and endogenous opioid release in pathological gamblers (PG) using [11C]carfentanil PET with an oral amphetamine challenge. Fourteen PG and 15 healthy volunteers (HV) underwent two [11C]carfentanil PET scans, before and after an oral administration of 0.5 mg/kg of d-amphetamine. The change in [11C]carfentanil binding between baseline and post-amphetamine scans (ΔBPND) was assessed in 10 regions of interest (ROI). MOR availability did not differ between PG and HV groups. As seen previously, oral amphetamine challenge led to significant reductions in [11C]carfentanil BPND in 8/10 ROI in HV. PG demonstrated significant blunting of opioid release compared with HV. PG also showed blunted amphetamine-induced euphoria and alertness compared with HV. Exploratory analysis revealed that impulsivity positively correlated with caudate baseline BPND in PG only. This study provides the first evidence of blunted endogenous opioid release in PG. Our findings are consistent with growing evidence that dysregulation of endogenous opioids may have an important role in the pathophysiology of addictions. PMID:26552847

Multiphase whole-body CT angiography before multiorgan retrieval in clinically brain dead patients: Role and influence on clinical practice.

PubMed

Tache, A; Badet, N; Azizi, A; Behr, J; Verdy, S; Delabrousse, E

2016-06-01

To evaluate the contribution of multiphase whole-body CT angiography (CTA) for identifying the contra-indications to multiorgan retrieval (MOR) and improving the preoperative organ harvesting strategy. One hundred and eleven consecutive patients who were clinically brain dead underwent multiphase whole-body CTA to confirm the diagnosis of brain death and for assessment of MOR. The CTA protocol included volumetric acquisitions of the brain and abdominopelvic cavity without IV administration of iodinated contrast material, then images of the thorax-abdomen-pelvis 25s after IV contrast administration, of the brain at 60s and finally an abdominopelvic CT acquisition at 90s. The diagnosis of brain death was based on well-established criteria. The assessment of thorax, abdomen and pelvis was based on a systematic checklist. Post-processing imaging techniques were used in all patients. No organs were retrieved from 21 patients due to patient refusal (19%). Twenty-two potential MOR were denied because of general contra-indications including 12/22 (54%) based on CTA criteria alone. Finally, 68 patients were eligible for MOR and 160 organs were harvested. The exclusion of specific organs was based on CTA alone for 2/16 livers, 4/70 kidneys and 5/55 lungs. Fifty hearts and 58 pancreases were not harvested, none based on CTA results alone. Hepatic abnormalities and vascular anatomical variants were identified in 10% of patients. At least one renal artery variant was found in 28% of patients, 13% presented with a double renal vein and 8% with a hepato-mesenteric artery. Multiphase whole-body CTA for MOR is based on the simultaneous association of cerebral CTA to determine brain death with CTA of the thorax, abdomen and pelvis. This rapid, standardized and easily accessible procedure has no harmful effects on harvested kidneys. It makes it possible to select the donors and the organs to be harvested and allows the retrieving surgeon to identify and anticipate technical difficulties. Copyright © 2015 Editions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

Opioidergic mechanisms underlying the actions of Vitex agnus-castus L

PubMed Central

Webster, Donna E.; He, Ying; Chen, Shao.-Nong; Pauli, Guido F.; Farnsworth, Norman R.; Wang, Zaijie Jim

2010-01-01

Vitex agnus-castus (VAC) has been used since ancient Greek times and has been shown clinically to be effective for the treatment of pre-menstrual syndrome. However, its mechanism of action has only been partially determined. Compounds, fractions, and extracts isolated from VAC were used in this study to thoroughly investigate possible opioidergic activity. First, an extract of VAC was found to bind and activate μ- and δ-, but not κ- opioid receptor subtypes (MOR, DOR, and KOR respectively). The extract was then resuspended in 10% methanol and partitioned sequentially with petroleum ether, CHCl3, and EtOAc to form four fractions including a water fraction. The highest affinity for MOR was concentrated in the CHCl3 fraction, whereas the highest affinity for DOR was found in the CHCl3 and EtOAc fractions. However, the petroleum ether fraction had the highest agonist activity at MOR and DOR. Several flavonoids from VAC were found to bind to both MOR and DOR in a dose-dependent manner; however only casticin, a marker compound for genus Vitex, was found to have agonist activity selective for DOR at high concentrations. These results suggest VAC may exert its therapeutic effects through the activation of MOR, DOR, but not KOR. PMID:20854795

Opioidergic mechanisms underlying the actions of Vitex agnus-castus L.

PubMed

Webster, Donna E; He, Ying; Chen, Shao-Nong; Pauli, Guido F; Farnsworth, Norman R; Wang, Zaijie Jim

2011-01-01

Vitex agnus-castus (VAC) has been used since ancient Greek times and has been shown clinically to be effective for the treatment of pre-menstrual syndrome. However, its mechanism of action has only been partially determined. Compounds, fractions, and extracts isolated from VAC were used in this study to thoroughly investigate possible opioidergic activity. First, an extract of VAC was found to bind and activate μ- and δ-, but not κ-opioid receptor subtypes (MOR, DOR, and KOR respectively). The extract was then resuspended in 10% methanol and partitioned sequentially with petroleum ether, CHCl(3), and EtOAc to form four fractions including a water fraction. The highest affinity for MOR was concentrated in the CHCl(3) fraction, whereas the highest affinity for DOR was found in the CHCl(3) and EtOAc fractions. The petroleum ether fraction had the highest agonist activity at MOR and DOR. Several flavonoids from VAC were found to bind to both MOR and DOR in a dose-dependent manner; however only casticin, a marker compound for genus Vitex, was found to have agonist activity selective for DOR at high concentrations. These results suggest VAC may exert its therapeutic effects through the activation of MOR, DOR, but not KOR. Copyright © 2010 Elsevier Inc. All rights reserved.

Association of time-dependent changes in mu opioid receptor mRNA, but not BDNF, TrkB, or MeCP2 mRNA and protein expression in the rat nucleus accumbens with incubation of heroin craving.

PubMed

Theberge, Florence R M; Pickens, Charles L; Goldart, Evan; Fanous, Sanya; Hope, Bruce T; Liu, Qing-Rong; Shaham, Yavin

2012-12-01

Responding to heroin cues progressively increases after cessation of heroin self-administration (incubation of heroin craving). We investigated whether this incubation is associated with time-dependent changes in brain-derived neurotrophic factor (BDNF) and methyl-CpG binding protein 2 (MeCP2) signaling and mu opioid receptor (MOR) expression in nucleus accumbens (NAc), dorsal striatum (DS), and medial prefrontal cortex (mPFC). We also investigated the effect of the preferential MOR antagonist naloxone on cue-induced heroin seeking during abstinence. We trained rats to self-administer heroin or saline for 9-10 days and then dissected the NAc, DS, and mPFC at different abstinence days and measured mRNA and protein levels of BDNF, TrkB, and MeCP2, as well as MOR mRNA (Oprm1). In other groups, we assessed cue-induced heroin seeking in extinction tests after 1, 11, and 30 abstinence days, and naloxone's (0-1.0 mg/kg) effect on extinction responding after 1 and 15 days. Cue-induced heroin seeking progressively increased or incubated during abstinence. This incubation was not associated with changes in BDNF, TrkB, or MeCP2 mRNA or protein levels in NAc, DS, or mPFC; additionally, no molecular changes were observed after extinction tests on day 11. In NAc, but not DS or mPFC, MOR mRNA decreased on abstinence day 1 and returned to basal levels over time. Naloxone significantly decreased cue-induced heroin seeking after 15 abstinence days but not 1 day. Results suggest a role of MOR in incubation of heroin craving. As previous studies implicated NAc BDNF in incubation of cocaine craving, our data suggest that different mechanisms contribute to incubation of heroin versus cocaine craving.

Association of time-dependent changes in mu opioid receptor mRNA, but not BDNF, TrkB, or MeCP2 mRNA and protein expression in the rat nucleus accumbens with incubation of heroin craving

PubMed Central

Theberge, Florence R. M.; Pickens, Charles L.; Goldart, Evan; Fanous, Sanya; Hope, Bruce T.; Liu, Qing-Rong

2013-01-01

Rationale and objectives Responding to heroin cues progressively increases after cessation of heroin self-administration (incubation of heroin craving). We investigated whether this incubation is associated with time-dependent changes in brain-derived neurotrophic factor (BDNF) and methyl-CpG binding protein 2 (MeCP2) signaling and mu opioid receptor (MOR) expression in nucleus accumbens (NAc), dorsal striatum (DS), and medial pre-frontal cortex (mPFC). We also investigated the effect of the preferential MOR antagonist naloxone on cue-induced heroin seeking during abstinence. Methods We trained rats to self-administer heroin or saline for 9–10 days and then dissected the NAc, DS, and mPFC at different abstinence days and measured mRNA and protein levels of BDNF, TrkB, and MeCP2, as well as MOR mRNA (Oprm1). In other groups, we assessed cue-induced heroin seeking in extinction tests after 1, 11, and 30 abstinence days, and naloxone’s (0–1.0 mg/kg) effect on extinction responding after 1 and 15 days. Results Cue-induced heroin seeking progressively increased or incubated during abstinence. This incubation was not associated with changes in BDNF, TrkB, or MeCP2 mRNA or protein levels in NAc, DS, or mPFC; additionally, no molecular changes were observed after extinction tests on day 11. In NAc, but not DS or mPFC, MOR mRNA decreased on abstinence day 1 and returned to basal levels over time. Naloxone significantly decreased cue-induced heroin seeking after 15 abstinence days but not 1 day. Conclusions Results suggest a role of MOR in incubation of heroin craving. As previous studies implicated NAc BDNF in incubation of cocaine craving, our data suggest that different mechanisms contribute to incubation of heroin versus cocaine craving. PMID:22790874

Effects of N-Substitutions on the Tetrahydroquinoline (THQ) Core of Mixed-Efficacy μ-Opioid Receptor (MOR)/δ-Opioid Receptor (DOR) Ligands.

PubMed

Harland, Aubrie A; Bender, Aaron M; Griggs, Nicholas W; Gao, Chao; Anand, Jessica P; Pogozheva, Irina D; Traynor, John R; Jutkiewicz, Emily M; Mosberg, Henry I

2016-05-26

N-Acetylation of the tetrahydroquinoline (THQ) core of a series of μ-opioid receptor (MOR) agonist/δ-opioid receptor (DOR) antagonist ligands increases DOR affinity, resulting in ligands with balanced MOR and DOR affinities. We report a series of N-substituted THQ analogues that incorporate various carbonyl-containing moieties to maintain DOR affinity and define the steric and electronic requirements of the binding pocket across the opioid receptors. 4h produced in vivo antinociception (ip) for 1 h at 10 mg/kg.

MOR23 promotes muscle regeneration and regulates cell adhesion and migration

PubMed Central

Griffin, Christine A.; Kafadar, Kimberly A.; Pavlath, Grace K.

2009-01-01

Summary Odorant receptors (ORs) in the olfactory epithelium bind to volatile small molecules leading to the perception of smell. ORs are expressed in many tissues but their functions are largely unknown. We show multiple ORs display distinct mRNA expression patterns during myogenesis in vitro and muscle regeneration in vivo. Mouse OR23 (MOR23) expression is induced during muscle regeneration when muscle cells are extensively fusing and plays a key role in regulating migration and adhesion of muscle cells in vitro, two processes common during tissue repair. A soluble ligand for MOR23 is secreted by muscle cells in vitro and muscle tissue in vivo. MOR23 is necessary for proper skeletal muscle regeneration as loss of MOR23 leads to increased myofiber branching, commonly associated with muscular dystrophy. Together these data identify a functional role for an OR outside of the nose and suggest a larger role for ORs during tissue repair. PMID:19922870

Anti-Analgesic Effect of the Mu/Delta Opioid Receptor Heteromer Revealed by Ligand-Biased Antagonism

PubMed Central

Milan-Lobo, Laura; Enquist, Johan; van Rijn, Richard M.; Whistler, Jennifer L.

2013-01-01

Delta (DOR) and mu opioid receptors (MOR) can complex as heteromers, conferring functional properties in agonist binding, signaling and trafficking that can differ markedly from their homomeric counterparts. Because of these differences, DOR/MOR heteromers may be a novel therapeutic target in the treatment of pain. However, there are currently no ligands selective for DOR/MOR heteromers, and, consequently, their role in nociception remains unknown. In this study, we used a pharmacological opioid cocktail that selectively activates and stabilizes the DOR/MOR heteromer at the cell surface by blocking its endocytosis to assess its role in antinociception. We found that mice treated chronically with this drug cocktail showed a significant right shift in the ED50 for opioid-mediated analgesia, while mice treated with a drug that promotes degradation of the heteromer did not. Furthermore, promoting degradation of the DOR/MOR heteromer after the right shift in the ED50 had occurred, or blocking signal transduction from the stabilized DOR/MOR heteromer, shifted the ED50 for analgesia back to the left. Taken together, these data suggest an anti-analgesic role for the DOR/MOR heteromer in pain. In conclusion, antagonists selective for DOR/MOR heteromer could provide an avenue for alleviating reduced analgesic response during chronic pain treatment. PMID:23554887

Parallel Synthesis of Hexahydrodiimidazodiazepines Heterocyclic Peptidomimetics and Their in Vitro and in Vivo Activities at μ (MOR), δ (DOR), and κ (KOR) Opioid Receptors.

PubMed

Eans, Shainnel O; Ganno, Michelle L; Mizrachi, Elisa; Houghten, Richard A; Dooley, Colette T; McLaughlin, Jay P; Nefzi, Adel

2015-06-25

In the development of analgesics with mixed-opioid agonist activity, peripherally selective activity is expected to decrease side effects, minimizing respiratory depression and reinforcing properties generating significantly safer analgesic therapeutics. We synthesized diazaheterocyclics from reduced tripeptides. In vitro screening with radioligand competition binding assays demonstrated variable affinity for μ (MOR), δ (DOR), and κ (KOR) opioid receptors across the series, with the diimidazodiazepine 14 (2065-14) displaying good affinity for DOR and KOR. Central (icv), intraperitoneal (ip), or oral (po) administration of 14 produced dose-dependent, opioid-receptor mediated antinociception in the mouse, as determined from a 55 °C warm-water tail-withdrawal assay. Only trace amounts of compound 14 was found in brain up to 90 min later, suggesting poor BBB penetration and possible peripherally restricted activity. Central administration of 14 did not produce locomotor effects, acute antinociceptive tolerance, or conditioned-place preference or aversion. The data suggest these diazaheterocyclic mixed activity opioid receptor agonists may hold potential as new analgesics with fewer liabilities of use.

Mu-opioid receptor redistribution in the locus coeruleus upon precipitation of withdrawal in opiate-dependent rats.

PubMed

Scavone, Jillian L; Van Bockstaele, Elisabeth J

2009-03-01

Administration of mu-opioid receptor (MOR) agonists is known to produce adaptive changes within noradrenergic neurons of the rat locus coeruleus (LC). Alterations in the subcellular distribution of MOR have been shown to occur in the LC in response to full agonists and endogenous peptides; however, there is considerable debate in the literature whether trafficking of MOR occurs after chronic exposure to the partial-agonist morphine. In the present study, we examined adaptations in MOR after chronic opioid exposure using immunofluorescence and electron microscopy (EM), using receptor internalization as a functional endpoint. MOR trafficking in LC neurons was characterized in morphine-dependent rats that were given naltrexone at a dose known to precipitate withdrawal. After chronic morphine exposure, a subtle redistribution of MOR immunoreactivity from the membrane to the cytosol was detected within dendrites of LC neurons. Interestingly, an acute injection of naltrexone in rats exposed to chronic morphine produced a robust internalization of MOR, whereas administration of naltrexone failed to do so in naïve animals. These findings provide anatomical evidence for modified regulation of MOR trafficking after chronic morphine treatment in brain noradrenergic neurons. Adaptations in the MOR signaling pathways that regulate internalization may occur as a consequence of chronic treatment and precipitation of withdrawal. Mechanisms underlying this effect might include differential MOR regulation in the LC, or downstream effects of withdrawal-induced enkephalin (ENK) release from afferents to the LC. (c) 2009 Wiley-Liss, Inc.

μ-Opioid receptor availability in the amygdala is associated with smoking for negative affect relief.

PubMed

Falcone, Mary; Gold, Allison B; Wileyto, E Paul; Ray, Riju; Ruparel, Kosha; Newberg, Andrew; Dubroff, Jacob; Logan, Jean; Zubieta, Jon-Kar; Blendy, Julie A; Lerman, Caryn

2012-08-01

The perception that smoking relieves negative affect contributes to smoking persistence. Endogenous opioid neurotransmission, and the μ-opioid receptor (MOR) in particular, plays a role in affective regulation and is modulated by nicotine. We examined the relationship of MOR binding availability in the amygdala to the motivation to smoke for negative affect relief and to the acute effects of smoking on affective responses. Twenty-two smokers were scanned on two separate occasions after overnight abstinence using [¹¹C]carfentanil positron emission tomography imaging: after smoking a nicotine-containing cigarette and after smoking a denicotinized cigarette. Self-reports of smoking motives were collected at baseline, and measures of positive and negative affect were collected pre- and post- cigarette smoking. Higher MOR availability in the amygdala was associated with motivation to smoke to relieve negative affect. However, MOR availability was unrelated to changes in affect after smoking either cigarette. Increased MOR availability in amygdala may underlie the motivation to smoke for negative affective relief. These results are consistent with previous data highlighting the role of MOR neurotransmission in smoking behavior.

Connections between EM2-containing terminals and GABA/μ-opioid receptor co-expressing neurons in the rat spinal trigeminal caudal nucleus

PubMed Central

Li, Meng-Ying; Wu, Zhen-Yu; Lu, Ya-Cheng; Yin, Jun-Bin; Wang, Jian; Zhang, Ting; Dong, Yu-Lin; Wang, Feng

2014-01-01

Endomorphin-2 (EM2) demonstrates a potent antinociceptive effect via the μ-opioid receptor (MOR). To provide morphological evidence for the pain control effect of EM2, the synaptic connections between EM2-immunoreactive (IR) axonal terminals and γ-amino butyric acid (GABA)/MOR co-expressing neurons in lamina II of the spinal trigeminal caudal nucleus (Vc) were investigated in the rat. Dense EM2-, MOR- and GABA-IR fibers and terminals were mainly observed in lamina II of the Vc. Within lamina II, GABA- and MOR-neuronal cell bodies were also encountered. The results of immunofluorescent histochemical triple-staining showed that approximately 14.2 or 18.9% of GABA-IR or MOR-IR neurons also showed MOR- or GABA-immunopositive staining in lamina II; approximately 45.2 and 36.1% of the GABA-IR and MOR-IR neurons, respectively, expressed FOS protein in their nuclei induced by injecting formalin into the left lower lip of the mouth. Most of the GABA/MOR, GABA/FOS, and MOR/FOS double-labeled neurons made close contacts with EM2-IR fibers and terminals. Immuno-electron microscopy confirmed that the EM2-IR terminals formed synapses with GABA-IR or MOR-IR dendritic processes and neuronal cell bodies in lamina II of the Vc. These results suggest that EM2 might participate in pain transmission and modulation by binding to MOR-IR and GABAergic inhibitory interneuron in lamina II of the Vc to exert inhibitory effect on the excitatory interneuron in lamina II and projection neurons in laminae I and III. PMID:25386121

Acute stimulation of brain mu opioid receptors inhibits glucose-stimulated insulin secretion via sympathetic innervation.

PubMed

Tudurí, Eva; Beiroa, Daniel; Stegbauer, Johannes; Fernø, Johan; López, Miguel; Diéguez, Carlos; Nogueiras, Rubén

2016-11-01

Pancreatic insulin-secreting β-cells express opioid receptors, whose activation by opioid peptides modulates hormone secretion. Opioid receptors are also expressed in multiple brain regions including the hypothalamus, where they play a role in feeding behavior and energy homeostasis, but their potential role in central regulation of glucose metabolism is unknown. Here, we investigate whether central opioid receptors participate in the regulation of insulin secretion and glucose homeostasis in vivo. C57BL/6J mice were acutely treated by intracerebroventricular (i.c.v.) injection with specific agonists for the three main opioid receptors, kappa (KOR), delta (DOR) and mu (MOR) opioid receptors: activation of KOR and DOR did not alter glucose tolerance, whereas activation of brain MOR with the specific agonist DAMGO blunted glucose-stimulated insulin secretion (GSIS), reduced insulin sensitivity, increased the expression of gluconeogenic genes in the liver and, consequently, impaired glucose tolerance. Pharmacological blockade of α2A-adrenergic receptors prevented DAMGO-induced glucose intolerance and gluconeogenesis. Accordingly, DAMGO failed to inhibit GSIS and to impair glucose tolerance in α2A-adrenoceptor knockout mice, indicating that the effects of central MOR activation on β-cells are mediated via sympathetic innervation. Our results show for the first time a new role of the central opioid system, specifically the MOR, in the regulation of insulin secretion and glucose metabolism. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis and Structure-Activity Relationships of (-)-cis-N-Normetazocine-Based LP1 Derivatives.

PubMed

Pasquinucci, Lorella; Parenti, Carmela; Amata, Emanuele; Georgoussi, Zafiroula; Pallaki, Paschalina; Camarda, Valeria; Calò, Girolamo; Arena, Emanuela; Montenegro, Lucia; Turnaturi, Rita

2018-05-05

(−)- cis - N -Normetazocine represents a rigid scaffold able to mimic the tyramine moiety of endogenous opioid peptides, and the introduction of different N -substituents influences affinity and efficacy of respective ligands at MOR (mu opioid receptor), DOR (delta opioid receptor), and KOR (kappa opioid receptor). We have previously identified LP1, a MOR/DOR multitarget opioid ligand, with an N -phenylpropanamido substituent linked to (−)- cis - N -Normetazocine scaffold. Herein, we report the synthesis, competition binding and calcium mobilization assays of new compounds 10 ⁻ 16 that differ from LP1 by the nature of the N -substituent. In radioligand binding experiments, the compounds 10 ⁻ 13 , featured by an electron-withdrawing or electron-donating group in the para position of phenyl ring, displayed improved affinity for KOR (K i = 0.85⁻4.80 μM) in comparison to LP1 (7.5 μM). On the contrary, their MOR and DOR affinities were worse (K i = 0.18⁻0.28 μM and K i = 0.38⁻1.10 μM, respectively) with respect to LP1 values (K i = 0.049 and 0.033 μM). Analogous trends was recorded for the compounds 14 ⁻ 16 , featured by indoline, tetrahydroquinoline, and diphenylamine functionalities in the N -substituent. In calcium mobilization assays, the compound 10 with a p -fluorophenyl in the N -substituent shared the functional profile of LP1 (pEC 50 MOR = 7.01), although it was less active. Moreover, the p -methyl- ( 11 ) and p -cyano- ( 12 ) substituted compounds resulted in MOR partial agonists and DOR/KOR antagonists. By contrast, the derivatives 13 ⁻ 15 resulted as MOR antagonists, and the derivative 16 as a MOR/KOR antagonist (pK B MOR = 6.12 and pK B KOR = 6.11). Collectively, these data corroborated the critical role of the N -substituent in (−)- cis - N -Normetazocine scaffold. Thus, the new synthesized compounds could represent a template to achieve a specific agonist, antagonist, or mixed agonist/antagonist functional profile.

Mixed Kappa/Mu Opioid Receptor Agonists: The 6β-Naltrexamines

PubMed Central

Cami-Kobeci, Gerta; Neal, Adrian P.; Bradbury, Faye A.; Purington, Lauren C.; Aceto, Mario D.; Harris, Louis S.; Lewis, John W.; Traynor, John R.; Husbands, Stephen M.

2011-01-01

Ligands from the naltrexamine series have consistently demonstrated agonist activity at kappa opioid receptors (KOR), with varying activity at the mu opioid receptor (MOR). Various 6β-cinnamoylamino derivatives were made with the aim of generating ligands with a KOR agonist/MOR partial agonist profile, as ligands with this activity may be of interest as treatment agents for cocaine abuse. The ligands all displayed the desired high affinity, non-selective binding in vitro and in the functional assays were high efficacy KOR agonists with some partial agonist activity at MOR. Two of the new ligands (12a, 12b) have been evaluated in vivo, with 12a acting as a KOR agonist, and therefore somewhat similar to the previously evaluated analogues 3–6, while 12b displayed predominant MOR agonist activity. PMID:19253970

SEIZURE ACTIVITY INVOLVED IN THE UP-REGULATION OF BDNF mRNA EXPRESSION BY ACTIVATION OF CENTRAL MU OPIOID RECEPTORS

PubMed Central

ZHANG, H. N.; KO, M. C.

2009-01-01

Chemical-induced seizures up-regulated brain-derived neurotrophic factor (BDNF) mRNA expression. Intracerebroventricular (i.c.v.) administration of endogenous opioids preferentially activating μ opioid receptor (MOR) could also increase BDNF mRNA expression. The aim of this study was to determine to what extent i.c.v. administration of synthetic MOR-selective agonists in rats can modulate both seizure activity and up-regulation of BDNF mRNA expression. Effects and potencies of i.c.v. administration of morphine and [D-Ala2,N-Me-Phe4,Gly5-ol]-enkephalin (DAMGO), were directly investigated by scoring behavioral seizures and measuring BDNF mRNA expression. In addition, effects of the opioid receptor antagonist naloxone and antiepileptic drugs, diazepam, phenobarbital, and valproate, on i.c.v. MOR agonist-induced behavioral seizures and up-regulation of BDNF mRNA expression were determined. A single i.c.v. administration of morphine (10–100 μg) or DAMGO (0.15–1.5 μg) dose-dependently elicited behavioral seizures and increased BDNF mRNA expression in the widespread brain regions. However, subcutaneous administration of MOR agonists neither produced behavioral seizures nor increased BDNF mRNA expression. Pretreatment with naloxone 1 mg/kg significantly reduced behavioral seizure scores and the up-regulation of BDNF mRNA expression elicited by i.c.v. morphine or DAMGO. Similarly, diazepam 10 mg/kg and phenobarbital 40 mg/kg significantly blocked i.c.v. MOR agonist-induced actions. Pretreatment with valproate 300 mg/kg only attenuated behavioral seizures, but it did not affect morphine-induced increase of BDNF mRNA expression. This study provides supporting evidence that seizure activity plays an important role in the up-regulation of BDNF mRNA expression elicited by central MOR activation and that decreased inhibitory action of GABAergic system through the modulation on GABA receptor synaptic function by central MOR activation is involved in its regulation of BDNF mRNA expression. PMID:19303919

uAUG-mediated translational initiations are responsible for human mu opioid receptor gene expression

PubMed Central

Song, Kyu Young; Kim, Chun Sung; Hwang, Cheol Kyu; Choi, Hack Sun; Law, Ping-Yee; Wei, Li-Na; Loh, Horace H

2010-01-01

Abstract Mu opioid receptor (MOR) is the main site of interaction for major clinical analgesics, particularly morphine. MOR expression is regulated at the transcriptional and post-transcriptional levels. However, the protein expression of the MOR gene is relatively low and the translational control of MOR gene has not been well studied. The 5′-untranslated region (UTR) of the human MOR (OPRM1) mRNA contains four upstream AUG codons (uAUG) preceding the main translation initiation site. We mutated the four uAUGs individually and in combination. Mutations of the third uAUG, containing the same open reading frame, had the strongest inhibitory effect. The inhibitory effect caused by the third in-frame uAUG was confirmed by in vitro translation and receptor-binding assays. Toeprinting results showed that OPRM1 ribosomes initiated efficiently at the first uAUG, and subsequently re-initiated at the in-frame #3 uAUG and the physiological AUG site. This re-initiation resulted in negative expression of OPRM1 under normal conditions. These results indicate that re-initiation in MOR gene expression could play an important role in OPRM1 regulation. PMID:19438807

Investigation of the interaction between the atypical agonist c[YpwFG] and MOR.

PubMed

Gentilucci, Luca; Squassabia, Federico; De Marco, Rossella; Artali, Roberto; Cardillo, Giuliana; Tolomelli, Alessandra; Spampinato, Santi; Bedini, Andrea

2008-05-01

Endogenous and exogenous opiates are currently considered the drugs of choice for treating different kinds of pain. However, their prolonged use produces several adverse symptoms, and in addition, many forms of pain are resistant to any kind of therapy. Therefore, the discovery of compounds active towards mu-opioid receptors (MORs) by alternative pharmacological mechanisms could be of value for developing novel classes of analgesics. There is evidence that some unusual molecules can bind opioid receptors, albeit lacking some of the typical opioid pharmacophoric features. In particular, the recent discovery of a few compounds that showed agonist behavior even in the absence of the primary pharmacophore, namely a protonable amine, led to a rediscussion of the importance of ionic interactions in stabilizing the ligand-receptor complex and in activating signal transduction. Very recently, we synthesized a library of cyclic analogs of the endogenous, MOR-selective agonist endomorphin-1 (YPWF-NH(2)), containing a Gly5 bridge between Tyr1 and Phe4. The cyclopeptide c[YpwFG] showed good affinity and agonist behavior. This atypical MOR agonist does not have the protonable Tyr amine. In order to gain more information about plausible mechanisms of interaction between c[YpwFG] and the opioid receptor, we synthesized a selected set of derivatives containing different bridges between Tyr1 and Phe4, and tested their affinities towards mu-opioid receptors. We performed conformational analysis of the cyclopeptides by NMR spectroscopy and molecular dynamics, and investigated plausible, unprecedented modes of interaction with the MOR by molecular docking. The successive quantum mechanics/molecular mechanics investigation of the complexes obtained by the molecular docking procedure furnished a more detailed description of the binding mode and the electronic properties of the ligands. The comparison with the binding mode of the potent agonist JOM-6 seems to indicate that the cyclic endomorphin-1 analogs interact with the receptor by way of an alternative mechanism, still maintaining the ability to activate the receptor.

Different amounts of ejaculatory activity, a natural rewarding behavior, induce differential mu and delta opioid receptor internalization in the rat's ventral tegmental area.

PubMed

Garduño-Gutiérrez, René; León-Olea, Martha; Rodríguez-Manzo, Gabriela

2013-12-06

Opioid receptors internalize upon specific agonist stimulation. The in vivo significance of receptor internalization is not well established, partly due to the limited in vivo models used to study this phenomenon. Ejaculation promotes endogenous opioid release which activates opioid receptors at the brain, including the mesolimbic system and medial preoptic area. The objective of the present work was to analyze if there was a correlation between the degree of in vivo mu (MOR) and delta opioid receptor (DOR) internalization in the ventral tegmental area and the execution of different amounts of ejaculatory behavior of male rats. To this aim, we analyzed the brains of rats that ejaculated once or six successive times and of sexually exhausted rats with an established sexual inhibition, using immunofluorescence and confocal microscopy. Results showed that MOR and DOR internalization increased as a consequence of ejaculation. There was a relationship between the amount of sexual activity executed and the degree of internalization for MOR, but not for DOR. MOR internalization was larger in rats that ejaculated repeatedly than in animals ejaculating only once. Significant DOR internalization was found only in animals ejaculating once. Changes in MOR, DOR and beta arrestin2 detection, associated to sexual activity, were also found. It is suggested that copulation to satiety might be useful as a model system to study the biological significance of receptor internalization. © 2013 Published by Elsevier B.V.

The effects of endomorphins and diprotin A on striatal dopamine release induced by electrical stimulation-an in vitro superfusion study in rats.

PubMed

Bagosi, Zsolt; Jászberényi, Miklós; Bujdosó, Erika; Szabó, Gyula; Telegdy, Gyula

2006-12-01

The endomorphins (EM1: Tyr-Pro-Trp-Phe-NH2, and EM2: Tyr-Pro-Phe-Phe-NH2) are recently discovered endogenous ligands for mu-opioid receptors (MORs) with role of neurotransmitters or neuromodulators in mammals. Cessation of their physiological action may be effected through rapid enzymatic degradation by the dipeptidyl-peptidase IV (DPPIV) found in the brain synaptic membranes. An in vitro superfusion system was utilized to investigate the actions of EM1, EM2 and specific DPPIV inhibitor diprotin A on the striatal release of dopamine (DA) induced by electrical stimulation in rats. The involvement of the different MORs (MOR1 and MOR2) in this process was studied by pretreatment with MOR antagonists beta-funaltrexamine (a MOR1 and MOR2 antagonist) and naloxonazine (a MOR1 antagonist). EM1 significantly increased the tritium-labelled dopamine DA release induced by electrical stimulation. EM2 was effective only when the slices were pretreated with diprotin A. beta-Funaltrexamine antagonized the stimulatory effects of both EM1 and EM2. The administration of naloxonazine did not appreciably influence the action of EM1, but blocked the action of EM2, at least when the slices were pretreated with diprotin A. These data suggest that both EM1 and EM2 increase DA release from the striatum and, though diprotin A does not affect the action of EM1, it inhibits the enzymatic degradation of EM2. The DA-stimulating action induced by EM1 seems to be mediated by MOR2, while that evoked by EM2 appears to be transmitted by MOR1.

Dopamine D4 Receptor Counteracts Morphine-Induced Changes in μ Opioid Receptor Signaling in the Striosomes of the Rat Caudate Putamen

PubMed Central

Suárez-Boomgaard, Diana; Gago, Belén; Valderrama-Carvajal, Alejandra; Roales-Buján, Ruth; Van Craenenbroeck, Kathleen; Duchou, Jolien; Borroto-Escuela, Dasiel O.; Medina-Luque, José; de la Calle, Adelaida; Fuxe, Kjell; Rivera, Alicia

2014-01-01

The mu opioid receptor (MOR) is critical in mediating morphine analgesia. However, prolonged exposure to morphine induces adaptive changes in this receptor leading to the development of tolerance and addiction. In the present work we have studied whether the continuous administration of morphine induces changes in MOR protein levels, its pharmacological profile, and MOR-mediated G-protein activation in the striosomal compartment of the rat CPu, by using immunohistochemistry and receptor and DAMGO-stimulated [35S]GTPγS autoradiography. MOR immunoreactivity, agonist binding density and its coupling to G proteins are up-regulated in the striosomes by continuous morphine treatment in the absence of changes in enkephalin and dynorphin mRNA levels. In addition, co-treatment of morphine with the dopamine D4 receptor (D4R) agonist PD168,077 fully counteracts these adaptive changes in MOR, in spite of the fact that continuous PD168,077 treatment increases the [3H]DAMGO Bmax values to the same degree as seen after continuous morphine treatment. Thus, in spite of the fact that both receptors can be coupled to Gi/0 protein, the present results give support for the existence of antagonistic functional D4R-MOR receptor-receptor interactions in the adaptive changes occurring in MOR of striosomes on continuous administration of morphine. PMID:24451133

It still hurts: altered endogenous opioid activity in the brain during social rejection and acceptance in major depressive disorder.

PubMed

Hsu, D T; Sanford, B J; Meyers, K K; Love, T M; Hazlett, K E; Walker, S J; Mickey, B J; Koeppe, R A; Langenecker, S A; Zubieta, J-K

2015-02-01

The μ-opioid receptor (MOR) system, well known for dampening physical pain, is also hypothesized to dampen 'social pain.' We used positron emission tomography scanning with the selective MOR radioligand [(11)C]carfentanil to test the hypothesis that MOR system activation (reflecting endogenous opioid release) in response to social rejection and acceptance is altered in medication-free patients diagnosed with current major depressive disorder (MDD, n=17) compared with healthy controls (HCs, n=18). During rejection, MDD patients showed reduced endogenous opioid release in brain regions regulating stress, mood and motivation, and slower emotional recovery compared with HCs. During acceptance, only HCs showed increased social motivation, which was positively correlated with endogenous opioid release in the nucleus accumbens, a reward structure. Altered endogenous opioid activity in MDD may hinder emotional recovery from negative social interactions and decrease pleasure derived from positive interactions. Both effects may reinforce depression, trigger relapse and contribute to poor treatment outcomes.

Endometriosis Is Associated With a Shift in MU Opioid and NMDA Receptor Expression in the Brain Periaqueductal Gray

PubMed Central

Torres-Reverón, Annelyn; Palermo, Karylane; Hernández-López, Anixa; Hernández, Siomara; Cruz, Myrella L.; Thompson, Kenira J.; Flores, Idhaliz; Appleyard, Caroline B.

2016-01-01

Studies have examined how endometriosis interacts with the nervous system, but little attention has been paid to opioidergic systems, which are relevant to pain signaling. We used the autotransplantation rat model of endometriosis and allowed to progress for 60 days. The brain was collected and examined for changes in endogenous opioid peptides, mu opioid receptors (MORs), and the N-methyl-d-aspartate subunit receptor (NR1) in the periaqueductal gray (PAG), since both of these receptors can regulate PAG activity. No changes in endogenous opioid peptides in met- and leu-enkephalin or β-endorphin levels were observed within the PAG. However, MOR immunoreactivity was significantly decreased in the ventral PAG in the endometriosis group. Endometriosis reduced by 20% the number of neuronal profiles expressing MOR and reduced by 40% the NR1 profiles. Our results suggest that endometriosis is associated with subtle variations in opioidergic and glutamatergic activity within the PAG, which may have implications for pain processing. PMID:27089914

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ray, R.; Logan, J.; Ray, R.

Evidence points to the endogenous opioid system, and the mu-opioid receptor (MOR) in particular, in mediating the rewarding effects of drugs of abuse, including nicotine. A single nucleotide polymorphism (SNP) in the human MOR gene (OPRM1 A118G) has been shown to alter receptor protein level in preclinical models and smoking behavior in humans. To clarify the underlying mechanisms for these associations, we conducted an in vivo investigation of the effects of OPRM1 A118G genotype on MOR binding potential (BP{sub ND} or receptor availability). Twenty-two smokers prescreened for genotype (12 A/A, 10 */G) completed two [{sup 11}C] carfentanil positron emission tomographymore » (PET) imaging sessions following overnight abstinence and exposure to a nicotine-containing cigarette and a denicotinized cigarette. Independent of session, smokers homozygous for the wild-type OPRM1 A allele exhibited significantly higher levels of MOR BP{sub ND} than smokers carrying the G allele in bilateral amygdala, left thalamus, and left anterior cingulate cortex. Among G allele carriers, the extent of subjective reward difference (denicotinized versus nicotine cigarette) was associated significantly with MOR BP{sub ND} difference in right amygdala, caudate, anterior cingulate cortex, and thalamus. Future translational investigations can elucidate the role of MORs in nicotine addiction, which may lead to development of novel therapeutics.« less

Residues W320 and Y328 within the binding site of the μ-opioid receptor influence opiate ligand bias.

PubMed

Hothersall, J Daniel; Torella, Rubben; Humphreys, Sian; Hooley, Monique; Brown, Alastair; McMurray, Gordon; Nickolls, Sarah A

2017-05-15

The development of G protein-biased agonists for the μ-opioid receptor (MOR) offers a clear drug discovery rationale for improved analgesia and reduced side-effects of opiate pharmacotherapy. However, our understanding of the molecular mechanisms governing ligand bias is limited, which hinders our ability to rationally design biased compounds. We have investigated the role of MOR binding site residues W320 and Y328 in controlling bias, by receptor mutagenesis. The pharmacology of a panel of ligands in a cAMP and a β-arrestin2 assay were compared between the wildtype and mutated receptors, with bias factors calculated by operational analysis using ΔΔlog(τ/K A ) values. [ 3 H]diprenorphine competition binding was used to estimate affinity changes. Introducing the mutations W320A and Y328F caused changes in pathway bias, with different patterns of change between ligands. For example, DAMGO increased relative β-arrestin2 activity at the W320A mutant, whilst its β-arrestin2 response was completely lost at Y328F. In contrast, endomorphin-1 gained activity with Y328F but lost activity at W320A, in both pathways. For endomorphin-2 there was a directional shift from cAMP bias at the wildtype towards more β-arrestin2 bias at W320A. We also observe clear uncoupling between mutation-driven changes in function and binding affinity. These findings suggest that the mutations influenced the balance of pathway activation in a ligand-specific manner, thus identifying residues in the MOR binding pocket that govern ligand bias. This increases our understanding of how ligand/receptor binding interactions can be translated into agonist-specific pathway activation. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

μ-Opioid Receptors Selectively Regulate Basal Inhibitory Transmission in the Central Amygdala: Lack of Ethanol Interactions

PubMed Central

Kang-Park, Maeng-Hee; Kieffer, Brigitte L.; Roberts, Amanda J.; Roberto, Marisa; Madamba, Samuel G.; Siggins, George Robert; Moore, Scott D.

2009-01-01

Endogenous opioid systems are implicated in the actions of ethanol. For example, μ-opioid receptor (MOR) knockout (KO) mice self-administer less alcohol than the genetically intact counterpart wild-type (WT) mice (Roberts et al., 2000). MOR KO mice also exhibit less anxiety-like behavior than WT mice (Filliol et al., 2000). To investigate the neurobiological mechanisms underlying these behaviors, we examined the effect of ethanol in brain slices from MOR KO and WT mice using sharp-electrode and whole-cell patch recording techniques. We focused our study in the central nucleus of the amygdala (CeA) because it is implicated in alcohol drinking behavior and stress behavior. We found that the amplitudes of evoked inhibitory postsynaptic currents (IPSCs) or inhibitory postsynaptic potentials (IPSPs) were significantly greater in MOR KO mice than WT mice. In addition, the baseline frequencies of spontaneous and miniature GABAA receptor-mediated inhibitory postsynaptic currents were significantly greater in CeA neurons from MOR KO than WT mice. However, ethanol enhancements of evoked IPSP and IPSC amplitudes and the frequency of miniature IPSCs were comparable between WT and MOR KO mice. Baseline spontaneous and miniature excitatory postsynaptic currents (EPSCs) and ethanol effects on EPSCs were not significantly different between MOR KO and WT mice. Based on knowledge of CeA circuitry and projections, we hypothesize that the role of MOR- and GABA receptor-mediated mechanisms in CeA underlying reinforcing effects of ethanol operate independently, possibly through pathway-specific responses within CeA. PMID:18854491

A Heroin Addiction Severity-Associated Intronic Single Nucleotide Polymorphism Modulates Alternative Pre-mRNA Splicing of the μ Opioid Receptor Gene OPRM1 via hnRNPH Interactions

PubMed Central

Xu, Jin; Lu, Zhigang; Xu, Mingming; Pan, Ling; Deng, Yi; Xie, Xiaohu; Liu, Huifen; Ding, Shixiong; Hurd, Yasmin L.; Pasternak, Gavril W.; Klein, Robert J.; Cartegni, Luca

2014-01-01

Single nucleotide polymorphisms (SNPs) in the OPRM1 gene have been associated with vulnerability to opioid dependence. The current study identifies an association of an intronic SNP (rs9479757) with the severity of heroin addiction among Han-Chinese male heroin addicts. Individual SNP analysis and haplotype-based analysis with additional SNPs in the OPRM1 locus showed that mild heroin addiction was associated with the AG genotype, whereas severe heroin addiction was associated with the GG genotype. In vitro studies such as electrophoretic mobility shift assay, minigene, siRNA, and antisense morpholino oligonucleotide studies have identified heterogeneous nuclear ribonucleoprotein H (hnRNPH) as the major binding partner for the G-containing SNP site. The G-to-A transition weakens hnRNPH binding and facilitates exon 2 skipping, leading to altered expressions of OPRM1 splice-variant mRNAs and hMOR-1 proteins. Similar changes in splicing and hMOR-1 proteins were observed in human postmortem prefrontal cortex with the AG genotype of this SNP when compared with the GG genotype. Interestingly, the altered splicing led to an increase in hMOR-1 protein levels despite decreased hMOR-1 mRNA levels, which is likely contributed by a concurrent increase in single transmembrane domain variants that have a chaperone-like function on MOR-1 protein stability. Our studies delineate the role of this SNP as a modifier of OPRM1 alternative splicing via hnRNPH interactions, and suggest a functional link between an SNP-containing splicing modifier and the severity of heroin addiction. PMID:25122903

Gz mediates the long-lasting desensitization of brain CB1 receptors and is essential for cross-tolerance with morphine

PubMed Central

Garzón, Javier; de la Torre-Madrid, Elena; Rodríguez-Muñoz, María; Vicente-Sánchez, Ana; Sánchez-Blázquez, Pilar

2009-01-01

Background Although the systemic administration of cannabinoids produces antinociception, their chronic use leads to analgesic tolerance as well as cross-tolerance to morphine. These effects are mediated by cannabinoids binding to peripheral, spinal and supraspinal CB1 and CB2 receptors, making it difficult to determine the relevance of each receptor type to these phenomena. However, in the brain, the CB1 receptors (CB1Rs) are expressed at high levels in neurons, whereas the expression of CB2Rs is marginal. Thus, CB1Rs mediate the effects of smoked cannabis and are also implicated in emotional behaviors. We have analyzed the production of supraspinal analgesia and the development of tolerance at CB1Rs by the direct injection of a series of cannabinoids into the brain. The influence of the activation of CB1Rs on supraspinal analgesia evoked by morphine was also evaluated. Results Intracerebroventricular (icv) administration of cannabinoid receptor agonists, WIN55,212-2, ACEA or methanandamide, generated a dose-dependent analgesia. Notably, a single administration of these compounds brought about profound analgesic tolerance that lasted for more than 14 days. This decrease in the effect of cannabinoid receptor agonists was not mediated by depletion of CB1Rs or the loss of regulated G proteins, but, nevertheless, it was accompanied by reduced morphine analgesia. On the other hand, acute morphine administration produced tolerance that lasted only 3 days and did not affect the CB1R. We found that both neural mu-opioid receptors (MORs) and CB1Rs interact with the HINT1-RGSZ module, thereby regulating pertussis toxin-insensitive Gz proteins. In mice with reduced levels of these Gz proteins, the CB1R agonists produced no such desensitization or morphine cross-tolerance. On the other hand, experimental enhancement of Gz signaling enabled an acute icv administration of morphine to produce a long-lasting tolerance at MORs that persisted for more than 2 weeks, and it also impaired the analgesic effects of cannabinoids. Conclusion In the brain, cannabinoids can produce analgesic tolerance that is not associated with the loss of surface CB1Rs or their uncoupling from regulated transduction. Neural specific Gz proteins are essential mediators of the analgesic effects of supraspinal CB1R agonists and morphine. These Gz proteins are also responsible for the long-term analgesic tolerance produced by single doses of these agonists, as well as for the cross-tolerance between CB1Rs and MORs. PMID:19284549

Anti-nociceptive effect of patchouli alcohol: Involving attenuation of cyclooxygenase 2 and modulation of mu-opioid receptor.

PubMed

Yu, Xuan; Wang, Xin-Pei; Yan, Xiao-Jin; Jiang, Jing-Fei; Lei, Fan; Xing, Dong-Ming; Guo, Yue-Ying; Du, Li-Jun

2017-08-09

To explore the anti-nociceptive effect of patchouli alcohol (PA), the essential oil isolated from Pogostemon cablin (Blanco) Bent, and determine the mechanism in molecular levels. The acetic acid-induced writhing test and formalin-induced plantar injection test in mice were employed to confifirm the effect in vivo. Intracellular calcium ion was imaged to verify PA on mu-opioid receptor (MOR). Cyclooxygenase 2 (COX2) and MOR of mouse brain were expressed for determination of PA's target. Cellular experiments were carried out to find out COX2 and MOR expression induced by PA. PA significantly reduced latency period of visceral pain and writhing induced by acetic acid saline solution (P<0.01) and allodynia after intra-plantar formalin (P<0.01) in mice. PA also up-regulated COX2 mRNA and protein (P<0.05) with a down-regulation of MOR (P<0.05) both in in vivo and in vitro experiments, which devote to the analgesic effect of PA. A decrease in the intracellular calcium level (P<0.05) induced by PA may play an important role in its anti-nociceptive effect. PA showed the characters of enhancing the MOR expression and reducing the intracellular calcium ion similar to opioid effect. Both COX2 and MOR are involved in the mechanism of PA's anti-nociceptive effect, and the up-regulation of the receptor expression and the inhibition of intracellular calcium are a new perspective to PA's effect on MOR.

Isolation and characterization of alternatively spliced variants of the mouse sigma1 receptor gene, Sigmar1.

PubMed

Pan, Ling; Pasternak, David A; Xu, Jin; Xu, Mingming; Lu, Zhigang; Pasternak, Gavril W; Pan, Ying-Xian

2017-01-01

The sigma1 receptor acts as a chaperone at the endoplasmic reticulum, associates with multiple proteins in various cellular systems, and involves in a number of diseases, such as addiction, pain, cancer and psychiatric disorders. The sigma1 receptor is encoded by the single copy SIGMAR1 gene. The current study identifies five alternatively spliced variants of the mouse sigma1 receptor gene using a polymerase chain reaction cloning approach. All the splice variants are generated by exon skipping or alternative 3' or 5' splicing, producing the truncated sigma1 receptor. Similar alternative splicing has been observed in the human SIGMAR1 gene based on the molecular cloning or genome sequence prediction, suggesting conservation of alternative splicing of SIGMAR1 gene. Using quantitative polymerase chain reactions, we demonstrate differential expression of several splice variants in mouse tissues and brain regions. When expressed in HEK293 cells, all the splice variants fail to bind sigma ligands, implicating that each truncated region in these splice variants is important for ligand binding. However, co-immunoprecipitation (Co-IP) study in HEK293 cells co-transfected with tagged constructs reveals that all the splice variants maintain their ability to physically associate with a mu opioid receptor (mMOR-1), providing useful information to correlate the motifs/sequences necessary for their physical association. Furthermore, a competition Co-IP study showed that all the variants can disrupt in a dose-dependent manner the dimerization of the original sigma1 receptor with mMOR-1, suggesting a potential dominant negative function and providing significant insights into their function.

17β-estradiol rapidly facilitates lordosis through G protein-coupled estrogen receptor 1 (GPER) via deactivation of medial preoptic nucleus μ-opioid receptors in estradiol primed female rats.

PubMed

Long, Nathan; Serey, Chhorvann; Sinchak, Kevin

2014-09-01

In female rats sexual receptivity (lordosis) can be induced with either a single large dose of estradiol benzoate (EB), or a priming dose of EB that does not induce sexual receptivity followed by 17β-estradiol (E2). Estradiol priming initially inhibits lordosis through a multi-synaptic circuit originating in the arcuate nucleus of the hypothalamus (ARH) that activates and internalizes μ-opioid receptors (MOR) in medial preoptic nucleus (MPN) neurons. Lordosis is facilitated when MPN MOR are deactivated after the initial estradiol-induced activation. We tested the hypothesis that E2 given 47.5 h post EB acts rapidly through G protein-coupled estrogen receptor 1 (GPER) in the ARH to deactivate MPN MOR and facilitate lordosis. Ovariectomized Long Evans rats implanted with a third ventricle cannula were primed with 2 μg EB. DMSO control, E2, or G1 (GPER selective agonist) was infused 47.5 h later, and rats were tested for sexual receptivity. E2 and G1 infusions significantly increased levels of sexual receptivity compared to DMSO controls and pretreatment with G15 (GPER antagonist) blocked the facilitation of sexual receptivity. Brains were processed for MPN MOR immunohistochemistry to measure MPN MOR activation levels. E2 and G1 both significantly reduced MPN MOR activation compared to DMSO controls, while pretreatment with G15 blocked MPN MOR deactivation. In another group of EB treated ovariectomized rats, GPER immunofluorescence positive staining was observed throughout the ARH. Together these data indicate that in the 2 μg EB primed rat, E2 rapidly signals through GPER in the ARH to deactivate MPN MOR and facilitate lordosis. Published by Elsevier Inc.

Opioid Peptidomimetics: Leads for the Design of Bioavailable Mixed Efficacy Mu Opioid Receptor (MOR) Agonist/Delta Opioid Receptor (DOR) Antagonist Ligands

PubMed Central

Mosberg, Henry I.; Yeomans, Larisa; Harland, Aubrie A.; Bender, Aaron M.; Sobczyk-Kojiro, Katarzyna; Anand, Jessica P.; Clark, Mary J.; Jutkiewicz, Emily M.; Traynor, John R.

2013-01-01

We have previously described opioid peptidomimetic, 1, employing a tetrahydroquinoline scaffold and modeled on a series of cyclic tetrapeptide opioid agonists. We have recently described modifications to these peptides that confer a mu opioid receptor (MOR) agonist, delta opioid receptor (DOR) antagonist profile, which has been shown to reduce the development of tolerance to the analgesic actions of MOR agonists. Several such bifunctional ligands have been reported, but none has been demonstrated to cross the blood brain barrier. Here we describe the transfer of structural features that evoked MOR agonist/DOR antagonist behavior in the cyclic peptides to the tetrahydroquinoline scaffold and show that the resulting peptidomimetics maintain the desired pharmacological profile. Further, the 4R diastereomer of 1 was fully efficacious and approximately equipotent to morphine in the mouse warm water tail withdrawal assay following intraperitoneal administration and thus a promising lead for the development of opioid analgesics with reduced tolerance. PMID:23419026

Endomorphin-2 is Released from Newborn Rat Primary Sensory Neurons in a Frequency- and Calcium- Dependent Manner

PubMed Central

Scanlin, Heather L.; Carroll, Elizabeth A.; Jenkins, Victoria K.; Balkowiec, Agnieszka

2008-01-01

Recent evidence indicates that endomorphins, endogenous mu-opioid receptor (MOR) agonists, modulate synaptic transmission in both somatic and visceral sensory pathways. Here we show that endomorphin-2 (END-2) is expressed in newborn rat dorsal root ganglion (DRG) and nodose-petrosal ganglion complex (NPG) neurons, and rarely co-localizes with brain-derived neurotrophic factor (BDNF). In order to examine activity-dependent release of END-2 from neurons, we established a model using dispersed cultures of DRG and NPG cells activated by patterned electrical field stimulation. To detect release of END-2, we developed a novel rapid capture ELISA, in which END-2 capture antibody was added to neuronal cultures shortly before their electrical stimulation. The conventional assay was effective at reliably detecting END-2 only when the cells were stimulated in the presence of CTAP, a MOR-selective antagonist. This suggests that the strength of the novel assay is related primarily to rapid capture of released END-2 before it binds to endogenous MORs. Using the rapid capture ELISA, we found that stimulation protocols known to induce plastic changes at sensory synapses were highly effective at releasing END-2. Removal of extracellular calcium or blocking voltage-activated calcium channels significantly reduced the release. Together, our data provide the first evidence that END-2 is expressed by newborn DRG neurons of all sizes found in this age group, and can be released from these, as well as from NPG neurons, in an activity-dependent manner. These results point to END-2 as a likely mediator of activity-dependent plasticity in sensory pathways. PMID:18513316

17-Cyclopropylmethyl-3,14β-dihydroxy-4,5α-epoxy-6β-(4'-pyridylcarboxamido)morphinan (NAP) Modulating the Mu Opioid Receptor in a Biased Fashion.

PubMed

Zhang, Yan; Williams, Dwight A; Zaidi, Saheem A; Yuan, Yunyun; Braithwaite, Amanda; Bilsky, Edward J; Dewey, William L; Akbarali, Hamid I; Streicher, John M; Selley, Dana E

2016-03-16

Mounting evidence has suggested that G protein-coupled receptors can be stabilized in multiple conformations in response to distinct ligands, which exert discrete functions through selective activation of various downstream signaling events. In accordance with this concept, we report biased signaling of one C6-heterocyclic substituted naltrexamine derivative, namely, 17-cyclopropylmethyl-3,14β-dihydroxy-4,5α-epoxy-6β-(4'-pyridylcarboxamido)morphinan (NAP) at the mu opioid receptor (MOR). NAP acted as a low efficacy MOR partial agonist in the G protein-mediated [(35)S]GTPγS binding assay, whereas it did not significantly induce calcium flux or β-arrestin2 recruitment. In contrast, it potently blocked MOR full agonist-induced β-arrestin2 recruitment and translocation. Additionally, NAP dose-dependently antagonized MOR full agonist-induced intracellular calcium flux and β-arrestin2 recruitment. Further results in an isolated organ bath preparation confirmed that NAP reversed the morphine-induced reduction in colon motility. Ligand docking and dynamics simulation studies of NAP at the MOR provided more supporting evidence for biased signaling of NAP at an atomic level. Due to the fact that NAP is MOR selective and preferentially distributed peripherally upon systemic administration while β-arrestin2 is reportedly required for impairment of intestinal motility by morphine, biased antagonism of β-arrestin2 recruitment by NAP further supports its utility as a treatment for opioid-induced constipation.

A unique role of RGS9-2 in the striatum as a positive or negative regulator of opiate analgesia.

PubMed

Psifogeorgou, Kassi; Psigfogeorgou, Kassi; Terzi, Dimitra; Papachatzaki, Maria Martha; Varidaki, Artemis; Ferguson, Deveroux; Gold, Stephen J; Zachariou, Venetia

2011-04-13

The signaling molecule RGS9-2 is a potent modulator of G-protein-coupled receptor function in striatum. Our earlier work revealed a critical role for RGS9-2 in the actions of the μ-opioid receptor (MOR) agonist morphine. In this study, we demonstrate that RGS9-2 may act as a positive or negative modulator of MOR-mediated behavioral responses in mice depending on the agonist administered. Paralleling these findings we use coimmunoprecipitation assays to show that the signaling complexes formed between RGS9-2 and Gα subunits in striatum are determined by the MOR agonist, and we identify RGS9-2 containing complexes associated with analgesic tolerance. In striatum, MOR activation promotes the formation of complexes between RGS9-2 and several Gα subunits, but morphine uniquely promotes an association between RGS9-2 and Gαi3. In contrast, RGS9-2/Gαq complexes assemble after acute application of several MOR agonists but not after morphine application. Repeated morphine administration leads to the formation of distinct complexes, which contain RGS9-2, Gβ5, and Gαq. Finally, we use simple pharmacological manipulations to disrupt RGS9-2 complexes formed during repeated MOR activation to delay the development of analgesic tolerance to morphine. Our data provide a better understanding of the brain-region-specific signaling events associated with opiate analgesia and tolerance and point to pharmacological approaches that can be readily tested for improving chronic analgesic responsiveness.

Endogenous central amygdala mu-opioid receptor signaling promotes sodium appetite in mice.

PubMed

Smith, Craig M; Walker, Lesley L; Leeboonngam, Tanawan; McKinley, Michael J; Denton, Derek A; Lawrence, Andrew J

2016-11-29

Due to the importance of dietary sodium and its paucity within many inland environments, terrestrial animals have evolved an instinctive sodium appetite that is commensurate with sodium deficiency. Despite a well-established role for central opioid signaling in sodium appetite, the endogenous influence of specific opioid receptor subtypes within distinct brain regions remains to be elucidated. Using selective pharmacological antagonists of opioid receptor subtypes, we reveal that endogenous mu-opioid receptor (MOR) signaling strongly drives sodium appetite in sodium-depleted mice, whereas a role for kappa (KOR) and delta (DOR) opioid receptor signaling was not detected, at least in sodium-depleted mice. Fos immunohistochemistry revealed discrete regions of the mouse brain displaying an increased number of activated neurons during sodium gratification: the rostral portion of the nucleus of the solitary tract (rNTS), the lateral parabrachial nucleus (LPB), and the central amygdala (CeA). The CeA was subsequently targeted with bilateral infusions of the MOR antagonist naloxonazine, which significantly reduced sodium appetite in mice. The CeA is therefore identified as a key node in the circuit that contributes to sodium appetite. Moreover, endogenous opioids, acting via MOR, within the CeA promote this form of appetitive behavior.

Endogenous central amygdala mu-opioid receptor signaling promotes sodium appetite in mice

PubMed Central

Smith, Craig M.; Walker, Lesley L.; Leeboonngam, Tanawan; McKinley, Michael J.; Denton, Derek A.; Lawrence, Andrew J.

2016-01-01

Due to the importance of dietary sodium and its paucity within many inland environments, terrestrial animals have evolved an instinctive sodium appetite that is commensurate with sodium deficiency. Despite a well-established role for central opioid signaling in sodium appetite, the endogenous influence of specific opioid receptor subtypes within distinct brain regions remains to be elucidated. Using selective pharmacological antagonists of opioid receptor subtypes, we reveal that endogenous mu-opioid receptor (MOR) signaling strongly drives sodium appetite in sodium-depleted mice, whereas a role for kappa (KOR) and delta (DOR) opioid receptor signaling was not detected, at least in sodium-depleted mice. Fos immunohistochemistry revealed discrete regions of the mouse brain displaying an increased number of activated neurons during sodium gratification: the rostral portion of the nucleus of the solitary tract (rNTS), the lateral parabrachial nucleus (LPB), and the central amygdala (CeA). The CeA was subsequently targeted with bilateral infusions of the MOR antagonist naloxonazine, which significantly reduced sodium appetite in mice. The CeA is therefore identified as a key node in the circuit that contributes to sodium appetite. Moreover, endogenous opioids, acting via MOR, within the CeA promote this form of appetitive behavior. PMID:27849613

Isolation and characterization of alternatively spliced variants of the mouse sigma1 receptor gene, Sigmar1

PubMed Central

Pan, Ling; Pasternak, David A.; Xu, Jin; Xu, Mingming; Lu, Zhigang; Pasternak, Gavril W.

2017-01-01

The sigma1 receptor acts as a chaperone at the endoplasmic reticulum, associates with multiple proteins in various cellular systems, and involves in a number of diseases, such as addiction, pain, cancer and psychiatric disorders. The sigma1 receptor is encoded by the single copy SIGMAR1 gene. The current study identifies five alternatively spliced variants of the mouse sigma1 receptor gene using a polymerase chain reaction cloning approach. All the splice variants are generated by exon skipping or alternative 3’ or 5’ splicing, producing the truncated sigma1 receptor. Similar alternative splicing has been observed in the human SIGMAR1 gene based on the molecular cloning or genome sequence prediction, suggesting conservation of alternative splicing of SIGMAR1 gene. Using quantitative polymerase chain reactions, we demonstrate differential expression of several splice variants in mouse tissues and brain regions. When expressed in HEK293 cells, all the splice variants fail to bind sigma ligands, implicating that each truncated region in these splice variants is important for ligand binding. However, co-immunoprecipitation (Co-IP) study in HEK293 cells co-transfected with tagged constructs reveals that all the splice variants maintain their ability to physically associate with a mu opioid receptor (mMOR-1), providing useful information to correlate the motifs/sequences necessary for their physical association. Furthermore, a competition Co-IP study showed that all the variants can disrupt in a dose-dependent manner the dimerization of the original sigma1 receptor with mMOR-1, suggesting a potential dominant negative function and providing significant insights into their function. PMID:28350844

Morphine drives internal ribosome entry site-mediated hnRNP K translation in neurons through opioid receptor-dependent signaling

PubMed Central

Lee, Pin-Tse; Chao, Po-Kuan; Ou, Li-Chin; Chuang, Jian-Ying; Lin, Yen-Chang; Chen, Shu-Chun; Chang, Hsiao-Fu; Law, Ping-Yee; Loh, Horace H.; Chao, Yu-Sheng; Su, Tsung-Ping; Yeh, Shiu-Hwa

2014-01-01

Heterogeneous nuclear ribonucleoprotein K (hnRNP K) binds to the promoter region of mu-opioid receptor (MOR) to regulate its transcriptional activity. How hnRNP K contributes to the analgesic effects of morphine, however, is largely unknown. We provide evidence that morphine increases hnRNP K protein expression via MOR activation in rat primary cortical neurons and HEK-293 cells expressing MORs, without increasing mRNA levels. Using the bicistronic reporter assay, we examined whether morphine-mediated accumulation of hnRNP K resulted from translational control. We identified potential internal ribosome entry site elements located in the 5′ untranslated regions of hnRNP K transcripts that were regulated by morphine. This finding suggests that internal translation contributes to the morphine-induced accumulation of hnRNP K protein in regions of the central nervous system correlated with nociceptive and antinociceptive modulatory systems in mice. Finally, we found that down-regulation of hnRNP K mediated by siRNA attenuated morphine-induced hyperpolarization of membrane potential in AtT20 cells. Silencing hnRNP K expression in the spinal cord increased nociceptive sensitivity in wild-type mice, but not in MOR-knockout mice. Thus, our findings identify the role of translational control of hnRNP K in morphine-induced analgesia through activation of MOR. PMID:25361975

Cancer mortality among Brazilian dentists.

PubMed

Koifman, Sergio; Malhão, Thainá Alves; Pinto de Oliveira, Gisele; de Magalhães Câmara, Volney; Koifman, Rosalina Jorge; Meyer, Armando

2014-11-01

Previous studies have variably shown excess risks of elected cancers among dentists. National Brazilian mortality data were used to obtain mortality patterns among dentists between 1996 and 2004. Cancer mortality odds ratios (MORs) and cancer proportional mortality ratios for all cancer sites were calculated, using the general population and physicians and lawyers as comparison groups. Female dentists from both age strata showed higher risks for breast, colon-rectum, lung, brain, and non-Hodgkin lymphoma. Compared to physicians and lawyers, higher MOR estimates were observed for brain cancer among female dentists 20-49 yr. Among male dentists, higher cancer mortality was found for colon-rectum, pancreas, lung, melanoma, and non-Hodgkin lymphoma. Higher risk estimates for liver, prostate, bladder, brain, multiple myeloma and leukemia were observed among 50-79 yr old male dentists. If confirmed, these results indicate the need for limiting occupational exposures among dentists in addition to establishing screening programs to achieve early detection of selected malignant tumors. © 2014 Wiley Periodicals, Inc.

Mu opioid receptors in GABAergic forebrain neurons moderate motivation for heroin and palatable food

PubMed Central

Charbogne, Pauline; Gardon, Olivier; Martín-García, Elena; Keyworth, Helen L.; Matsui, Aya; Mechling, Anna E.; Bienert, Thomas; Nasseef, Taufiq; Robé, Anne; Moquin, Luc; Darcq, Emmanuel; Ben Hamida, Sami; Robledo, Patricia; Matifas, Audrey; Befort, Katia; Gavériaux-Ruff, Claire; Harsan, Laura-Adela; Von Everfeldt, Dominik; Hennig, Jurgen; Gratton, Alain; Kitchen, Ian; Bailey, Alexis; Alvarez, Veronica A.; Maldonado, Rafael; Kieffer, Brigitte L.

2016-01-01

BACKGROUND Mu opioid receptors (MORs) are central to pain control, drug reward and addictive behaviors, but underlying circuit mechanisms have been poorly explored by genetic approaches. Here we investigate the contribution of MORs expressed in GABAergic forebrain neurons to major biological effects of opiates, and also challenge the canonical disinhibition model of opiate reward. METHODS We used Dlx5/6-mediated recombination to create conditional Oprm1 mice in GABAergic forebrain neurons. We characterized the genetic deletion by histology, electrophysiology and microdialysis, probed neuronal activation by c-Fos immunohistochemistry and resting state-functional magnetic resonance imaging, and investigated main behavioral responses to opiates, including motivation to obtain heroin and palatable food. RESULTS Mutant mice showed MOR transcript deletion mainly in the striatum. In the ventral tegmental area (VTA), local MOR activity was intact, and reduced activity was only observed at the level of striatonigral afferents. Heroin-induced neuronal activation was modified at both sites, and whole-brain functional networks were altered in live animals. Morphine analgesia was not altered, neither was physical dependence to chronic morphine. In contrast, locomotor effects of heroin were abolished, and heroin-induced catalepsy was increased. Place preference to heroin was not modified, but remarkably, motivation to obtain heroin and palatable food was enhanced in operant self-administration procedures. CONCLUSIONS Our study reveals dissociable MOR functions across mesocorticolimbic networks. Thus beyond a well-established role in reward processing, operating at the level of local VTA neurons, MORs also moderate motivation for appetitive stimuli within forebrain circuits that drive motivated behaviors. PMID:28185645

Aberrant mesolimbic dopamine-opiate interaction in obesity.

PubMed

Tuominen, Lauri; Tuulari, Jetro; Karlsson, Henry; Hirvonen, Jussi; Helin, Semi; Salminen, Paulina; Parkkola, Riitta; Hietala, Jarmo; Nuutila, Pirjo; Nummenmaa, Lauri

2015-11-15

Dopamine and opioid neurotransmitter systems share many functions such as regulation of reward and pleasure. μ-Opioid receptors (MOR) modulate the mesolimbic dopamine system in ventral tegmental area and striatum, key areas implicated in reward. We hypothesized that dopamine and opioid receptor availabilities correlate in vivo and that this correlation is altered in obesity, a disease with altered reward processing. Twenty lean females (mean BMI 22) and 25 non-binge eating morbidly obese females (mean BMI 41) underwent two positron emission tomography scans with [(11)C]carfentanil and [(11)C]raclopride to measure the MOR and dopamine D2 receptor (DRD2) availability, respectively. In lean subjects, the MOR and DRD2 availabilities were positively associated in the ventral striatum (r=0.62, p=0.003) and dorsal caudate nucleus (r=0.62, p=0.004). Moreover, DRD2 availability in the ventral striatum was associated with MOR availability in other regions of the reward circuitry, particularly in the ventral tegmental area. In morbidly obese subjects, this receptor interaction was significantly weaker in ventral striatum but unaltered in the caudate nucleus. Finally, the association between DRD2 availability in the ventral striatum and MOR availability in the ventral tegmental area was abolished in the morbidly obese. The study demonstrates a link between DRD2 and MOR availabilities in living human brain. This interaction is selectively disrupted in mesolimbic dopamine system in morbid obesity. We propose that interaction between the dopamine and opioid systems is a prerequisite for normal reward processing and that disrupted cross-talk may underlie altered reward processing in obesity. Copyright © 2015 Elsevier Inc. All rights reserved.

Mu Opioid Receptors in Gamma-Aminobutyric Acidergic Forebrain Neurons Moderate Motivation for Heroin and Palatable Food.

PubMed

Charbogne, Pauline; Gardon, Olivier; Martín-García, Elena; Keyworth, Helen L; Matsui, Aya; Mechling, Anna E; Bienert, Thomas; Nasseef, Taufiq; Robé, Anne; Moquin, Luc; Darcq, Emmanuel; Ben Hamida, Sami; Robledo, Patricia; Matifas, Audrey; Befort, Katia; Gavériaux-Ruff, Claire; Harsan, Laura-Adela; von Elverfeldt, Dominik; Hennig, Jurgen; Gratton, Alain; Kitchen, Ian; Bailey, Alexis; Alvarez, Veronica A; Maldonado, Rafael; Kieffer, Brigitte L

2017-05-01

Mu opioid receptors (MORs) are central to pain control, drug reward, and addictive behaviors, but underlying circuit mechanisms have been poorly explored by genetic approaches. Here we investigate the contribution of MORs expressed in gamma-aminobutyric acidergic forebrain neurons to major biological effects of opiates, and also challenge the canonical disinhibition model of opiate reward. We used Dlx5/6-mediated recombination to create conditional Oprm1 mice in gamma-aminobutyric acidergic forebrain neurons. We characterized the genetic deletion by histology, electrophysiology, and microdialysis; probed neuronal activation by c-Fos immunohistochemistry and resting-state functional magnetic resonance imaging; and investigated main behavioral responses to opiates, including motivation to obtain heroin and palatable food. Mutant mice showed MOR transcript deletion mainly in the striatum. In the ventral tegmental area, local MOR activity was intact, and reduced activity was only observed at the level of striatonigral afferents. Heroin-induced neuronal activation was modified at both sites, and whole-brain functional networks were altered in live animals. Morphine analgesia was not altered, and neither was physical dependence to chronic morphine. In contrast, locomotor effects of heroin were abolished, and heroin-induced catalepsy was increased. Place preference to heroin was not modified, but remarkably, motivation to obtain heroin and palatable food was enhanced in operant self-administration procedures. Our study reveals dissociable MOR functions across mesocorticolimbic networks. Thus, beyond a well-established role in reward processing, operating at the level of local ventral tegmental area neurons, MORs also moderate motivation for appetitive stimuli within forebrain circuits that drive motivated behaviors. Copyright © 2017 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Production of G protein-coupled receptors in an insect-based cell-free system.

PubMed

Sonnabend, Andrei; Spahn, Viola; Stech, Marlitt; Zemella, Anne; Stein, Christoph; Kubick, Stefan

2017-10-01

The biochemical analysis of human cell membrane proteins remains a challenging task due to the difficulties in producing sufficient quantities of functional protein. G protein-coupled receptors (GPCRs) represent a main class of membrane proteins and drug targets, which are responsible for a huge number of signaling processes regulating various physiological functions in living cells. To circumvent the current bottlenecks in GPCR studies, we propose the synthesis of GPCRs in eukaryotic cell-free systems based on extracts generated from insect (Sf21) cells. Insect cell lysates harbor the fully active translational and translocational machinery allowing posttranslational modifications, such as glycosylation and phosphorylation of de novo synthesized proteins. Here, we demonstrate the production of several GPCRs in a eukaryotic cell-free system, performed within a short time and in a cost-effective manner. We were able to synthesize a variety of GPCRs ranging from 40 to 133 kDa in an insect-based cell-free system. Moreover, we have chosen the μ opioid receptor (MOR) as a model protein to analyze the ligand binding affinities of cell-free synthesized MOR in comparison to MOR expressed in a human cell line by "one-point" radioligand binding experiments. Biotechnol. Bioeng. 2017;114: 2328-2338. © 2017 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc. © 2017 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc.

Synthesis of iboga-like isoquinuclidines: Dual opioid receptors agonists having antinociceptive properties.

PubMed

Banerjee, Tuhin Suvro; Paul, Sibasish; Sinha, Surajit; Das, Sumantra

2014-11-01

Some novel iboga-analogues consisting of benzofuran moiety and dehydroisoquinuclidine ring connected by -CH2-, (CH2)2 and (CH2)3 linkers have been synthesized with the view to develop potential antinociceptive drugs. The compounds 14 and 21 showed binding at the μ-opioid receptor (MOR), while the compound 11a exhibited dual affinities at both MOR and κ-opioid receptor (KOR). MAP kinase activation indicated all three compounds have opioid agonistic properties. The presence of a double bond and endo-methylcarboxylate group in the dehydroisoquinuclidine ring and the benzofuran and methylene spacer appeared to be essential for opioid receptor binding. Further studies demonstrated 11a caused significant antinociception in mice in the hot-plate test which was comparable to that produced by morphine. The compound 11a was also found to be nontremorigenic unlike various iboga congeners. This study identifies a new pharmacophore which may lead to the development of suitable substitute of morphine in the treatment of pain. Copyright © 2014 Elsevier Ltd. All rights reserved.

Direct nuclear magnetic resonance observation of odorant binding to mouse odorant receptor MOR244-3.

PubMed

Burger, Jessica L; Jeerage, Kavita M; Bruno, Thomas J

2016-06-01

Mammals are able to perceive and differentiate a great number of structurally diverse odorants through the odorant's interaction with odorant receptors (ORs), proteins found within the cell membrane of olfactory sensory neurons. The natural gas industry has used human olfactory sensitivity to sulfur compounds (thiols, sulfides, etc.) to increase the safety of fuel gas transport, storage, and use through the odorization of this product. In the United States, mixtures of sulfur compounds are used, but the major constituent of odorant packages is 2-methylpropane-2-thiol, also known as tert-butyl mercaptan. It has been fundamentally challenging to understand olfaction and odorization due to the low affinity of odorous ligands to the ORs and the difficulty in expressing a sufficient number of OR proteins. Here, we directly observed the binding of tert-butyl mercaptan and another odiferous compound, cis-cyclooctene, to mouse OR MOR244-3 on living cells by saturation transfer difference (STD) nuclear magnetic resonance (NMR) spectroscopy. This effort lays the groundwork for resolving molecular mechanisms responsible for ligand binding and resulting signaling, which in turn will lead to a clearer understanding of odorant recognition and competition. Published by Elsevier Inc.

Opioid receptor and β-arrestin2 densities and distribution change after sexual experience in the ventral tegmental area of male rats.

PubMed

Garduño-Gutiérrez, René; León-Olea, Martha; Rodríguez-Manzo, Gabriela

2018-05-15

Sexual experience modifies brain functioning and copulatory efficiency. Sexual activity, ejaculation in particular, is a rewarding behavior associated with the release of endogenous opioids, which modulate the activity of the mesolimbic dopaminergic system (MLS). In sexually exhausted rats, repeated ejaculation produces μ (MOR) and δ opioid receptor (DOR) internalization in ventral tegmental area (VTA) neurons, as well as long-lasting behavioral changes suggestive of brain plasticity processes. We hypothesized that in sexually naïve rats the endogenous opioids released during sexual experience acquisition, might contribute to brain plasticity processes involved in the generation of the behavioral changes induced by sexual experience. To this aim, using double immunohistochemistry and confocal microscopy, we compared in vivo MOR, DOR and β-arrestin2 densities and activation in the VTA of sexually naïve males, sexually experienced rats not executing sexual activity prior to sacrifice and sexually experienced animals that ejaculated once before sacrifice. Results showed that sexual experience acquisition improved male's copulatory ability and induced persistent changes in the density, cellular distribution and activation of MOR and β-arrestin2 in VTA neurons. DOR density was not modified, but its cellular location changed after sexual experience, revealing that these two opioid receptors were differentially activated during sexual experience acquisition. It is concluded that the endogenous opioids released during sexual activity produce adjustments in VTA neurons of sexually naïve male rats that might contribute to the behavioral plasticity expressed as an improvement in male copulatory parameters, promoted by the acquisition of sexual experience. Copyright © 2018 Elsevier Inc. All rights reserved.

Development of 5-Substituted N-Methylmorphinan-6-ones as Potent Opioid Analgesics with Improved Side-Effect Profile.

PubMed

Schmidhammer, Helmut; Spetea, Mariana

2012-01-01

One of the most important functions of the opioid system is the control of pain. Among the three main opioid receptor classes (μ, δ, κ), the μ (MOR) is the main type targeted for pharmacotherapy of pain. Opioid analgesics such as morphine, oxycodone and fentanyl are agonists at the MOR and are the mainstay for the treatment of moderate-to-severe pain. However, adverse effects related to opioid use are severe and often lead to early discontinuation and inadequate analgesia. The development of more effective and safer medications for the management of pain still remains a major direction in pharmaceutical research. Chemical approaches towards the identification of novel MOR analgesics with reduced side effects include structural modifications of 14-alkoxy-N-methylmorphinan-6-ones in key positions that are important for binding, selectivity, potency, and efficacy at opioid receptors. This paper describes a representative strategy to improve the therapeutic usefulness of opioid analgesics from the morphinan class of drugs by targeting position 5. The focus is on chemical and biological studies and structure-activity relationships of this series of ligands. We report on 14-alkoxymorphinan-6-ones having a methyl and benzyl group at position 5 as strong opioid antinociceptive agents with reduced propensity to cause undesired effects compared to morphine although interacting selectively with MORs.

Asymmetric synthesis and in vitro and in vivo activity of tetrahydroquinolines featuring a diverse set of polar substitutions at the 6 position as mixed-efficacy μ opioid receptor/δ opioid receptor ligands.

PubMed

Bender, Aaron M; Griggs, Nicholas W; Anand, Jessica P; Traynor, John R; Jutkiewicz, Emily M; Mosberg, Henry I

2015-08-19

We previously reported a small series of mixed-efficacy μ opioid receptor (MOR) agonist/δ opioid receptor (DOR) antagonist peptidomimetics featuring a tetrahydroquinoline scaffold and showed the promise of this series as effective analgesics after intraperitoneal administration in mice. We report here an expanded structure-activity relationship study of the pendant region of these compounds and focus in particular on the incorporation of heteroatoms into this side chain. These analogues provide new insight into the binding requirements for this scaffold at MOR, DOR, and the κ opioid receptor (KOR), and several of them (10j, 10k, 10m, and 10n) significantly improve upon the overall MOR agonist/DOR antagonist profile of our previous compounds. In vivo data for 10j, 10k, 10m, and 10n are also reported and show the antinociceptive potency and duration of action of compounds 10j and 10m to be comparable to those of morphine.

Risk factors for headache in the UK military: cross-sectional and longitudinal analyses.

PubMed

Rona, Roberto J; Jones, Margaret; Goodwin, Laura; Hull, Lisa; Wessely, Simon

2013-05-01

To assess the importance of service demographic, mental disorders, and deployment factors on headache severity and prevalence, and to assess the impact of headache on functional impairment. There is no information on prevalence and risk factors of headache in the UK military. Recent US reports suggest that deployment, especially a combat role, is associated with headache. Such an association may have serious consequences on personnel during deployment. A survey was carried out between 2004 and 2006 (phase 1) and again between 2007 and 2009 (phase 2) of randomly selected UK military personnel to study the health consequences of the Iraq and Afghanistan wars. This study is based on those who participated in phase 2 and includes cross-sectional and longitudinal analyses. Headache severity in the last month and functional impairment at phase 2 were the main outcomes. Forty-six percent complained of headache in phase 2, half of whom endorsed moderate or severe headache. Severe headache was strongly associated with probable post-traumatic stress disorder (multinomial odds ratio [MOR] 9.6, 95% confidence interval [CI] 6.4-14.2), psychological distress (MOR 6.15, 95% CI 4.8-7.9), multiple physical symptoms (MOR 18.2, 95% CI 13.4-24.6) and self-reported mild traumatic brain injury (MOR 3.5, 95% CI 1.4-8.6) after adjustment for service demographic factors. Mild headache was also associated with these variables but at a lower level. Moderate and severe headache were associated with functional impairment, but the association was partially explained by mental disorders. Mental ill health was also associated with reporting moderate and severe headache at both phase 1 and phase 2. Deployment and a combat role were not associated with headache. Moderate and severe headache are common in the military and have an impact on functional impairment. They are more strongly associated with mental disorders than with mild traumatic brain injury. © 2013 American Headache Society.

Mu-opioid receptors in nociceptive afferents produce a sustained suppression of hyperalgesia in chronic pain.

PubMed

Severino, Amie; Chen, Wenling; Hakimian, Joshua K; Kieffer, Brigitte L; Gaveriaux-Ruff, Claire; Walwyn, Wendy; Marvizon, Juan Carlos

2018-04-17

The latent sensitization model of chronic pain reveals that recovery from some types of long-term hyperalgesia is an altered state in which nociceptive sensitization persists but is suppressed by the ongoing activity of analgesic receptors such as µ-opioid receptors (MORs). To determine whether these MORs are the ones present in nociceptive afferents, we bred mice expressing Cre-recombinase under the Nav1.8 channel promoter (Nav1.8cre) with MOR-floxed mice (flMOR). These Nav1.8cre/flMOR mice had reduced MOR expression in primary afferents, as revealed by quantitative PCR, in situ hybridization and immunofluorescence colocalization with the neuropeptide CGRP. We then studied the recovery from chronic pain of these mice and their flMOR littermates. When Nav1.8cre/flMOR mice were injected in the paw with complete Freund's adjuvant they developed mechanical hyperalgesia that persisted for over two months, whereas the responses of flMOR mice returned to baseline after three weeks. We then used the inverse agonist naltrexone to assess ongoing MOR activity. Naltrexone produced a robust reinstatement of hyperalgesia in control flMOR mice, but produced no effect in the Nav1.8/flMOR males and a weak reinstatement of hyperalgesia in Nav1.8/flMOR females. Naltrexone also reinstated swelling of the hind paw in flMOR mice and female Nav1.8cre/flMOR mice, but not male Nav1.8cre/flMOR mice. The MOR agonist DAMGO inhibited substance P release in flMOR mice but not Nav1.8cre/flMOR mice, demonstrating a loss of MOR function at the central terminals of primary afferents. We conclude that MORs in nociceptive afferents mediate an ongoing suppression of hyperalgesia to produce remission from chronic pain.

A Targeted Mulifunctional Platform for Imaging and Treatment of Breast Cancer and Its Metastases Based on Adenoviral Vectors and Magnetic Nanoparticles

DTIC Science & Technology

2008-02-01

tu- mor cells. In this regard, herpesvirus samiri (HVS) was de- monstrated to be naturally selectively oncolytic for the pancreatic cancer line PANC-1...the hexon virus. Therefore, Ad can provide a versatile platform for selective binding of AuNPs, resulting in a multifunctional agent capable of...utility remained unaffected. Therefore, Ad can provide a versatile platform for selective binding of nanoparticles, resulting in a multifunctional agent

Differential activation of G-proteins by mu-opioid receptor agonists.

PubMed

Saidak, Zuzana; Blake-Palmer, Katherine; Hay, Debbie L; Northup, John K; Glass, Michelle

2006-03-01

We investigated the ability of the activated mu-opioid receptor (MOR) to differentiate between myristoylated G(alphai1) and G(alphaoA) type G(alpha) proteins, and the maximal activity of a range of synthetic and endogenous agonists to activate each G(alpha) protein. Membranes from HEK293 cells stably expressing transfected MOR were chaotrope extracted to denature endogenous G-proteins and reconstituted with specific purified G-proteins. The G(alpha) subunits were generated in bacteria and were demonstrated to be recognised equivalently to bovine brain purified G(alpha) protein by CB(1) cannabinoid receptors. The ability of agonists to catalyse the MOR-dependent GDP/[(35)S]GTP(gamma)S exchange was then compared for G(alphai1) and G(alphaoA). Activation of MOR by DAMGO produced a high-affinity saturable interaction for G(alphaoA) (K(m)=20+/-1 nM) but a low-affinity interaction with G(alphai1) (K(m)=116+/-12 nM). DAMGO, met-enkephalin and leucine-enkephalin displayed maximal G(alpha) activation among the agonists evaluated. Endomorphins 1 and 2, methadone and beta-endorphin activated both G(alpha) to more than 75% of the maximal response, whereas fentanyl partially activated both G-proteins. Buprenorphine and morphine demonstrated a statistically significant difference between the maximal activities between G(alphai1) and G(alphaoA). Interestingly, DAMGO, morphine, endomorphins 1 and 2, displayed significant differences in the potencies for the activation of the two G(alpha). Differences in maximal activity and potency, for G(alphai1) versus G(alphaoA), are both indicative of agonist selective activation of G-proteins in response to MOR activation. These findings may provide a starting point for the design of drugs that demonstrate greater selectivity between these two G-proteins and therefore produce a more limited range of effects.

Effect of acute and continuous morphine treatment on transcription factor expression in subregions of the rat caudate putamen. Marked modulation by D4 receptor activation.

PubMed

Gago, Belén; Suárez-Boomgaard, Diana; Fuxe, Kjell; Brené, Stefan; Reina-Sánchez, María Dolores; Rodríguez-Pérez, Luis M; Agnati, Luigi F; de la Calle, Adelaida; Rivera, Alicia

2011-08-17

Acute administration of the dopamine D(4) receptor (D(4)R) agonist PD168,077 induces a down-regulation of the μ opioid receptor (MOR) in the striosomal compartment of the rat caudate putamen (CPu), suggesting a striosomal D(4)R/MOR receptor interaction in line with their high co-distribution in this brain subregion. The present work was designed to explore if a D(4)R/MOR receptor interaction also occurs in the modulation of the expression pattern of several transcription factors in striatal subregions that play a central role in drug addiction. Thus, c-Fos, FosB/ΔFosB and P-CREB immunoreactive profiles were quantified in the rat CPu after either acute or continuous (6-day) administration of morphine and/or PD168,077. Acute and continuous administration of morphine induced different patterns of expression of these transcription factors, effects that were time-course and region dependent and fully blocked by PD168,077 co-administration. Moreover, this effect of the D(4)R agonist was counteracted by the D(4)R antagonist L745,870. Interestingly, at some time-points, combined treatment with morphine and PD168,077 substantially increased c-Fos, FosB/ΔFosB and P-CREB expression. The results of this study give indications for a general antagonistic D(4)R/MOR receptor interaction at the level of transcription factors. The change in the transcription factor expression by D(4)R/MOR interactions in turn suggests a modulation of neuronal activity in the CPu that could be of relevance for drug addiction. Copyright © 2011 Elsevier B.V. All rights reserved.

μ-Opioid Receptor-Mediated Inhibition of Intercalated Neurons and Effect on Synaptic Transmission to the Central Amygdala.

PubMed

Blaesse, Peter; Goedecke, Lena; Bazelot, Michaël; Capogna, Marco; Pape, Hans-Christian; Jüngling, Kay

2015-05-13

The amygdala is a key region for the processing of information underlying fear, anxiety, and fear extinction. Within the local neuronal networks of the amygdala, a population of inhibitory, intercalated neurons (ITCs) modulates the flow of information among various nuclei of amygdala, including the basal nucleus (BA) and the centromedial nucleus (CeM) of the amygdala. These ITCs have been shown to be important during fear extinction and are target of a variety of neurotransmitters and neuropeptides. Here we provide evidence that the activation of μ-opioid receptors (MORs) by the specific agonist DAMGO ([D-Ala2,N-Me-Phe4,Gly5-ol]-Enkephalin) hyperpolarizes medially located ITCs (mITCs) in acute brain slices of mice. Moreover, we use whole-cell patch-clamp recordings in combination with local electrical stimulation or glutamate uncaging to analyze the effect of MOR activation on local microcircuits. We show that the GABAergic transmission between mITCs and CeM neurons is attenuated by DAMGO, whereas the glutamatergic transmission on CeM neurons and mITCs is unaffected. Furthermore, MOR activation induced by theta burst stimulation in BA suppresses plastic changes of feedforward inhibitory transmission onto CeM neurons as revealed by the MOR antagonist CTAP d-Phe-Cys-Tyr-d-Trp-Arg-Thr-Pen-Thr-NH2. In summary, the mITCs constitute a target for the opioid system, and therefore, the activation of MOR in ITCs might play a central role in the modulation of the information processing between the basolateral complex of the amygdala and central nuclei of the amygdala. Copyright © 2015 Blaesse, Goedecke et al.

Opiate agonist-induced re-distribution of Wntless, a mu-opioid receptor interacting protein, in rat striatal neurons.

PubMed

Reyes, B A S; Vakharia, K; Ferraro, T N; Levenson, R; Berrettini, W H; Van Bockstaele, E J

2012-01-01

Wntless (WLS), a mu-opioid receptor (MOR) interacting protein, mediates Wnt protein secretion that is critical for neuronal development. We investigated whether MOR agonists induce re-distribution of WLS within rat striatal neurons. Adult male rats received either saline, morphine or [d-Ala2, N-Me-Phe4, Gly-ol5]-enkephalin (DAMGO) directly into the lateral ventricles. Following thirty minutes, brains were extracted and tissue sections were processed for immunogold silver detection of WLS. In saline-treated rats, WLS was distributed along the plasma membrane and within the cytoplasmic compartment of striatal dendrites as previously described. The ratio of cytoplasmic to total dendritic WLS labeling was 0.70±0.03 in saline-treated striatal tissue. Morphine treatment decreased this ratio to 0.48±0.03 indicating a shift of WLS from the intracellular compartment to the plasma membrane. However, following DAMGO treatment, the ratio was 0.85±0.05 indicating a greater distribution of WLS intracellularly. The difference in the re-distribution of the WLS following different agonist exposure may be related to DAMGO's well known ability to induce internalization of MOR in contrast to morphine, which is less effective in producing receptor internalization. Furthermore, these data are consistent with our hypothesis that MOR agonists promote dimerization of WLS and MOR, thereby preventing WLS from mediating Wnt secretion. In summary, our findings indicate differential agonist-induced trafficking of WLS in striatal neurons following distinct agonist exposure. Adaptations in WLS trafficking may represent a novel pharmacological target in the treatment of opiate addiction and/or pain. Copyright © 2011 Elsevier Inc. All rights reserved.

Differential activation of G-proteins by μ-opioid receptor agonists

PubMed Central

Saidak, Zuzana; Blake-Palmer, Katherine; Hay, Debbie L; Northup, John K; Glass, Michelle

2006-01-01

We investigated the ability of the activated μ-opioid receptor (MOR) to differentiate between myristoylated Gαi1 and GαoA type Gα proteins, and the maximal activity of a range of synthetic and endogenous agonists to activate each Gα protein. Membranes from HEK293 cells stably expressing transfected MOR were chaotrope extracted to denature endogenous G-proteins and reconstituted with specific purified G-proteins. The Gα subunits were generated in bacteria and were demonstrated to be recognised equivalently to bovine brain purified Gα protein by CB1 cannabinoid receptors. The ability of agonists to catalyse the MOR-dependent GDP/[35S]GTPγS exchange was then compared for Gαi1 and GαoA. Activation of MOR by DAMGO produced a high-affinity saturable interaction for GαoA (Km=20±1 nM) but a low-affinity interaction with Gαi1 (Km=116±12 nM). DAMGO, met-enkephalin and leucine-enkephalin displayed maximal Gα activation among the agonists evaluated. Endomorphins 1 and 2, methadone and β-endorphin activated both Gα to more than 75% of the maximal response, whereas fentanyl partially activated both G-proteins. Buprenorphine and morphine demonstrated a statistically significant difference between the maximal activities between Gαi1 and GαoA. Interestingly, DAMGO, morphine, endomorphins 1 and 2, displayed significant differences in the potencies for the activation of the two Gα. Differences in maximal activity and potency, for Gαi1 versus GαoA, are both indicative of agonist selective activation of G-proteins in response to MOR activation. These findings may provide a starting point for the design of drugs that demonstrate greater selectivity between these two G-proteins and therefore produce a more limited range of effects. PMID:16415903

Identification of olfactory receptor genes in the Japanese grenadier anchovy Coilia nasus.

PubMed

Zhu, Guoli; Wang, Liangjiang; Tang, Wenqiao; Wang, Xiaomei; Wang, Cong

2017-01-01

Olfaction is essential for fish to detect odorant elements in the environment and plays a critical role in navigating, locating food and detecting predators. Olfactory function is produced by the olfactory transduction pathway and is activated by olfactory receptors (ORs) through the binding of odorant elements. Recently, four types of olfactory receptors have been identified in vertebrate olfactory epithelium, including main odorant receptors (MORs), vomeronasal type receptors (VRs), trace-amine associated receptors (TAARs) and formyl peptide receptors (FPRs). It has been hypothesized that migratory fish, which have the ability to perform spawning migration, use olfactory cues to return to natal rivers. Therefore, obtaining OR genes from migratory fish will provide a resource for the study of molecular mechanisms that underlie fish spawning migration behaviors. Previous studies of OR genes have mainly focused on genomic data, however little information has been gained at the transcript level. In this study, we identified the OR genes of an economically important commercial fish Coilia nasus through searching for olfactory epithelium transcriptomes. A total of 142 candidate MOR, 52 V2R/OlfC, 32 TAAR and two FPR putative genes were identified. In addition, through genomic analysis we identified several MOR genes containing introns, which is unusual for vertebrate MOR genes. The transcriptome-scale mining strategy proved to be fruitful in identifying large sets of OR genes from species whose genome information is unavailable. Our findings lay the foundation for further research into the possible molecular mechanisms underlying the spawning migration behavior in C. nasus .

Safety, immunogenicity, and clinical outcomes in patients with Morquio A syndrome participating in 2 sequential open-label studies of elosulfase alfa enzyme replacement therapy (MOR-002/MOR-100), representing 5 years of treatment.

PubMed

Hendriksz, Christian; Santra, Saikat; Jones, Simon A; Geberhiwot, Tarekegn; Jesaitis, Lynne; Long, Brian; Qi, Yulan; Hawley, Sara M; Decker, Celeste

2018-04-01

Elosulfase alfa is an enzyme replacement therapy for Morquio A syndrome (mucopolysaccharidosis IVA), a multisystemic progressive lysosomal storage disorder. This report includes the primary treatment outcomes and immunogenicity profile of elosulfase alfa in patients with Morquio A syndrome from 2 sequential studies, MOR-002 (ClinicalTrials.govNCT00884949) and MOR-100 (NCT01242111), representing >5 years of clinical study data. MOR-002 was an open-label, single-arm phase 1/2 study that evaluated the pharmacokinetics, safety, immunogenicity, and preliminary efficacy of 3 sequential doses of elosulfase alfa (0.1, 1.0, and 2.0 mg/kg/week) in patients with Morquio A syndrome (n = 20) over 36 weeks, followed by an optional 36- to 48-week treatment period using elosulfase alfa 1.0 mg/kg once weekly (qw). During the 0.1 mg/kg dosing phase, 1 patient discontinued due to a type I hypersensitivity adverse event (AE), and that patient's sibling voluntarily discontinued in the absence of AEs. An additional patient discontinued due to recurrent infusion reactions during the 1.0 mg/kg continuation phase. The remaining 17 patients completed MOR-002 and enrolled in MOR-100, an open-label, long-term extension study that further evaluated safety and clinical outcomes with elosulfase alfa administered at 2.0 mg/kg qw. During the course of MOR-100, patients were given the option of receiving elosulfase alfa infusions at home with nursing assistance. Over the course of both studies, all patients experienced ≥1 AE and most patients experienced a drug-related AE, generally of mild or moderate severity. Hypersensitivity reactions reported as related to study drug occurred in 25% of patients. Thirteen patients who chose to receive infusions at home had the same tolerability and safety profile, as well as comparable compliance rates, as patients who chose to receive on-site infusions. All patients developed antibodies to elosulfase alfa. Positivity for neutralizing antibodies was associated with increased drug half-life and decreased drug clearance. Despite formation of antidrug-binding (total antidrug antibodies, TAb) and in vitro neutralizing antibodies (NAb) in all patients, these types of immunogenicity to elosulfase alfa were not correlated with safety or clinical outcomes. In contrast with the reported natural history of Morquio A, no trends toward decreasing endurance, respiratory function, or ability to perform activities of daily living were observed in this cohort over the 5-year period. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Complementary roles for amygdala and periaqueductal gray in temporal-difference fear learning.

PubMed

Cole, Sindy; McNally, Gavan P

2009-01-01

Pavlovian fear conditioning is not a unitary process. At the neurobiological level multiple brain regions and neurotransmitters contribute to fear learning. At the behavioral level many variables contribute to fear learning including the physical salience of the events being learned about, the direction and magnitude of predictive error, and the rate at which these are learned about. These experiments used a serial compound conditioning design to determine the roles of basolateral amygdala (BLA) NMDA receptors and ventrolateral midbrain periaqueductal gray (vlPAG) mu-opioid receptors (MOR) in predictive fear learning. Rats received a three-stage design, which arranged for both positive and negative prediction errors producing bidirectional changes in fear learning within the same subjects during the test stage. Intra-BLA infusion of the NR2B receptor antagonist Ifenprodil prevented all learning. In contrast, intra-vlPAG infusion of the MOR antagonist CTAP enhanced learning in response to positive predictive error but impaired learning in response to negative predictive error--a pattern similar to Hebbian learning and an indication that fear learning had been divorced from predictive error. These findings identify complementary but dissociable roles for amygdala NMDA receptors and vlPAG MOR in temporal-difference predictive fear learning.

A qualitative exploration of malaria operational research situation in Nigeria.

PubMed

Ajayi, IkeOluwapo O; Ughasoro, Maduka D; Ogunwale, Akintayo; Odeyinka, Oluwaseun; Babalola, Obafemi; Sharafadeen, Salami; Adamu, Al-Mukhtar Y; Ajumobi, Olufemi; Orimogunje, Taiwo; Nguku, Patrick

2017-01-01

Malaria, remains one of the leading causes of high morbidity and mortality in Nigeria despite implementation of several public health interventions for its control. Operational limitations and methodological gaps have been associated with malaria control interventions and research, and these have necessitated the need for a well-tailored Malaria Operational Research (MOR) agenda. However, there is paucity of evidence-based information on relevant stakeholders' experience, awareness, perceptions and use of MOR and suggestions on setting MOR agenda. As part of a larger study to provide data for national MOR agenda setting, we assessed the MOR research situation from the perspectives of key stakeholders in Nigeria and contribution of MOR to the malaria elimination agenda. We conducted key informant interviews among 40 purposively selected stakeholders from the six geo-political zones in Nigeria. Data was collected using a pre-tested key informant interview guide which comprised issues related to experience, awareness, use of MOR and MOR needs, and suggestions for MOR. We conducted a detailed content analysis. Half of the participants had participated in MOR. Participants perceived MOR as important. Only few were aware of existing framework for MOR in Nigeria while above half expressed that MOR is yet to be used to inform policy in Nigeria. Participants identified several MOR needs such as development of improved diagnostic techniques, and interventions for promoting early diagnosis, prompt treatment and quality programmatic data. Participants opined the need for country-specific prioritised MOR agenda that cut across malaria thematic areas including malaria prevention and case management. Participants suggested the involvement of various stakeholders and multi-disciplinary approach in setting MOR. Although some stakeholders have been involved in MOR, it is still rarely used to inform policy and several needs exist across thematic areas. A broad-based stakeholder involvement, multi-disciplinary approach to agenda setting and its wide dissemination have been suggested.

Electrical stimulation of the insular cortex as a novel target for the relief of refractory pain: An experimental approach in rodents.

PubMed

Dimov, Luiz Fabio; Toniolo, Elaine Flamia; Alonso-Matielo, Heloísa; de Andrade, Daniel Ciampi; Garcia-Larrea, Luis; Ballester, Gerson; Teixeira, Manoel Jacobsen; Dale, Camila Squarzoni

2018-07-02

Cortical electrical stimulation (CES) has shown to be an effective therapeutic alternative for neuropathic pain refractory to pharmacological treatment. The primary motor cortex(M1) was the main cortical target used in the vast majority of both invasive and non-invasive studies. Despite positive results M1-based approaches still fail to relieve pain in a significant proportion of individuals. It has been advocated that the direct stimulation of cortical areas directly implicated in the central integration of pain could increase the efficacy of analgesic brain stimulation. Here, we evaluated the behavioral effects of electrical stimulation of the insular cortex (ESI) on pain sensitivity in an experimental rat model of peripheral neuropathy, and have described the pathways involved. Animals underwent chronic constriction of the sciatic nerve in the right hind limb and had concentric electrodes implanted in the posterior dysranular insular cortex. Mechanical nociception responses were evaluated before and at the end of a 15-min session of ESI (60Hz, 210μs, 1V). ESI reversed mechanical hypersensitivity in the paw contralateral to the brain hemisphere stimulated, without inducing motor impairment in the open-field test. Pharmacological blockade of μ-opioid (MOR) or type 1-cannabinoid receptors (CB1R) abolished ESI-induced antinociceptive effects. Evaluation of CB1R and MOR spatial expression demonstrated differential modulation of CB1R and MOR in the periaqueductal gray matter (PAG) of ESI-treated rats in sub-areas involved in pain processing/modulation. These results indicate that ESI induces antinociception by functionally modulating opioid and cannabinoid systems in the PAG pain circuitry in rats with experimentally induced neuropathic pain. Copyright © 2017 Elsevier B.V. All rights reserved.

Heteromerization of the μ- and δ-Opioid Receptors Produces Ligand-Biased Antagonism and Alters μ-Receptor TraffickingS⃞

PubMed Central

Milan-Lobo, Laura

2011-01-01

Heteromerization of opioid receptors has been shown to alter opioid receptor pharmacology. However, how receptor heteromerization affects the processes of endocytosis and postendocytic sorting has not been closely examined. This question is of particular relevance for heteromers of the μ-opioid receptor (MOR) and δ-opioid receptor (DOR), because the MOR is recycled primarily after endocytosis and the DOR is degraded in the lysosome. Here, we examined the endocytic and postendocytic fate of MORs, DORs, and DOR/MOR heteromers in human embryonic kidney 293 cells stably expressing each receptor alone or coexpressing both receptors. We found that the clinically relevant MOR agonist methadone promotes endocytosis of MOR but also the DOR/MOR heteromer. Furthermore, we show that DOR/MOR heteromers that are endocytosed in response to methadone are targeted for degradation, whereas MORs in the same cell are significantly more stable. It is noteworthy that we found that the DOR-selective antagonist naltriben mesylate could block both methadone- and [d-Ala2,NMe-Phe4,Gly-ol5]-enkephalin-induced endocytosis of the DOR/MOR heteromers but did not block signaling from this heteromer. Together, our results suggest that the MOR adopts novel trafficking properties in the context of the DOR/MOR heteromer. In addition, they suggest that the heteromer shows “biased antagonism,” whereby DOR antagonist can inhibit trafficking but not signaling of the DOR/MOR heteromer. PMID:21422164

Multimodal Imaging of Pathophysiological Changes and Their Role in Development of Breast Cancer Brain Metastasis

DTIC Science & Technology

2010-09-01

vascular and tissue oxygenation. Moreover, by introducing hypoxia reporter gene ( HRE -luciferase) into breast tumor lines, we will be able to use...luciferase re porter gene under the re gulation of an artificial HIF-1-dependent promoter, 5 HRE (14, 1 5). Integrati on of MRI and BLI will provide...mor hypoxi a. 5 x 10 4 MDA-MB231- HRE -ODD-luc cells were directly inje cted into caudal nucle ar area of right side mouse brain. BLI was applied to

Distortion in the spacer region of Pm during activation of middle transcription of phage Mu.

PubMed Central

Artsimovitch, I; Kahmeyer-Gabbe, M; Howe, M M

1996-01-01

Transcription from the middle promoter, Pm, of phage Mu is initiated by Escherichia coli RNA polymerase holoenzyme (E sigma 70; RNAP) and the phage-encoded activator, Mor. Point mutations in the spacer region between the -10 hexamer and the Mor binding site result in changes of promoter activity in vivo. These mutations are located at the junction between a rigid T-tract and adjacent, potentially deformable G + C-rich DNA segment, suggesting that deformation of the spacer region may play a role in the transcriptional activation of Pm. This prediction was tested by using dimethyl sulfate and potassium permanganate footprinting analyses. Helical distortion involving strand separation was detected at positions -32 to -34, close to the predicted interface between Mor and RNAP. Promoter mutants in which this distortion was not detected exhibited a lack of melting in the -12 to -1 region and reduced promoter activity in vivo. We propose that complexes containing the distortion represent stressed intermediates rather than stable open complexes and thus can be envisaged as a transition state in the kinetic pathway of Pm activation in which stored torsional energy could be used to facilitate melting around the transcription start point. Images Fig. 2 Fig. 3 Fig. 4 PMID:8790343

Concentrating Solar Power Projects - Morón | Concentrating Solar Power |

Science.gov Websites

, 2018 Project Overview Project Name: Morón Country: Spain Location: Morón de la Frontera (Seville ? Background Technology: Parabolic trough Status: Operational Country: Spain City: Morón de la Frontera Region NREL Morón This page provides information on Morón, a concentrating solar power (CSP) project

On the G-Protein-Coupled Receptor Heteromers and Their Allosteric Receptor-Receptor Interactions in the Central Nervous System: Focus on Their Role in Pain Modulation

PubMed Central

Borroto-Escuela, Dasiel O.; Romero-Fernandez, Wilber; Rivera, Alicia; Van Craenenbroeck, Kathleen; Tarakanov, Alexander O.; Agnati, Luigi F.; Fuxe, Kjell

2013-01-01

The modulatory role of allosteric receptor-receptor interactions in the pain pathways of the Central Nervous System and the peripheral nociceptors has become of increasing interest. As integrators of nociceptive and antinociceptive wiring and volume transmission signals, with a major role for the opioid receptor heteromers, they likely have an important role in the pain circuits and may be involved in acupuncture. The delta opioid receptor (DOR) exerts an antagonistic allosteric influence on the mu opioid receptor (MOR) function in a MOR-DOR heteromer. This heteromer contributes to morphine-induced tolerance and dependence, since it becomes abundant and develops a reduced G-protein-coupling with reduced signaling mainly operating via β-arrestin2 upon chronic morphine treatment. A DOR antagonist causes a return of the Gi/o binding and coupling to the heteromer and the biological actions of morphine. The gender- and ovarian steroid-dependent recruitment of spinal cord MOR/kappa opioid receptor (KOR) heterodimers enhances antinociceptive functions and if impaired could contribute to chronic pain states in women. MOR1D heterodimerizes with gastrin-releasing peptide receptor (GRPR) in the spinal cord, mediating morphine induced itch. Other mechanism for the antinociceptive actions of acupuncture along meridians may be that it enhances the cross-desensitization of the TRPA1 (chemical nociceptor)-TRPV1 (capsaicin receptor) heteromeric channel complexes within the nociceptor terminals located along these meridians. Selective ionotropic cannabinoids may also produce cross-desensitization of the TRPA1-TRPV1 heteromeric nociceptor channels by being negative allosteric modulators of these channels leading to antinociception and antihyperalgesia. PMID:23956775

Comparing analgesia and μ-opioid receptor internalization produced by intrathecal enkephalin

PubMed Central

Chen, Wenling; Song, Bingbing; Lao, Lijun; Pérez, Orlando A.; Kim, Woojae; Marvizón, Juan Carlos G.

2007-01-01

Summary Opioid receptors in the spinal cord produce strong analgesia, but the mechanisms controlling their activation by endogenous opioids remain unclear. We have previously shown in spinal cord slices that peptidases preclude μ-opioid receptor (MOR) internalization by opioids. Our present goals were to investigate whether enkephalin-induced analgesia is also precluded by peptidases, and whether it is mediated by MORs or δ-opioid receptors (DORs). Tail-flick analgesia and MOR internalization were measured in rats injected intrathecally with Leu-enkephalin and peptidase inhibitors. Without peptidase inhibitors, Leu-enkephalin produced neither analgesia nor MOR internalization at doses up to 100 nmol, whereas with peptidase inhibitors it produced analgesia at 0.3 nmol and MOR internalization at 1 nmol. Leu-enkephalin was ten times more potent to produce analgesia than to produce MOR internalization, suggesting that DORs were involved. Selective MOR or DOR antagonists completely blocked the analgesia elicited by 0.3 nmol Leu-enkephalin (a dose that produced little MOR internalization), indicating that it involved these two receptors, possibly by an additive or synergistic interaction. The selective MOR agonist endomorphin-2 produced analgesia even in the presence of a DOR antagonist, but at doses substantially higher than Leu-enkephalin. Unlike Leu-enkephalin, endomorphin-2 had the same potencies to induce analgesia and MOR internalization. We concluded that low doses of enkephalins produce analgesia by activating both MORs and DORs. Analgesia can also be produced exclusively by MORs at higher agonist doses. Since peptidases prevent the activation of spinal opioid receptors by enkephalins, the coincident release of opioids and endogenous peptidase inhibitors may be required for analgesia. PMID:17845806

Response of the μ-opioid system to social rejection and acceptance.

PubMed

Hsu, D T; Sanford, B J; Meyers, K K; Love, T M; Hazlett, K E; Wang, H; Ni, L; Walker, S J; Mickey, B J; Korycinski, S T; Koeppe, R A; Crocker, J K; Langenecker, S A; Zubieta, J-K

2013-11-01

The endogenous opioid system, which alleviates physical pain, is also known to regulate social distress and reward in animal models. To test this hypothesis in humans (n=18), we used an μ-opioid receptor (MOR) radiotracer to measure changes in MOR availability in vivo with positron emission tomography during social rejection (not being liked by others) and acceptance (being liked by others). Social rejection significantly activated the MOR system (i.e., reduced receptor availability relative to baseline) in the ventral striatum, amygdala, midline thalamus and periaqueductal gray (PAG). This pattern of activation is consistent with the hypothesis that the endogenous opioids have a role in reducing the experience of social pain. Greater trait resiliency was positively correlated with MOR activation during rejection in the amygdala, PAG and subgenual anterior cingulate cortex (sgACC), suggesting that MOR activation in these areas is protective or adaptive. In addition, MOR activation in the pregenual ACC was correlated with reduced negative affect during rejection. In contrast, social acceptance resulted in MOR activation in the amygdala and anterior insula, and MOR deactivation in the midline thalamus and sgACC. In the left ventral striatum, MOR activation during acceptance predicted a greater desire for social interaction, suggesting a role for the MOR system in social reward. The ventral striatum, amygdala, midline thalamus, PAG, anterior insula and ACC are rich in MORs and comprise a pathway by which social cues may influence mood and motivation. MOR regulation of this pathway may preserve and promote emotional well being in the social environment.

Glasgow Coma Scale Scores, Early Opioids, and 4-year Psychological Outcomes among Combat Amputees

DTIC Science & Technology

2014-01-01

psychological outcomes, loss of consciousness, military and VA health data, morphine , posttraumatic stress disorder, traumatic brain injury. INTRODUCTION...appropriate for postinjury analgesia [15–17]. Unfortu- nately, little research has compared the psychological benefits of morphine or fentanyl...that morphine reduced PTSD compared with fentanyl because mor- phine produced more long-lasting pain relief and/or was more effective at blocking

The effects of endomorphins on striatal [3H]GABA release induced by electrical stimulation: an in vitro superfusion study in rats.

PubMed

Bagosi, Zsolt; Jászberényi, Miklós; Telegdy, Gyula

2009-05-01

The endomorphins (EM1 and EM2) are selective endogenous ligands for mu-opioid receptors (MOR1 and MOR2) with neurotransmitter and neuromodulator roles in mammals. In the present study we investigated the potential actions of EMs on striatal GABA release and the implication of different MORs in these processes. Rat striatal slices were preincubated with tritium-labelled GABA ([(3)H]GABA), pretreated with selective MOR1 and MOR2 antagonist beta-funaltrexamine and selective MOR1 antagonist naloxonazine and then superfused with the selective MOR agonists, EM1 and EM2. EM1 significantly decreased the striatal [(3)H]GABA release induced by electrical stimulation. Beta-funaltrexamine antagonized the inhibitory action of EM1, but naloxonazine did not affect it considerably. EM2 was ineffective, even in case of specific enzyme inhibitor diprotin A pretreatment. The results demonstrate that EM1 decreases GABA release in the basal ganglia through MOR2, while EM2 does not influence it.

Acute myeloid leukemia risk by industry and occupation.

PubMed

Tsai, Rebecca J; Luckhaupt, Sara E; Schumacher, Pam; Cress, Rosemary D; Deapen, Dennis M; Calvert, Geoffrey M

2014-11-01

Acute myeloid leukemia (AML) is the most common type of leukemia found in adults. Identifying jobs that pose a risk for AML may be useful for identifying new risk factors. A matched case-control analysis was conducted using California Cancer Registry data from 1988 to 2007. This study included 8999 cases of AML and 24 822 controls. Industries with a statistically significant increased AML risk were construction (matched odds ratio [mOR] = 1.13); crop production (mOR = 1.41); support activities for agriculture and forestry (mOR = 2.05); and animal slaughtering and processing (mOR = 2.09). Among occupations with a statistically significant increased AML risk were miscellaneous agricultural workers (mOR = 1.76); fishers and related fishing workers (mOR = 2.02); nursing, psychiatric and home health aides (mOR = 1.65); and janitors and building cleaners (mOR = 1.54). Further investigation is needed to confirm study findings and to identify specific exposures responsible for the increased risks.

Acute myeloid leukemia risk by industry and occupation

PubMed Central

Tsai, Rebecca J.; Luckhaupt, Sara E.; Schumacher, Pam; Cress, Rosemary D.; Deapen, Dennis M.; Calvert, Geoffrey M.

2015-01-01

Acute myeloid leukemia (AML) is the most common type of leukemia found in adults. Identifying jobs that pose a risk for AML may be useful for identifying new risk factors. A matched case–control analysis was conducted using California Cancer Registry data from 1988 to 2007. This study included 8999 cases of AML and 24 822 controls. Industries with a statistically significant increased AML risk were construction (matched odds ratio [mOR] = 1.13); crop production (mOR = 1.41); support activities for agriculture and forestry (mOR = 2.05); and animal slaughtering and processing (mOR = 2.09). Among occupations with a statistically significant increased AML risk were miscellaneous agricultural workers (mOR = 1.76); fishers and related fishing workers (mOR = 2.02); nursing, psychiatric and home health aides (mOR = 1.65); and janitors and building cleaners (mOR = 1.54). Further investigation is needed to confirm study findings and to identify specific exposures responsible for the increased risks. PMID:24547710

Mu opioid receptor stimulation activates c-Jun N-terminal kinase 2 by distinct arrestin-dependent and independent mechanisms.

PubMed

Kuhar, Jamie Rose; Bedini, Andrea; Melief, Erica J; Chiu, Yen-Chen; Striegel, Heather N; Chavkin, Charles

2015-09-01

G protein-coupled receptor desensitization is typically mediated by receptor phosphorylation by G protein-coupled receptor kinase (GRK) and subsequent arrestin binding; morphine, however, was previously found to activate a c-Jun N-terminal kinase (JNK)-dependent, GRK/arrestin-independent pathway to produce mu opioid receptor (MOR) inactivation in spinally-mediated, acute anti-nociceptive responses [Melief et al.] [1]. In the current study, we determined that JNK2 was also required for centrally-mediated analgesic tolerance to morphine using the hotplate assay. We compared JNK activation by morphine and fentanyl in JNK1(-/-), JNK2(-/-), JNK3(-/-), and GRK3(-/-) mice and found that both compounds specifically activate JNK2 in vivo; however, fentanyl activation of JNK2 was GRK3-dependent, whereas morphine activation of JNK2 was GRK3-independent. In MOR-GFP expressing HEK293 cells, treatment with either arrestin siRNA, the Src family kinase inhibitor PP2, or the protein kinase C (PKC) inhibitor Gö6976 indicated that morphine activated JNK2 through an arrestin-independent Src- and PKC-dependent mechanism, whereas fentanyl activated JNK2 through a Src-GRK3/arrestin-2-dependent and PKC-independent mechanism. This study resolves distinct ligand-directed mechanisms of JNK activation by mu opioid agonists and understanding ligand-directed signaling at MOR may improve opioid therapeutics. Copyright © 2015 Elsevier Inc. All rights reserved.

Morphine induces endocytosis of neuronal μ-opioid receptors through the sustained transfer of Gα subunits to RGSZ2 proteins

PubMed Central

Rodríguez-Muñoz, María; de la Torre-Madrid, Elena; Sánchez-Blázquez, Pilar; Garzón, Javier

2007-01-01

Background In general, opioids that induce the recycling of μ-opioid receptors (MORs) promote little desensitization, although morphine is one exception to this rule. While morphine fails to provoke significant internalization of MORs in cultured cells, it does stimulate profound desensitization. In contrast, morphine does promote some internalization of MORs in neurons although this does not prevent this opioid from inducing strong antinociceptive tolerance. Results In neurons, morphine stimulates the long-lasting transfer of MOR-activated Gα subunits to proteins of the RGS-R7 and RGS-Rz subfamilies. We investigated the influence of this regulatory process on the capacity of morphine to promote desensitization and its association with MOR recycling in the mature nervous system. In parallel, we also studied the effects of [D-Ala2, N-MePhe4, Gly-ol5] encephalin (DAMGO), a potent inducer of MOR internalization that promotes little tolerance. We observed that the initial exposure to icv morphine caused no significant internalization of MORs but rather, a fraction of the Gα subunits was stably transferred to RGS proteins in a time-dependent manner. As a result, the antinociception produced by a second dose of morphine administered 6 h after the first was weaker. However, this opioid now stimulated the phosphorylation, internalization and recycling of MORs, and further exposure to morphine promoted little tolerance to this moderate antinociception. In contrast, the initial dose of DAMGO stimulated intense phosphorylation and internalization of the MORs associated with a transient transfer of Gα subunits to the RGS proteins, recovering MOR control shortly after the effects of the opioid had ceased. Accordingly, the recycled MORs re-established their association with G proteins and the neurons were rapidly resensitized to DAMGO. Conclusion In the nervous system, morphine induces a strong desensitization before promoting the phosphorylation and recycling of MORs. The long-term sequestering of morphine-activated Gα subunits by certain RGS proteins reduces the responses to this opioid in neurons. This phenomenon probably increases free Gβγ dimers in the receptor environment and leads to GRK phosphorylation and internalization of the MORs. Although, the internalization of the MORs permits the transfer of opioid-activated Gα subunits to the RGSZ2 proteins, it interferes with the stabilization of this regulatory process and recycled MORs recover the control on these Gα subunits and opioid tolerance develops slowly. PMID:17634133

Micro-opioid receptor agonist diminishes POMC gene expression and anorexia by central insulin in neonatal chicks.

PubMed

Shiraishi, Jun-Ichi; Yanagita, Kouchi; Fujita, Masanori; Bungo, Takashi

2008-07-18

Pro-opiomelanocortin (POMC) neurons in the hypothalamus are direct targets of peripheral satiety signals, such as leptin and insulin in mammals. The stimulation of these signals activates hypothalamic POMC neurons and elevates POMC-derived melanocortin peptides that inhibit food intake in mammals. On the other hand, it has been recognized that beta-endorphin, a post-translational processing of POMC, acts in an autoreceptor manner to the micro-opioid receptor (MOR) on POMC neurons, diminishing POMC neuronal activity in mammals. Recently, we found that central insulin functions as an anorexic peptide in chicks. Thus, the present study was done to elucidate whether beta-endorphin affects the activation of POMC neurons by insulin in neonatal chicks. Consequently, quantitative real-time PCR analysis shows that intracerebroventricular (ICV) injection of insulin with beta-endorphin significantly decreases brain POMC mRNA expression when compared with insulin alone. In addition, co-injection of MOR agonist (beta-endorphin or [d-Ala2, N-MePhe4, Gly5-ol]-enkephalin (DAMGO)) significantly attenuates insulin-induced hypophagia in chicks. These data suggest that beta-endorphin regulates the activity of the central melanocortin system, and its activation may provide an inhibitory feedback mechanism in the brain of neonatal chicks.

Caged Naloxone Reveals Opioid Signaling Deactivation Kinetics

PubMed Central

Banghart, Matthew R.; Shah, Ruchir C.; Lavis, Luke D.

2013-01-01

The spatiotemporal dynamics of opioid signaling in the brain remain poorly defined. Photoactivatable opioid ligands provide a means to quantitatively measure these dynamics and their underlying mechanisms in brain tissue. Although activation kinetics can be assessed using caged agonists, deactivation kinetics are obscured by slow clearance of agonist in tissue. To reveal deactivation kinetics of opioid signaling we developed a caged competitive antagonist that can be quickly photoreleased in sufficient concentrations to render agonist dissociation effectively irreversible. Carboxynitroveratryl-naloxone (CNV-NLX), a caged analog of the competitive opioid antagonist NLX, was readily synthesized from commercially available NLX in good yield and found to be devoid of antagonist activity at heterologously expressed opioid receptors. Photolysis in slices of rat locus coeruleus produced a rapid inhibition of the ionic currents evoked by multiple agonists of the μ-opioid receptor (MOR), but not of α-adrenergic receptors, which activate the same pool of ion channels. Using the high-affinity peptide agonist dermorphin, we established conditions under which light-driven deactivation rates are independent of agonist concentration and thus intrinsic to the agonist-receptor complex. Under these conditions, some MOR agonists yielded deactivation rates that are limited by G protein signaling, whereas others appeared limited by agonist dissociation. Therefore, the choice of agonist determines which feature of receptor signaling is unmasked by CNV-NLX photolysis. PMID:23960100

Translational repression of mouse mu opioid receptor expression via leaky scanning

PubMed Central

Song, Kyu Young; Hwang, Cheol Kyu; Kim, Chun Sung; Choi, Hack Sun; Law, Ping-Yee; Wei, Li-Na; Loh, Horace H.

2007-01-01

Mu opioid receptor (MOR) expression is under temporal and spatial controls, but expression levels of the MOR gene are relatively low in vivo. In addition to transcriptional regulations, upstream AUGs (uAUGs) and open reading frames (uORFs) profoundly affect the translation of the primary ORF and thus the protein levels in several genes. The 5′-untranslated region (UTR) of mouse MOR mRNA contains three uORFs preceding the MOR main initiation codon. In MOR-fused EGFP or MOR promoter/luciferase reporter constructs, mutating each uAUG individually or in combinations increased MOR transient heterologous expression in neuroblastoma NMB and HEK293 cells significantly. Translation of such constructs increased up to 3-fold without altering the mRNA levels if either the third uAUG or both the second and third AUGs were mutated. Additionally, these uAUG-mediated translational inhibitions were independent of their peptide as confirmed by internal mutation analyses in each uORF. Translational studies indicated that protein syntheses were initiated at these uAUG initiation sites, with the third uAUG initiating the highest translation level. These results support the hypothesis that uORFs in mouse MOR mRNA act as negative regulators through a ribosome leaky scanning mechanism. Such leaky scanning resulted in the suppression of mouse MOR under normal conditions. PMID:17284463

Trivalent ions modification for high-silica mordenite: A first principles study

NASA Astrophysics Data System (ADS)

Chen, Fayun; Zhang, Laijun; Feng, Gang; Wang, Xuewen; Zhang, Rongbin; Liu, Jianwen

2018-03-01

Using periodic DFT-D3-U methods, the present work give a mechanistic insight into the high silica B-, Al-, Ga- and Fe-MOR with H, Li, Na, and K as charge balance ions. The acid properties of the zeolite were probed via NH3 and pyridine adsorption. It is found that the charge balance ions influence the location of the trivalent ions, the cell volumes, as well as the synthesis difficulty of the zeolites. The energy differences for B, Al, Ga and Fe in different T sites are small for the H-form zeolites, while large for the Na- and K-form zeolites. For H-form MOR, the proton of the sbnd OH group prefers to bond to O(7) and O(3) and pointing to the 12MR for trivalent ions in T1 sites. The proton bonds to O(3), O(2), O(2) and O(5), respectively, for B, Al, Ga and Fe in T2 site of MOR, with the sbnd OH group pointing to intersection of 12MR and the side-pocket, except for the B-MOR that sbnd OH group pointing to the 12MR. For trivalent ions located in T3 and T4 sites, the protons prefers to bond to O(1) and O(2), respectively, with the sbnd OH group pointing to the intersection of 8MR and side-pocket as well as the intersection of 12MR and side-pocket. All incorporated B, Al, Ga, and Fe framework ions are tetra-coordinated, except the B atoms are tri-coordinated. The NH4-form MOR has smaller cell volume than the other form MOR. Na and K are energetically more favored charge balance ions than Li and NH3 for MOR zeolites synthesis, and the H-form zeolite is the most difficult to be synthesized directly. The strength of the Brønsted acidity follows the order: HBMOR < HFeMOR ≈ HGaMOR < HAlMOR, vs. the Lewis acidity order: HBMOR < HAlMOR < HFeMOR ≈ HGaMOR. NH3 could be adsorbed inside all kinds of channels, and especially favors in the small 8MR vs. pyridine could only be adsorbed in the main channel of MOR due to the steric effect. It indicates that the acid sites in the side pocket and the small 8-membered ring and the side pocket could not be effectively determined just by the pyridine adsorption experiments. In comparison, the NH3 adsorption experiments could detect all kinds of Brønsted sites of the MOR zeolites.

MorTAL Kombat: the story of defense against TAL effectors through loss-of-susceptibility

PubMed Central

Hutin, Mathilde; Pérez-Quintero, Alvaro L.; Lopez, Camilo; Szurek, Boris

2015-01-01

Many plant-pathogenic xanthomonads rely on Transcription Activator-Like (TAL) effectors to colonize their host. This particular family of type III effectors functions as specific plant transcription factors via a programmable DNA-binding domain. Upon binding to the promoters of plant disease susceptibility genes in a sequence-specific manner, the expression of these host genes is induced. However, plants have evolved specific strategies to counter the action of TAL effectors and confer resistance. One mechanism is to avoid the binding of TAL effectors by mutations of their DNA binding sites, resulting in resistance by loss-of-susceptibility. This article reviews our current knowledge of the susceptibility hubs targeted by Xanthomonas TAL effectors, possible evolutionary scenarios for plants to combat the pathogen with loss-of-function alleles, and how this knowledge can be used overall to develop new pathogen-informed breeding strategies and improve crop resistance. PMID:26236326

Cocaine Dysregulates Opioid Gating of GABA Neurotransmission in the Ventral Pallidum

PubMed Central

Scofield, Michael D.; Rice, Kenner C.; Cheng, Kejun; Roques, Bernard P.

2014-01-01

The ventral pallidum (VP) is a target of dense nucleus accumbens projections. Many of these projections coexpress GABA and the neuropeptide enkephalin, a δ and μ opioid receptor (MOR) ligand. Of these two, the MOR in the VP is known to be involved in reward-related behaviors, such as hedonic responses to palatable food, alcohol intake, and reinstatement of cocaine seeking. Stimulating MORs in the VP decreases extracellular GABA, indicating that the effects of MORs in the VP on cocaine seeking are via modulating GABA neurotransmission. Here, we use whole-cell patch-clamp on a rat model of withdrawal from cocaine self-administration to test the hypothesis that MORs presynaptically regulate GABA transmission in the VP and that cocaine withdrawal changes the interaction between MORs and GABA. We found that in cocaine-extinguished rats pharmacological activation of MORs no longer presynaptically inhibited GABA release, whereas blocking the MORs disinhibited GABA release. Moreover, MOR-dependent long-term depression of GABA neurotransmission in the VP was lost in cocaine-extinguished rats. Last, GABA neurotransmission was found to be tonically suppressed in cocaine-extinguished rats. These substantial synaptic changes indicated that cocaine was increasing tone on MOR receptors. Accordingly, increasing endogenous tone by blocking the enzymatic degradation of enkephalin inhibited GABA neurotransmission in yoked saline rats but not in cocaine-extinguished rats. In conclusion, our results indicate that following withdrawal from cocaine self-administration enkephalin levels in the VP are elevated and the opioid modulation of GABA neurotransmission is impaired. This may contribute to the difficulties withdrawn addicts experience when trying to resist relapse. PMID:24431463

Phosphorylation state of mu-opioid receptor determines the alternative recycling of receptor via Rab4 or Rab11 pathway.

PubMed

Wang, Feifei; Chen, Xiaoqing; Zhang, Xiaoqing; Ma, Lan

2008-08-01

Agonist-induced phosphorylation, internalization, and intracellular trafficking of G protein-coupled receptors are critical in regulating both cellular responsiveness and signal transduction. The current study investigated the role of receptor phosphorylation state in regulation of agonist-induced internalization and intracellular trafficking of mu-opioid receptor (MOR). Our results showed that after agonist stimulation, the recycle of a mutant MOR that lacks the C-terminal residues after Asn(362) (MOR362T) was greatly decreased, whereas a C-terminal phosphorylation sites-mutated MOR (MOR3A), which is deficient in agonist-induced phosphorylation recycled back to the membrane at a level comparable to that of the wild-type receptor, however, interestingly at a slower rate. Inhibition of functions of either Rab4 or Rab11 by dominant-negative mutants and small interfering RNA both significantly impaired the recycling of the wild-type MOR, whereas the recycling of the phosphorylation-deficient mutant was only inhibited by the dominant-negative mutant and small interfering RNA of Rab11, suggesting that the recycling of nonphosphorylated MOR is exclusively via Rab11-mediated pathway. Furthermore, phosphorylated MOR was observed accumulated in Rab5- and Rab4-, but not Rab11-positive vesicles. Our data indicate that both phosphorylated and nonphosphorylated MOR internalize via Rab5-dependent pathway after agonist stimulation, and the phosphorylated and nonphosphorylated MORs recycle through distinct vesicular trafficking pathways mediated by Rab4 and Rab11, respectively, which may ultimately lead to differential cellular responsiveness or downstream signaling.

The µ-opioid system promotes visual attention to faces and eyes.

PubMed

Chelnokova, Olga; Laeng, Bruno; Løseth, Guro; Eikemo, Marie; Willoch, Frode; Leknes, Siri

2016-12-01

Paying attention to others' faces and eyes is a cornerstone of human social behavior. The µ-opioid receptor (MOR) system, central to social reward-processing in rodents and primates, has been proposed to mediate the capacity for affiliative reward in humans. We assessed the role of the human MOR system in visual exploration of faces and eyes of conspecifics. Thirty healthy males received a novel, bidirectional battery of psychopharmacological treatment (an MOR agonist, a non-selective opioid antagonist, or placebo, on three separate days). Eye-movements were recorded while participants viewed facial photographs. We predicted that the MOR system would promote visual exploration of faces, and hypothesized that MOR agonism would increase, whereas antagonism decrease overt attention to the information-rich eye region. The expected linear effect of MOR manipulation on visual attention to the stimuli was observed, such that MOR agonism increased while antagonism decreased visual exploration of faces and overt attention to the eyes. The observed effects suggest that the human MOR system promotes overt visual attention to socially significant cues, in line with theories linking reward value to gaze control and target selection. Enhanced attention to others' faces and eyes represents a putative behavioral mechanism through which the human MOR system promotes social interest. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Functional μ-Opioid-Galanin Receptor Heteromers in the Ventral Tegmental Area.

PubMed

Moreno, Estefanía; Quiroz, César; Rea, William; Cai, Ning-Sheng; Mallol, Josefa; Cortés, Antoni; Lluís, Carme; Canela, Enric I; Casadó, Vicent; Ferré, Sergi

2017-02-01

The neuropeptide galanin has been shown to interact with the opioid system. More specifically, galanin counteracts the behavioral effects of the systemic administration of μ-opioid receptor (MOR) agonists. Yet the mechanism responsible for this galanin-opioid interaction has remained elusive. Using biophysical techniques in mammalian transfected cells, we found evidence for selective heteromerization of MOR and the galanin receptor subtype Gal1 (Gal1R). Also in transfected cells, a synthetic peptide selectively disrupted MOR-Gal1R heteromerization as well as specific interactions between MOR and Gal1R ligands: a negative cross talk, by which galanin counteracted MAPK activation induced by the endogenous MOR agonist endomorphin-1, and a cross-antagonism, by which a MOR antagonist counteracted MAPK activation induced by galanin. These specific interactions, which represented biochemical properties of the MOR-Gal1R heteromer, could then be identified in situ in slices of rat ventral tegmental area (VTA) with MAPK activation and two additional cell signaling pathways, AKT and CREB phosphorylation. Furthermore, in vivo microdialysis experiments showed that the disruptive peptide selectively counteracted the ability of galanin to block the dendritic dopamine release in the rat VTA induced by local infusion of endomorphin-1, demonstrating a key role of MOR-Gal1R heteromers localized in the VTA in the direct control of dopamine cell function and their ability to mediate antagonistic interactions between MOR and Gal1R ligands. The results also indicate that MOR-Gal1R heteromers should be viewed as targets for the treatment of opioid use disorders. The μ-opioid receptor (MOR) localized in the ventral tegmental area (VTA) plays a key role in the reinforcing and addictive properties of opioids. With parallel in vitro experiments in mammalian transfected cells and in situ and in vivo experiments in rat VTA, we demonstrate that a significant population of these MORs form functional heteromers with the galanin receptor subtype Gal1 (Gal1R), which modulate the activity of the VTA dopaminergic neurons. The MOR-Gal1R heteromer can explain previous results showing antagonistic galanin-opioid interactions and offers a new therapeutic target for the treatment of opioid use disorder. Copyright © 2017 the authors 0270-6474/17/371176-11$15.00/0.

Functional μ-Opioid-Galanin Receptor Heteromers in the Ventral Tegmental Area

PubMed Central

Moreno, Estefanía; Quiroz, César; Rea, William; Cai, Ning-Sheng; Cortés, Antoni

2017-01-01

The neuropeptide galanin has been shown to interact with the opioid system. More specifically, galanin counteracts the behavioral effects of the systemic administration of μ-opioid receptor (MOR) agonists. Yet the mechanism responsible for this galanin–opioid interaction has remained elusive. Using biophysical techniques in mammalian transfected cells, we found evidence for selective heteromerization of MOR and the galanin receptor subtype Gal1 (Gal1R). Also in transfected cells, a synthetic peptide selectively disrupted MOR–Gal1R heteromerization as well as specific interactions between MOR and Gal1R ligands: a negative cross talk, by which galanin counteracted MAPK activation induced by the endogenous MOR agonist endomorphin-1, and a cross-antagonism, by which a MOR antagonist counteracted MAPK activation induced by galanin. These specific interactions, which represented biochemical properties of the MOR-Gal1R heteromer, could then be identified in situ in slices of rat ventral tegmental area (VTA) with MAPK activation and two additional cell signaling pathways, AKT and CREB phosphorylation. Furthermore, in vivo microdialysis experiments showed that the disruptive peptide selectively counteracted the ability of galanin to block the dendritic dopamine release in the rat VTA induced by local infusion of endomorphin-1, demonstrating a key role of MOR-Gal1R heteromers localized in the VTA in the direct control of dopamine cell function and their ability to mediate antagonistic interactions between MOR and Gal1R ligands. The results also indicate that MOR-Gal1R heteromers should be viewed as targets for the treatment of opioid use disorders. SIGNIFICANCE STATEMENT The μ-opioid receptor (MOR) localized in the ventral tegmental area (VTA) plays a key role in the reinforcing and addictive properties of opioids. With parallel in vitro experiments in mammalian transfected cells and in situ and in vivo experiments in rat VTA, we demonstrate that a significant population of these MORs form functional heteromers with the galanin receptor subtype Gal1 (Gal1R), which modulate the activity of the VTA dopaminergic neurons. The MOR-Gal1R heteromer can explain previous results showing antagonistic galanin–opioid interactions and offers a new therapeutic target for the treatment of opioid use disorder. PMID:28007761

A substance P-opioid chimeric peptide as a unique nontolerance-forming analgesic

PubMed Central

Foran, Stacy E.; Carr, Daniel B.; Lipkowski, Andrzej W.; Maszczynska, Iwona; Marchand, James E.; Misicka, Aleksandra; Beinborn, Martin; Kopin, Alan S.; Kream, Richard M.

2000-01-01

To elucidate mechanisms of acute and chronic pain, it is important to understand how spinal excitatory systems influence opioid analgesia. The tachykinin substance P (SP) represents the prototypic spinal excitatory peptide neurotransmitter/neuromodulator, acting in concert with endogenous opioid systems to regulate analgesic responses to nociceptive stimuli. We have synthesized and pharmacologically characterized a chimeric peptide containing overlapping NH2- and COOH-terminal functional domains of the endogenous opioid endomorphin-2 (EM-2) and the tachykinin SP, respectively. Repeated administration of the chimeric molecule YPFFGLM-NH2, designated ESP7, into the rat spinal cord produces opioid-dependent analgesia without loss of potency over 5 days. In contrast, repeated administration of ESP7 with concurrent SP receptor (SPR) blockade results in a progressive loss of analgesic potency, consistent with the development of tolerance. Furthermore, tolerant animals completely regain opioid sensitivity after post hoc administration of ESP7 alone, suggesting that coactivation of SPRs is essential to maintaining opioid responsiveness. Radioligand binding and signaling assays, using recombinant receptors, confirm that ESP7 can coactivate μ-opioid receptors (MOR) and SPRs in vitro. We hypothesize that coincidental activation of the MOR- and SPR-expressing systems in the spinal cord mimics an ongoing state of reciprocal excitation and inhibition, which is normally encountered in nociceptive processing. Due to the ability of ESP7 to interact with both MOR and SPRs, it represents a unique prototypic, anti-tolerance-forming analgesic with future therapeutic potential. PMID:10852965

Small Sample Properties of Asymptotically Efficient Estimators of the Parameters of a Bivariate Gaussian–Weibull Distribution

Treesearch

Steve P. Verrill; James W. Evans; David E. Kretschmann; Cherilyn A. Hatfield

2012-01-01

Two important wood properties are stiffness (modulus of elasticity or MOE) and bending strength (modulus of rupture or MOR). In the past, MOE has often been modeled as a Gaussian and MOR as a lognormal or a two or three parameter Weibull. It is well known that MOE and MOR are positively correlated. To model the simultaneous behavior of MOE and MOR for the purposes of...

Maximum likelihood estimation of the parameters of a bivariate Gaussian-Weibull distribution from machine stress-rated data

Treesearch

Steve P. Verrill; David E. Kretschmann; James W. Evans

2016-01-01

Two important wood properties are stiffness (modulus of elasticity, MOE) and bending strength (modulus of rupture, MOR). In the past, MOE has often been modeled as a Gaussian and MOR as a lognormal or a two- or threeparameter Weibull. It is well known that MOE and MOR are positively correlated. To model the simultaneous behavior of MOE and MOR for the purposes of wood...

Functional interactions between endogenous cannabinoid and opioid systems: focus on alcohol, genetics and drug-addicted behaviors.

PubMed

López-Moreno, J A; López-Jiménez, A; Gorriti, M A; de Fonseca, F Rodríguez

2010-04-01

Although the first studies regarding the endogenous opioid system and addiction were published during the 1940s, addiction and cannabinoids were not addressed until the 1970s. Currently, the number of opioid addiction studies indexed in PubMed-Medline is 16 times greater than the number of cannabinoid addiction reports. More recently, functional interactions have been demonstrated between the endogenous cannabinoid and opioid systems. For example, the cannabinoid brain receptor type 1 (CB1) and mu opioid receptor type 1 (MOR1) co-localize in the same presynaptic nerve terminals and signal through a common receptor-mediated G-protein pathway. Here, we review a great variety of behavioral models of drug addiction and alcohol-related behaviors. We also include data providing clear evidence that activation of the cannabinoid and opioid endogenous systems via WIN 55,512-2 (0.4-10 mg/kg) and morphine (1.0-10 mg/kg), respectively, produces similar levels of relapse to alcohol in operant alcohol self-administration tasks. Finally, we discuss genetic studies that reveal significant associations between polymorphisms in MOR1 and CB1 receptors and drug addiction. For example, the SNP A118G, which changes the amino acid aspartate to asparagine in the MOR1 gene, is highly associated with altered opioid system function. The presence of a microsatellite polymorphism of an (AAT)n triplet near the CB1 gene is associated with drug addiction phenotypes. But, studies exploring haplotypes with regard to both systems, however, are lacking.

Platinum-mordenite catalysts for n-Hexane isomerization: Characterization by X-ray absorption spectroscopy and chemical probes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Otten, M.M.; Clayton, M.J.; Lamb, H.H.

Platinum-mordenite (Pt-MOR) catalysts were prepared from NH{sub 4}-MOR by ion exchange with (Pt{sup II}(NH{sub 3}){sub 4})(OH){sub 2}, calcination in O{sub 2} at 350{degrees}C, and reduction in H{sub 2} at 350{degrees}C. The resultant Pt-H-MOR was active for n-hexane isomerization and hydrocracking via bifunctional catalysis at 240-300{degrees}C and 1 atm. The observed activation energies for C{sub 6} branched-isomer formation are unusually low, suggesting that the isomerization rates were controlled by pore diffusion. A Pt-KH-MOR catalyst was prepared by ion exchange with aqueous KNO{sub 3} and re-reduction at 350{degrees}C; elemental analysis evidenced 90% exchange of protons for K{sup +} ions. The product distributionmore » and observed activation energies for C{sub 6} branched-isomer formation over Pt-KH-MOR are consistent with n-hexane isomerization via bifunctional catalysis. Hydrocracking was strongly suppressed, and light hydrocarbons were formed primarily by Pt-catalyzed hydrogenolysis. From in-situ extended X-ray absorption fine structure spectroscopy and H{sub 2} temperature-programmed desorption, we conclude that the Pt-MOR catalysts consist of small Pt clusters hosted within the mordenite crystals. The PtL{sub III}X-ray absorption near-edge structure (XANES) spectra of Pt-H-MOR and Pt-KH-MOR are closely similar, suggesting that the electronic structure of the Pt clusters is unaffected by mordenite acid-base chemistry. The infrared spectrum of CO adsorbed on Pt-H-MOR contains an intense band at 2084 cm{sup -1}, which is assigned to linear CO moieties on Pt clusters. The infrared spectrum of CO adsorbed on Pt-KH-MOR evidences a red shift of the linear CO band, which the authors suggest is due to electrostatic interactions between carbonyl O atoms and nearby K{sup +} ions. 45 refs., 9 figs., 6 tabs.« less

Identification of a Putative Mexican Strain of Serratia entomophila Pathogenic against Root-Damaging Larvae of Scarabaeidae (Coleoptera)▿ †

PubMed Central

Nuñez-Valdez, M. Eugenia; Calderón, Marco A.; Aranda, Eduardo; Hernández, Luciano; Ramírez-Gama, Rosa M.; Lina, Laura; Rodríguez-Segura, Zitlhally; Gutiérrez, María del C.; Villalobos, Francisco J.

2008-01-01

The larvae of scarab beetles, known as “white grubs” and belonging to the genera Phyllophaga and Anomala (Coleoptera: Scarabaeidae), are regarded as soil-dwelling pests in Mexico. During a survey conducted to find pathogenic bacteria with the potential to control scarab larvae, a native Serratia sp. (strain Mor4.1) was isolated from a dead third-instar Phyllophaga blanchardi larva collected from a cornfield in Tres Marías, Morelos, Mexico. Oral bioassays using healthy P. blanchardi larvae fed with the Mor4.1 isolate showed that this strain was able to cause an antifeeding effect and a significant loss of weight. Mortality was observed for P. blanchardi, P. trichodes, and P. obsoleta in a multidose experiment. The Mor4.1 isolate also caused 100% mortality 24 h after intracoelomic inoculation of the larvae of P. blanchardi, P. ravida, Anomala donovani and the lepidopteran insect Manduca sexta. Oral and injection bioassays were performed with concentrated culture broths of the Mor4.1 isolate to search for disease symptoms and mortality caused by extracellular proteins. The results have shown that Mor4.1 broths produce significant antifeeding effects and mortality. Mor4.1 broths treated with proteinase K lost the ability to cause disease symptoms and mortality, in both the oral and the injection bioassays, suggesting the involvement of toxic proteins in the disease. The Mor4.1 isolate was identified as a putative Serratia entomophila Mor4.1 strain based on numerical taxonomy and phylogenetic analyses done with the 16S rRNA gene sequence. The potential of S. entomophila Mor4.1 and its toxins to be used in an integrated pest management program is discussed. PMID:18083879

Regulation of µ-Opioid Receptors: Desensitization, Phosphorylation, Internalization, and Tolerance

PubMed Central

Williams, John T.; Ingram, Susan L.; Henderson, Graeme; Chavkin, Charles; von Zastrow, Mark; Schulz, Stefan; Koch, Thomas; Evans, Christopher J.

2013-01-01

Morphine and related µ-opioid receptor (MOR) agonists remain among the most effective drugs known for acute relief of severe pain. A major problem in treating painful conditions is that tolerance limits the long-term utility of opioid agonists. Considerable effort has been expended on developing an understanding of the molecular and cellular processes that underlie acute MOR signaling, short-term receptor regulation, and the progression of events that lead to tolerance for different MOR agonists. Although great progress has been made in the past decade, many points of contention and controversy cloud the realization of this progress. This review attempts to clarify some confusion by clearly defining terms, such as desensitization and tolerance, and addressing optimal pharmacological analyses for discerning relative importance of these cellular mechanisms. Cellular and molecular mechanisms regulating MOR function by phosphorylation relative to receptor desensitization and endocytosis are comprehensively reviewed, with an emphasis on agonist-biased regulation and areas where knowledge is lacking or controversial. The implications of these mechanisms for understanding the substantial contribution of MOR signaling to opioid tolerance are then considered in detail. While some functional MOR regulatory mechanisms contributing to tolerance are clearly understood, there are large gaps in understanding the molecular processes responsible for loss of MOR function after chronic exposure to opioids. Further elucidation of the cellular mechanisms that are regulated by opioids will be necessary for the successful development of MOR-based approaches to new pain therapeutics that limit the development of tolerance. PMID:23321159

Peripheral μ-opioid receptor mediated inhibition of calcium signaling and action potential-evoked calcium fluorescent transients in primary afferent CGRP nociceptive terminals.

PubMed

Baillie, Landon D; Schmidhammer, Helmut; Mulligan, Sean J

2015-06-01

While μ-opioid receptor (MOR) agonists remain the most powerful analgesics for the treatment of severe pain, serious adverse side effects that are secondary to their central nervous system actions pose substantial barriers to therapeutic use. Preclinical and clinical evidence suggest that peripheral MORs play an important role in opioid analgesia, particularly under inflammatory conditions. However, the mechanisms of peripheral MOR signaling in primary afferent pain fibres remain to be established. We have recently introduced a novel ex vivo optical imaging approach that, for the first time, allows the study of physiological functioning within individual peripheral nociceptive fibre free nerve endings in mice. In the present study, we found that MOR activation in selectively identified, primary afferent CGRP nociceptive terminals caused inhibition of N-type Ca(2+) channel signaling and suppression of action potential-evoked Ca(2+) fluorescent transients mediated by 'big conductance' Ca(2+)-activated K(+) channels (BKCa). In the live animal, we showed that the peripherally acting MOR agonist HS-731 produced analgesia and that BKCa channels were the major effectors of the peripheral MOR signaling. We have identified two key molecular transducers of MOR activation that mediate significant inhibition of nociceptive signaling in primary afferent terminals. Understanding the mechanisms of peripheral MOR signaling may promote the development of pathway selective μ-opioid drugs that offer improved therapeutic profiles for achieving potent analgesia while avoiding serious adverse central side effects. Copyright © 2015 Elsevier Ltd. All rights reserved.

Fast Modulation of μ-Opioid Receptor (MOR) Recycling Is Mediated by Receptor Agonists*

PubMed Central

Roman-Vendrell, Cristina; Yu, Y. Joy; Yudowski, Guillermo Ariel

2012-01-01

The μ-opioid receptor (MOR) is a member of the G protein-coupled receptor family and the main target of endogenous opioid neuropeptides and morphine. Upon activation by ligands, MORs are rapidly internalized via clathrin-coated pits in heterologous cells and dissociated striatal neurons. After initial endocytosis, resensitized receptors recycle back to the cell surface by vesicular delivery for subsequent cycles of activation. MOR trafficking has been linked to opioid tolerance after acute exposure to agonist, but it is also involved in the resensitization process. Several studies describe the regulation and mechanism of MOR endocytosis, but little is known about the recycling of resensitized receptors to the cell surface. To study this process, we induced internalization of MOR with [d-Ala2, N-Me-Phe4, Gly5-ol]-enkephalin (DAMGO) and morphine and imaged in real time single vesicles recycling receptors to the cell surface. We determined single vesicle recycling kinetics and the number of receptors contained in them. Then we demonstrated that rapid vesicular delivery of recycling MORs to the cell surface was mediated by the actin-microtubule cytoskeleton. Recycling was also dependent on Rab4, Rab11, and the Ca2+-sensitive motor protein myosin Vb. Finally, we showed that recycling is acutely modulated by the presence of agonists and the levels of cAMP. Our work identifies a novel trafficking mechanism that increases the number of cell surface MORs during acute agonist exposure, effectively reducing the development of opioid tolerance. PMID:22378794

Stability of bound species during alkene reactions on solid acids

NASA Astrophysics Data System (ADS)

Sarazen, Michele L.; Iglesia, Enrique

2017-05-01

This study reports the thermodynamics of bound species derived from ethene, propene, n-butene, and isobutene on solid acids with diverse strength and confining voids. Density functional theory (DFT) and kinetic data indicate that covalently bound alkoxides form C-C bonds in the kinetically relevant step for dimerization turnovers on protons within TON (0.57 nm) and MOR (0.67 nm) zeolitic channels and on stronger acids HPW (polyoxometalate clusters on silica). Turnover rates for mixed alkenes give relative alkoxide stabilities; the respective adsorption constants are obtained from in situ infrared spectra. Tertiary alkoxides (from isobutene) within larger voids (MOR, HPW) are more stable than less substituted isomers but are destabilized within smaller concave environments (TON) because framework distortions are required to avoid steric repulsion. Adsorption constants are similar on MOR and HPW for each alkoxide, indicating that binding is insensitive to acid strength for covalently bound species. DFT-derived formation free energies for alkoxides with different framework attachments and backbone length/structure agree with measurements when dispersion forces, which mediate stabilization by confinement in host-guest systems, are considered. Theory reveals previously unrecognized framework distortions that balance the C-O bond lengths required for covalency with host-guest distances that maximize van der Waals contacts. These distortions, reported here as changes in O-atom locations and dihedral angles, become stronger for larger, more substituted alkoxides. The thermodynamic properties reported here for alkoxides and acid hosts differing in size and conjugate-anion stability are benchmarked against DFT-derived free energies; their details are essential to design host-guest pairs that direct alkoxide species toward specific products.

Residential exposure to pesticides as risk factor for childhood and young adult brain tumors: A systematic review and meta-analysis.

PubMed

Van Maele-Fabry, Geneviève; Gamet-Payrastre, Laurence; Lison, Dominique

2017-09-01

Accumulating evidence suggests a positive association between exposure to non-agricultural pesticides and childhood brain tumors (CBT). (1) To conduct a systematic review and meta-analysis of published studies on the association between residential/household/domestic exposure to pesticides and childhood brain tumors. (2) To clarify variables that could impact the results. Publications in English were identified from a MEDLINE search through 28 February 2017 and from the reference list of identified publications. Risk estimates were extracted from 18 case-control studies published between 1979 and 2016 and study quality assessments were performed. Summary odds ratios (mOR) were calculated according to fixed and random-effect meta-analysis models. Separate analyses were conducted after stratification for study quality, critical exposure period, exposure location, specific exposures, pesticide category, application methods, type of pest treated, type of CBT, child's age at diagnosis and geographic location. Statistically significant associations were observed with CBT after combining all studies (mOR: 1.26; 95% CI: 1.13-1.40) without evidence of inconsistency between study results or publication bias. Specifically, increased risks were observed for several groupings and more particularly for gliomas and exposure involving insecticides. Statistical significance was also reached for high quality studies, for all exposure periods, for indoor exposure and, more particularly, during the prenatal period for all stratifications involving insecticides (except for outdoor use), for pet treatments, for flea/tick treatment, for studies from USA/Canada and studies from Europe (borderline) as well as for data from studies including children of up to 10years at diagnosis and of up to 15years. Our findings support an association between residential exposure to pesticides and childhood brain tumors. Although causality cannot be established, these results add to the evidence leading to recommend limiting residential use of pesticides and to support public health policies serving this objective. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dacite petrogenesis on mid-ocean ridges: Evidence for oceanic crustal melting and assimilation

USGS Publications Warehouse

Wanless, V.D.; Perfit, M.R.; Ridley, W.I.; Klein, E.

2010-01-01

Whereas the majority of eruptions at oceanic spreading centers produce lavas with relatively homogeneous mid-ocean ridge basalt (MORB) compositions, the formation of tholeiitic andesites and dacites at mid-ocean ridges (MORs) is a petrological enigma. Eruptions of MOR high-silica lavas are typically associated with ridge discontinuities and have produced regionally significant volumes of lava. Andesites and dacites have been observed and sampled at several locations along the global MOR system; these include propagating ridge tips at ridge-transform intersections on the Juan de Fuca Ridge and eastern Gal??pagos spreading center, and at the 9??N overlapping spreading center on the East Pacific Rise. Despite the formation of these lavas at various ridges, MOR dacites show remarkably similar major element trends and incompatible trace element enrichments, suggesting that similar processes are controlling their chemistry. Although most geochemical variability in MOR basalts is consistent with low-pressure fractional crystallization of various mantle-derived parental melts, our geochemical data for MOR dacitic glasses suggest that contamination from a seawater-altered component is important in their petrogenesis. MOR dacites are characterized by elevated U, Th, Zr, and Hf, low Nb and Ta concentrations relative to rare earth elements (REE), and Al2O3, K2O, and Cl concentrations that are higher than expected from low-pressure fractional crystallization alone. Petrological modeling of MOR dacites suggests that partial melting and assimilation are both integral to their petrogenesis. Extensive fractional crystallization of a MORB parent combined with partial melting and assimilation of amphibole-bearing altered crust produces a magma with a geochemical signature similar to a MOR dacite. This supports the hypothesis that crustal assimilation is an important process in the formation of highly evolved MOR lavas and may be significant in the generation of evolved MORB in general. Additionally, these processes are likely to be more common in regions of episodic magma supply and enhanced magma-crust interaction such as at the ends of ridge segments. ?? The Author 2010. Published by Oxford University Press. All rights reserved.

Mu opioid receptor expression is increased in inflammatory bowel diseases: implications for homeostatic intestinal inflammation

PubMed Central

Philippe, D; Chakass, D; Thuru, X; Zerbib, P; Tsicopoulos, A; Geboes, K; Bulois, P; Breisse, M; Vorng, H; Gay, J; Colombel, J‐F; Desreumaux, P; Chamaillard, M

2006-01-01

Background and aims Recent studies with μ opioid receptor (MOR) deficient mice support a physiological anti‐inflammatory effect of MOR at the colon interface. To better understand the potential pharmacological effect of certain opiates in inflammatory bowel diseases (IBD), we (1) evaluated the regulation in vivo and in vitro of human MOR expression by inflammation; and (2) tested the potential anti‐inflammatory function of a specific opiate (DALDA) in inflamed and resting human mucosa. Patients and methods Expression of MOR mRNA and protein was evaluated in healthy and inflamed small bowel and colonic tissues, isolated peripheral blood mononuclear cells and purified monocytes, and CD4+ and CD8+ T cells from healthy donors and IBD patients. The effect of cytokines and nuclear factor κB (NFκB) activation on MOR expression in lymphocyte T and monocytic human cell lines was assessed. Finally, DALDA induced anti‐inflammatory effect was investigated in mucosal explants from controls and IBD patients. Results MOR was expressed in ileal and colonic enteric neurones as well as in immunocytes such as myeloid cells and CD4+ and CD8+ T cells. Overexpressed in active IBD mucosa, MOR was significantly enhanced by cytokines and repressed by NFκB inhibitor in myeloid and lymphocytic cell lines. Furthermore, ex vivo DALDA treatment dampened tumour necrosis factor α mRNA expression in the colon of active IBD patients. Conclusions Given the increased expression of MOR and the ex vivo beneficial effect of DALDA in active IBD, natural and/or synthetic opioid agonists could help to prevent overt pathological intestinal inflammation. PMID:16299031

Effects of gravity on growth phenotype in MAPs mutants of Arabidopsis

NASA Astrophysics Data System (ADS)

Higuchi, Sayoko; Kumasaki, Saori; Matsumoto, Shouhei; Soga, Kouichi; Wakabayashi, Kazuyuki; Hashimoto, Takashi; Hoson, Takayuki

Hypergravity suppresses elongation growth and promotes lateral expansion of stem organs in various plants. It has been shown that cortical microtubules are involved in gravity-induced modifications of growth and development. Because microtubule-associated proteins (MAPs) are important in dynamics of microtubules, they may also play a role in the gravity response. In the present study, the roles of MAPs (MOR1, SPR1, SPR2, MAP65, and KTN1) in hypergravityinduced changes in growth and development were examined in Arabidopsis hypocotyls. The expression of MOR1, SPR1, SPR2 , and MAP65 genes was down-regulated, whereas that of KTN1 gene was increased transiently by hypergravity. We analyzed the growth behavior of MAPs mutants (mor1/rid5, spr1-2 , spr2-2, and katanin mutants) under hypergravity conditions. Hypergravity inhibited elongation growth of hypocotyls in spr1-2 as in wild-type. On the other hand, elongation growth of hypocotyls in mor1/rid5, spr2-2, and katanin mutants was suppressed as compared with wild-type under 1 g conditions, and was not affected further by hypergravity stimuli. Hypocotyls of mor1/rid5, spr1-2 , and spr2-2 also showed helical growth even under 1 g conditions, and in mor1/rid5 such a phenotype was intensified under hypergravity conditions. The alignment of cell line was abnormal in hypocotyls of katanin mutants under both 1 g and hypergravity conditions. The orientation of cortical microtubules in wildtype hypocotyls was changed from transverse direction to longitudinal or random directions by hypergravity stimuli. In mor1/rid5 hypocotyls, the orientation of microtubules was random even under 1 g condition, which was not affected by hypergravity. Furthermore, partial disruption of cortical microtubules was observed in mor1/rid5 hypocotyls. These results suggest that MAPs, especially MOR1, play an important role in maintenance of normal growth phenotype against gravity in plants probably via stabilization of microtubule structure.

MOR103, a human monoclonal antibody to granulocyte–macrophage colony-stimulating factor, in the treatment of patients with moderate rheumatoid arthritis: results of a phase Ib/IIa randomised, double-blind, placebo-controlled, dose-escalation trial

PubMed Central

Behrens, Frank; Tak, Paul P; Østergaard, Mikkel; Stoilov, Rumen; Wiland, Piotr; Huizinga, Thomas W; Berenfus, Vadym Y; Vladeva, Stoyanka; Rech, Juergen; Rubbert-Roth, Andrea; Korkosz, Mariusz; Rekalov, Dmitriy; Zupanets, Igor A; Ejbjerg, Bo J; Geiseler, Jens; Fresenius, Julia; Korolkiewicz, Roman P; Schottelius, Arndt J; Burkhardt, Harald

2015-01-01

Objectives To determine the safety, tolerability and signs of efficacy of MOR103, a human monoclonal antibody to granulocyte–macrophage colony-stimulating factor (GM-CSF), in patients with rheumatoid arthritis (RA). Methods Patients with active, moderate RA were enrolled in a randomised, multicentre, double-blind, placebo-controlled, dose-escalation trial of intravenous MOR103 (0.3, 1.0 or 1.5 mg/kg) once a week for 4 weeks, with follow-up to 16 weeks. The primary outcome was safety. Results Of the 96 randomised and treated subjects, 85 completed the trial (n=27, 24, 22 and 23 for pooled placebo and MOR103 0.3, 1.0 and 1.5 mg/kg, respectively). Treatment emergent adverse events (AEs) in the MOR103 groups were mild or moderate in intensity and generally reported at frequencies similar to those in the placebo group. The most common AE was nasopharyngitis. In two cases, AEs were classified as serious because of hospitalisation: paronychia in a placebo subject and pleurisy in a MOR103 0.3 mg/kg subject. Both patients recovered fully. In exploratory efficacy analyses, subjects in the MOR103 1.0 and 1.5 mg/kg groups showed significant improvements in Disease Activity Score-28 scores and joint counts and significantly higher European League Against Rheumatism response rates than subjects receiving placebo. MOR103 1.0 mg/kg was associated with the largest reductions in disease activity parameters. Conclusions MOR103 was well tolerated and showed preliminary evidence of efficacy in patients with active RA. The data support further investigation of this monoclonal antibody to GM-CSF in RA patients and potentially in those with other immune-mediated inflammatory diseases. Trial registration number NCT01023256 PMID:24534756

Long-term outcome following medial open reduction in developmental dysplasia of the hip: a retrospective cohort study.

PubMed

Gardner, Richard O E; Bradley, Catharine S; Sharma, Om P; Feng, Lin; Shin, Michelle EyunJung; Kelley, Simon P; Wedge, J H

2016-06-01

Avascular necrosis (AVN) is a serious complication of treatment for developmental dysplasia of the hip. There is ongoing controversy regarding AVN and its influence on hip development following medial open reduction (MOR). The aim of our study was to (1) determine the long-term prevalence of AVN following MOR, (2) evaluate hip development after MOR, and (3) identify predictors of AVN and radiographic outcome at skeletal maturity after MOR. A retrospective cohort analysis of 60 patients (70 hips) who underwent MOR with a mean follow-up of 10.83 years (5.23-16.74) was conducted. AVN was recorded according to Bucholz and Ogden classification and radiographic outcome based on Severin grading. AVN and hip morphology related to length of follow-up were evaluated. Chi-squared and t-tests were used to identify relationships between AVN and other variables. Logistic regression was used to assess predictors of AVN and Severin outcome. The rate of clinically significant AVN (types 2-4) following MOR was 32.9 % with type 2 accounting for 82.6 % of these cases. While early acetabular development was satisfactory, long-term outcome was unsatisfactory in 26 % of cases with AVN (vs 8.7 % of cases without AVN). A higher rate of AVN was identified when hips were immobilized in ≥60° of abduction postoperatively. A higher rate of poor Severin outcome was identified in hips with AVN. Our findings suggest that there is a high rate of AVN and unsatisfactory long-term outcome following MOR. AVN remains a significant concern following MOR surgery for developmental dysplasia of the hip that may not be apparent until long-term evaluation.

Postnatal odorant exposure induces peripheral olfactory plasticity at the cellular level.

PubMed

Cadiou, Hervé; Aoudé, Imad; Tazir, Bassim; Molinas, Adrien; Fenech, Claire; Meunier, Nicolas; Grosmaitre, Xavier

2014-04-02

Mammalian olfactory sensory neurons (OSNs) form the primary elements of the olfactory system. Inserted in the olfactory mucosa lining of the nasal cavity, they are exposed to the environment and their lifespan is brief. Several reports say that OSNs are regularly regenerated during the entire life and that odorant environment affects the olfactory epithelium. However, little is known about the impact of the odorant environment on OSNs at the cellular level and more precisely in the context of early postnatal olfactory exposure. Here we exposed MOR23-green fluorescent protein (GFP) and M71-GFP mice to lyral or acetophenone, ligands for MOR23 or M71, respectively. Daily postnatal exposure to lyral induces plasticity in the population of OSNs expressing MOR23. Their density decreases after odorant exposure, whereas the amount of MOR23 mRNA and protein remain stable in the whole epithelium. Meanwhile, quantitative PCR indicates that each MOR23 neuron has higher levels of olfactory receptor transcripts and also expresses more CNGA2 and phosphodiesterase 1C, fundamental olfactory transduction pathway proteins. Transcript levels return to baseline after 4 weeks recovery. Patch-clamp recordings reveal that exposed MOR23 neurons respond to lyral with higher sensitivity and broader dynamic range while the responses' kinetics were faster. These effects are specific to the odorant-receptor pair lyral-MOR23: there was no effect of acetophenone on MOR23 neurons and no effect of acetophenone and lyral on the M71 population. Together, our results clearly demonstrate that OSNs undergo specific anatomical, molecular, and functional adaptation when chronically exposed to odorants in the early stage of life.

Platinum Nickel Nanowires as Methanol Oxidation Electrocatalysts

DOE PAGES

Alia, Shaun M.; Pylypenko, Svitlana; Neyerlin, Kenneth C.; ...

2015-08-27

We investigated platinum(Pt) nickel (Ni) nanowires (PtNiNWs) as methanol oxidation reaction (MOR) catalysts in rotating disk electrode (RDE) half-cells under acidic conditions. Pt-ruthenium (Ru) nanoparticles have long been the state of the art MOR catalyst for direct methanol fuel cells (DMFCs) where Ru provides oxophilic sites, lowering the potential for carbon monoxide oxidation and the MOR onset. Ru, however, is a precious metal that has long term durability concerns. Ni/Ni oxide species offer a potential to replace Ru in MOR electrocatalysis. PtNiNWs were investigated for MOR and oxygen annealing was investigated as a route to improve catalyst performance (mass activitymore » 65% greater) and stability to potential cycling. Our results presented show that PtNiNWs offer significant promise in the area, but also result in Ni ion leaching that is a concern requiring further evaluation in fuel cells.« less

Cloning and functional identification of moricins from the diamondback moth, Plutella xylostella (L.).

PubMed

Xia, X-F; Li, Y; Yu, X-Q; Lin, J-H; Li, S-Y; Li, Q; You, M-S

2017-10-01

Antimicrobial peptides (AMPs) are small-molecule peptides that play crucial roles in insect innate immune responses. To better understand the function of AMPs in Plutella xylostella, one of the main pests of cruciferous vegetables, three full-length cDNAs encoding moricins were cloned from Pl. xylostella. Two variants of the moricin named PxMor2 and PxMor3 were heterologously expressed and purified. A secondary structure analysis using circular dichroism demonstrated that the two peptides adopted an α-helical structure in the membrane-like environment, but in aqueous solution, they were present in random coiled conformation. Antimicrobial activity assays demonstrated that PxMor2 exhibited high activity against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli; however, PxMor3 only demonstrated high activity against E. coli. Scanning electron microscopy and confocal laser-scanning microscopy analyses suggest that PxMors can lead to the disruption of bacterial membrane, which might be the mechanism by which PxMors inhibit bacterial growth. This study contributes to the understanding of Pl. xylostella AMPs and immune responses, and also enriches the knowledge of insect moricin. © 2017 The Royal Entomological Society.

Opioid Modulation of Value-Based Decision-Making in Healthy Humans.

PubMed

Eikemo, Marie; Biele, Guido; Willoch, Frode; Thomsen, Lotte; Leknes, Siri

2017-08-01

Modifying behavior to maximize reward is integral to adaptive decision-making. In rodents, the μ-opioid receptor (MOR) system encodes motivation and preference for high-value rewards. Yet it remains unclear whether and how human MORs contribute to value-based decision-making. We reasoned that if the human MOR system modulates value-based choice, this would be reflected by opposite effects of agonist and antagonist drugs. In a double-blind pharmacological cross-over study, 30 healthy men received morphine (10 mg), placebo, and the opioid antagonist naltrexone (50 mg). They completed a two-alternative decision-making task known to induce a considerable bias towards the most frequently rewarded response option. To quantify MOR involvement in this bias, we fitted accuracy and reaction time data with the drift-diffusion model (DDM) of decision-making. The DDM analysis revealed the expected bidirectional drug effects for two decision subprocesses. MOR stimulation with morphine increased the preference for the stimulus with high-reward probability (shift in starting point). Compared to placebo, morphine also increased, and naltrexone reduced, the efficiency of evidence accumulation. Since neither drug affected motor-coordination, speed-accuracy trade-off, or subjective state (indeed participants were still blinded after the third session), we interpret the MOR effects on evidence accumulation efficiency as a consequence of changes in effort exerted in the task. Together, these findings support a role for the human MOR system in value-based choice by tuning decision-making towards high-value rewards across stimulus domains.

Recent Advances in the Realm of Allosteric Modulators for Opioid Receptors for Future Therapeutics.

PubMed

Remesic, Michael; Hruby, Victor J; Porreca, Frank; Lee, Yeon Sun

2017-06-21

Opioids, and more specifically μ-opioid receptor (MOR) agonists such as morphine, have long been clinically used as therapeutics for severe pain states but often come with serious side effects such as addiction and tolerance. Many studies have focused on bringing about analgesia from the MOR with attenuated side effects, but its underlying mechanism is not fully understood. Recently, focus has been geared toward the design and elucidation of the orthosteric site with ligands of various biological profiles and mixed subtype opioid activities and selectivities, but targeting the allosteric site is an area of increasing interest. It has been shown that allosteric modulators play key roles in influencing receptor function such as its tolerance to a ligand and affect downstream pathways. There has been a high variance of chemical structures that provide allosteric modulation at a given receptor, but recent studies and reviews tend to focus on the altered cellular mechanisms instead of providing a more rigorous description of the allosteric ligand's structure-function relationship. In this review, we aim to explore recent developments in the structural motifs that potentiate orthosteric binding and their influences on cellular pathways in an effort to present novel approaches to opioid therapeutic design.

14-O-Methylmorphine: A Novel Selective Mu-Opioid Receptor Agonist with High Efficacy and Affinity.

PubMed

Zádor, Ferenc; Balogh, Mihály; Váradi, András; Zádori, Zoltán S; Király, Kornél; Szűcs, Edina; Varga, Bence; Lázár, Bernadette; Hosztafi, Sándor; Riba, Pál; Benyhe, Sándor; Fürst, Susanna; Al-Khrasani, Mahmoud

2017-11-05

14-O-methyl (14-O-Me) group in morphine-6-O-sulfate (M6SU) or oxymorphone has been reported to be essential for enhanced affinity, potency and antinociceptive effect of these opioids. Herein we report on the pharmacological properties (potency, affinity and efficacy) of the new compound, 14-O-methylmorphine (14-O-MeM) in in vitro. Additionally, we also investigated the antinociceptive effect of the novel compound, as well as its inhibitory action on gastrointestinal transit in in vivo. The potency and efficacy of test compound were measured by [ 35 S]GTPγS binding, isolated mouse vas deferens (MVD) and rat vas deferens (RVD) assays. The affinity of 14-O-MeM for opioid receptors was assessed by radioligand binding and MVD assays. The antinociceptive and gastrointestinal effects of the novel compound were evaluated in the rat tail-flick test and charcoal meal test, respectively. Morphine, DAMGO, Ile 5,6 deltorphin II, deltorphin II and U-69593 were used as reference compounds. 14-O-MeM showed higher efficacy (E max ) and potency (EC 50 ) than morphine in MVD, RVD or [ 35 S]GTPγS binding. In addition, 14-O-MeM compared to morphine showed higher affinity for μ-opioid receptor (MOR). In vivo, in rat tail-flick test 14-O-MeM proved to be stronger antinociceptive agent than morphine after peripheral or central administration. Additionally, both compounds inhibited the gastrointestinal peristalsis. However, when the antinociceptive and antitransit doses for each test compound are compared, 14-O-MeM proved to have slightly more favorable pharmacological profile. Our results affirm that 14-O-MeM, an opioid of high efficacy and affinity for MOR can be considered as a novel analgesic agent of potential clinical value. Copyright © 2017 Elsevier B.V. All rights reserved.

MOR103, a human monoclonal antibody to granulocyte-macrophage colony-stimulating factor, in the treatment of patients with moderate rheumatoid arthritis: results of a phase Ib/IIa randomised, double-blind, placebo-controlled, dose-escalation trial.

PubMed

Behrens, Frank; Tak, Paul P; Østergaard, Mikkel; Stoilov, Rumen; Wiland, Piotr; Huizinga, Thomas W; Berenfus, Vadym Y; Vladeva, Stoyanka; Rech, Juergen; Rubbert-Roth, Andrea; Korkosz, Mariusz; Rekalov, Dmitriy; Zupanets, Igor A; Ejbjerg, Bo J; Geiseler, Jens; Fresenius, Julia; Korolkiewicz, Roman P; Schottelius, Arndt J; Burkhardt, Harald

2015-06-01

To determine the safety, tolerability and signs of efficacy of MOR103, a human monoclonal antibody to granulocyte-macrophage colony-stimulating factor (GM-CSF), in patients with rheumatoid arthritis (RA). Patients with active, moderate RA were enrolled in a randomised, multicentre, double-blind, placebo-controlled, dose-escalation trial of intravenous MOR103 (0.3, 1.0 or 1.5 mg/kg) once a week for 4 weeks, with follow-up to 16 weeks. The primary outcome was safety. Of the 96 randomised and treated subjects, 85 completed the trial (n=27, 24, 22 and 23 for pooled placebo and MOR103 0.3, 1.0 and 1.5 mg/kg, respectively). Treatment emergent adverse events (AEs) in the MOR103 groups were mild or moderate in intensity and generally reported at frequencies similar to those in the placebo group. The most common AE was nasopharyngitis. In two cases, AEs were classified as serious because of hospitalisation: paronychia in a placebo subject and pleurisy in a MOR103 0.3 mg/kg subject. Both patients recovered fully. In exploratory efficacy analyses, subjects in the MOR103 1.0 and 1.5 mg/kg groups showed significant improvements in Disease Activity Score-28 scores and joint counts and significantly higher European League Against Rheumatism response rates than subjects receiving placebo. MOR103 1.0 mg/kg was associated with the largest reductions in disease activity parameters. MOR103 was well tolerated and showed preliminary evidence of efficacy in patients with active RA. The data support further investigation of this monoclonal antibody to GM-CSF in RA patients and potentially in those with other immune-mediated inflammatory diseases. NCT01023256. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Cell-autonomous regulation of Mu-opioid receptor recycling by substance P.

PubMed

Bowman, Shanna L; Soohoo, Amanda L; Shiwarski, Daniel J; Schulz, Stefan; Pradhan, Amynah A; Puthenveedu, Manojkumar A

2015-03-24

How neurons coordinate and reprogram multiple neurotransmitter signals is an area of broad interest. Here, we show that substance P (SP), a neuropeptide associated with inflammatory pain, reprograms opioid receptor recycling and signaling. SP, through activation of the neurokinin 1 (NK1R) receptor, increases the post-endocytic recycling of the mu-opioid receptor (MOR) in trigeminal ganglion (TG) neurons in an agonist-selective manner. SP-mediated protein kinase C (PKC) activation is both required and sufficient for increasing recycling of exogenous and endogenous MOR in TG neurons. The target of this cross-regulation is MOR itself, given that mutation of either of two PKC phosphorylation sites on MOR abolishes the SP-induced increase in recycling and resensitization. Furthermore, SP enhances the resensitization of fentanyl-induced, but not morphine-induced, antinociception in mice. Our results define a physiological pathway that cross-regulates opioid receptor recycling via direct modification of MOR and suggest a mode of homeostatic interaction between the pain and analgesic systems.

Cell-Autonomous Regulation of Mu-Opioid Receptor Recycling by Substance P

PubMed Central

Bowman, Shanna L.; Soohoo, Amanda L.; Shiwarski, Daniel J.; Schulz, Stefan; Pradhan, Amynah A.; Puthenveedu, Manojkumar A.

2015-01-01

SUMMARY How neurons coordinate and reprogram multiple neurotransmitter signals is an area of broad interest. Here, we show that substance P (SP), a neuropep-tide associated with inflammatory pain, reprograms opioid receptor recycling and signaling. SP, through activation of the neurokinin 1 (NK1R) receptor, increases the post-endocytic recycling of the muopioid receptor (MOR) in trigeminal ganglion (TG) neurons in an agonist-selective manner. SP-mediated protein kinase C (PKC) activation is both required and sufficient for increasing recycling of exogenous and endogenous MOR in TG neurons. The target of this cross-regulation is MOR itself, given that mutation of either of two PKC phosphorylation sites on MOR abolishes the SP-induced increase in recycling and resensitization. Furthermore, SP enhances the resensitization of fentanyl-induced, but not morphine-induced, antinociception in mice. Our results define a physiological pathway that cross-regulates opioid receptor recycling via direct modification of MOR and suggest a mode of homeo-static interaction between the pain and analgesic systems. PMID:25801029

Further Optimization and Evaluation of Bioavailable, Mixed-Efficacy μ-Opioid Receptor (MOR) Agonists/δ-Opioid Receptor (DOR) Antagonists: Balancing MOR and DOR Affinities.

PubMed

Harland, Aubrie A; Yeomans, Larisa; Griggs, Nicholas W; Anand, Jessica P; Pogozheva, Irina D; Jutkiewicz, Emily M; Traynor, John R; Mosberg, Henry I

2015-11-25

In a previously described peptidomimetic series, we reported the development of bifunctional μ-opioid receptor (MOR) agonist and δ-opioid receptor (DOR) antagonist ligands with a lead compound that produced antinociception for 1 h after intraperitoneal administration in mice. In this paper, we expand on our original series by presenting two modifications, both of which were designed with the following objectives: (1) probing bioavailability and improving metabolic stability, (2) balancing affinities between MOR and DOR while reducing affinity and efficacy at the κ-opioid receptor (KOR), and (3) improving in vivo efficacy. Here, we establish that, through N-acetylation of our original peptidomimetic series, we are able to improve DOR affinity and increase selectivity relative to KOR while maintaining the desired MOR agonist/DOR antagonist profile. From initial in vivo studies, one compound (14a) was found to produce dose-dependent antinociception after peripheral administration with an improved duration of action of longer than 3 h.

mu-Opioid receptor-independent fashion of the suppression of sodium currents by mu-opioid analgesics in thalamic neurons.

PubMed

Hashimoto, Keisuke; Amano, Taku; Kasakura, Akiko; Uhl, George R; Sora, Ichiro; Sakai, Norio; Kuzumaki, Naoko; Suzuki, Tsutomu; Narita, Minoru

2009-03-27

Most reports in the literature have shown that the effects of opioid analgesics are primarily mediated by mu-opioid receptor (MOR), whereas other potential targets of opioid analgesics have not been thoroughly characterized. In this study, we found that extracellular application of morphine, fentanyl or oxycodone, which are all considered to be MOR agonists, at relatively high concentrations, but not endogenous mu-opioid peptides, produced a concentration-dependent suppression of sodium currents in cultured thalamic neurons. These effects of opioids were not affected by either a MOR antagonist naloxone or a deletion of MOR gene. Among these opioids, fentanyl strongly suppressed sodium currents to the same degree as lidocaine, and both morphine and oxycodone slightly but significantly reduced sodium currents when they were present extracellularly. In contrast, the intracellular application of morphine, but not oxycodone, fentanyl or lidocaine, reduced sodium currents. These results suggest that morphine, fentanyl and oxycodone each produce the MOR-independent suppression of sodium currents by distinct mechanisms in thalamic neurons.

Multiple opiate receptors: déjà vu all over again.

PubMed

Pasternak, Gavril W

2004-01-01

The concept of multiple opioid receptors has changed dramatically since their initial proposal by Martin nearly 40 years ago. Three major opioid receptor families have now been proposed: mu, kappa and delta. Most of the opioid analgesics used clinically selectively bind to mu opioid receptors. Yet, clinicians have long appreciated subtle, but significant, differences in their pharmacology. These observations suggested more than one mu opioid receptor mechanism of action and led us to propose multiple mu opioid receptors over 20 years ago based upon a range of pharmacological and receptor binding approaches. A mu opioid receptor, MOR-1, was cloned about a decade ago. More recent studies have now identified a number of splice variants of this clone. These splice variants may help explain the pharmacology of the mu opioids and open interesting directions for future opioid research.

Decreased consumption of sweet fluids in mu opioid receptor knockout mice: a microstructural analysis of licking behavior

PubMed Central

Ostlund, Sean B.; Kosheleff, Alisa; Maidment, Nigel T.; Murphy, Niall P.

2013-01-01

Summary Rationale Evidence suggests that the palatability of food (i.e., the hedonic impact produced by its sensory features) can promote feeding and may underlie compulsive eating, leading to obesity. Pharmacological studies implicate opioid transmission in the hedonic control of feeding, though these studies often rely on agents lacking specificity for particular opioid receptors. Objectives Here, we investigated the role of mu opioid receptors (MORs) specifically in determining hedonic responses to palatable sweet stimuli. Methods In Experiment 1, licking microstructure when consuming sucrose solution (2 to 20 %) was compared in MOR knockout and wildtype mice as a function of sucrose concentration and level of food deprivation. In Experiment 2, a similar examination was conducted using the palatable but calorie-free stimulus sucralose (0.001 to 1%), allowing study of licking behavior independent of homeostatic variables. Results In Experiment 1, MOR knockout mice exhibited several alterations in sucrose licking. Although wildtype mice exhibited a two-fold increase in the burst length when food deprived, relative to the nondeprived test, this aspect of sucrose licking was generally insensitive to manipulations of food deprivation for MOR knockout mice. Furthermore, during concentration testing, their rate of sucrose licking was less than half that of wildtype mice. During sucralose testing (Experiment 2), MOR knockout mice licked at approximately half the wildtype rate, providing more direct evidence that MOR knockout mice were impaired in processing stimulus palatability. Conclusions These results suggest that transmission through MORs mediates hedonic responses to palatable stimuli, and therefore likely contributes to normal and pathological eating. PMID:23568577

Morphine decreases social interaction of adult male rats, while THC does not affect it.

PubMed

Šlamberová, R; Mikulecká, A; Macúchová, E; Hrebíčková, I; Ševčíková, M; Nohejlová, K; Pometlová, M

2016-12-22

The aim of the present study was to compare effect of three low doses of morphine (MOR) and delta9-tetrahydrocannabinol (THC) on social behavior tested in Social interaction test (SIT). 45 min prior to testing adult male rats received one of the drugs or solvents: MOR (1; 2.5; 5 mg/kg); saline as a solvent for MOR; THC (0.5; 1; 2 mg/kg); ethanol as a solvent for THC. Occurrence and time spent in specific patterns of social interactions (SI) and non-social activities (locomotion and rearing) was video-recorded for 5 min and then analyzed. MOR in doses of 1 and 2.5 mg/kg displayed decreased SI in total. Detailed analysis of specific patterns of SI revealed decrease in mutual sniffing and allo-grooming after all doses of MOR. The highest dose (5 mg/kg) of MOR decreased following and increased genital investigation. Rearing activity was increased by lower doses of MOR (1 and 2.5 mg/kg). THC, in each of the tested doses, did not induce any specific changes when compared to matching control group (ethanol). However, an additional statistical analysis showed differences between all THC groups and their ethanol control group when compared to saline controls. There was lower SI in total, lower mutual sniffing and allo-grooming, but higher rearing in THC and ethanol groups than in saline control group. Thus, changes seen in THC and ethanol groups are seemed to be attributed mainly to the effect of the ethanol. Based on the present results we can assume that opioids affect SI more than cannabinoid.

Oxycodone Plus Ultra-Low-Dose Naltrexone Attenuates Neuropathic Pain and Associated μ-Opioid Receptor–Gs Coupling

PubMed Central

Largent-Milnes, Tally M.; Guo, Wenhong; Wang, Hoau-Yan; Burns, Lindsay H.; Vanderah, Todd W.

2017-01-01

Both peripheral nerve injury and chronic opioid treatment can result in hyperalgesia associated with enhanced excitatory neurotransmission at the level of the spinal cord. Chronic opioid administration leads to a shift in μ-opioid receptor (MOR)–G protein coupling from Gi/o to Gs that can be prevented by cotreatment with an ultra-low-dose opioid antagonist. In this study, using lumbar spinal cord tissue from rats with L5/L6 spinal nerve ligation (SNL), we demonstrated that SNL injury induces MOR linkage to Gs in the damaged (ipsilateral) spinal dorsal horn. This MOR-Gs coupling occurred without changing Gi/o coupling levels and without changing the expression of MOR or Gα proteins. Repeated administration of oxycodone alone or in combination with ultra-low-dose naltrexone (NTX) was assessed on the SNL-induced MOR-Gs coupling as well as on neuropathic pain behavior. Repeated spinal oxycodone exacerbated the SNL-induced MOR-Gs coupling, whereas ultra-low-dose NTX cotreatment slightly but significantly attenuated this Gs coupling. Either spinal or oral administration of oxycodone plus ultra-low-dose NTX markedly enhanced the reductions in allodynia and thermal hyperalgesia produced by oxycodone alone and minimized tolerance to these effects. The MOR-Gs coupling observed in response to SNL may in part contribute to the excitatory neurotransmission in spinal dorsal horn in neuropathic pain states. The antihyperalgesic and antiallodynic effects of oxycodone plus ultra-low-dose NTX (Oxytrex, Pain Therapeutics, Inc., San Mateo, CA) suggest a promising new treatment for neuropathic pain. PMID:18468954

Comparative study on the sedative effects of morphine, methadone, butorphanol or tramadol, in combination with acepromazine, in dogs.

PubMed

Monteiro, Eduardo Raposo; Junior, Adolfo Rodrigues; Assis, Hemir Martins Quirilos; Campagnol, Daniela; Quitzan, Juliany Gomes

2009-01-01

To compare the effects of morphine (MOR), methadone (MET), butorphanol (BUT) and tramadol (TRA), in combination with acepromazine, on sedation, cardiorespiratory variables, body temperature and incidence of emesis in dogs. Prospective randomized, blinded, experimental trial. Six adult mixed-breed male dogs weighing 12.0 +/- 4.3 kg. Dogs received intravenous administration (IV) of acepromazine (0.05 mg kg(-1)) and 15 minutes later, one of four opioids was randomly administered IV in a cross-over design, with at least 1-week intervals. Dogs then received MOR 0.5 mg kg(-1); MET 0.5 mg kg(-1); BUT 0.15 mg kg(-1); or TRA 2.0 mg kg(-1). Indirect systolic arterial pressure (SAP), heart rate (HR), respiratory rate (f(R)), rectal temperature, pedal withdrawal reflex and sedation were evaluated at regular intervals for 90 minutes. Acepromazine administration decreased SAP, HR and temperature and produced mild sedation. All opioids further decreased temperature and MOR, BUT and TRA were associated with further decreases in HR. Tramadol decreased SAP whereas BUT decreased f(R) compared with values before opioid administration. Retching was observed in five of six dogs and vomiting occurred in one dog in MOR, but not in any dog in the remaining treatments. Sedation scores were greater in MET followed by MOR and BUT. Tramadol was associated with minor changes in sedation produced by acepromazine alone. When used with acepromazine, MET appears to provide better sedation than MOR, BUT and TRA. If vomiting is to be avoided, MET, BUT and TRA may be better options than MOR.

Impact of Lipid Composition and Receptor Conformation on the Spatio-temporal Organization of μ-Opioid Receptors in a Multi-component Plasma Membrane Model

PubMed Central

Marino, Kristen A.; Prada-Gracia, Diego; Provasi, Davide; Filizola, Marta

2016-01-01

The lipid composition of cell membranes has increasingly been recognized as playing an important role in the function of various membrane proteins, including G Protein-Coupled Receptors (GPCRs). For instance, experimental and computational evidence has pointed to lipids influencing receptor oligomerization directly, by physically interacting with the receptor, and/or indirectly, by altering the bulk properties of the membrane. While the exact role of oligomerization in the function of class A GPCRs such as the μ-opioid receptor (MOR) is still unclear, insight as to how these receptors oligomerize and the relevance of the lipid environment to this phenomenon is crucial to our understanding of receptor function. To examine the effect of lipids and different MOR conformations on receptor oligomerization we carried out extensive coarse-grained molecular dynamics simulations of crystal structures of inactive and/or activated MOR embedded in an idealized mammalian plasma membrane composed of 63 lipid types asymmetrically distributed across the two leaflets. The results of these simulations point, for the first time, to specific direct and indirect effects of the lipids, as well as the receptor conformation, on the spatio-temporal organization of MOR in the plasma membrane. While sphingomyelin-rich, high-order lipid regions near certain transmembrane (TM) helices of MOR induce an effective long-range attractive force on individual protomers, both long-range lipid order and interface formation are found to be conformation dependent, with a larger number of different interfaces formed by inactive MOR compared to active MOR. PMID:27959924

State-dependent μ-opioid modulation of social motivation

PubMed Central

Loseth, Guro E.; Ellingsen, Dan-Mikael; Leknes, Siri

2014-01-01

Social mammals engage in affiliative interactions both when seeking relief from negative affect and when searching for pleasure and joy. These two motivational states are both modulated by μ-opioid transmission. The μ-opioid receptor (MOR) system in the brain mediates pain relief and reward behaviors, and is implicated in social reward processing and affiliative bonding across mammalian species. However, pharmacological manipulation of the μ-opioid system has yielded opposite effects on rodents and primates: in rodents, social motivation is generally increased by MOR agonists and reduced by antagonists, whereas the opposite pattern has been shown in primates. Here, we address this paradox by taking into account differences in motivational state. We first review evidence for μ-opioid mediation of reward processing, emotion regulation, and affiliation in humans, non-human primates, rodents and other species. Based on the consistent cross-species similarities in opioid functioning, we propose a unified, state-dependent model for μ-opioid modulation of affiliation across the mammalian species. Finally, we show that this state-dependent model is supported by evidence from both rodent and primate studies, when species and age differences in social separation response are taken into account. PMID:25565999

Adenosine A2a blockade prevents synergy between mu-opiate and cannabinoid CB1 receptors and eliminates heroin-seeking behavior in addicted rats.

PubMed

Yao, Lina; McFarland, Krista; Fan, Peidong; Jiang, Zhan; Ueda, Takashi; Diamond, Ivan

2006-05-16

Relapse is the most serious limitation of effective medical treatment of opiate addiction. Opiate-related behaviors appear to be modulated by cannabinoid CB1 receptors (CB1) through poorly understood cross-talk mechanisms. Opiate and CB1 receptors are coexpressed in the nucleus accumbens (NAc) and dorsal striatum. These regions also have the highest density of adenosine A2a receptors (A2a) in the brain. We have been investigating the postsynaptic signaling mechanisms of mu-opiate receptors (MORs) and CB1 receptors in primary NAc/striatal neurons. In this article, we present evidence that MOR and CB1 act synergistically on cAMP/PKA signaling in NAc/striatal neurons. In addition, we find that synergy requires adenosine and A2a. Importantly, an A2a antagonist administered either directly into the NAc or indirectly by i.p. injection eliminates heroin-induced reinstatement in rats trained to self-administer heroin, a model of human craving and relapse. These findings suggest that A2a antagonists might be effective therapeutic agents in the management of abstinent heroin addicts.

Adenosine A2a blockade prevents synergy between μ-opiate and cannabinoid CB1 receptors and eliminates heroin-seeking behavior in addicted rats

PubMed Central

Yao, Lina; McFarland, Krista; Fan, Peidong; Jiang, Zhan; Ueda, Takashi; Diamond, Ivan

2006-01-01

Relapse is the most serious limitation of effective medical treatment of opiate addiction. Opiate-related behaviors appear to be modulated by cannabinoid CB1 receptors (CB1) through poorly understood cross-talk mechanisms. Opiate and CB1 receptors are coexpressed in the nucleus accumbens (NAc) and dorsal striatum. These regions also have the highest density of adenosine A2a receptors (A2a) in the brain. We have been investigating the postsynaptic signaling mechanisms of μ-opiate receptors (MORs) and CB1 receptors in primary NAc/striatal neurons. In this article, we present evidence that MOR and CB1 act synergistically on cAMP/PKA signaling in NAc/striatal neurons. In addition, we find that synergy requires adenosine and A2a. Importantly, an A2a antagonist administered either directly into the NAc or indirectly by i.p. injection eliminates heroin-induced reinstatement in rats trained to self-administer heroin, a model of human craving and relapse. These findings suggest that A2a antagonists might be effective therapeutic agents in the management of abstinent heroin addicts. PMID:16684876

Phalanx. Volume 48, Number 1. March 2015

DTIC Science & Technology

2015-03-01

There are many reasons that people present their work at conferences in the year 2015, such as justifying their travel, advertising their work...Dr. Patrick Allen Lt Col Andrew Armacost Donald Bates Col (s) Suzanne Beers , FS Dr. Ted Bennett Jr. Joseph Bonnet Mary T. Bonnet Dr. W...received the MOR Journal Award. MORS Presidents 40th MORS President: Suzanne Beers , 2005–2006 Suzanne Beers served as Secretary in 2001–2002, Vice

Reliability Implications in Wood Systems of a Bivariate Gaussian-Weibull Distribution and the Associated Univariate Pseudo-truncated Weibull

Treesearch

Steve P. Verrill; James W. Evans; David E. Kretschmann; Cherilyn A. Hatfield

2014-01-01

Two important wood properties are the modulus of elasticity (MOE) and the modulus of rupture (MOR). In the past, the statistical distribution of the MOE has often been modeled as Gaussian, and that of the MOR as lognormal or as a two- or three-parameter Weibull distribution. It is well known that MOE and MOR are positively correlated. To model the simultaneous behavior...

Enhancing mud supply from the Lower Missouri River to the Mississippi River Delta USA: Dam bypassing and coastal restoration

NASA Astrophysics Data System (ADS)

Kemp, G. Paul; Day, John W.; Rogers, J. David; Giosan, Liviu; Peyronnin, Natalie

2016-12-01

Sand transport to the Mississippi River Delta (MRD) remains sufficient to build wetlands in shallow, sheltered coastal bays fed by engineered diversions on the Mississippi River (MR) and its Atchafalaya River (AR) distributary. But suspended mud (silt & clay) flux to the coast has dropped from a mean of 390 Mt y-1 in the early 1950s, to 100 Mt y-1 since 1970. This fine-grained sediment travels deeper into receiving estuarine basins and plays a critical role in sustaining existing marshes. Virtually all of the 300 Mt y-1 of missing mud once flowed from the Missouri River (MOR) Basin before nearly 100 dams were built as part of the Pick-Sloan water development project. About 100 Mt y-1 is now intercepted by main-stem Upper MOR dams closed in 1953. But the remaining 200 Mt y-1 is trapped by impoundments built on tributaries to the Lower MOR in the 1950s and 1960s. Sediment flux during the post-dam high MOR discharge years of 1973, 1993 and 2011 approached pre-dam levels when tributaries to the Lower MOR, including the Platte and Kansas Rivers, contributed to flood flows. West bank tributaries drain a vast, arid part of the Great Plains, while those entering from the east bank traverse the lowlands of the MOR floodplain. Both provinces are dominated by highly erodible loess soils. Staunching the continued decline in MR fine-grained sediment flux has assumed greater importance now that engineered diversions are being built to reconnect the Lowermost MR to the MRD. Tributary dam bypassing in the Lower MOR basin could increase mud supply to the MRD by 100-200 Mt y-1 within 1-2 decades. Such emergency measures to save the MRD are compatible with objectives of the Missouri River Restoration and Platte River Recovery Programs to restore MOR riparian habitat for endangered species. Rapid mobilization to shunt fine-grained sediments past as many as 50 Lower MOR tributary dams in several U.S. states will undoubtedly require as much regional coordination and funding in the 21st century as the monumental effort it took to build the dams in the last century.

Impact of morphine on the expression of insulin receptor and protein levels of insulin/IGFs in rat neural stem cells.

PubMed

Salarinasab, Sadegh; Nourazarian, AliReza; Nikanfar, Masoud; Abdyazdani, Nima; Kazemi, Masoumeh; Feizy, Navid; Rahbarghazi, Reza

2017-11-01

Alzheimer's disease is correlated with neuronal degeneration and loss of neuronal precursors in different parts of the brain. It has been found disturbance in the homeostasis neural stem cells (NSCs) can cause neurodegeneration. Morphine, an analgesic agent, can disrupt the dynamic and normal state of NSCs. However, more investigations are required to clearly address underlying mechanisms. The current experiment aimed to investigate the effects of morphine on the cell distribution of insulin factor and receptor and insulin-like growth factors (IGF1, IGF2) in NSCs. NSCs were isolated from rats and stemness feature confirmed by antibodies against nestin and Sox2. The cells were exposed to 100μM morphine, 50μM naloxone and combination of these two drugs for 72h. The neural cell growth, changes in levels of insulin and insulin-like growth factors secreted by NSCs as well as the insulin-receptor-gene expression were assessed by flow cytometry, ELlSA, and real-time PCR, respectively. Cell cycle assay revealed the exposure of cells to morphine for 72h increased cell apoptosis and decreased neural stem cell growth. The biosynthesis of insulin, insulin-like growth factors, and insulin receptor were reduced (p<0.05) after NSCs exposure to morphine at the concentration of 100μM for 24, 48 and 72h. Naloxone is a competitive antagonist which binds MOR where morphine (and endogenous opioids) bind, and reversed the detrimental effects of morphine. It can be concluded that morphine initiated irregularity in NSCs kinetics and activity by reducing the secretion of insulin and insulin-like growth factors and down-regulation of insulin receptor. Copyright © 2017 Elsevier B.V. All rights reserved.

Acute inflammation induces segmental, bilateral, supraspinally mediated opioid release in the rat spinal cord, as measured by μ-opioid receptor internalization

PubMed Central

Chen, Wenling; Marvizón, Juan Carlos G.

2009-01-01

The objective of this study was to measure opioid release in the spinal cord during acute and long-term inflammation using μ-opioid receptor (MOR) internalization. In particular, we determined whether opioid release occurs in the segments receiving the noxious signals or in the entire spinal cord, and whether it involves supraspinal signals. Internalization of neurokinin 1 receptors (NK1Rs) was measured to track the intensity of the noxious stimulus. Rats received peptidase inhibitors intrathecally to protect opioids from degradation. Acute inflammation of the hindpaw with formalin induced moderate MOR internalization in the L5 segment bilaterally, whereas NK1R internalization occurred only ipsilaterally. MOR internalization was restricted to the lumbar spinal cord, regardless of whether the peptidase inhibitors were injected in a lumbar or thoracic site. Formalin-induced MOR internalization was substantially reduced by isoflurane anesthesia. It was also markedly reduced by a lidocaine block of the cervical-thoracic spinal cord (which did not affect the evoked NK1R internalization) indicating that spinal opioid release is mediated supraspinally. In the absence of peptidase inhibitors, formalin and hindpaw clamp induced a small amount of MOR internalization, which was significantly higher than in controls. To study spinal opioid release during chronic inflammation, we injected Complete Freund's Adjuvant (CFA) in the hindpaw and peptidase inhibitors intrathecally. Two days later, no MOR or NK1R internalization was detected. Furthermore, CFA inflammation decreased MOR internalization induced by clamping the inflamed hindpaw. These results show that acute inflammation, but not chronic inflammation, induce segmental opioid release in the spinal cord that involves supraspinal signals. PMID:19298846

Peptidases prevent mu-opioid receptor internalization in dorsal horn neurons by endogenously released opioids.

PubMed

Song, Bingbing; Marvizón, Juan Carlos G

2003-03-01

To evaluate the effect of peptidases on mu-opioid receptor (MOR) activation by endogenous opioids, we measured MOR-1 internalization in rat spinal cord slices. A mixture of inhibitors of aminopeptidases (amastatin), dipeptidyl carboxypeptidase (captopril), and neutral endopeptidase (phosphoramidon) dramatically increased the potencies of Leu-enkephalin and dynorphin A to produce MOR-1 internalization, and also enhanced the effects of Met-enkephalin and alpha-neoendorphin, but not endomorphins or beta-endorphin. The omission of any one inhibitor abolished Leu-enkephalin-induced internalization, indicating that all three peptidases degraded enkephalins. Amastatin preserved dynorphin A-induced internalization, and phosphoramidon, but not captopril, increased this effect, indicating that the effect of dynorphin A was prevented by aminopeptidases and neutral endopeptidase. Veratridine (30 microm) or 50 mm KCl produced MOR-1 internalization in the presence of peptidase inhibitors, but little or no internalization in their absence. These effects were attributed to opioid release, because they were abolished by the selective MOR antagonist CTAP (D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH(2)) and were Ca(2+) dependent. The effect of veratridine was protected by phosphoramidon plus amastatin or captopril, but not by amastatin plus captopril or by phosphoramidon alone, indicating that released opioids are primarily cleaved by neutral endopeptidase, with a lesser involvement of aminopeptidases and dipeptidyl carboxypeptidase. Therefore, because the potencies of endomorphin-1 and endomorphin-2 to elicit internalization were unaffected by peptidase inhibitors, the opioids released by veratridine were not endomorphins. Confocal microscopy revealed that MOR-1-expressing neurons were in close proximity to terminals containing opioids with enkephalin-like sequences. These findings indicate that peptidases prevent the activation of extrasynaptic MOR-1 in dorsal horn neurons.

Peptidases prevent μ-opioid receptor internalization in dorsal horn neurons by endogenously released opioids

PubMed Central

Song, Bingbing; Marvizón, Juan Carlos G.

2008-01-01

To evaluate the effect of peptidases on μ-opioid receptor (MOR) activation by endogenous opioids, we measured MOR-1 internalization in rat spinal cord slices. A mixture of inhibitors of aminopeptidases (amastatin), dipeptidyl carboxypeptidase (captopril), and neutral endopeptidase (phosphoramidon) dramatically increased the potencies of Leu-enkephalin and dynorphin A to produce MOR-1 internalization, and also enhanced the effects of Met-enkephalin and α-neoendorphin, but not endomorphins or β-endorphin. Omission of any one inhibitor abolished Leu-enkephalin-induced internalization, indicating that all three peptidases degraded enkephalins. Amastatin preserved dynorphin A-induced internalization, and phosphoramidon, but not captopril, increased this effect, indicating that the effect of dynorphin A was prevented by aminopeptidases and neutral endopeptidase. Veratridine (30 μM) or 50 mM KCl produced MOR-1 internalization in the presence of peptidase inhibitors, but little or no internalization in their absence. These effects were attributed to opioid release, because they were abolished by the selective MOR antagonist CTAP and were Ca2+-dependent. The effect of veratridine was protected by phosphoramidon plus amastatin or captopril, but not by amastatin plus captopril or by phosphoramidon alone, indicating that released opioids are mainly cleaved by neutral endopeptidase, with a lesser involvement of aminopeptidases and dipeptidyl carboxypeptidase. Therefore, since the potencies of endomorphin-1 and -2 to elicit internalization were unaffected by peptidase inhibitors, the opioids released by veratridine were not endomorphins. Confocal microscopy revealed that MOR-1-expressing neurons were in close proximity to terminals containing opioids with enkephalin-like sequences. These findings indicate that peptidases prevent the activation of extrasynaptic MOR-1 in dorsal horn neurons. PMID:12629189

Acute inflammation induces segmental, bilateral, supraspinally mediated opioid release in the rat spinal cord, as measured by mu-opioid receptor internalization.

PubMed

Chen, W; Marvizón, J C G

2009-06-16

The objective of this study was to measure opioid release in the spinal cord during acute and long-term inflammation using mu-opioid receptor (MOR) internalization. In particular, we determined whether opioid release occurs in the segments receiving the noxious signals or in the entire spinal cord, and whether it involves supraspinal signals. Internalization of neurokinin 1 receptors (NK1Rs) was measured to track the intensity of the noxious stimulus. Rats received peptidase inhibitors intrathecally to protect opioids from degradation. Acute inflammation of the hind paw with formalin induced moderate MOR internalization in the L5 segment bilaterally, whereas NK1R internalization occurred only ipsilaterally. MOR internalization was restricted to the lumbar spinal cord, regardless of whether the peptidase inhibitors were injected in a lumbar or thoracic site. Formalin-induced MOR internalization was substantially reduced by isoflurane anesthesia. It was also markedly reduced by a lidocaine block of the cervical-thoracic spinal cord (which did not affect the evoked NK1R internalization) indicating that spinal opioid release is mediated supraspinally. In the absence of peptidase inhibitors, formalin and hind paw clamp induced a small amount of MOR internalization, which was significantly higher than in controls. To study spinal opioid release during chronic inflammation, we injected complete Freund's adjuvant (CFA) in the hind paw and peptidase inhibitors intrathecally. Two days later, no MOR or NK1R internalization was detected. Furthermore, CFA inflammation decreased MOR internalization induced by clamping the inflamed hind paw. These results show that acute inflammation, but not chronic inflammation, induces segmental opioid release in the spinal cord that involves supraspinal signals.

THE ROLE OF AMYGDALAR MU OPIOID RECEPTORS IN ANXIETY-RELATED RESPONSES IN TWO RAT MODELS

PubMed Central

Wilson, Marlene A.; Junor, Lorain

2009-01-01

Amygdala opioids such as enkephalin appear to play some role in the control of anxiety and the anxiolytic effects of benzodiazepines, although the opioid receptor subtypes mediating such effects are unclear. This study compared the influences of mu opioid receptor (MOR) activation in the central nucleus of the amygdala (CEA) on unconditioned fear or anxiety-like responses in two models, the elevated plus maze and the defensive burying test. The role of MOR in the anxiolytic actions of the benzodiazepine agonist diazepam was also examined using both models. Either the MOR agonist [D-Ala2, NMe-Phe4, Gly-ol5]-enkephalin (DAMGO) or the MOR antagonists Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2 (CTAP) or β-funaltrexamine (FNA) were bilaterally infused into the CEA of rats prior to testing. The results show that microinjection of DAMGO in the CEA decreased open arm time in the plus maze, while CTAP increased open arm behaviors. In contrast, DAMGO injections in the CEA reduced burying behaviors and increased rearing following exposure to a predator odor, suggesting a shift in the behavioral response in this context. Amygdala injections of the MOR agonist DAMGO or the MOR antagonist CTAP failed to change the anxiolytic effects of diazepam in either test. Our results demonstrate that MOR activation in the central amygdala exerts distinctive effects in two different models of unconditioned fear or anxiety-like responses, and suggest that opioids may exert context-specific regulation of amygdala output circuits and behavioral responses during exposure to potential threats (open arms of the maze) versus discrete threats (predator odor). PMID:18216773

Multiple Oral Re-reading treatment for alexia: The parts may be greater than the whole.

PubMed

Lacey, Elizabeth H; Lott, S N; Snider, S F; Sperling, A; Friedman, R B

2010-08-01

This study examines the reasons for the success of Multiple Oral Re-reading (MOR; Moyer, 1979), a non-invasive, easily administered alexia treatment that has been reported in the literature and is currently in clinical use. The treatment consists of reading text passages aloud multiple times a day. Findings that MOR improves reading speed on practised as well as novel text have been inconsistent, making MOR's role in the rehabilitation of alexia unclear. We hypothesised that MOR's treatment mechanism works through repetition of high frequency words (i.e., bottom-up processing). We designed and controlled our text passages to test the hypothesis that participants would not improve on all novel text but would improve on text that includes a critical mass of the words contained in the passages they were re-reading. We further hypothesised that the improvement would be at the level of their specific alexic deficit. We tested four participants with phonological alexia and two with pure alexia during 8 weeks of MOR treatment. Contrary to the conclusions of previous studies, our results indicate that improvements in top-down processing cannot explain generalisation in MOR and that much of the improvement in reading is through repetition of the practised words. However, most patients also showed improvement when specific phrases were re-used in novel passages, indicating that practice of difficult words in context may be crucial to reading improvement.

Pharmacological evidence for the mediation of the panicolytic effect of fluoxetine by dorsal periaqueductal gray matter μ-opioid receptors.

PubMed

Roncon, Camila Marroni; Almada, Rafael Carvalho; Maraschin, Jhonatan Christian; Audi, Elisabeth Aparecida; Zangrossi, Hélio; Graeff, Frederico Guilherme; Coimbra, Norberto Cysne

2015-12-01

Previously reported results have shown that the inhibitory effect of fluoxetine on escape behavior, interpreted as a panicolytic-like effect, is blocked by pretreatment with either the opioid receptor antagonist naloxone or the 5-HT1A receptor (5-HT1A-R) antagonist WAY100635 via injection into the dorsal periaqueductal gray matter (dPAG). Additionally, reported evidence indicates that the μ-opioid receptor (MOR) interacts with the 5-HT1A-R in the dPAG. In the present work, pretreatment of the dPAG with the selective MOR blocker CTOP antagonized the anti-escape effect of chronic fluoxetine (10 mg/kg, i.p., daily, for 21 days), as measured in the elevated T-maze (ETM) test, indicating mediation of this effect by the MOR. In addition, the combined administration of sub-effective doses of the selective MOR agonist DAMGO (intra-dPAG) and sub-effective doses of chronic as well as subchronic (7 days) fluoxetine increased avoidance and escape latencies, suggesting that the activation of MORs may facilitate and accelerate the effects of fluoxetine. The current observation that MORs located in the dPAG mediate the anti-escape effect of fluoxetine may open new perspectives for the development of more efficient and fast-acting panic-alleviating drugs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Nucleus accumbens mu opioid receptors regulate context-specific social preferences in the juvenile rat.

PubMed

Smith, Caroline J W; Wilkins, Kevin B; Li, Sara; Tulimieri, Maxwell T; Veenema, Alexa H

2018-03-01

The μ opioid receptor (MOR) in the nucleus accumbens (NAc) is involved in assigning pleasurable, or hedonic value to rewarding stimuli. Importantly, the hedonic value of a given rewarding stimulus likely depends on an individual's current motivational state. Here, we examined the involvement of MORs in the motivation to interact with a novel or a familiar (cage mate) conspecific in juvenile rats. First, we demonstrated that the selective MOR antagonist CTAP administered into the NAc reduces social novelty preference of juvenile males, by decreasing the interaction time with the novel conspecific and increasing the interaction time with the cage mate. Next, we found that a 3-h separation period from the cage mate reduces social novelty preference in both juvenile males and females, which was primarily driven by an increase in interaction time with the cage mate. Last, we showed that MOR agonism (intracerebroventricularly or in the NAc) restored social novelty preference in juvenile males that did not show social novelty preference following social isolation. Taken together, these data support a model in which endogenous MOR activation in the NAc facilitates the relative hedonic value of novel over familiar social stimuli. Our results may implicate the MOR in neuropsychiatric disorders characterized by altered social motivation, such as major depression and autism spectrum disorder. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mu-Opioid Receptors in Ganglia, But Not in Muscle, Mediate Peripheral Analgesia in Rat Muscle Pain.

PubMed

Bagues, Ana; Martín, María Isabel; Higuera-Matas, Alejandro; Esteban-Hernández, Jesús; Ambrosio, Emilio; Sánchez-Robles, Eva María

2018-04-01

Previous studies have demonstrated the participation of peripheral μ-opioid receptors (MOR) in the antinociceptive effect of systemically administered morphine and loperamide in an orofacial muscle pain model, induced by hypertonic saline, but not in a spinally innervated one, in rats. In this study, we determine whether this peripheral antinociceptive effect is due to the activation of MOR localized in the muscle, ganglia, or both. To determine the local antinociceptive effect of morphine and loperamide, 2 models of acute muscle pain (trigeminal and spinal) were used. Also, to study the MOR expression, protein quantification was performed in the trigeminal and spinal ganglia, and in the muscles. The behavioral results show that the intramuscular injection of morphine and loperamide did not exert an antinociceptive effect in either muscle (morphine: P = .63, loperamide: P = .9). On the other hand, MOR expression was found in the ganglia but not in the muscles. This expression was on average 44% higher (95% confidence interval, 33.3-53.9) in the trigeminal ganglia than in the spinal one. The peripheral antinociceptive effect of systemically administered opioids may be due to the activation of MOR in ganglia. The greater expression of MOR in trigeminal ganglia could explain the higher antinociceptive effect of opioids in orofacial muscle pain than in spinal muscle pain. Therefore, peripheral opioids could represent a promising approach for the treatment of orofacial pain.

An Outbreak of Vibrio cholerae O1 infections on Ebeye Island, Republic of the Marshall Islands, associated with use of an adequately chlorinated water source.

PubMed

Beatty, Mark E; Jack, Tom; Sivapalasingam, Sumathi; Yao, Sandra S; Paul, Irene; Bibb, Bill; Greene, Kathy D; Kubota, Kristy; Mintz, Eric D; Brooks, John T

2004-01-01

In December 2000, physicians in the Republic of the Marshall Islands reported the first known outbreak of Vibrio cholerae O1 infection (biotype El Tor, serotype Ogawa) from this country. In a matched case-control study on Ebeye Island, patients with cholera (n=53) had greater odds than persons without cholera (n=104) to have drunk adequately chlorinated water collected from a US military installation on neighboring Kwajalein Island and transported back to Ebeye (matched odds ratio [MOR], 8.0; P=.01). Transporting or storing drinking water in a water cooler with a spout and a tight-fitting lid was associated with reduced odds of illness (MOR, 0.24; P<.01), as was drinking bottled water (MOR, 0.08; P<.01), boiled water (MOR, 0.47; P=.02), or water flavored with powdered drink mixes (MOR, 0.18; P<.01). No cases of cholera were reported among Kwajalein residents. This outbreak highlights the critical importance of handling and storing drinking water safely, especially during outbreaks of gastrointestinal illness.

(-)-Norpseudoephedrine, a metabolite of cathinone with amphetamine-like stimulus properties, enhances the analgesic and rate decreasing effects of morphine, but inhibits its discriminative properties.

PubMed

Nencini, P; Fraioli, S; Pascucci, T; Nucerito, C V

1998-04-01

Like psychomotor stimulants, a weak amphetamine-like agent, such as phenylpropanolamine, enhances the analgesic effects of morphine (MOR). Thus, it is possible that full psychomotor stimulant potency is not required to increase the analgesic action of opiates. The validity of this assumption is here tested by studying the ability of (-)-norpseudoephedrine (NPE), an enantiomer of phenylpropanolamine and a metabolite of cathinone, to influence both the analgesic effects of MOR and its discriminative stimulus properties. In mice NPE (5.6-10.0-17.0 mg/kg i.p.) did not prolong the latency to lick or to remove paws from a plate warmed at 54 degrees C. However, it significantly potentiated the analgesic effect of 3.2 mg/kg of MOR. These results were replicated in rats by use of the formalin test, which measures the numbers of hind paw flinches produced by injecting 50 microl of formalin into the dorsal surface of the paw. The higher dose of NPE (17 mg/kg) increased the effect of sub-analgesic doses of MOR (0.56 and 1.0 mg/kg). In rats trained to discriminate between 0.5 mg/kg of amphetamine and solvent in a two-lever operant behavior reinforced by water access. NPE induced a dose-dependent increment of drug lever responding from 0% at 1.0 mg/kg to 100% at 32.0 mg/kg. In contrast, NPE did not generalize for the MOR cue up to the dose of 56.0 mg/kg, which produced a substantial reduction of the response rate. However, when given in combination, NPE attenuated the discriminative effects of MOR and potentiated its inhibitory action on the response rate. These results exclude a direct action of NPE on the mu opiate system. In conclusion, NPE preserves amphetamine-like properties and these properties are probably responsible for the interaction of the drug with the analgesic and discriminative effects of MOR. Therefore, this study contradicts the assumption that the analgesic effects of MOR can be enhanced by a sympathomimetic drug that lacks significant psychostimulant actions.

Mor-Bell Logger: Skidding Case Study

Treesearch

Bryce J. Stokes; Jerry L. Koger; Frank J. Pickle

1983-01-01

A production equation was developed for the Mor-Bell logger for skidding while thinning a loblolly pine plantation. Production and costs for skidding and iron gate delimbing were determined for a range of operating conditions.

Risk Factors for Measles Virus Infection Among Adults During a Large Outbreak in Postelimination Era in Mongolia, 2015.

PubMed

Hagan, José E; Takashima, Yoshihiro; Sarankhuu, Amarzaya; Dashpagma, Otgonbayar; Jantsansengee, Baigalmaa; Pastore, Roberta; Nyamaa, Gunregjav; Yadamsuren, Buyanjargal; Mulders, Mick N; Wannemuehler, Kathleen A; Anderson, Raydel; Bankamp, Bettina; Rota, Paul; Goodson, James L

2017-12-05

In 2015, a large nationwide measles outbreak occurred in Mongolia, with very high incidence in the capital city of Ulaanbaatar and among young adults. We conducted an outbreak investigation including a matched case-control study of risk factors for laboratory-confirmed measles among young adults living in Ulaanbaatar. Young adults with laboratory-confirmed measles, living in the capital city of Ulaanbaatar, were matched with 2-3 neighborhood controls. Conditional logistic regression was used to estimate adjusted matched odds ratios (aMORs) for risk factors, with 95% confidence intervals. During March 1-September 30, 2015, 20 077 suspected measles cases were reported; 14 010 cases were confirmed. Independent risk factors for measles included being unvaccinated (adjusted matched odds ratio [aMOR] 2.0, P < .01), being a high school graduate without college education (aMOR 2.6, P < .01), remaining in Ulaanbaatar during the outbreak (aMOR 2.5, P < .01), exposure to an inpatient healthcare facility (aMOR 4.5 P < .01), and being born outside of Ulaanbaatar (aMOR 1.8, P = .02). This large, nationwide outbreak shortly after verification of elimination had high incidence among young adults, particularly those born outside the national capital. In addition, findings indicated that nosocomial transmission within health facilities helped amplify the outbreak. Published by Oxford University Press for the Infectious Diseases Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Functional characterization of a mouse testicular olfactory receptor and its role in chemosensing and in regulation of sperm motility.

PubMed

Fukuda, Nanaho; Yomogida, Kentaro; Okabe, Masaru; Touhara, Kazushige

2004-11-15

Although a subset of the olfactory receptor (OR) gene family is expressed in testis, neither their developmental profile nor their physiological functions have been fully characterized. Here, we show that MOR23 (a mouse OR expressed in the olfactory epithelium and testis) functions as a chemosensing receptor in mouse germ cells. In situ hybridization showed that MOR23 was expressed in round spermatids during stages VI-VIII of spermatogenesis. Lyral, a cognate ligand of MOR23, caused an increase in intracellular Ca2+ in a fraction of spermatogenic cells and spermatozoa. We also generated transgenic mice that express high levels of MOR23 in the testis and examined the response of their germ cells to lyral. The results provided evidence that lyral-induced Ca2+ increases were indeed mediated by MOR23. In a sperm accumulation assay, spermatozoa migrated towards an increasing gradient of lyral. Tracking and sperm flagellar analyses suggest that Ca2+ increases caused by MOR23 activation lead to modulation of flagellar configuration, resulting in chemotaxis. By contrast, a gradient of a cAMP analog or K8.6 solution, which elicit Ca2+ influx in spermatozoa, did not cause sperm accumulation, indicating that chemosensing and regulation of sperm motility was due to an OR-mediated local Ca2+ increase. The present studies indicate that mouse testicular ORs might play a role in chemoreception during sperm-egg communication and thereby regulate fertilization.

Region specific up-regulation of oxytocin receptors in the opioid oprm1 (-/-) mouse model of autism.

PubMed

Gigliucci, Valentina; Leonzino, Marianna; Busnelli, Marta; Luchetti, Alessandra; Palladino, Viola Stella; D'Amato, Francesca R; Chini, Bice

2014-01-01

Autism spectrum disorders (ASDs) are characterized by impaired communication, social impairments, and restricted and repetitive behaviors and interests. Recently, altered motivation and reward processes have been suggested to participate in the physiopathology of ASDs, and μ-opioid receptors (MORs) have been investigated in relation to social reward due to their involvement in the neural circuitry of reward. Mice lacking a functional MOR gene (Oprm1 (-/-) mice) display abnormal social behavior and major autistic-like core symptoms, making them an animal model of autism. The oxytocin (OXT) system is a key regulator of social behavior and co-operates with the opioidergic system in the modulation of social behavior. To better understand the opioid-OXT interplay in the central nervous system, we first determined the expression of the oxytocin receptor (OXTR) in the brain of WT C57BL6/J mice by quantitative autoradiography; we then evaluated OXTR regional alterations in Oprm1 (-/-) mice. Moreover, we tested these mice in a paradigm of social behavior, the male-female social interaction test, and analyzed the effects of acute intranasal OXT treatment on their performance. In autoradiography, Oprm1 (-/-) mice selectively displayed increased OXTR expression in the Medial Anterior Olfactory Nucleus, the Central and Medial Amygdaloid nuclei, and the Nucleus Accumbens. Our behavioral results confirmed that Oprm1 (-/-) male mice displayed social impairments, as indicated by reduced ultrasonic calls, and that these were rescued by a single intranasal administration of OXT. Taken together, our results provide evidence of an interaction between OXT and opioids in socially relevant brain areas and in the modulation of social behavior. Moreover, they suggest that the oxytocinergic system may act as a compensative mechanism to bypass and/or restore alterations in circuits linked to impaired social behavior.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chibani, Siwar, E-mail: siwar.chibani@univ-lorraine.fr; Chebbi, Mouheb; Badawi, Michael, E-mail: michael.badawi@univ-lorraine.fr

The potential use of some cation-exchanged mordenite (H{sup +}, Na{sup +}, Cu{sup +}, and Ag{sup +}) as a selective adsorbent for volatile iodine species (ICH{sub 3} and I{sub 2}), which can be released during a nuclear accident together with a steam carrier gas, is investigated using density functional theory. It is found that in the case of Cu-MOR and Ag-MOR, the absolute values of interaction energies of ICH{sub 3} and I{sub 2} are higher than that of water which indicates that these forms of zeolite could be suitable for selective adsorption of iodine species. In contrast, the H-MOR and Na-MORmore » are found to be unsuitable for this purpose. A systematic investigation of all adsorption sites allowed us to analyze the structural effects affecting the adsorption behavior. For the Ag-MOR and Cu-MOR zeolites, the iodine compounds are adsorbed preferentially in the large channel of mordenite (main channel) while water prefers the small channel or the side pocket where it forms stronger hydrogen bonds. The factors governing the interaction energies between the cationic sites and the different molecules are analyzed and the important role of van der Waals interactions in these systems is highlighted.« less

Distribution of Non-AT1, Non-AT2 Binding of 125I-Sarcosine1, Isoleucine8 Angiotensin II in Neurolysin Knockout Mouse Brains

PubMed Central

Speth, Robert C.; Carrera, Eduardo J.; Bretón, Catalina; Linares, Andrea; Gonzalez-Reiley, Luz; Swindle, Jamala D.; Santos, Kira L.; Schadock, Ines; Bader, Michael; Karamyan, Vardan T.

2014-01-01

The recent identification of a novel binding site for angiotensin (Ang) II as the peptidase neurolysin (E.C. 3.4.24.16) has implications for the renin-angiotensin system (RAS). This report describes the distribution of specific binding of 125I-Sarcosine1, Isoleucine8 Ang II (125I-SI Ang II) in neurolysin knockout mouse brains compared to wild-type mouse brains using quantitative receptor autoradiography. In the presence of p-chloromercuribenzoic acid (PCMB), which unmasks the novel binding site, widespread distribution of specific (3 µM Ang II displaceable) 125I-SI Ang II binding in 32 mouse brain regions was observed. Highest levels of binding >700 fmol/g initial wet weight were seen in hypothalamic, thalamic and septal regions, while the lowest level of binding <300 fmol/g initial wet weight was in the mediolateral medulla. 125I-SI Ang II binding was substantially higher by an average of 85% in wild-type mouse brains compared to neurolysin knockout brains, suggesting the presence of an additional non-AT1, non-AT2, non-neurolysin Ang II binding site in the mouse brain. Binding of 125I-SI Ang II to neurolysin in the presence of PCMB was highest in hypothalamic and ventral cortical brain regions, but broadly distributed across all regions surveyed. Non-AT1, non-AT2, non-neurolysin binding was also highest in the hypothalamus but had a different distribution than neurolysin. There was a significant reduction in AT2 receptor binding in the neurolysin knockout brain and a trend towards decreased AT1 receptor binding. In the neurolysin knockout brains, the size of the lateral ventricles was increased by 56% and the size of the mid forebrain (−2.72 to +1.48 relative to Bregma) was increased by 12%. These results confirm the identity of neurolysin as a novel Ang II binding site, suggesting that neurolysin may play a significant role in opposing the pathophysiological actions of the brain RAS and influencing brain morphology. PMID:25147932

Validation of the mothers object relations scales in 2–4 year old children and comparison with the child–parent relationship scale

PubMed Central

2013-01-01

Background The quality of the parent–child relationship has an important effect on a wide range of child outcomes. The evaluation of interventions to promote healthy parenting and family relationships is dependent on outcome measures which can quantify the quality of parent–child relationships. Between the Mothers’ Object Relations – Short Form (MORS-SF) scale for babies and the Child–parent Relationship Scale (C-PRS) there is an age gap where no validated scales are available. We report the development and testing of an adaptation of the MORS-SF; the MORS (Child) scale and its use in children from the age of 2 years to 4 years. This scale aims to capture the nature of the parent–child relationship in a form which is short enough to be used in population surveys and intervention evaluations. Methods Construct and criterion validity, item salience and internal consistency were assessed in a sample of 166 parents of children aged 2–4 years old and compared with that of the C-PRS. The performance of the MORS (Child) as part of a composite measure with the HOME inventory was compared with that of the C-PRS using data collected in a randomised controlled trial and the national evaluation of Sure Start. Results MORS (Child) performed well in children aged 2–4 with high construct and criterion validity, item salience and internal consistency. One item in the C-PRS failed to load on either subscale and parents found this scale slightly more difficult to complete than the MORS (Child). The two measures performed very similarly in a factor analysis with the HOME inventory producing almost identical loadings. Conclusions Adapting the MORS-SF for children aged 2–4 years old produces a scale to assess parent–child relationships that is easy to use and outperforms the more commonly used C-PRS in several respects. PMID:23518176

Influence of candidate polymorphisms on the dipeptidyl peptidase IV and μ-opioid receptor genes expression in aspect of the β-casomorphin-7 modulation functions in autism.

PubMed

Cieślińska, Anna; Sienkiewicz-Szłapka, Edyta; Wasilewska, Jolanta; Fiedorowicz, Ewa; Chwała, Barbara; Moszyńska-Dumara, Małgorzata; Cieśliński, Tomasz; Bukało, Marta; Kostyra, Elżbieta

2015-03-01

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder with population prevalence of approximately 60-70 per 10,000. Data shows that both opioid system function enhancement and opiate administration can result in autistic-like symptoms. Cow milk opioid peptides, including β-casomorphin-7 (BCM7, Tyr-Pro-Phe-Pro-Gly-Pro-Ile), affect the μ-opioid receptor (MOR) and are subjected to degradation resulting from the proline dipeptidyl peptidase IV (DPPIV, EC 3.4.14.5) enzyme activity. The presence of MOR and DPPIV activity are crucial factors determining biological activity of BCM7 in the human body. Our study examined the effect of β-casomorphin-7 on the MOR and DPPIV genes expression according to specific point mutations in these genes. In addition, we investigated frequency of A118G SNP in the MOR gene and rs7608798 of the DPPIV (A/G) gene in healthy and autistic children. Our research indicated correlation in DPPIV gene expression under the influence of BCM7 and hydrolyzed milk between healthy and ASD-affected children with genotype GG (P<0.0001). We also observed increased MOR gene expression in healthy children with genotype AG at polymorphic site A118G under influence of BCM7 and hydrolyzed milk. The G allele frequency was 0.09 in MOR gene and 0.68 in the DPPIV gene. But our results suggest no association between presence of the alleles G and A at position rs7608798 in DPPIV gene nor alleles A and G at position A118G of the MOR and increased incidence of ASD. Our studies emphasize the compulsion for genetic analysis in correlation with genetic factors affecting development and enhancement of autism symptoms. Copyright © 2015 Elsevier Inc. All rights reserved.

Silver(I) Binding Properties of Organic Soil Materials Are Different from Those of Isolated Humic Substances.

PubMed

B Kleja, Dan; Nakata, Satomi; Persson, Ingmar; Gustafsson, Jon Petter

2016-07-19

The solubility of silver(I) in many soils is controlled by complexation reactions with organic matter. In this work we have compared the ability of isolated humic and fulvic acids to bind silver(I) with that of mor and peat materials. One new data set for Suwannee River Fulvic Acid was produced, which was consistent with published data sets for isolated fulvic and humic acids. The ability of soil materials to bind silver(I) was studied as a function of pH in the range 2.5-5.0, at a wide range of silver(I)-to-soil ratios (10(-4.2) - 10(-1.9) mol kg(-1)). By calibrating the Stockholm Humic Model on the humic and fulvic acids data sets, we showed that binding of silver(I) to both types of soil materials was much stronger (up to 2 orders of magnitude) than predicted from the silver(I) binding properties of the isolated humic materials. Thus, the approach taken for many other metals, that is, to model solubility in soils by using metal and proton binding parameters derived from isolated humic and fulvic acids, cannot be used for silver(I). One possible explanation for the discrepancy could be that silver(I) predominately interacted with various biomolecules in the soil samples, instead of humic- and fulvic-acid type materials.

Optimum concentration gradient of the electrocatalyst, Nafion® and poly(tetrafluoroethylene) in a membrane-electrode-assembly for enhanced performance of direct methanol fuel cells.

PubMed

Liu, Jing Hua; Jeon, Min Ku; Lee, Ki Rak; Woo, Seong Ihl

2010-12-14

A combinatorial library of membrane-electrode-assemblies (MEAs) which consisted of 27 different compositions was fabricated to optimize the multilayer structure of direct methanol fuel cells. Each spot consisted of three layers of ink and a gradient was generated by employing different concentrations of the three components (Pt catalyst, Nafion® and polytetrafluoroethylene (PTFE)) of each layer. For quick evaluation of the library, a high-throughput optical screening technique was employed for methanol electro-oxidation reaction (MOR) activity. The screening results revealed that gradient layers could lead to higher MOR activity than uniform layers. It was found that the MOR activity was higher when the concentrations of Pt catalyst and Nafion ionomer decreased downward from the top layer to the bottom layer. On the other hand, higher MOR activity was observed when PTFE concentration increased downward from the top to the bottom layer.

Molecular details of dimerization kinetics reveal negligible populations of transient µ-opioid receptor homodimers at physiological concentrations.

PubMed

Meral, Derya; Provasi, Davide; Prada-Gracia, Diego; Möller, Jan; Marino, Kristen; Lohse, Martin J; Filizola, Marta

2018-05-16

Various experimental and computational techniques have been employed over the past decade to provide structural and thermodynamic insights into G Protein-Coupled Receptor (GPCR) dimerization. Here, we use multiple microsecond-long, coarse-grained, biased and unbiased molecular dynamics simulations (a total of ~4 milliseconds) combined with multi-ensemble Markov state models to elucidate the kinetics of homodimerization of a prototypic GPCR, the µ-opioid receptor (MOR), embedded in a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)/cholesterol lipid bilayer. Analysis of these computations identifies kinetically distinct macrostates comprising several different short-lived dimeric configurations of either inactive or activated MOR. Calculated kinetic rates and fractions of dimers at different MOR concentrations suggest a negligible population of MOR homodimers at physiological concentrations, which is supported by acceptor photobleaching fluorescence resonance energy transfer (FRET) experiments. This study provides a rigorous, quantitative explanation for some conflicting experimental data on GPCR oligomerization.

Volatile abundances and oxygen isotopes in basaltic to dacitic lavas on mid-ocean ridges: The role of assimilation at spreading centers

USGS Publications Warehouse

Wanless, V.D.; Perfit, M.R.; Ridley, W.I.; Wallace, P.J.; Grimes, Craig B.; Klein, E.M.

2011-01-01

Most geochemical variability in MOR basalts is consistent with low- to moderate-pressure fractional crystallization of various mantle-derived parental melts. However, our geochemical data from MOR high-silica glasses, including new volatile and oxygen isotope data, suggest that assimilation of altered crustal material plays a significant role in the petrogenesis of dacites and may be important in the formation of basaltic lavas at MOR in general. MOR high-silica andesites and dacites from diverse areas show remarkably similar major element trends, incompatible trace element enrichments, and isotopic signatures suggesting similar processes control their chemistry. In particular, very high Cl and elevated H2O concentrations and relatively light oxygen isotope ratios (~ 5.8‰ vs. expected values of ~ 6.8‰) in fresh dacite glasses can be explained by contamination of magmas from a component of ocean crust altered by hydrothermal fluids. Crystallization of silicate phases and Fe-oxides causes an increase in δ18O in residual magma, but assimilation of material initially altered at high temperatures results in lower δ18O values. The observed geochemical signatures can be explained by extreme fractional crystallization of a MOR basalt parent combined with partial melting and assimilation (AFC) of amphibole-bearing altered oceanic crust. The MOR dacitic lavas do not appear to be simply the extrusive equivalent of oceanic plagiogranites. The combination of partial melting and assimilation produces a distinct geochemical signature that includes higher incompatible trace element abundances and distinct trace element ratios relative to those observed in plagiogranites.

Framework of calculating the measures of resilience (MOR) for intermodal transportation systems.

DOT National Transportation Integrated Search

2010-07-01

Recent catastrophic events, such as Hurricane Katrina, have accentuated the value of measures of resilience (MOR) for the response and : restoration of transportation systems following a disaster and have therefore become a topic of great concern for...

Human factors analysis of workstation design: Earth Radiation Budget Satellite Mission Operations Room

NASA Technical Reports Server (NTRS)

Stewart, L. J.; Murphy, E. D.; Mitchell, C. M.

1982-01-01

A human factors analysis addressed three related yet distinct issues within the area of workstation design for the Earth Radiation Budget Satellite (ERBS) mission operation room (MOR). The first issue, physical layout of the MOR, received the most intensive effort. It involved the positioning of clusters of equipment within the physical dimensions of the ERBS MOR. The second issue for analysis was comprised of several environmental concerns, such as lighting, furniture, and heating and ventilation systems. The third issue was component arrangement, involving the physical arrangement of individual components within clusters of consoles, e.g., a communications panel.

Inhibition of Histone Deacetylases Attenuates Morphine Tolerance and Restores MOR Expression in the DRG of BCP Rats.

PubMed

He, Xiao-Tao; Zhou, Kai-Xiang; Zhao, Wen-Jun; Zhang, Chen; Deng, Jian-Ping; Chen, Fa-Ming; Gu, Ze-Xu; Li, Yun-Qing; Dong, Yu-Lin

2018-01-01

The easily developed morphine tolerance in bone cancer pain (BCP) significantly hindered its clinical use. Increasing evidence suggests that histone deacetylases (HDACs) regulate analgesic tolerance subsequent to continuous opioid exposure. However, whether HDACs contribute to morphine tolerance in the pathogenesis of BCP is still unknown. In the current study, we explored the possible engagement of HDACs in morphine tolerance during the pathogenesis of BCP. After intra-tibia tumor cell inoculation (TCI), we found that the increased expression of HDACs was negatively correlated with the decreased expression of MOR in the DRG following TCI. The paw withdrawal threshold (PWT) and percentage maximum possible effects (MPEs) decreased rapidly in TCI rats when morphine was used alone. In contrast, the concomitant use of SAHA and morphine significantly elevated the PWT and MPEs of TCI rats compared to morphine alone. Additionally, we found that SAHA administration significantly elevated MOR expression in the DRG of TCI rats with or without morphine treatment. Moreover, the TCI-induced increase in the co-expression of MOR and HDAC1 in neurons was significantly decreased after SAHA administration. These results suggest that HDACs are correlated with the downregulation of MOR in the DRG during the pathogenesis of BCP. Inhibition of HDACs using SAHA can be used to attenuate morphine tolerance in BCP.

Supraspinal inhibitory effects of chimeric peptide MCRT on gastrointestinal motility in mice.

PubMed

He, Chunbo; Li, Hailan; Zhang, Jing; Kang, Yanping; Jia, Fang; Dong, Shouliang; Zhou, Lanxia

2017-09-01

Chimeric peptide MCRT, based on morphiceptin and PFRTic-NH 2 , was a bifunctional ligand of μ- and δ-opioid receptors (MOR-DOR) and produced potent analgesia in tail-withdrawal test. The study focused on the supraspinal effects of morphiceptin, PFRTic-NH 2 and MCRT on gastrointestinal motility. Moreover, opioid receptor antagonists, naloxone (non-selective), cyprodime (MOR selective) and naltrindole (DOR selective) were utilized to explore the mechanisms. Intracerebroventricular administration was achieved via the implanted cannula. Gastric emptying and intestinal transit were measured to evaluate gastrointestinal motility. (1) At supraspinal level, morphiceptin, PFRTic-NH 2 and MCRT significantly decreased gastric emptying and intestinal transit; (2) MCRT at 1 nmol/mouse, far higher than its analgesic dose (ED 50  = 29.8 pmol/mouse), failed to regulate the gastrointestinal motility; (3) MCRT-induced gastrointestinal dysfunction could be completely blocked by naloxone and naltrindole, but not affected by cyprodime. (1) Morphiceptin and PFRTic-NH 2 played important roles in the regulation of gastrointestinal motility; (2) MCRT possessed higher bioactivity of pain relief than gastrointestinal regulation, suggesting its promising analgesic property; (3) MCRT-induced motility disorders were sensitive to DOR but not to MOR blockade, indicating the pain-relieving specificity of speculated MOR subtype or splice variant or MOR-DOR heterodimer. © 2017 Royal Pharmaceutical Society.

Tyrosinase is the modifier of retinoschisis in mice.

PubMed

Johnson, Britt A; Cole, Brian S; Geisert, Eldon E; Ikeda, Sakae; Ikeda, Akihiro

2010-12-01

X-linked retinoschisis (XLRS) is a form of macular degeneration with a juvenile onset. This disease is caused by mutations in the retinoschisin (RS1) gene. The major clinical pathologies of this disease include splitting of the retina (schisis) and a loss in synaptic transmission. Human XLRS patients display a broad range in phenotypic severity, even among family members with the same mutation. This variation suggests the existence of genetic modifiers that may contribute to disease severity. Previously, we reported the identification of a modifier locus, named Mor1, which affects severity of schisis in a mouse model of XLRS (the Rs1tmgc1 mouse). Homozygosity for the protective AKR allele of Mor1 restores cell adhesion in Rs1tmgc1 mice. Here, we report our study to identify the Mor1 gene. Through collecting recombinant mice followed by progeny testing, we have localized Mor1 to a 4.4-Mb region on chromosome 7. In this genetic region, the AKR strain is known to carry a mutation in the tyrosinase (Tyr) gene. We observed that the schisis phenotype caused by the Rs1 mutation is rescued by a Tyr mutation in the C57BL/6J genetic background, strongly suggesting that Tyr is the Mor1 gene.

The framework for calculating the measure of resilience for intermodal transportation systems.

DOT National Transportation Integrated Search

2009-08-14

A literature review indicates no conforming approval on the measure of resilience (MOR) for intermodal : transportation systems (1, 2, 3). The objective of this report is to develop a framework for calculating the : measure of resilience (MOR) to dis...

Rapid, transient, and dose-dependent expression of Hsp70 messenger RNA in the rat brain after morphine treatment

PubMed Central

Ammon-Treiber, Susanne; Grecksch, Gisela; Stumm, Ralf; Riechert, Uta; Tischmeyer, Helga; Reichenauer, Anke; Höllt, Volker

2004-01-01

Induction of Hsp70 in the brain has been reported after intake of drugs of abuse like amphetamine and lysergic acid diethylamide. In this investigation, gene expression of Hsp70 and other heat shock genes in the rat brain was studied in response to morphine. Twenty milligrams per kilogram morphine intraperitoneally resulted in a marked induction of Hsp70 messenger RNA (mRNA) expression in the frontal cortex with a maximum increase of 13.2-fold after 2 hours. A moderate increase of Hsp27 mRNA expression (6.7-fold) could be observed after 4 hours, whereas mRNA expression of Hsp90 and of the constitutive Hsc70 did not exceed a mean factor of 1.8-fold during the 24 hours interval. The increase in Hsp70 mRNA was dose dependent, showing a significant elevation after doses ranging from 10 to 50 mg/kg morphine. In situ hybridization revealed enhanced Hsp70 mRNA expression mainly in cortical areas, in the hippocampus, in the paraventricular and supraoptic nuclei of the hypothalamus, in the locus coeruleus, as well in the pineal body. The double in situ hybridization technique revealed increased Hsp70 mRNA expression mainly in VGLUT1-positive neurons and to a lesser extent in olig1-positive oligodendroglia. Immunohistochemistry revealed a marked increase of Hsp70 protein in neuronal cells and blood vessels after 12 hours. In contrast to animal experiments, morphine did not increase Hsp70 mRNA expression in vitro in μ-opioid receptor (MOR1)–expressing human embryonic kidney 293 cells, suggesting no direct MOR1-mediated cellular effect. To exclude a body temperature–related morphine effect on Hsp70 mRNA expression, the temperature was recorded. Five to 20 mg/kg resulted in hyperthermia (maximum 40.6°), whereas a high dose (50 mg/kg) that produced the highest mRNA induction, showed a clear hypothermia (minimum 37.2°C). These findings argue against the possibility that Hsp70 induction by morphine is caused by its effect on body temperature. It may be speculated that increased expression of Hsp70 after morphine application protects brain structures against potentially hazardous effects of opiates. PMID:15497504

Autoradiographic evidence for two classes of mu opioid binding sites in rat brain using (/sup 125/I)FK33824

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rothman, R.B.; Jacobson, A.E.; Rice, K.C.

1987-11-01

Previous studies demonstrated that pretreatment of brain membranes with the irreversible mu antagonist, beta-funaltrexamine (beta-FNA), partially eliminated mu binding sites (25,35), consistent with the existence of two mu binding sites distinguished by beta-FNA. This paper tests the hypothesis that the FNA-sensitive and FNA-insensitive mu binding sites have different anatomical distributions in rat brain. Prior to autoradiographic visualization of mu binding sites, (/sup 3/H)oxymorphone, (/sup 3/H)D-ala2-MePhe4, Gly-ol5-enkephalin (DAGO), and (/sup 125/I)D-ala2-Me-Phe4-met(o)-ol)enkephalin (FK33824) were shown to selectively label mu binding sites using slide mounted sections of molded minced rat brain. As found using membranes, beta-FNA eliminated only a portion of mu bindingmore » sites. Autoradiographic visualization of mu binding sites using the mu-selective ligand (/sup 125/I)FK33824 in control and FNA-treated sections of rat brain demonstrated that the proportion of mu binding sites sensitive to beta-FNA varied across regions of the brain, particularly the dorsal thalamus, ventrobasal complex and the hypothalamus, providing anatomical data supporting the existence of two classes of mu binding sites in rat brain.« less

μ Opioid receptor: novel antagonists and structural modeling

NASA Astrophysics Data System (ADS)

Kaserer, Teresa; Lantero, Aquilino; Schmidhammer, Helmut; Spetea, Mariana; Schuster, Daniela

2016-02-01

The μ opioid receptor (MOR) is a prominent member of the G protein-coupled receptor family and the molecular target of morphine and other opioid drugs. Despite the long tradition of MOR-targeting drugs, still little is known about the ligand-receptor interactions and structure-function relationships underlying the distinct biological effects upon receptor activation or inhibition. With the resolved crystal structure of the β-funaltrexamine-MOR complex, we aimed at the discovery of novel agonists and antagonists using virtual screening tools, i.e. docking, pharmacophore- and shape-based modeling. We suggest important molecular interactions, which active molecules share and distinguish agonists and antagonists. These results allowed for the generation of theoretically validated in silico workflows that were employed for prospective virtual screening. Out of 18 virtual hits evaluated in in vitro pharmacological assays, three displayed antagonist activity and the most active compound significantly inhibited morphine-induced antinociception. The new identified chemotypes hold promise for further development into neurochemical tools for studying the MOR or as potential therapeutic lead candidates.

Spatiotemporal control of opioid signaling and behavior

PubMed Central

Siuda, Edward R.; Copits, Bryan A.; Schmidt, Martin J.; Baird, Madison A.; Al-Hasani, Ream; Planer, William J.; Funderburk, Samuel C.; McCall, Jordan G.; Gereau, Robert W.; Bruchas, Michael R.

2015-01-01

Summary Optogenetics is now a widely accepted tool for spatiotemporal manipulation of neuronal activity. However, a majority of optogenetic approaches use binary on/off control schemes. Here we extend the optogenetic toolset by developing a neuromodulatory approach using a rationale-based design to generate a Gi-coupled, optically-sensitive, mu-opioid-like receptor, we term opto-MOR. We demonstrate that opto-MOR engages canonical mu-opioid signaling through inhibition of adenylyl cyclase, activation of MAPK and G protein-gated inward rectifying potassium (GIRK) channels, and internalizes with similar kinetics as the mu-opioid receptor. To assess in vivo utility we expressed a Cre-dependent viral opto-MOR in RMTg/VTA GABAergic neurons, which led to a real-time place preference. In contrast, expression of opto-MOR in GABAergic neurons of the ventral pallidum hedonic cold spot, led to real-time place aversion. This tool has generalizable application for spatiotemporal control of opioid signaling and, furthermore, can be used broadly for mimicking endogenous neuronal inhibition pathways. PMID:25937173

Radioligand binding analysis of α 2 adrenoceptors with [11C]yohimbine in brain in vivo: Extended Inhibition Plot correction for plasma protein binding.

PubMed

Phan, Jenny-Ann; Landau, Anne M; Jakobsen, Steen; Wong, Dean F; Gjedde, Albert

2017-11-22

We describe a novel method of kinetic analysis of radioligand binding to neuroreceptors in brain in vivo, here applied to noradrenaline receptors in rat brain. The method uses positron emission tomography (PET) of [ 11 C]yohimbine binding in brain to quantify the density and affinity of α 2 adrenoceptors under condition of changing radioligand binding to plasma proteins. We obtained dynamic PET recordings from brain of Spraque Dawley rats at baseline, followed by pharmacological challenge with unlabeled yohimbine (0.3 mg/kg). The challenge with unlabeled ligand failed to diminish radioligand accumulation in brain tissue, due to the blocking of radioligand binding to plasma proteins that elevated the free fractions of the radioligand in plasma. We devised a method that graphically resolved the masking of unlabeled ligand binding by the increase of radioligand free fractions in plasma. The Extended Inhibition Plot introduced here yielded an estimate of the volume of distribution of non-displaceable ligand in brain tissue that increased with the increase of the free fraction of the radioligand in plasma. The resulting binding potentials of the radioligand declined by 50-60% in the presence of unlabeled ligand. The kinetic unmasking of inhibited binding reflected in the increase of the reference volume of distribution yielded estimates of receptor saturation consistent with the binding of unlabeled ligand.

The transcription factor C/EBPβ in the dorsal root ganglion contributes to peripheral nerve trauma–induced nociceptive hypersensitivity

PubMed Central

Li, Zhisong; Mao, Yuanyuan; Liang, Lingli; Wu, Shaogen; Yuan, Jingjing; Mo, Kai; Cai, Weihua; Mao, Qingxiang; Cao, Jing; Bekker, Alex; Zhang, Wei; Tao, Yuan-Xiang

2017-01-01

Changes in gene transcription in the dorsal root ganglion (DRG) after nerve trauma contribute to the genesis of neuropathic pain. We report that peripheral nerve trauma caused by chronic constriction injury (CCI) increased the abundance of the transcription factor C/EBPβ (CCAAT/enhancer binding protein β) in the DRG. Blocking this increase mitigated the development and maintenance of CCI-induced mechanical, thermal, and cold pain hypersensitivities without affecting basal responses to acute pain and locomotor activity. Conversely, mimicking this increase produced hypersensitivity to mechanical, thermal, or cold pain. In the ipsilateral DRG, C/EBPβ promoted a decrease in the abundance of the voltage-gated potassium channel subunit Kv1.2 and µ opioid receptor (MOR) at the mRNA and protein levels, which would be predicted to increase excitability in the ipsilateral DRG neurons and reduce the efficacy of morphine analgesia. These effects required C/EPBβ-mediated transcriptional activation of Ehmt2 (euchromatic histonelysine N-methyltransferase 2), which encodes G9a, an epigenetic silencer of the genes encoding Kv1.2 and MOR. Blocking the increase in C/EBPβ in the DRG improved morphine analgesia after CCI. These results suggest that C/EBPβ is an endogenous initiator of neuropathic pain and could be a potential target for the prevention and treatment of this disorder. PMID:28698219

Oxycodone plus ultra-low-dose naltrexone attenuates neuropathic pain and associated mu-opioid receptor-Gs coupling.

PubMed

Largent-Milnes, Tally M; Guo, Wenhong; Wang, Hoau-Yan; Burns, Lindsay H; Vanderah, Todd W

2008-08-01

Both peripheral nerve injury and chronic opioid treatment can result in hyperalgesia associated with enhanced excitatory neurotransmission at the level of the spinal cord. Chronic opioid administration leads to a shift in mu-opioid receptor (MOR)-G protein coupling from G(i/o) to G(s) that can be prevented by cotreatment with an ultra-low-dose opioid antagonist. In this study, using lumbar spinal cord tissue from rats with L(5)/L(6) spinal nerve ligation (SNL), we demonstrated that SNL injury induces MOR linkage to G(s) in the damaged (ipsilateral) spinal dorsal horn. This MOR-G(s) coupling occurred without changing G(i/o) coupling levels and without changing the expression of MOR or Galpha proteins. Repeated administration of oxycodone alone or in combination with ultra-low-dose naltrexone (NTX) was assessed on the SNL-induced MOR-G(s) coupling as well as on neuropathic pain behavior. Repeated spinal oxycodone exacerbated the SNL-induced MOR-G(s) coupling, whereas ultra-low-dose NTX cotreatment slightly but significantly attenuated this G(s) coupling. Either spinal or oral administration of oxycodone plus ultra-low-dose NTX markedly enhanced the reductions in allodynia and thermal hyperalgesia produced by oxycodone alone and minimized tolerance to these effects. The MOR-G(s) coupling observed in response to SNL may in part contribute to the excitatory neurotransmission in spinal dorsal horn in neuropathic pain states. The antihyperalgesic and antiallodynic effects of oxycodone plus ultra-low-dose NTX (Oxytrex, Pain Therapeutics, Inc., San Mateo, CA) suggest a promising new treatment for neuropathic pain. The current study investigates whether Oxytrex (oxycodone with an ultra-low dose of naltrexone) alleviates mechanical and thermal hypersensitivities in an animal model of neuropathic pain over a period of 7 days, given locally or systemically. In this report, we first describe an injury-induced shift in mu-opioid receptor coupling from G(i/o) to G(s), suggesting why a mu-opioid agonist may have reduced efficacy in the nerve-injured state. These data present a novel approach to neuropathic pain therapy.

HDAC inhibitor TSA ameliorates mechanical hypersensitivity and potentiates analgesic effect of morphine in a rat model of bone cancer pain by restoring μ-opioid receptor in spinal cord.

PubMed

Hou, Xinran; Weng, Yingqi; Ouyang, Bihan; Ding, Zhuofeng; Song, Zongbin; Zou, Wangyuan; Huang, Changsheng; Guo, Qulian

2017-08-15

Bone cancer pain (BCP) is a common complication with inadequate management in patients suffering from advanced cancer. Histone deacetylase inhibitors showed significant analgesic effect in multiple inflammatory and neuropathic pain models, but their effect in bone cancer pain has never been explored. In this study, we utilized a BCP rat model with intra-tibial inoculation of Walker 256 mammary gland carcinoma cells, which developed progressive mechanical hypersensitivity but not thermal hypersensitivity. Intrathecal application of trichostatin A (TSA), a classic pan-HDAC inhibitor, ameliorated tactile hypersensitivity and enhanced the analgesic effect of morphine in BCP rats. The analgesic effect of TSA was blocked by co-administration of CTAP, a specific MOR antagonist, confirming the involvement of mu-opioid receptor (MOR). A reduction of MOR expression was observed in the lumbar spinal cord of BCP rats and TSA treatment was able to partially reverse it. In vitro study in PC12 cells also demonstrated the dose-dependent enhancement of MOR expression by TSA treatment. Taking all into consideration, we could draw the conclusion that HDAC inhibitor TSA ameliorates mechanical hypersensitivity and potentiates analgesic effect of morphine in BCP rats, probably by restoring MOR expression in spinal cord. Copyright © 2017 Elsevier B.V. All rights reserved.

Human blood-brain barrier insulin-like growth factor receptor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duffy, K.R.; Pardridge, W.M.; Rosenfeld, R.G.

1988-02-01

Insulin-like growth factor (IGF)-1 and IGF-2, may be important regulatory molecules in the CNS. Possible origins of IGFs in brain include either de novo synthesis or transport of circulating IGFs from blood into brain via receptor mediated transcytosis mechanisms at the brain capillary endothelial wall, ie, the blood-brain barrier (BBB). In the present studies, isolated human brain capillaries are used as an in vitro model system of the human BBB and the characteristics of IGF-1 or IGF-2 binding to this preparation were assessed. The total binding of IGF-2 at 37 degrees C exceeded 130% per mg protein and was threefoldmore » greater than the total binding for IGF-1. However, at 37 degrees C nonsaturable binding equaled total binding, suggesting that endocytosis is rate limiting at physiologic temperatures. Binding studies performed at 4 degrees C slowed endocytosis to a greater extent than membrane binding, and specific binding of either IGF-1 or IGF-2 was detectable. Scatchard plots for either peptide were linear and the molar dissociation constant of IGF-1 and IGF-2 binding was 2.1 +/- 0.4 and 1.1 +/- 0.1 nmol/L, respectively. Superphysiologic concentrations of porcine insulin inhibited the binding of both IGF-1 (ED50 = 2 micrograms/mL) and IGF-2 (ED50 = 0.5 microgram/mL). Affinity cross linking of /sup 125/I-IGF-1, /sup 125/I-IGF-2, and /sup 125/I-insulin to isolated human brain capillaries was performed using disuccinimidylsuberate (DSS). These studies revealed a 141 kd binding site for both IGF-1 and IGF-2, and a 133 kd binding site for insulin.« less

Existence of three subtypes of bradykinin B2 receptors in guinea pig.

PubMed

Seguin, L; Widdowson, P S; Giesen-Crouse, E

1992-12-01

We describe the binding of [3H]bradykinin to homogenates of guinea pig brain, lung, and ileum. Analysis of [3H]bradykinin binding kinetics in guinea pig brain, lung, and ileum suggests the existence of two binding sites in each tissue. The finding of two binding sites for [3H]bradykinin in ileum, lung, and brain was further supported by Scatchard analysis of equilibrium binding in each tissue. [3H]Bradykinin binds to a high-affinity site in brain, lung, and ileum (KD = 70-200 pM), which constitutes approximately 20% of the bradykinin binding, and to a second, lower-affinity site (0.63-0.95 nM), which constitutes the remaining 80% of binding. Displacement studies with various bradykinin analogues led us to subdivide the high- and lower-affinity sites in each tissue and to suggest the existence of three subtypes of B2 receptors in the guinea pig, which we classify as B2a, B2b, and B2c. Binding of [3H]bradykinin is largely to a B2b receptor subtype, which constitutes the majority of binding in brain, lung, and ileum and represents the lower-affinity site in our binding studies. Receptor subtype B2c constitutes approximately 20% of binding sites in the brain and lung and is equivalent to the high-affinity site in brain and lung. We suggest that a third subtype of B2 receptor (high-affinity site in ileum), B2a, is found only in the ileum. All three subtypes of B2 receptors display a high affinity for bradykinin, whereas they show different affinities for various bradykinin analogues displaying agonist or antagonist activities.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of [3H] oxymorphone binding sites in mouse brain: Quantitative autoradiography in opioid receptor knockout mice.

PubMed

Yoo, Ji Hoon; Borsodi, Anna; Tóth, Géza; Benyhe, Sándor; Gaspar, Robert; Matifas, Audrey; Kieffer, Brigitte L; Metaxas, Athanasios; Kitchen, Ian; Bailey, Alexis

2017-03-16

Oxymorphone, one of oxycodone's metabolic products, is a potent opioid receptor agonist which is thought to contribute to the analgesic effect of its parent compound and may have high potential abuse liability. Nonetheless, the in vivo pharmacological binding profile of this drug is still unclear. This study uses mice lacking mu (MOP), kappa (KOP) or delta (DOP) opioid receptors as well as mice lacking all three opioid receptors to provide full characterisation of oxymorphone binding sites in the brain. Saturation binding studies using [ 3 H]oxymorphone revealed high affinity binding sites in mouse brain displaying Kd of 1.7nM and Bmax of 147fmol/mg. Furthermore, we performed quantitative autoradiography binding studies using [ 3 H]oxymorphone in mouse brain. The distribution of [ 3 H]oxymorphone binding sites was found to be similar to the selective MOP agonist [ 3 H]DAMGO in the mouse brain. [ 3 H]Oxymorphone binding was completely abolished across the majority of the brain regions in mice lacking MOP as well as in mice lacking all three opioid receptors. DOP and KOP knockout mice retained [ 3 H]oxymorphone binding sites suggesting oxymorphone may not target DOP or KOP. These results confirm that the MOP, and not the DOP or the KOP is the main high affinity binding target for oxymorphone. Copyright © 2017 Elsevier B.V. All rights reserved.

ARC-2010-ACD10-0066-004

NASA Image and Video Library

2010-04-09

Netherlands Memorandum of Record (MOR) agreement signing the NASA Ames Research Center, Mofffett Field, California. Signing the MOR are on left Dr. Louis B.J.Vertegaal, Director of Physical Sciences, Chemistry, and Advanced Chemical Technologies for Sustainability, of the Netherlands Organisation for Scientific Research (NWO) and on right Dr. S. Pete Worden, Director NASA Ames Research Center

14-Alkoxy- and 14-acyloxypyridomorphinans: μ agonist/δ antagonist opioid analgesics with diminished tolerance and dependence side effects.

PubMed

Ananthan, Subramaniam; Saini, Surendra K; Dersch, Christina M; Xu, Heng; McGlinchey, Nicholas; Giuvelis, Denise; Bilsky, Edward J; Rothman, Richard B

2012-10-11

In the search for opioid ligands with mixed functional activity, a series of 5'-(4-chlorophenyl)-4,5α-epoxypyridomorphinans possessing alkoxy or acyloxy groups at C-14 was synthesized and evaluated. In this series, the affinity and functional activity of the ligands were found to be influenced by the nature of the substituent at C-14 as well as by the substituent at N-17. Whereas the incorporation of a 3-phenylpropoxy group at C-14 on N-methylpyridomorhinan gave a dual MOR agonist/DOR agonist 17h, its incorporation on N-cyclopropylmethylpyridomorphinan gave a MOR agonist/DOR antagonist 17d. Interestingly, 17d, in contrast to 17h, did not produce tolerance or dependence effects upon prolonged treatment in cells expressing MOR and DOR. Moreover, 17d displayed greatly diminished analgesic tolerance as compared to morphine upon repeated administration, thus supporting the hypothesis that ligands with MOR agonist/DOR antagonist functional activity could emerge as novel analgesics devoid of tolerance, dependence, and related side effects.

Molecular signatures of mu opioid receptor and somatostatin receptor 2 in pancreatic cancer

PubMed Central

Jorand, Raphael; Biswas, Sunetra; Wakefield, Devin L.; Tobin, Steven J.; Golfetto, Ottavia; Hilton, Kelsey; Ko, Michelle; Ramos, Joe W.; Small, Alexander R.; Chu, Peiguo; Singh, Gagandeep; Jovanovic-Talisman, Tijana

2016-01-01

Pancreatic ductal adenocarcinoma (PDAC), a particularly aggressive malignancy, has been linked to atypical levels, certain mutations, and aberrant signaling of G-protein–coupled receptors (GPCRs). GPCRs have been challenging to target in cancer because they organize into complex networks in tumor cells. To dissect such networks with nanometer-scale precision, here we combine traditional biochemical approaches with superresolution microscopy methods. A novel interaction specific to PDAC is identified between mu opioid receptor (MOR) and somatostatin receptor 2 (SSTR2). Although MOR and SSTR2 did not colocalize in healthy pancreatic cells or matching healthy patient tissues, the pair did significantly colocalize in pancreatic cancer cells, multicellular tumor spheroids, and cancerous patient tissues. Moreover, this association in pancreatic cancer cells correlated with functional cross-talk and increased metastatic potential of cells. Coactivation of MOR and SSTR2 in PDAC cells led to increased expression of mesenchymal markers and decreased expression of an epithelial marker. Together these results suggest that the MOR-SSTR2 heteromer may constitute a novel therapeutic target for PDAC. PMID:27682590

14-Alkoxy- and 14-Acyloxypyridomorphinans: Mu Agonist/Delta Antagonist Opioid Analgesics with Diminished Tolerance and Dependence Side Effects

PubMed Central

Ananthan, Subramaniam; Saini, Surendra K.; Dersch, Christina M.; Xu, Heng; McGlinchey, Nicholas; Giuvelis, Denise; Bilsky, Edward J.; Rothman, Richard B.

2012-01-01

In the search for opioid ligands with mixed functional activity, a series of 5′-(4-chlorophenyl)-4,5α-epoxypyridomorphinans possessing alkoxy or acyloxy groups at C-14 was synthesized and evaluated. In this series, the affinity and functional activity of the ligands were found to be influenced by the nature of the substituent at C-14 as well as by the substituent at N-17. Whereas the incorporation of a 3-phenylpropoxy group at C-14 on N-methylpyridomorhinan gave a dual MOR agonist/DOR agonist 17h its incorporation on N-cyclopropylmethylpyridomorphinan gave a MOR agonist/DOR antagonist 17d. Interestingly, 17d, in contrast to 17h, did not produce tolerance or dependence effects on prolonged treatment in cells expressing MOR and DOR. Moreover, 17d displayed greatly diminished analgesic tolerance as compared to morphine on repeated administration, thus supporting the hypothesis that ligands with MOR agonist/DOR antagonist functional activity could emerge as novel analgesics devoid of tolerance, dependence and related side effects. PMID:23016952

Spatiotemporal control of opioid signaling and behavior.

PubMed

Siuda, Edward R; Copits, Bryan A; Schmidt, Martin J; Baird, Madison A; Al-Hasani, Ream; Planer, William J; Funderburk, Samuel C; McCall, Jordan G; Gereau, Robert W; Bruchas, Michael R

2015-05-20

Optogenetics is now a widely accepted tool for spatiotemporal manipulation of neuronal activity. However, a majority of optogenetic approaches use binary on/off control schemes. Here, we extend the optogenetic toolset by developing a neuromodulatory approach using a rationale-based design to generate a Gi-coupled, optically sensitive, mu-opioid-like receptor, which we term opto-MOR. We demonstrate that opto-MOR engages canonical mu-opioid signaling through inhibition of adenylyl cyclase, activation of MAPK and G protein-gated inward rectifying potassium (GIRK) channels and internalizes with kinetics similar to that of the mu-opioid receptor. To assess in vivo utility, we expressed a Cre-dependent viral opto-MOR in RMTg/VTA GABAergic neurons, which led to a real-time place preference. In contrast, expression of opto-MOR in GABAergic neurons of the ventral pallidum hedonic cold spot led to real-time place aversion. This tool has generalizable application for spatiotemporal control of opioid signaling and, furthermore, can be used broadly for mimicking endogenous neuronal inhibition pathways. Copyright © 2015 Elsevier Inc. All rights reserved.

Solar photocatalytic degradation of isoproturon over TiO2/H-MOR composite systems.

PubMed

Sharma, Mangalampalli V Phanikrishna; Durgakumari, Valluri; Subrahmanyam, Machiraju

2008-12-30

The photocatalytic degradation and mineralization of isoproturon herbicide was investigated in aqueous solution containing TiO2 over H-mordenite (H-MOR) photocatalysts under solar light. The catalysts are characterized by X-ray diffraction (XRD), UV-Vis diffused reflectance spectra (UV-Vis DRS), Fourier transform-infra red spectra (FT-IR) and scanning electron microscopy (SEM) techniques. The effect of TiO2, H-MOR support and different wt% of TiO2 over the support on the photocatalytic degradation and influence of parameters such as TiO2 loading, catalyst amount, pH and initial concentration of isoproturon on degradation are evaluated. 15wt% TiO2/H-MOR composite is found to be optimum. The degradation reaction follows pseudo-first order kinetics and is discussed in terms of Langmuir-Hinshelwood (L-H) kinetic model. The extent of isoproturon mineralization studied with chemical oxygen demand (COD) and total organic carbon (TOC) measurements and approximately 80% mineralization occurred in 5h. A plausible mechanism is proposed based on the intermediates identified by liquid chromatography-mass spectroscopy (LC-MS).

The sodium channel in membranes of electroplax. Binding of batrachotoxinin-a [(3)H]benzoate to particulate preparations from electric eel (electrophorus).

PubMed

McNeal, E T; Daly, J W

1986-01-01

Batrachotoxinin-A [(3)H]benzoate ([(3)H]BTX-B) binds specifically and with high affinity (K(D) 48 nM) to sites (B(max) 2.1 pmol/mg protein) associated with voltage-dependent sodium channels in rodent brain vesicular preparations. High affinity binding requires the presence of scorpion (Leiurus) venom and a membrane potential. Local anesthetics antagonize the binding. Nonspecific binding is defined in the presence of veratridine. In particulate preparations from electroplax of the eel Electrophorus electricus, [(3)H]BTX-B binds with a K(D) of about 140 nM and a B(max) of 2.5 pmol/mg protein in the presence of scorpion venom. Higher concentrations of scorpion venom are required to enhance binding in Electrophorus preparations than in brain preparations. Local anesthetics antagonize binding in Electrophorus preparations with potencies similar to those in brain preparations. Veratridine and batrachotoxin are less potent in blocking binding in Electrophorus than in brain preparations. It appears likely that binding in Electrophorus preparations is primarily to membrane fragments rather than vesicular entities as in brain. Binding of [(3)H]BTX-B to particulate preparations from electroplax of the ray Torpedo californica and the catfish Malapterurus electricus is mainly nonspecific. Scorpion venom does not enhance total binding and local anesthetics are not effective in antagonizing binding.

Effect of antemortem and postmortem factors on ( sup 3 H)MK-801 binding in the human brain: Transient elevation during early childhood

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kornhuber, J.; Mack-Burkhardt, F.; Konradi, C.

1989-01-01

The effect of a number of antemortem and postmortem factors on ({sup 3}H)MK-801 binding was investigated under equilibrium conditions in the frontal cortex of human brains of 38 controls. Binding values transiently increased during the early postnatal period reaching a maximum at the age of about 2 years. After age 10 years ({sup 3}H)MK-801 binding sites disappeared at 5.7% per decade. The storage time of brain tissue had a reducing effect on these binding sites. There was no effect of gender, brain weight or postmortem time interval and the binding sites were bilaterally symmetrically distributed in the frontal cortex.

Origin of geochemical mantle components: Role of spreading ridges and thermal evolution of mantle

NASA Astrophysics Data System (ADS)

Kimura, Jun-Ichi; Gill, James B.; van Keken, Peter E.; Kawabata, Hiroshi; Skora, Susanne

2017-02-01

We explore the element redistribution at mid-ocean ridges (MOR) using a numerical model to evaluate the role of decompression melting of the mantle in Earth's geochemical cycle, with focus on the formation of the depleted mantle component. Our model uses a trace element mass balance based on an internally consistent thermodynamic-petrologic computation to explain the composition of MOR basalt (MORB) and residual peridotite. Model results for MORB-like basalts from 3.5 to 0 Ga indicate a high mantle potential temperature (Tp) of 1650-1500°C during 3.5-1.5 Ga before decreasing gradually to ˜1300°C today. The source mantle composition changed from primitive (PM) to depleted as Tp decreased, but this source mantle is variable with an early depleted reservoir (EDR) mantle periodically present. We examine a two-stage Sr-Nd-Hf-Pb isotopic evolution of mantle residues from melting of PM or EDR at MORs. At high-Tp (3.5-1.5 Ga), the MOR process formed extremely depleted DMM. This coincided with formation of the majority of the continental crust, the subcontinental lithospheric mantle, and the enriched mantle components formed at subduction zones and now found in OIB. During cooler mantle conditions (1.5-0 Ga), the MOR process formed most of the modern ocean basin DMM. Changes in the mode of mantle convection from vigorous deep mantle recharge before ˜1.5 Ga to less vigorous afterward is suggested to explain the thermochemical mantle evolution.

Soft-x-ray magneto-optical Kerr effect and element-specific hysteresis measurement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kortright, J.B.; Rice, M.

1997-04-01

Interest in the utilization of x-ray magneto-optical properties to provide element-specific magnetic information, combined with recent development of tunable linear polarizers for spectroscopic polarization measurement, have led the authors to the study of magneto-optical rotation (MOR) near core levels of magnetic atoms in magnetic multilayer and alloy films. Their initial observation of Faraday rotation (in transmission) demonstrated that for Fe MOR is easily measured and is larger at its L{sub 3} resonance than in the near-visible spectral regions. This work also demonstrated that the spectroscopic behavior of the MOR signal in transmission, resulting from the differential reaction of left- andmore » right-circular components of a linearly polarized beam, is related to the magnetic circular dichroism (MCD), or differential absorption, as expected by a Kramers-Kronig transformation. Thus MCD measurements using circular polarization and MOR measurements using linear polarization can provide complementary, and in some cases equivalent, information. On beamline 6.3.2 the authors have begun to investigate soft x-ray MOR in the reflection geometry, the x-ray magneto-optic Kerr effect (XMOKE). Early measurements have demonstrated the ability to measure element-specific hysteresis loops and large rotations compared to analogous near-visible measurements. The authors are investigating the spectral dependence of the XMOKE signal, and have initiated systematic materials studies of sputter-deposited films of Fe, Fe{sub x}Cr{sub 1{minus}x} alloys, and Fe/Cr multilayers.« less

Blunted endogenous opioid release following an oral dexamphetamine challenge in abstinent alcohol-dependent individuals.

PubMed

Turton, Samuel; Myers, James Fm; Mick, Inge; Colasanti, Alessandro; Venkataraman, Ashwin; Durant, Claire; Waldman, Adam; Brailsford, Alan; Parkin, Mark C; Dawe, Gemma; Rabiner, Eugenii A; Gunn, Roger N; Lightman, Stafford L; Nutt, David J; Lingford-Hughes, Anne

2018-06-25

Addiction has been proposed as a 'reward deficient' state, which is compensated for with substance use. There is growing evidence of dysregulation in the opioid system, which plays a key role in reward, underpinning addiction. Low levels of endogenous opioids are implicated in vulnerability for developing alcohol dependence (AD) and high mu-opioid receptor (MOR) availability in early abstinence is associated with greater craving. This high MOR availability is proposed to be the target of opioid antagonist medication to prevent relapse. However, changes in endogenous opioid tone in AD are poorly characterised and are important to understand as opioid antagonists do not help everyone with AD. We used [ 11 C]carfentanil, a selective MOR agonist positron emission tomography (PET) radioligand, to investigate endogenous opioid tone in AD for the first time. We recruited 13 abstinent male AD and 15 control participants who underwent two [ 11 C]carfentanil PET scans, one before and one 3 h following a 0.5 mg/kg oral dose of dexamphetamine to measure baseline MOR availability and endogenous opioid release. We found significantly blunted dexamphetamine-induced opioid release in 5 out of 10 regions-of-interest including insula, frontal lobe and putamen in AD compared with controls, but no significantly higher MOR availability AD participants compared with HC in any region. This study is comparable to our previous results of blunted dexamphetamine-induced opioid release in gambling disorder, suggesting that this dysregulation in opioid tone is common to both behavioural and substance addictions.

Convergent, not serial, striatal and pallidal circuits regulate opioid-induced food intake

PubMed Central

Taha, Sharif A.; Katsuura, Yoshihiro; Noorvash, David; Seroussi, Ariel; Fields, Howard L.

2009-01-01

Mu opioid receptor (MOR) signaling in the nucleus accumbens (NAcc) elicits marked increases in the consumption of palatable tastants. However, the mechanism and circuitry underlying this effect are not fully understood. Multiple downstream target regions have been implicated in mediating this effect but the role of the ventral pallidum (VP), a primary target of NAcc efferents, has not been well defined. To probe the mechanisms underlying increased consumption, we identified behavioral changes in licking patterns following NAcc MOR stimulation. Because the temporal structure of licking reflects the physiological substrates modulating consumption, these measures provide a useful tool in dissecting the cause of increased consumption following NAcc MOR stimulation. Next, we used a combination of pharmacological inactivation and lesions to define the role of the VP in hyperphagia following infusion of the MOR-specific agonist [D-Ala2, N-MePhe4, Gly-ol]-enkephalin (DAMGO) into the NAcc. In agreement with previous studies, results from lick microstructure analysis suggest that NAcc MOR stimulation augments intake through a palatability-driven mechanism. Our results also demonstrate an important role for the VP in normal feeding behavior: pharmacological inactivation of the VP suppresses baseline and NAcc DAMGO-induced consumption. However, this interaction does not occur through a serial circuit requiring direct projections from the NAcc to the VP. Rather, our results indicate that NAcc and VP circuits converge on a common downstream target that regulates food intake. PMID:19336249

Endogenous opioid system: a promising target for future smoking cessation medications.

PubMed

Norman, Haval; D'Souza, Manoranjan S

2017-05-01

Nicotine addiction continues to be a health challenge across the world. Despite several approved medications, smokers continue to relapse. Several human and animal studies have evaluated the role of the endogenous opioid system as a potential target for smoking cessation medications. In this review, studies that have elucidated the role of the mu (MORs), delta (DORs), and kappa (KORs) opioid receptors in nicotine reward, nicotine withdrawal, and reinstatement of nicotine seeking will be discussed. Additionally, the review will discuss discrepancies in the literature and therapeutic potential of the endogenous opioid system, and suggest studies to address gaps in knowledge with respect to the role of the opioid receptors in nicotine dependence. Data available till date suggest that blockade of the MORs and DORs decreased the rewarding effects of nicotine, while activation of the MORs and DORs decreased nicotine withdrawal-induced aversive effects. In contrast, activation of the KORs decreased the rewarding effects of nicotine, while blockade of the KORs decreased nicotine withdrawal-induced aversive effects. Interestingly, blockade of the MORs and KORs attenuated reinstatement of nicotine seeking. In humans, MOR antagonists have shown benefits in select subpopulations of smokers and further investigation is required to realize their full therapeutic potential. Future work must assess the influence of polymorphisms in opioid receptor-linked genes in nicotine dependence, which will help in both identifying individuals vulnerable to nicotine addiction and the development of opioid-based smoking cessation medications. Overall, the endogenous opioid system continues to be a promising target for future smoking cessation medications.

Pharmacological characterization of CCKB receptors in human brain: no evidence for receptor heterogeneity.

PubMed

Kinze, S; Schöneberg, T; Meyer, R; Martin, H; Kaufmann, R

1996-10-11

In this paper, cholecystokinin (CCK) B-type binding sites were characterized with receptor binding studies in different human brain regions (various parts of cerebral cortex, basal ganglia, hippocampus, thalamus, cerebellar cortex) collected from 22 human postmortem brains. With the exception of the thalamus, where no specific CCK binding sites were found, a pharmacological characterization demonstrated a single class of high affinity CCK sites in all brain areas investigated. Receptor densities ranged from 0.5 fmol/mg protein (hippocampus) to 8.4 fmol/mg protein (nucleus caudatus). These CCK binding sites displayed a typical CCKA binding profile as shown in competition studies by using different CCK-related compounds and non peptide CCK antagonists discriminating between CCKA and CCKB sites. The rank order of agonist or antagonist potency in inhibiting specific sulphated [propionyl-3H]cholecystokinin octapeptide binding was similar and highly correlated for the brain regions investigated as demonstrated by a computer-assisted analysis. Therefore it is concluded that CCKB binding sites in human cerebral cortex, basal ganglia, cerebellar cortex share identical ligand binding characteristics.

Inflammatory Pain Promotes Increased Opioid Self-Administration: Role of Dysregulated Ventral Tegmental Area μ Opioid Receptors

PubMed Central

Hipólito, Lucia; Wilson-Poe, Adrianne; Campos-Jurado, Yolanda; Zhong, Elaine; Gonzalez-Romero, Jose; Virag, Laszlo; Whittington, Robert; Comer, Sandra D.; Carlton, Susan M.; Walker, Brendan M.; Bruchas, Michael R.

2015-01-01

Pain management in opioid abusers engenders ethical and practical difficulties for clinicians, often resulting in pain mismanagement. Although chronic opioid administration may alter pain states, the presence of pain itself may alter the propensity to self-administer opioids, and previous history of drug abuse comorbid with chronic pain promotes higher rates of opioid misuse. Here, we tested the hypothesis that inflammatory pain leads to increased heroin self-administration resulting from altered mu opioid receptor (MOR) regulation of mesolimbic dopamine (DA) transmission. To this end, the complete Freund's adjuvant (CFA) model of inflammation was used to assess the neurochemical and functional changes induced by inflammatory pain on MOR-mediated mesolimbic DA transmission and on rat intravenous heroin self-administration under fixed ratio (FR) and progressive ratio (PR) schedules of reinforcement. In the presence of inflammatory pain, heroin intake under an FR schedule was increased for high, but attenuated for low, heroin doses with concomitant alterations in mesolimbic MOR function suggested by DA microdialysis. Consistent with the reduction in low dose FR heroin self-administration, inflammatory pain reduced motivation for a low dose of heroin, as measured by responding under a PR schedule of reinforcement, an effect dissociable from high heroin dose PR responding. Together, these results identify a connection between inflammatory pain and loss of MOR function in the mesolimbic dopaminergic pathway that increases intake of high doses of heroin. These findings suggest that pain-induced loss of MOR function in the mesolimbic pathway may promote opioid dose escalation and contribute to opioid abuse-associated phenotypes. SIGNIFICANCE STATEMENT This study provides critical new insights that show that inflammatory pain alters heroin intake through a desensitization of MORs located within the VTA. These findings expand our knowledge of the interactions between inflammatory pain and opioid abuse liability, and should help to facilitate the development of novel and safer opioid-based strategies for treating chronic pain. PMID:26338332

On the global distribution of hydrothermal vent fields: One decade later

NASA Astrophysics Data System (ADS)

Beaulieu, S. E.; Baker, E. T.; German, C. R.

2012-12-01

Since the last global compilation one decade ago, the known number of active submarine hydrothermal vent fields has almost doubled. At the end of 2009, a total of 518 active vent fields was catalogued, with about half (245) visually confirmed and others (273) inferred active at the seafloor. About half (52%) of these vent fields are at mid-ocean ridges (MORs), 25% at volcanic arcs, 21% at back-arc spreading centers (BASCs), and 2% at intra-plate volcanoes and other settings. One third are in high seas, and the nations with the most known active vent fields within EEZs are Tonga, USA, Japan, and New Zealand. The increase in known vent fields reflects a number of factors, including increased national and commercial interests in seafloor hydrothermal deposits as mineral resources. Here, we have comprehensively documented the percentage of strike length at MORs and BASCs that has been systematically explored for hydrothermal activity. As of the end of 2009, almost 30% of the ~60,000 km of MORs had been surveyed at least with spaced vertical profiles to detect hydrothermal plumes. A majority of the vents discovered at MORs in the past decade occurred at segments with < 60 mm/yr full spreading rate. Discoveries at ultra-slow MORs in the past decade included the deepest known vent (Beebe at Mid-Cayman Rise) and high-temperature black smoker vents (e.g., Dragon at SWIR and Loki's Castle at Mohns Ridge), and the highest temperature vent was measured at the slow-spreading S MAR (Turtle Pits). Using a previously published equation for the linear relationship between the number of active vent fields per 100 km strike length (F_s) vs. weighted-average full spreading rate (u_s), we predicted 676 vent fields remaining to be discovered at MORs. Even accounting for the lower F_s at slower spreading rates, almost half of the vents that are predicted remaining to be discovered at MORs are at ultra-slow to slow spreading rates (< 40 mm/yr) and about 1/3 at intermediate rates (40-80 mm/yr). MOR regions that are little explored tend to be at high latitudes, such as the ultra-slow to slow spreading Arctic MORs (e.g., Kolbeinsey and Mohns Ridges), the ultra-slow American-Antarctic Ridge, and the intermediate spreading Pacific-Antarctic Ridge. Although a greater percentage of the ~11,000 km of BASCs has been surveyed for hydrothermal activity, the discoveries at BASCs in the past decade were mainly at segments with intermediate to fast spreading rates. Using the same equation for F_s vs. u_s, we predicted 71 vent fields remaining to be discovered at BASCs, and most are likely to be found at ultra-slow and slow spreading segments (e.g., Andaman Basin, and central to northern Mariana Trough). With 2/3 of our overall predicted total vent fields at spreading ridges remaining to be discovered, we expect that the next decade of exploration will continue to yield new discoveries, leading to new insights into biogeography of vent fauna and the global impacts of fluxes of heat and materials from vents into our oceans.

Binding characteristics of levetiracetam to synaptic vesicle protein 2A (SV2A) in human brain and in CHO cells expressing the human recombinant protein.

PubMed

Gillard, Michel; Chatelain, Pierre; Fuks, Bruno

2006-04-24

A specific binding site for the antiepileptic drug levetiracetam (2S-(oxo-1-pyrrolidinyl)butanamide, Keppra) in rat brain, referred to as the levetiracetam binding site, was discovered several years ago. More recently, this binding site has been identified as the synaptic vesicle protein 2A (SV2A), a protein present in synaptic vesicles [Lynch, B., Lambeng, N., Nocka, K., Kensel-Hammes, P., Bajjalieh, S.M., Matagne, A., Fuks, B., 2004. The synaptic vesicle protein SV2A is the binding site for the antiepileptic drug levetiracetam. Proc. Natl. Acad. Sci. USA, 101, 9861-9866.]. In this study, we characterized the binding properties of levetiracetam in post-mortem human brain and compared them to human SV2A expressed in Chinese hamster ovary (CHO) cells. The results showed that the binding properties of levetiracetam and [3H]ucb 30889, an analogue that was previously characterized as a suitable ligand for levetiracetam binding site/SV2A in rat brain [Gillard, M., Fuks, B., Michel, P., Vertongen, P., Massingham, R. Chatelain, P., 2003. Binding characteristics of [3H]ucb 30889 to levetiracetam binding sites in rat brain. Eur. J. Pharmacol. 478, 1-9.], are almost identical in human brain samples (cerebral cortex, hippocampus and cerebellum) and in CHO cell membranes expressing the human SV2A protein. Moreover, the results are also similar to those previously obtained in rat brain. [3H]ucb 30889 binding in human brain and to SV2A was saturable and reversible. At 4 degrees C, its binding kinetics were best fitted assuming a two-phase model in all tissues. The half-times of association for the fast component ranged between 1 to 2 min and represent 30% to 36% of the sites whereas the half-times for the slow component ranged from 20 to 29 min. In dissociation experiments, the half-times were from 2 to 4 min for the fast component (33% to 49% of the sites) and 20 to 41 min for the slow component. Saturation binding curves led to Kd values for [3H]ucb 30889 of 53+/-7, 55+/-9, 70+/-11 and 75+/-33 nM in human cerebral cortex, hippocampus, cerebellum and CHO cells expressing SV2A respectively. Bmax values around 3-4 pmol/mg protein were calculated in all brain regions. Some of the saturation curves displayed curvilinear Scatchard plots indicating the presence of high and low affinity binding sites. When this was the case, Kd values from 25 to 30 nM for the high affinity sites (24% to 34% of total sites) and from 200 to 275 nM for the low affinity sites were calculated. This was observed in all brain regions and in CHO cell membranes expressing the SV2A protein. It cannot be explained by putative binding of [3H]ucb 30889 to SV2B or C isoforms but may reflect different patterns of SV2A glycosylation or the formation of SV2A oligomers. Competition experiments were performed to determine the affinities for SV2A of a variety of compounds including levetiracetam, some of its analogues and other molecules known to interact with levetiracetam binding sites in rat brain such as bemegride, pentylenetetrazol and chlordiazepoxide. We found an excellent correlation between the affinities of these compounds measured in human brain, rat brain and CHO cells expressing human SV2A. In conclusion, we report for the first time that the binding characteristics of native levetiracetam binding sites/SV2A in human brain and rat brain share very similar properties with human recombinant SV2A expressed in CHO cells.

Alterations in L-Glutamate Binding in Alzheimer's and Huntington's Diseases

NASA Astrophysics Data System (ADS)

Greenamyre, J. Timothy; Penney, John B.; Young, Anne B.; D'Amato, Constance J.; Hicks, Samuel P.; Shoulson, Ira

1985-03-01

Brain sections from patients who had died with senile dementia of the Alzheimer's type (SDAT), Huntington's disease (HD), or no neurologic disease were studied by autoradiography to measure sodium-independent L-[3H]glutamate binding. In brain sections from SDAT patients, glutamate binding was normal in the caudate, putamen, and claustrum but was lower than normal in the cortex. The decreased cortical binding represented a reduction in numbers of binding sites, not a change in binding affinity, and appeared to be the result of a specific decrease in numbers of the low-affinity quisqualate binding site. No significant changes in cortical binding of other ligands were observed. In brains from Huntington's disease patients, glutamate binding was lower in the caudate and putamen than in the same regions of brains from control and SDAT patients but was normal in the cortex. It is possible that development of positron-emitting probes for glutamate receptors may permit diagnosis of SDAT in vivo by means of positron emission tomographic scanning.

Impact of Neurodegenerative Diseases on Drug Binding to Brain Tissues: From Animal Models to Human Samples.

PubMed

Ugarte, Ana; Corbacho, David; Aymerich, María S; García-Osta, Ana; Cuadrado-Tejedor, Mar; Oyarzabal, Julen

2018-04-19

Drug efficacy in the central nervous system (CNS) requires an additional step after crossing the blood-brain barrier. Therapeutic agents must reach their targets in the brain to modulate them; thus, the free drug concentration hypothesis is a key parameter for in vivo pharmacology. Here, we report the impact of neurodegeneration (Alzheimer's disease (AD) and Parkinson's disease (PD) compared with healthy controls) on the binding of 10 known drugs to postmortem brain tissues from animal models and humans. Unbound drug fractions, for some drugs, are significantly different between healthy and injured brain tissues (AD or PD). In addition, drugs binding to brain tissues from AD and PD animal models do not always recapitulate their binding to the corresponding human injured brain tissues. These results reveal potentially relevant implications for CNS drug discovery.

Effects of bingeing on fat during adolescence on the reinforcing effects of cocaine in adult male mice.

PubMed

Blanco-Gandía, M Carmen; Cantacorps, Lídia; Aracil-Fernández, Auxiliadora; Montagud-Romero, Sandra; Aguilar, María A; Manzanares, Jorge; Valverde, Olga; Miñarro, José; Rodríguez-Arias, Marta

2017-02-01

Binge eating is a specific form of overeating characterized by intermittent excessive eating. In addition to altering the neurobiological reward system, several studies have highlighted that consumption of palatable food increases vulnerability to drug use. The aim of the present study was to evaluate the effects of a high-fat diet consumed in a binge pattern during adolescence on the reinforcing effects of cocaine. After 40 days of binge-eating for 2 h, three days a week (PND 29-69), the reinforcing effects of cocaine on conditioning place preference and intravenous self-administration paradigm were evaluated in adolescent male mice. Circulating leptin and ghrelin levels and the effects of bingeing on fat on CB1 mu opioid receptor (MOr) and ghrelin receptor (GHSR) gene expression in the Nucleus Accumbens (NAcc) and Ventral Tegmental Area (VTA) were also assessed. Our results showed a significant escalation in the consumption of a high-fat diet between the first and last week. High-fat binge (HFB) animals were more sensitive to the reinforcing effects of a subthreshold dose of cocaine in the paradigms assayed, and animals under fat withdrawal were more vulnerable to the reinstatement of conditioned place preference. HFB mice also showed enhanced cocaine self-administration. After fat withdrawal, exposure to a new fat binge reinstated cocaine seeking. Although HFB did not modify leptin levels, a decrease in plasmatic ghrelin was observed. Moreover, this pattern of fatty diet resulted in a reduction of MOr and CB1 gene expression in the NAcc and an increase in GHSR expression in the VTA. We propose that bingeing on fat during adolescence induces long-lasting changes in the brain through the sensitization of brain reward circuits, which predisposes individuals to seek cocaine during adulthood. Copyright © 2016 Elsevier Ltd. All rights reserved.

Neuroscience: toward unbinding the binding problem.

PubMed

Whitney, David

2009-03-24

How the brain 'binds' information to create a coherent perceptual experience is an enduring question. Recent research in the psychophysics of perceptual binding and developments in fMRI analysis techniques are bringing us closer to an understanding of how the brain solves the binding problem.

Interaction of D-LSD with binding sites in brain: a study in vivo and in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ebersole, B.L.J.

The localization of (/sup 3/H)-d-lysergic acid diethylamide ((/sup 3/H)LSD) binding sites in the mouse brain was compared in vivo and in vitro. Radioautography of brain sections incubated with (/sup 3/H)LSD in vitro revealed substantial specific (/sup 3/H)LSD binding in cortical layers III-IV and areas CA1 and dentate gyrus in hippocampus. In contrast, in brain sections from animals that received (/sup 3/H)LSD in vivo, binding in hippocampus was scant and diffuse, although the pattern of labeling in cortex was similar to that seen in vitro. The low specific binding in hippocampus relative to cortex was confirmed by homogenate filtration studies ofmore » brain areas from mice that received injections of (/sup 3/H)LSD. Time-course studies established that peak specific binding at ten minutes was the same in cortex and hippocampus. At all times, binding in hippocampus was about one-third of that in cortex; in contrast, the concentration of free (/sup 3/H)LSD did not vary between regions. This finding was unexpected, because binding studies in vitro in membrane preparations indicated that the density and affinity of (/sup 3/H)LSD binding sites were similar in both brain regions. Saturation binding studies in vivo showed that the lower amount of (/sup 3/H)LSD binding in hippocampus was attributable to a lower density of sites labeled by (/sup 3/H)LSD. The pharmacological identify of (/sub 3/H)LSD binding sites in vivo may be relevant to the hallucinogenic properties of LSD and of other related hallucinogens.« less

NPYFa, A Chimeric Peptide of Met-Enkephalin, and NPFF Induces Tolerance-Free Analgesia.

PubMed

Mudgal, Annu; Kumar, Krishan; Mollereau, Catherine; Pasha, Santosh

2016-06-01

Methionine-enkephalin-Arg-Phe is an endogenous amphiactive analgesic peptide. Neuropeptide FF, on the other hand, is reported for its role in opioid modulation and tolerance development. Based on these reports, in the present study we designed a chimeric peptide NPYFa (YGGFMKKKPQRFamide), having the Met-enkephalin (opioid) and PQRFamide sequence of neuropeptide FF, which can then target both the opioid and neuropeptide FF receptors. We hypothesized that the chimeric peptide so designed would have both analgesic properties and further aid in understanding of the role of neuropeptide FF in the development of opiate tolerance. Our studies indicated that NPYFa induced an early onset, potent, dose-dependent and prolonged antinociception. Additionally, antagonists (MOR, KOR, and DOR) pretreatment studies determined a KOR-mediated antinociception activity of the ligand. Further, in vitro binding studies using the Eu-GTP-γS binding assay on cell lines expressing opioid and NPFF receptors showed binding to both the opioid and neuropeptide FF receptors suggesting a multiple receptor binding character of NPYFa. Moreover, chronic (6 days) treatment with NPYFa exhibited an absence of tolerance development subsequent to its analgesia. The current study proposes NPYFa as a potent, long-acting antinociceptor lacking tolerance development as well as a probe to study opioid analgesia and the associated complex mechanisms of tolerance development. © 2016 John Wiley & Sons A/S.

Demonstrate Scale-up Procedure for Glass Composite Material (GCM) for Incorporation of Iodine Loaded AgZ.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nenoff, Tina M.; Garino, Terry J.; Croes, Kenneth James

2015-07-01

Two large size Glass Composite Material (GCM) waste forms containing AgI-MOR were fabricated. One contained methyl iodide-loaded AgI-MOR that was received from Idaho National Laboratory (INL, Test 5, Beds 1 – 3) and the other contained iodine vapor loaded AgIMOR that was received from Oak Ridge National Laboratory (ORNL, SHB 2/9/15 ). The composition for each GCM was 20 wt% AgI-MOR and 80 wt% Ferro EG2922 low sintering temperature glass along with enough added silver flake to prevent any I2 loss during the firing process. The silver flake amounts were 1.2 wt% for the GCM with the INL AgI-MOR andmore » 3 wt% for the GCM contained the ORNL AgI-MOR. The GCMs, nominally 100 g, were first uniaxially pressed to 6.35 cm (2.5 inch) diameter disks then cold isostatically pressed, before firing in air to 550°C for 1hr. They were cooled slowly (1°C/min) from the firing temperature to avoid any cracking due to temperature gradients. The final GCMs were ~5 cm in diameter (~2 inches) and non-porous with densities of ~4.2 g/cm³. X-ray diffraction indicated that they consisted of the amorphous glass phase with small amounts of mordenite and AgI. Furthermore, the presence of the AgI was confirmed by X-ray fluorescence. Methodology for the scaled up production of GCMs to 6 inch diameter or larger is also presented.« less

Molecular interactions of alcohols with zeolite BEA and MOR frameworks.

PubMed

Stückenschneider, Kai; Merz, Juliane; Schembecker, Gerhard

2013-12-01

Zeolites can adsorb small organic molecules such as alcohols from a fermentation broth. Also in the zeolite-catalyzed conversion of alcohols to biofuels, biochemicals, or gasoline, adsorption is the first step. Several studies have investigated the adsorption of alcohols in different zeolites experimentally, but computational investigations in this field have mostly been restricted to zeolite MFI. In this study, the adsorption of C1-C4 alcohols in BEA and MOR was investigated using density functional theory (DFT). Calculated adsorption geometries and the corresponding energies of the designed cluster models were comparable to periodic calculations, and the adsorption energies were in the same range as the corresponding computational and experimental values reported in the literature for zeolite MFI. Thus, BEA and MOR may be good adsorption materials for alcohols in the field of downstream processing and catalysis. Aside from the DFT calculations, adsorption isotherms were determined experimentally in this study from aqueous solutions. For BEA, the adsorption of significant amounts of alcohol from aqueous solution was observed experimentally. In contrast, MOR was loaded with only a very small amount of alcohol. Although differences were found between the affinities obtained from gas-phase DFT calculations and those observed experimentally in aqueous solution, the computational data presented here represent molecular level information on the geometries and energies of C1-C4 alcohols adsorbed in zeolites BEA and MOR. This knowledge should prove very useful in the design of zeolite materials intended for use in adsorption and catalytic processes, as it allows adsorption behavior to be predicted via judiciously designed computational models.

Interacting Cannabinoid and Opioid Receptors in the Nucleus Accumbens Core Control Adolescent Social Play

PubMed Central

Manduca, Antonia; Lassalle, Olivier; Sepers, Marja; Campolongo, Patrizia; Cuomo, Vincenzo; Marsicano, Giovanni; Kieffer, Brigitte; Vanderschuren, Louk J. M. J; Trezza, Viviana; Manzoni, Olivier J. J.

2016-01-01

Social play behavior is a highly rewarding, developmentally important form of social interaction in young mammals. However, its neurobiological underpinnings remain incompletely understood. Previous work has suggested that opioid and endocannabinoid neurotransmission interact in the modulation of social play. Therefore, we combined behavioral, pharmacological, electrophysiological, and genetic approaches to elucidate the role of the endocannabinoid 2-arachidonoylglycerol (2-AG) in social play, and how cannabinoid and opioid neurotransmission interact to control social behavior in adolescent rodents. Systemic administration of the 2-AG hydrolysis inhibitor JZL184 or the opioid receptor agonist morphine increased social play behavior in adolescent rats. These effects were blocked by systemic pretreatment with either CB1 cannabinoid receptor (CB1R) or mu-opioid receptor (MOR) antagonists. The social play-enhancing effects of systemic morphine or JZL184 treatment were also prevented by direct infusion of the CB1R antagonist SR141716 and the MOR antagonist naloxone into the nucleus accumbens core (NAcC). Searching for synaptic correlates of these effects in adolescent NAcC excitatory synapses, we observed that CB1R antagonism blocked the effect of the MOR agonist DAMGO and, conversely, that naloxone reduced the effect of a cannabinoid agonist. These results were recapitulated in mice, and completely abolished in CB1R and MOR knockout mice, suggesting that the functional interaction between CB1R and MOR in the NAcC in the modulation of social behavior is widespread in rodents. The data shed new light on the mechanism by which endocannabinoid lipids and opioid peptides interact to orchestrate rodent socioemotional behaviors. PMID:27899885

Relationships of density, microfibril angle, and sound velocity with stiffness and strength in mature wood of Douglas-fir

Treesearch

B. Lachenbruch; G.R. Johnson; G.M. Downes; R. Evans

2010-01-01

The relative importance of density, acoustic velocity, and microfibril angle (MFA) for the prediction of stiffness (MOE) and strength (MOR) has not been well established for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). MOE and MOR of small clear specimens of mature wood were better predicted by density and velocity than by either variable...

Graphene decorated with mu-opioid receptor: the ionic screening effect and detection of enkephalin

NASA Astrophysics Data System (ADS)

Ping, Jinglei; Johnson, A. T. Charlie; Liu, Renyu; A. T. Charlie Johnson Team; Renyu Liu Collaboration

2015-03-01

We investigated the properties of graphene field effect transistors (GFETs) decorated with a computaionally redesigned, water-soluble variant of the human mu-opioid receptor (wsMOR) in physiological buffer solution. The shift of the Fermi level in the GFETs is quantitatively described by chemical-gating effect of charges on the wsMOR that are screened by the ionic solution. Our results suggest that sensitivity to the molecular target is lost when the Debye screening length of the solution is shorter than the distance from the graphene to the wsMOR; thus de-salting may be necessary when wsMOR decorated GFETs are used as biosensors in solution. We used this insight to detect DAMGO, a synthetic analog to the endogenous opioid peptide encephalin, at a concentration of 10 pM (5.1 pg/mL) in artificial cerebrospinal fluid (aCSF) diluted to 5% of its normal salt concentration. When the sensors were measured in a dry state, the limit of detection for DAGMO was 1 pM (0.5 pg/mL), one-third of the baseline in human body.Funding for this work was provided by DARPA.

Numerical Analysis of the Bending Properties of Cathay Poplar Glulam

PubMed Central

Gao, Ying; Wu, Yuxuan; Zhu, Xudong; Zhu, Lei; Yu, Zhiming; Wu, Yong

2015-01-01

This paper presents the formulae and finite element analysis models for predicting the Modulus of Elastic (MOE) and Modulus of Rupture (MOR) of Cathay poplar finger-jointed glulam. The formula of the MOE predicts the MOE of Cathay poplar glulam glued with one-component polyurethane precisely. Three formulae are used to predict the MOR, and Equation (12) predicts the MOR of Cathay poplar glulam precisely. The finite element analysis simulation results of both the MOE and MOR are similar to the experimental results. The predicted results of the finite element analysis are shown to be more accurate than those of the formulae, because the finite element analysis considers the glue layers, but the formulae do not. Three types of typical failure modes due to bending were summarized. The bending properties of Cathay poplar glulam were compared to those of Douglas fir glulam. The results show that Cathay poplar glulam has a lower stiffness, but a marginally higher strength. One-component polyurethane adhesive is shown to be more effective than resorcinol formaldehyde resin adhesive for Cathay poplar glulam. This study shows that Cathay poplar has the potential to be a glulam material in China. PMID:28793619

Platinum-ruthenium nanotubes and platinum-ruthenium coated copper nanowires as efficient catalysts for electro-oxidation of methanol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Jie; Cullen, David A.; Forest, Robert V.

2015-01-15

The sluggish kinetics of methanol oxidation reaction (MOR) is a major barrier to the commercialization of direct methanol fuel cells (DMFCs). In this study, we report a facile synthesis of platinum–ruthenium nanotubes (PtRuNTs) and platinum–ruthenium-coated copper nanowires (PtRu/CuNWs) by galvanic displacement reaction using copper nanowires as a template. The PtRu compositional effect on MOR is investigated; the optimum Pt/Ru bulk atomic ratio is about 4 and surface atomic ratio about 1 for both PtRuNTs and PtRu/CuNWs. Enhanced specific MOR activities are observed on both PtRuNTs and PtRu/CuNWs compared with the benchmark commercial carbon-supported PtRu catalyst (PtRu/C, Hispec 12100). Finally, x-raymore » photoelectron spectroscopy (XPS) reveals a larger extent of electron transfer from Ru to Pt on PtRu/CuNWs, which may lead to a modification of the d-band center of Pt and consequently a weaker bonding of CO (the poisoning intermediate) on Pt and a higher MOR activity on PtRu/CuNWs.« less

Occupational risks for idiopathic pulmonary fibrosis mortality in the United States.

PubMed

Pinheiro, Germania A; Antao, Vinicius C; Wood, John M; Wassell, James T

2008-01-01

Metal and wood dust exposures have been identified as possible occupational risk factors for idiopathic pulmonary fibrosis (IPF). We analyzed mortality data using ICD-10 code J84.1--"Other interstitial pulmonary diseases with fibrosis," derived age-adjusted mortality rates for 1999-2003, and assessed occupational risks for 1999, by calculating proportionate mortality ratios (PMRs) and mortality odds ratios (MORs) using a matched case-control approach. We identified 84,010 IPF deaths, with an age-adjusted mortality rate of 75.7 deaths/million. Mortality rates were highest among males, whites, and those aged 85 and older. Three industry categories with potential occupational exposures recognized as risk factors for IPF were identified: "Wood buildings and mobile homes" (PMR = 4.5, 95% confidence interval (CI) 1.2-11.6 and MOR = 5.3, 95% CI 1.2-23.8), "Metal mining" (PMR = 2.4, 95% CI 1.3-4.0 and MOR = 2.2, 95% CI 1.1-4.4), and "Fabricated structural metal products" (PMR = 1.9, 95% CI 1.1-3.1 and MOR = 1.7, 95% CI 1.0-3.1). Workers in these industry categories may benefit from toxicological studies and improved surveillance for this disease.

Molecular receptive range variation among mouse odorant receptors for aliphatic carboxylic acids

PubMed Central

Repicky, Sarah E.; Luetje, Charles W.

2009-01-01

The ability of mammals to identify and distinguish among many thousands of different odorants suggests a combinatorial use of odorant receptors, with each receptor detecting multiple odorants and each odorant interacting with multiple receptors. Numerous receptors may be devoted to the sampling of particularly important regions of odor space. Here we explore the similarities and differences in the molecular receptive ranges of four mouse odorant receptors (MOR23-1, MOR31-4, MOR32-11 and MOR40-4), which have previously been identified as receptors for aliphatic carboxylic acids. Each receptor was expressed in Xenopus oocytes, along with Gαolf and the cystic fibrosis transmembrane regulator to allow electrophysiological assay of receptor responses. We find that even though these receptors are relatively unrelated, there is extensive overlap among their receptive ranges. That is, these receptors sample a similar region of odor space. However, the receptive range of each receptor is unique. Thus, these receptors contribute to the depth of coverage of this small region of odor space. Such a group of receptors with overlapping, but distinct receptive ranges, may participate in making fine distinctions among complex mixtures of closely related odorant compounds. PMID:19166503

Quantitative autoradiography of the binding sites for ( sup 125 I) iodoglyburide, a novel high-affinity ligand for ATP-sensitive potassium channels in rat brain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gehlert, D.R.; Gackenheimer, S.L.; Mais, D.E.

1991-05-01

We have developed a high specific activity ligand for localization of ATP-sensitive potassium channels in the brain. When brain sections were incubated with ({sup 125}I)iodoglyburide (N-(2-((((cyclohexylamino)carbonyl)amino)sulfonyl)ethyl)-5-{sup 125}I-2- methoxybenzamide), the ligand bound to a single site with a KD of 495 pM and a maximum binding site density of 176 fmol/mg of tissue. Glyburide was the most potent inhibitor of specific ({sup 125}I)iodoglyburide binding to rat forebrain sections whereas iodoglyburide and glipizide were slightly less potent. The binding was also sensitive to ATP which completely inhibited binding at concentrations of 10 mM. Autoradiographic localization of ({sup 125}I)iodoglyburide binding indicated a broadmore » distribution of the ATP-sensitive potassium channel in the brain. The highest levels of binding were seen in the globus pallidus and ventral pallidum followed by the septohippocampal nucleus, anterior pituitary, the CA2 and CA3 region of the hippocampus, ventral pallidum, the molecular layer of the cerebellum and substantia nigra zona reticulata. The hilus and dorsal subiculum of the hippocampus, molecular layer of the dentate gyrus, cerebral cortex, lateral olfactory tract nucleus, olfactory tubercle and the zona incerta contained relatively high levels of binding. A lower level of binding (approximately 3- to 4-fold) was found throughout the remainder of the brain. These results indicate that the ATP-sensitive potassium channel has a broad presence in the rat brain and that a few select brain regions are enriched in this subtype of neuronal potassium channels.« less

14-Amino-4,5-Epoxymorphinan Derivatives and Their Pharmacological Actions

NASA Astrophysics Data System (ADS)

Lewis, John W.; Husbands, Stephen M.

14-Hydroxy-7,8-dihydromorphinone (oxymorphone) and its derivatives (oxycodone, naloxone, naltrexone) have become among the most important clinical agents to have been produced from opium. 14-Aminocodeinone and its 7,8-dihydro and morphinone derivatives are of more recent origin thanks to the work of Professor Gordon Kirby and his collaborators. The 14-amino parent compounds have proved of limited interest but their 14-acylamino- and 14-alkylamino derivatives have been extensively studied. The 4'-substituted cinnamoylamino-17-cyclopropylmethyl-7,8-dihydronormorphinones, C-CAM and M-CAM are the best available selective MOR irreversible antagonists and the related dihydrocodeinone MC-CAM, 4'-chlorocinnamoylamino-17-cyclopropylmethyl-7,8-dihydronorcodeinone, is a long-acting MOR partial agonist with extended MOR-pseudoirreversible antagonist activity that could be a candidate for pharmacotherapy of opiate abuse/dependence.

Evaluation of the In Vivo and Ex Vivo Binding of Novel BC1 Cannabinoid Receptor Radiotracers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, A.; Gatley, J.; Gifford, A.

The primary active ingredient of marijuana, 9-tetrahydrocannabinol, exerts its psychoactive effects by binding to cannabinoid CB1 receptors. These receptors are found throughout the brain with high concentrations in the hippocampus and cerebellum. The current study was conducted to evaluate the binding of a newly developed putative cannabinoid antagonist, AM630, and a classical cannabinoid 8-tetrahydrocannabinol as potential PET and/or SPECT imaging agents for brain CB1 receptors. For both of these ligands in vivo and ex vivo studies in mice were conducted. AM630 showed good overall brain uptake (as measure by %IA/g) and a moderately rapid clearance from the brain with amore » half-clearance time of approximately 30 minutes. However, AM630 did not show selective binding to CB1 cannabinoid receptors. Ex vivo autoradiography supported the lack of selective binding seen in the in vivo study. Similar to AM630, 8-tetrahydrocanibol also failed to show selective binding to CB1 receptor rich brain areas. The 8-tetrahydrocanibol showed moderate overall brain uptake and relatively slow brain clearance as compared to AM630. Further studies were done with AM2233, a cannabinoid ligand with a similar structure as AM630. These studies were done to develop an ex vivo binding assay to quantify the displacement of [131I]AM2233 binding by other ligands in Swiss-Webster and CB1 receptor knockout mice. By developing this assay we hoped to determine the identity of an unknown binding site for AM2233 present in the hippocampus of CB1 knockout mice. Using an approach based on incubation of brain slices prepared from mice given intravenous [131I]AM2233 in either the presence or absence of AM2233 (unlabelled) it was possible to demonstrate a significant AM2233-displacable binding in the Swiss-Webster mice. Future studies will determine if this assay is appropriate for identifying the unknown binding site for AM2233 in the CB1 knockout mice.« less

Comparison of nondestructive testing methods for evaluating No. 2 Southern Pine lumber: Part B, modulus of rupture

Treesearch

B.Z. Yang; R.D. Seale; R. Shmulsky; J. Dahlen; X. Wang

2017-01-01

The identification of strength-reducing characteristics that impact modulus of rupture (MOR) is a key differentiation between lumber grades. Because global design values for MOR are at the fifth percentile level and in-grade lumber can be highly variable, it is important that nondestructive evaluation technology be used to better discern the potential wood strength. In...

Maritime Mass Rescue Interventions: Availability and Associated Technology

DTIC Science & Technology

2010-12-01

MOR Liferaft Description: The Zodiac MOR (Means of Rescue) was specially developed to meet the latest requirements introduced for Roll On/Roll Off...Mass Rescue Interventions; Availability and Associated Technology NOTICE This document is disseminated under the sponsorship of the Department of...Homeland Security in the interest of information exchange. The United States Government assumes no liability for its contents or use thereof. The

Statistical models for the distribution of modulus of elasticity and modulus of rupture in lumber with implications for reliability calculations

Treesearch

Steve P. Verrill; Frank C. Owens; David E. Kretschmann; Rubin Shmulsky

2017-01-01

It is common practice to assume that a two-parameter Weibull probability distribution is suitable for modeling lumber properties. Verrill and co-workers demonstrated theoretically and empirically that the modulus of rupture (MOR) distribution of visually graded or machine stress rated (MSR) lumber is not distributed as a Weibull. Instead, the tails of the MOR...

Follow-Up Care for Older Women With Breast Cancer

DTIC Science & Technology

1999-08-01

range of patient outcomes, including primary tumor therapy and mortality, self -reported upper body function, and overall physical function. Methods...mor therapy, all cause mortality, self -reported function and overall physical function than upper body function, and overall physical was the interview...Major Analytic Variables mor therapy and all cause mortality, as well as self -reported upper body and overall physical Dependent Variables. Our first

Draft Genome Sequence of Arthrobacter chlorophenolicus Strain Mor30.16, Isolated from the Bean Rhizosphere.

PubMed

Miranda-Ríos, José Antonio; Ramírez-Trujillo, José Augusto; Nova-Franco, Bárbara; Lozano-Aguirre Beltrán, Luis Fernando; Iturriaga, Gabriel; Suárez-Rodríguez, Ramón

2015-05-07

Bacteria of the genus Arthrobacter are commonly found in the soil and plant rhizosphere. In this study we report the draft genome of Arthrobacter chlorophenolicus strain Mor30.16 that was isolated from rhizosphere of beans grown in Cuernavaca Morelos, Mexico. This strain promotes growth and ameliorates drought stress in bean plants. Copyright © 2015 Miranda-Ríos et al.

Heterogeneity of D2 dopamine receptors in different brain regions.

PubMed Central

Leonard, M N; Macey, C A; Strange, P G

1987-01-01

The binding of [3H]spiperone has been examined in membranes derived from different regions of bovine brain. In caudate nucleus, nucleus accumbens, olfactory tubercle and putamen binding is to D2 dopamine and 5HT2 serotonin receptors, whereas in cingulate cortex only serotonin 5HT2 receptor binding can be detected. D2 dopamine receptors were examined in detail in caudate nucleus, olfactory tubercle and putamen using [3H]spiperone binding in the presence of 0.3 microM-mianserin (to block 5HT2 serotonin receptors). No evidence for heterogeneity among D2 dopamine receptors either between brain regions or within a brain region was found from the displacements of [3H]spiperone binding by a range of antagonists, including dibenzazepines and substituted benzamides. Regulation of agonist binding by guanine nucleotides did, however, differ between regions. In caudate nucleus a population of agonist binding sites appeared resistant to guanine nucleotide regulation, whereas this was not the case in olfactory tubercle and putamen. PMID:2963621

Welding occupations and mortality from Parkinson's disease and other neurodegenerative diseases among United States men, 1985-1999.

PubMed

Stampfer, Meir J

2009-05-01

Metal welding produces gaseous fumes that contain manganese, resulting in potential occupational exposure to welders. It has been hypothesized that occupational exposure among welders could increase risk of Parkinson's disease and other neurodegenerative diseases. The present study examines welding occupation and mortality from neurodegenerative diseases among men in the United States using the National Cause of Death databases 1985 to 1999. Information was abstracted from death certificates for states that collected data on occupation. Of 4,252,490 men who died during the study period, 107,773 had welding-related occupations. Multivariable logistic regression models were used to calculate mortality odds ratios (MOR) and 95% confidence intervals (CI) for odds of dying from Parkinson's disease or other neurodegenerative diseases among men who were welders as compared with men of other occupations, adjusting for attained age, race, region of residence, and year of death. During the study period, 49,174 deaths were attributed to Parkinson's disease, 54,892 to Alzheimer's disease, and 19,018 to presenile dementia. There was no evidence of an increased odds of Parkinson's disease mortality among welders as compared with men with other occupations (MOR = 0.83, 95% CI 0.78-0.88). Furthermore, welding occupation was unrelated to the odds of mortality from Alzheimer's disease (MOR = 0.94, 95% CI 0.89-1.00) or presenile dementia (MOR = 0.96, 95% CI 0.87-1.06). Earlier research suggested that welding exposures could predispose individuals to earlier onset Parkinson's disease. However, there was no evidence in this data of an increased mortality odds ratio associated with welding occupations among men younger than 65 (MOR = 1.03, 95% CI 0.74-1.44); while there was a suggestion of a lower odds Parkinson's disease death among men age 65 years and older (MOR = 0.82, 95% CI 0.77-0.88). Data from this large study do not support an association between welding occupations and death from Parkinson's disease or other neurodegenerative diseases, nor that welders are at increased odds of dying from Parkinson's disease at a younger age.

(/sup 3/H)Ethylketocyclazocine binding to mouse brain membranes: evidence for a kappa opioid receptor type

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garzon, J.; Sanchez-Blazquez, P.; Lee, N.M.

1984-10-01

The binding of the putative kappa agonist ethylketocyclazocine (EKC) to synaptosomal membranes of mouse brain was studied. This benzomorphan was able to bind to different opioid receptors. A portion of this binding was not inhibited by the agonist naloxone, even at high concentrations (10 microM). This population of receptors, to which opioate alkaloids and opiod peptides display very low affinity, is probably the sigma receptor. Another class of binding sites was identified by the simultaneous addition of the selective agonists Sandoz FK-33824 and D-Ala2-D-Leu5-enkephalin, which blocked the access of EKC to mu and delta opioid receptors, respectively, leaving a portionmore » of naloxone-displaceable benzomorphan binding still detectable. Analysis of this remaining binding revealed a small population of receptors of high affinity, the kappa receptor. Therefore, EKC binds to the mu, delta, kappa and sigma receptors in the mouse brain, with similar affinities for the mu and kappa (0.22 and 0.15 nM). These results confirm the existence of a kappa opioid receptor type in the mouse brain.« less

Brain Information Sharing During Visual Short-Term Memory Binding Yields a Memory Biomarker for Familial Alzheimer's Disease.

PubMed

Parra, Mario A; Mikulan, Ezequiel; Trujillo, Natalia; Sala, Sergio Della; Lopera, Francisco; Manes, Facundo; Starr, John; Ibanez, Agustin

2017-01-01

Alzheimer's disease (AD) as a disconnection syndrome which disrupts both brain information sharing and memory binding functions. The extent to which these two phenotypic expressions share pathophysiological mechanisms remains unknown. To unveil the electrophysiological correlates of integrative memory impairments in AD towards new memory biomarkers for its prodromal stages. Patients with 100% risk of familial AD (FAD) and healthy controls underwent assessment with the Visual Short-Term Memory binding test (VSTMBT) while we recorded their EEG. We applied a novel brain connectivity method (Weighted Symbolic Mutual Information) to EEG data. Patients showed significant deficits during the VSTMBT. A reduction of brain connectivity was observed during resting as well as during correct VSTM binding, particularly over frontal and posterior regions. An increase of connectivity was found during VSTM binding performance over central regions. While decreased connectivity was found in cases in more advanced stages of FAD, increased brain connectivity appeared in cases in earlier stages. Such altered patterns of task-related connectivity were found in 89% of the assessed patients. VSTM binding in the prodromal stages of FAD are associated to altered patterns of brain connectivity thus confirming the link between integrative memory deficits and impaired brain information sharing in prodromal FAD. While significant loss of brain connectivity seems to be a feature of the advanced stages of FAD increased brain connectivity characterizes its earlier stages. These findings are discussed in the light of recent proposals about the earliest pathophysiological mechanisms of AD and their clinical expression. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Sub-4 nm PtZn Intermetallic Nanoparticles for Enhanced Mass and Specific Activities in Catalytic Electrooxidation Reaction

DOE PAGES

Qi, Zhiyuan; Xiao, Chaoxian; Liu, Cong; ...

2017-03-08

Atomically ordered intermetallic nanoparticles (iNPs) have sparked considerable interest in fuel cell applications by virtue of their exceptional electronic and structural properties. However, the synthesis of small iNPs in a controllable manner remains a formidable challenge because of the high temperature generally required in the formation of intermetallic phases. Here in this paper we report a general method for the synthesis of PtZn iNPs (3.2 ± 0.4 nm) on multiwalled carbon nanotubes (MWNT) via a facile and capping agent free strategy using a sacrificial mesoporous silica (mSiO 2) shell. The as-prepared PtZn iNPs exhibited ca. 10 times higher mass activitymore » in both acidic and basic solution toward the methanol oxidation reaction (MOR) compared to larger PtZn iNPs synthesized on MWNT without the mSiO 2 shell. Density functional theory (DFT) calculations predict that PtZn systems go through a “non-CO” pathway for MOR because of the stabilization of the OH* intermediate by Zn atoms, while a pure Pt system forms highly stable COH* and CO* intermediates, leading to catalyst deactivation. Experimental studies on the origin of the backward oxidation peak of MOR coincide well with DFT predictions. Moreover, the calculations demonstrate that MOR on smaller PtZn iNPs is energetically more favorable than larger iNPs, due to their high density of corner sites and lower-lying energetic pathway. Therefore, smaller PtZn iNPs not only increase the number but also enhance the activity of the active sites in MOR compared with larger ones. This work opens a new avenue for the synthesis of small iNPs with more undercoordinated and enhanced active sites for fuel cell applications.« less

Differential cardiorespiratory effects of endomorphin 1, endomorphin 2, DAMGO, and morphine.

PubMed

Czapla, M A; Gozal, D; Alea, O A; Beckerman, R C; Zadina, J E

2000-09-01

The novel endogenous mu-opioid receptor (MOR) agonists endomorphin 1 (EM1) and 2 (EM2) were tested for their cardiorespiratory effects in conscious, freely behaving rats. After systemic (intravenous) administration of EM1, EM2, or the selective MOR agonist DAMGO, analgesia, minute ventilation (V E), heart rate (HR) and mean arterial blood pressure (BP) were measured. The threshold dose for analgesia was similar for all 3 peptides ( approximately 900 nmol/kg). All 3 compounds elicited biphasic V E responses, with marked, short-lived V E depressions (4-6 s) followed by more sustained V E increases (10-12 min). However, compared with responses elicited by EM2 or DAMGO, EM1 decreased V E only at higher doses, and produced greater V E stimulation. Morphine produced a V E decrease, but no subsequent V E increase. EM2 and DAMGO decreased HR and BP, while EM1 decreased HR, but did not decrease BP in conscious rats at doses up to 9,600 nmol/kg. In anesthetized rats, all 3 peptides decreased HR and BP. The decreases in V E, HR, and BP were blocked by the MOR antagonist, naloxone HCI (NIx). Only the HR and BP responses, however, were blocked by naloxone-methiodide (MeNIx), indicating central mediation of V E responses and peripheral mediation of cardiovascular responses. We conclude that MOR-selective compounds vary in their cardiorespiratory response characteristics which could be linked to differential cellular actions. The results support the concept that the analgesic, respiratory, and cardiovascular effects of MOR agonists can be dissociated and that EM1-like compounds could provide the basis for novel, safer analgesics.

A tracer experiment to study flow paths of water in a forest soil

NASA Astrophysics Data System (ADS)

Feyen, H.; Wunderli, H.; Wydler, H.; Papritz, A.

1999-12-01

This contribution discusses a tracer experiment, which was performed to study the flow paths of water in a macroporous forest soil. The experiment was performed in the framework of a study on the cycling of nitrogen in forested Prealpine catchments, in which losses of nitrate from virtually pristine areas were observed. Two soil plots with distinct micro-topography and top-soil were investigated: a well drained mor humus on a mound and a wet muck humus in a small depression. To reveal the effect of the soil horizons on the flow regime, tracers were applied both onto the soil surface and injected into the sub-soil. Tracers injected directly into the gleyic sub-soil reached the outlet (at a distance of 3.3 m) about 1000 times faster than could be expected from the saturated hydraulic conductivity of the soil matrix. Peak concentrations were observed after 18 (muck humus, tracer recovery 31%) to 70 min (mor humus, tracer recovery 40%). The peak concentration was 10 times smaller on the drier mor humus plot as compared to the muck humus. The mobile water content of the sub-soil varied between 0.5 (muck humus) and 1.3% (mor humus) of the total available soil water. The discrepancy in residence time, peak concentration and volume of mobile water between both sub-soils can be attributed to the differently structured sub-soil (longer travel distance and mixing volume in the drier mor humus). Tracers applied onto the soil surface resulted in a much slower breakthrough (tracer peaks after 400-700 min). Thus, in contrast to the sub-soil, flow through the matrix was the predominating transport process in the upper humus layers of both plots.

Risk factors for typhoid in Darjeeling, West Bengal, India: evidence for practical action.

PubMed

Sharma, Puran K; Ramakrishnan, R; Hutin, Y; Manickam, P; Gupte, M D

2009-06-01

To identify risk factors for typhoid and propose prevention measures. Case-control study; we compared hospital-based typhoid cases defined as fever>38 degrees C for >or=3 days with four-fold rise in 'O' antibodies on paired sera (Widal) with community, age and neighbourhood matched controls. We obtained information on drinking water, fruits, vegetables, milk products and sanitation; and calculated matched odds ratios (MOR) and attributable fractions in the population (AFP) for the risk factors or failure to use prevention measures. The 123 typhoid cases (median age: 25 years, 47% female) and 123 controls did not differ with respect to baseline characteristics. Cases were less likely to store drinking water in narrow-mouthed containers (MOR: 0.4, 95% CI: 0.2-0.7, AFP 29%), tip containers to draw water (MOR: 0.4, 95% CI: 0.2-0.7, AFP 33%) and have home latrines (MOR: 0.5, 95% CI: 0.3-0.8, AFP 23%). Cases were more likely to consume butter (OR: 2.3, 95% CI: 1.3-4.1, AFP 28%), yoghurt (OR: 2.3, 95% CI: 1.4-3.7, AFP 34%) and raw fruits and vegetables, including onions (MOR: 2.1, 95% CI: 1.2-3.9, AFP 34%), cabbages (OR: 2.8, 95% CI: 1.7-4.8, AFP 44%) and unwashed guavas (OR: 1.9, 95% CI: 1.2-3, AFP 25%). Typhoid was associated with unsafe water and sanitation practices as well as with consumption of milk products, fruits and vegetables. We propose to chlorinate drinking water at the point of use, wash/cook raw fruits and vegetables and ensure safer preparation/storage of local milk products.

Endogenous Opioid Antagonism in Physiological Experimental Pain Models: A Systematic Review

PubMed Central

Werner, Mads U.; Pereira, Manuel P.; Andersen, Lars Peter H.; Dahl, Jørgen B.

2015-01-01

Opioid antagonists are pharmacological tools applied as an indirect measure to detect activation of the endogenous opioid system (EOS) in experimental pain models. The objective of this systematic review was to examine the effect of mu-opioid-receptor (MOR) antagonists in placebo-controlled, double-blind studies using ʻinhibitoryʼ or ʻsensitizingʼ, physiological test paradigms in healthy human subjects. The databases PubMed and Embase were searched according to predefined criteria. Out of a total of 2,142 records, 63 studies (1,477 subjects [male/female ratio = 1.5]) were considered relevant. Twenty-five studies utilized ʻinhibitoryʼ test paradigms (ITP) and 38 studies utilized ʻsensitizingʼ test paradigms (STP). The ITP-studies were characterized as conditioning modulation models (22 studies) and repetitive transcranial magnetic stimulation models (rTMS; 3 studies), and, the STP-studies as secondary hyperalgesia models (6 studies), ʻpainʼ models (25 studies), summation models (2 studies), nociceptive reflex models (3 studies) and miscellaneous models (2 studies). A consistent reversal of analgesia by a MOR-antagonist was demonstrated in 10 of the 25 ITP-studies, including stress-induced analgesia and rTMS. In the remaining 14 conditioning modulation studies either absence of effects or ambiguous effects by MOR-antagonists, were observed. In the STP-studies, no effect of the opioid-blockade could be demonstrated in 5 out of 6 secondary hyperalgesia studies. The direction of MOR-antagonist dependent effects upon pain ratings, threshold assessments and somatosensory evoked potentials (SSEP), did not appear consistent in 28 out of 32 ʻpainʼ model studies. In conclusion, only in 2 experimental human pain models, i.e., stress-induced analgesia and rTMS, administration of MOR-antagonist demonstrated a consistent effect, presumably mediated by an EOS-dependent mechanisms of analgesia and hyperalgesia. PMID:26029906

Sub-4 nm PtZn Intermetallic Nanoparticles for Enhanced Mass and Specific Activities in Catalytic Electrooxidation Reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qi, Zhiyuan; Xiao, Chaoxian; Liu, Cong

2017-03-22

Atomically ordered intermetallic nanoparticles (iNPs) have sparked considerable interest in fuel cell applications by virtue of their exceptional electronic and structural properties. However, the synthesis of small iNPs in a controllable manner remains a formidable challenge because of the high temperature generally required in the formation of intermetallic phases. Here we report a general method for the synthesis of PtZn. iNPs (3.2 +/- 0.4 nm) on multiwalled carbon nanotubes (MWNT) via a facile and capping agent free strategy using a sacrificial mesoporous silica (mSiO(2)) shell. The as-prepared PtZn iNPs exhibited ca. 10 times higher mass activity in both acidic andmore » basic solution toward the methanol oxidation reaction (MOR) compared to larger PtZn iNPs synthesized on MWNT without the mSiO2 shell. Density functional theory (DFT) calculations predict that PtZn systems go through a "non-CO" pathway for MOR because of the stabilization of the OH* intermediate by Zn atoms, while a pure Pt system forms highly stable COH* and CO* intermediates, leading to catalyst deactivation. Experimental studies on the origin of the backward oxidation peak of MOR coincide well with DFT predictions. Moreover, the calculations demonstrate that MOR on smaller PtZn iNPs is energetically more favorable than larger iNPs, due to their high density of corner sites and lower-lying energetic pathway. Therefore, smaller PtZn iNPs not only increase the number but also enhance the activity of the active sites in MOR compared with larger ones. This work opens a new avenue for the synthesis of small iNPs with more undercoordinated and enhanced active sites for fuel cell applications.« less

Enhanced Delivery of Galanin Conjugates to the Brain through Bioengineering of the Anti-Transferrin Receptor Antibody OX26.

PubMed

Thom, George; Burrell, Matthew; Haqqani, Arsalan S; Yogi, Alvaro; Lessard, Etienne; Brunette, Eric; Delaney, Christie; Baumann, Ewa; Callaghan, Deborah; Rodrigo, Natalia; Webster, Carl I; Stanimirovic, Danica B

2018-04-02

The blood-brain barrier (BBB) is a formidable obstacle for brain delivery of therapeutic antibodies. However, antibodies against the transferrin receptor (TfR), enriched in brain endothelial cells, have been developed as delivery carriers of therapeutic cargoes into the brain via a receptor-mediated transcytosis pathway. In vitro and in vivo studies demonstrated that either a low-affinity or monovalent binding of these antibodies to the TfR improves their release on the abluminal side of the BBB and target engagement in brain parenchyma. However, these studies have been performed with mouse-selective TfR antibodies that recognize different TfR epitopes and have varied binding characteristics. In this study, we evaluated serum pharmacokinetics and brain and CSF exposure of the rat TfR-binding antibody OX26 affinity variants, having K D s of 5 nM, 76 nM, 108 nM, and 174 nM, all binding the same epitope in bivalent format. Pharmacodynamic responses were tested in the Hargreaves chronic pain model after conjugation of OX26 affinity variants with the analgesic and antiepileptic peptide, galanin. OX26 variants with affinities of 76 nM and 108 nM showed enhanced brain and cerebrospinal fluid (CSF) exposure and higher potency in the Hargreaves model, compared to a 5 nM affinity variant; lowering affinity to 174 nM resulted in prolonged serum pharmacokinetics, but reduced brain and CSF exposure. The study demonstrates that binding affinity optimization of TfR-binding antibodies could improve their brain and CSF exposure even in the absence of monovalent TfR engagement.

Brain functional network connectivity based on a visual task: visual information processing-related brain regions are significantly activated in the task state.

PubMed

Yang, Yan-Li; Deng, Hong-Xia; Xing, Gui-Yang; Xia, Xiao-Luan; Li, Hai-Fang

2015-02-01

It is not clear whether the method used in functional brain-network related research can be applied to explore the feature binding mechanism of visual perception. In this study, we investigated feature binding of color and shape in visual perception. Functional magnetic resonance imaging data were collected from 38 healthy volunteers at rest and while performing a visual perception task to construct brain networks active during resting and task states. Results showed that brain regions involved in visual information processing were obviously activated during the task. The components were partitioned using a greedy algorithm, indicating the visual network existed during the resting state. Z-values in the vision-related brain regions were calculated, confirming the dynamic balance of the brain network. Connectivity between brain regions was determined, and the result showed that occipital and lingual gyri were stable brain regions in the visual system network, the parietal lobe played a very important role in the binding process of color features and shape features, and the fusiform and inferior temporal gyri were crucial for processing color and shape information. Experimental findings indicate that understanding visual feature binding and cognitive processes will help establish computational models of vision, improve image recognition technology, and provide a new theoretical mechanism for feature binding in visual perception.

Sulphur geodynamic cycle

PubMed Central

Kagoshima, Takanori; Sano, Yuji; Takahata, Naoto; Maruoka, Teruyuki; Fischer, Tobias P.; Hattori, Keiko

2015-01-01

Evaluation of volcanic and hydrothermal fluxes to the surface environments is important to elucidate the geochemical cycle of sulphur and the evolution of ocean chemistry. This paper presents S/3He ratios of vesicles in mid-ocean ridge (MOR) basalt glass together with the ratios of high-temperature hydrothermal fluids to calculate the sulphur flux of 100 Gmol/y at MOR. The S/3He ratios of high-temperature volcanic gases show sulphur flux of 720 Gmol/y at arc volcanoes (ARC) with a contribution from the mantle of 2.9%, which is calculated as 21 Gmol/y. The C/S flux ratio of 12 from the mantle at MOR and ARC is comparable to the C/S ratio in the surface inventory, which suggests that these elements in the surface environments originated from the upper mantle. PMID:25660256

Opiate receptor binding in the brain of the seizure sensitive Mongolian gerbil (Meriones unguiculatus).

PubMed

Lee, R J; Olsen, R W; Lomax, P; McCabe, R T; Wamsley, J K

1984-12-01

Opiate receptor binding was studied in seizure sensitive (SS) and seizure resistant (SR) strains of the Mongolian gerbil. Cryostat sections of the brain were labeled with [3H]-dihydromorphine, subjected to autoradiography and analysed by microdensitometry. SS gerbils, prior to seizure induction, demonstrated overall greater brain opiate binding when compared to SR animals. Immediately following a seizure, binding in the interpeduncular nucleus fell to levels found in SR animals. The increased opiate binding in the SS (pre-seizure) compared to SR gerbils could reflect a deficit of endogenous ligand which could underlie the seizure diathesis in the gerbil.

Specific binding of [(18)F]fluoroethyl-harmol to monoamine oxidase A in rat brain cryostat sections, and compartmental analysis of binding in living brain.

PubMed

Maschauer, Simone; Haller, Adelina; Riss, Patrick J; Kuwert, Torsten; Prante, Olaf; Cumming, Paul

2015-12-01

We investigated [(18)F]fluoroethyl-harmol ([(18)F]FEH) as a reversible and selective ligand for positron emission tomography (PET) studies of monoamine oxidase A (MAO-A). Binding of [(18)F]FEH in rat brain cryostat sections indicated high affinity (KD = 3 nM), and density (Bmax; 600 pmol/g). The plasma free fraction was 45%, and untransformed parent constituted only 13% of plasma radioactivity at 10 min after injection. Compartmental analysis of PET recordings in pargyline-treated rats showed high permeability to brain (K1; 0.32 mL/g/min) and slow washout (k2; 0.024/min), resulting in a uniformly high equilibrium distribution volume (VD; 20 mL/g). Using this VD to estimate unbound ligand in brain of untreated rats, the binding potential ranged from 4.2 in cerebellum to 7.2 in thalamus. We also calculated maps of rats receiving [(18)F]FEH at a range of specific activities, and then estimated saturation binding parameters in the living brain. In thalamus, striatum and frontal cortex KD was globally close to 300 nM and Bmax was close to 1600 pmol/g; the 100-fold discrepancy in affinity suggests a very low free fraction for [(18)F]FEH in the living brain. Based on a synthesis of findings, we calculate the endogenous dopamine concentration to be 0.4 μM in the striatal compartment containing MAO-A, thus unlikely to exert competition against [(18)F]FEH binding in vivo. In summary, [(18)F]FEH has good properties for the detection of MAO-A in the rat brain by PET, and may present logistic advantages for clinical research at centers lacking a medical cyclotron. We made a compartmental analysis of [(18)F]fluoroethylharmol ([(18)F]FEH) binding to monoamine oxidase A (MAO-A) in living rat brain and estimated the saturation binding parameters from the binding potential (BPND). The Bmax was of comparable magnitude to that in vitro, but with apparent affinity (300 nM), it was 100-fold lower in vivo. PET imaging with [(18) F]FEH is well suited for quantitation of MAO-A in living brain. © 2015 International Society for Neurochemistry.

Follow-Up Care for Older Women With Breast Cancer

DTIC Science & Technology

2000-05-01

better predictor of upper body mor therapy, all cause mortality, self -reported function and overall physical function than upper body function, and...outcomes, including primary tu- Major Analytic Variables mor therapy and all cause mortality, as well as self -reported upper body and overall physical ...comorbidity and their relation to a range of patient outcomes, including primary tumor therapy and mortality, self -reported upper body function, and overall

Morphine administration during low ovarian hormone stage results in transient over expression of fear memories in females.

PubMed

Perez-Torres, Emily M; Ramos-Ortolaza, Dinah L; Morales, Roberto; Santini, Edwin; Rios-Ruiz, Efrain J; Torres-Reveron, Annelyn

2015-01-01

Acute exposure to morphine after a traumatic event reduces trauma related symptoms in humans and conditioned fear expression in male rats. We aimed to determine whether acute administration of morphine alters consolidation of fear learning and extinction. Male and female rats in proestrus and metaestrus (high and low ovarian hormones respectively) underwent fear conditioning and received saline or morphine (2.5 mg/kg s.c.). The next day they underwent extinction. Results showed increased freezing during extinction only in the morphine metaestrus group while morphine did not affect males or proestrus females. Recall of extinction was similar on all groups. On a second experiment, a subset of rats conditioned during metaestrus was administered morphine prior to extinction producing no effects. We then measured mu opioid receptor (MOR) expression in the amygdala and periaqueductal gray (PAG) at the end of extinction (day 2). In males and proestrus females, morphine caused an increase in MOR in the amygdala but no in the PAG. In metaestrus females, morphine did not change MOR expression in either structure. These data suggests that ovarian hormones may interact with MORs in the amygdala to transiently alter memory consolidation. Morphine given after trauma to females with low ovarian hormones might increase the recall of fear responses, making recovery harder.

Characterization and localization of /sup 3/H-arginine8-vasopressin binding to rat kidney and brain tissue

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dorsa, D.M.; Majumdar, L.A.; Petracca, F.M.

Anatomic, behavioral and pharmacologic evidence suggests that arginine8-vasopressin (AVP) serves as a CNS neurotransmitter or neuromodulator. AVP binding to membrane and tissue slice preparations from brain and kidney was characterized, and the anatomical distribution of these binding sites was examined. Conditions for the binding assay were optimized using kidney medullary tissue. Binding of /sup 3/H-AVP (S.A. . 30-51 Ci/mmol, NEN) to brain and kidney membranes and tissue slices was saturable, temperature dependent, linearly related to protein concentration (or number of tissue slices), reversible, and specific since the ability of cold AVP to displace /sup 3/H-AVP from binding was greater thanmore » oxytocin and other related peptide fragments. Autoradiographic localization of /sup 3/H-AVP binding was restricted to kidney medullary tissue. In brain tissue, /sup 3/H-AVP binding was found to occur in concentrated foci. Brainstem areas such as the nucleus tractus solitarius (NTS) showed a high density of AVP binding sites. Since local injections of AVP into the NTS have been shown to influence blood pressure, the present study presents the first anatomical evidence for the presence of AVP specific binding sites which might mediate this effect.« less

Differential Effects of Structural Modifications on the Competition of Chalcones for the PIB Amyloid Imaging Ligand-Binding Site in Alzheimer's Disease Brain and Synthetic Aβ Fibrils.

PubMed

Fosso, Marina Y; McCarty, Katie; Head, Elizabeth; Garneau-Tsodikova, Sylvie; LeVine, Harry

2016-02-17

Alzheimer's disease (AD) is a complex brain disorder that still remains ill defined. In order to understand the significance of binding of different clinical in vivo imaging ligands to the polymorphic pathological features of AD brain, the molecular characteristics of the ligand interacting with its specific binding site need to be defined. Herein, we observed that tritiated Pittsburgh Compound B ((3)H-PIB) can be displaced from synthetic Aβ(1-40) and Aβ(1-42) fibrils and from the PIB binding complex purified from human AD brain (ADPBC) by molecules containing a chalcone structural scaffold. We evaluated how substitution on the chalcone scaffold alters its ability to displace (3)H-PIB from the synthetic fibrils and ADPBC. By comparing unsubstituted core chalcone scaffolds along with the effects of bromine and methyl substitution at various positions, we found that attaching a hydroxyl group on the ring adjacent to the carbonyl group (ring I) of the parent member of the chalcone family generally improved the binding affinity of chalcones toward ADPBC and synthetic fibrils F40 and F42. Furthermore, any substitution on ring I at the ortho-position of the carbonyl group greatly decreases the binding affinity of the chalcones, potentially as a result of steric hindrance. Together with the finding that neither our chalcones nor PIB interact with the Congo Red/X-34 binding site, these molecules provide new tools to selectively probe the PIB binding site that is found in human AD brain, but not in brains of AD pathology animal models. Our chalcone derivatives also provide important information on the effects of fibril polymorphism on ligand binding.

Fatty Acid Amide Hydrolase Binding in Brain of Cannabis Users: Imaging With the Novel Radiotracer [11C]CURB.

PubMed

Boileau, Isabelle; Mansouri, Esmaeil; Williams, Belinda; Le Foll, Bernard; Rusjan, Pablo; Mizrahi, Romina; Tyndale, Rachel F; Huestis, Marilyn A; Payer, Doris E; Wilson, Alan A; Houle, Sylvain; Kish, Stephen J; Tong, Junchao

2016-11-01

One of the major mechanisms for terminating the actions of the endocannabinoid anandamide is hydrolysis by fatty acid amide hydrolase (FAAH), and inhibitors of the enzyme were suggested as potential treatment for human cannabis dependence. However, the status of brain FAAH in cannabis use disorder is unknown. Brain FAAH binding was measured with positron emission tomography and [ 11 C]CURB in 22 healthy control subjects and ten chronic cannabis users during early abstinence. The FAAH genetic polymorphism (rs324420) and blood, urine, and hair levels of cannabinoids and metabolites were determined. In cannabis users, FAAH binding was significantly lower by 14%-20% across the brain regions examined than in matched control subjects (overall Cohen's d = 0.96). Lower binding was negatively correlated with cannabinoid concentrations in blood and urine and was associated with higher trait impulsiveness. Lower FAAH binding levels in the brain may be a consequence of chronic and recent cannabis exposure and could contribute to cannabis withdrawal. This effect should be considered in the development of novel treatment strategies for cannabis use disorder that target FAAH and endocannabinoids. Further studies are needed to examine possible changes in FAAH binding during prolonged cannabis abstinence and whether lower FAAH binding predates drug use. Copyright © 2016 Society of Biological Psychiatry. All rights reserved.

Fatty Acid Amide Hydrolase Binding in Brain of Cannabis Users: Imaging with the Novel Radiotracer [11C]CURB

PubMed Central

Boileau, Isabelle; Mansouri, Esmaeil; Williams, Belinda; Le Foll, Bernard; Rusjan, Pablo; Mizrahi, Romina; Tyndale, Rachel F.; Huestis, Marilyn A.; Payer, Doris E.; Wilson, Alan A.; Houle, Sylvain; Kish, Stephen J.; Tong, Junchao

2016-01-01

Background One of the major mechanisms for terminating the actions of the endocannabinoid anandamide is hydrolysis by fatty acid amide hydrolase (FAAH) and inhibitors of the enzyme were suggested as potential treatment for human cannabis dependence. However, the status of brain FAAH in cannabis use disorder is unknown. Methods Brain FAAH binding was measured with positron emission tomography and [11C]CURB in 22 healthy control subjects and ten chronic, frequent cannabis users during early abstinence. The FAAH genetic polymorphism (rs324420) and blood, urine and hair levels of cannabinoids and metabolites were determined. Results In cannabis users FAAH binding was significantly lower by 14–20% across the brain regions examined as compared to matched control subjects (overall Cohen’s d=0.96). Lower binding was negatively correlated with cannabinoid concentrations in blood and urine and was associated with higher trait impulsiveness. Conclusions Lower FAAH binding levels in the brain may be a consequence of chronic and recent cannabis exposure and could contribute to cannabis withdrawal. This effect should be considered in the development of novel treatment strategies for cannabis use disorder that target FAAH and endocannabinoids. Further studies are needed to examine possible changes in FAAH binding during prolonged cannabis abstinence and whether lower FAAH binding predates drug use. PMID:27345297

Mimicking brain tissue binding in an in vitro model of the blood-brain barrier illustrates differences between in vitro and in vivo methods for assessing the rate of brain penetration.

PubMed

Heymans, Marjolein; Sevin, Emmanuel; Gosselet, Fabien; Lundquist, Stefan; Culot, Maxime

2018-06-01

Assessing the rate of drug delivery to the central nervous system (CNS) in vitro has been used for decades to predict whether CNS drug candidates are likely to attain their pharmacological targets, located within the brain parenchyma, at an effective dose. The predictive value of in vitro blood-brain barrier (BBB) models is therefore frequently assessed by comparing in vitro BBB permeability, usually quoted as the endothelial permeability coefficient (P e ) or apparent permeability (P app ), to their rate of BBB permeation measured in vivo, the latter being commonly assessed in rodents. In collaboration with AstraZeneca (DMPK department, Södertälje, Sweden), the in vitro BBB permeability (P app and P e ) of 27 marketed CNS drugs has been determined using a bovine in vitro BBB model and compared to their in vivo permeability (P vivo ), obtained by rat in-situ brain perfusion. The latter was taken from published data from Summerfield et al. (2007). This comparison confirmed previous reports, showing a strong in vitro/in vivo correlation for hydrophilic compounds, characterized by low brain tissue binding and a weak correlation for lipophilic compounds, characterized by high brain tissue binding. This observation can be explained by the influence of brain tissue binding on the uptake of drugs into the CNS in vivo and the absence of possible brain tissue binding in vitro. The use of glial cells (GC) in the in vitro BBB model to mimic brain tissue binding and the introduction of a new calculation method for in vitro BBB permeability (P vitro ) resulted in a strong correlation between the in vitro and in vivo rate of BBB permeation for the whole set of compounds. These findings might facilitate further in vitro to in vivo extrapolation for CNS drug candidates. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

The Genomic Evolution of Prostate Cancer

DTIC Science & Technology

2017-06-01

This study is supported by the AACI Fellowship for Trans- lational Cancer Research and DOD Prostate Cancer Research Program PRTA (DVW) and the...degraded during post -mor- tem time before fixation, which is supported by the low quality of RNA from matched frozen tissue. A limitation of this study ...is that a portion of the study used autopsy specimens, which have already undergone some degree of post -mor- tem degradation prior to PAXgene and

[Effect of calcium and magnesium ions on the interaction of corticosterone with the cytosol receptor(s) in the rat brain].

PubMed

Ueda, M

1981-01-01

The effects of calcium and magnesium ions on the corticosterone binding to rat brain cytosol receptor protein(s) were investigated. The increasing amounts of CaCl2 or MgCl2 up to 5.0 mM were added, the specific [3H] corticosterone binding increased 1.3-fold and 1.5 respectively. The addition of MnCl2 and KCl did not affect this binding. The binding of corticosterone with rat brain cytosol receptor(s) were decreased by increasing amounts of EDTA and complete inhibition was observed at concentration equal to and greater than 2.5 mM. Inhibition of this binding by EDTA was less than by EGTA. Either theophylline or dibutyryl cyclic AMP had no effect on this binding.

Ictal lack of binding to brain parenchyma suggests integrity of the blood-brain barrier for 11C-dihydroergotamine during glyceryl trinitrate-induced migraine.

PubMed

Schankin, Christoph J; Maniyar, Farooq H; Seo, Youngho; Kori, Shashidar; Eller, Michael; Chou, Denise E; Blecha, Joseph; Murphy, Stephanie T; Hawkins, Randall A; Sprenger, Till; VanBrocklin, Henry F; Goadsby, Peter J

2016-07-01

SEE DREIER DOI 101093/AWW112 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: For many decades a breakdown of the blood-brain barrier has been postulated to occur in migraine. Hypothetically this would facilitate access of medications, such as dihydroergotamine or triptans, to the brain despite physical properties otherwise restricting their entry. We studied the permeability of the blood-brain barrier in six migraineurs and six control subjects at rest and during acute glyceryl trinitrate-induced migraine attacks using positron emission tomography with the novel radioligand (11)C-dihydroergotamine, which is chemically identical to pharmacologically active dihydroergotamine. The influx rate constant Ki, average dynamic image and time activity curve were assessed using arterial blood sampling and served as measures for receptor binding and thus blood-brain barrier penetration. At rest, there was binding of (11)C-dihydroergotamine in the choroid plexus, pituitary gland, and venous sinuses as expected from the pharmacology of dihydroergotamine. However, there was no binding to the brain parenchyma, including the hippocampus, the area with the highest density of the highest-affinity dihydroergotamine receptors, and the raphe nuclei, a postulated brainstem site of action during migraine, suggesting that dihydroergotamine is not able to cross the blood-brain barrier. This binding pattern was identical in migraineurs during glyceryl trinitrate-induced migraine attacks as well as in matched control subjects. We conclude that (11)C-dihydroergotamine is unable to cross the blood-brain barrier interictally or ictally demonstrating that the blood-brain barrier remains tight for dihydroergotamine during acute glyceryl trinitrate-induced migraine attacks. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved.

Positron emission tomographic evaluation of the putative dopamine-D3 receptor ligand, [11C]RGH-1756 in the monkey brain.

PubMed

Sóvágó, Judit; Farde, Lars; Halldin, Christer; Langer, Oliver; Laszlovszky, István; Kiss, Béla; Gulyás, Balázs

2004-10-01

The dopamine-D3 receptor is of special interest due to its postulated role in the pathophysiology and treatment of schizophrenia and Parkinson's Disease. Increasing evidences support the assumption that the D3 receptors are occupied to a high degree by dopamine at physiological conditions. Research on the functional role of the D3 receptors in brain has however been hampered by the lack of D3 selective ligands. In the present Positron Emission Tomography (PET) study the binding of the novel, putative dopamine-D3 receptor ligand, [11C]RGH-1756 was characterized in the cynomolgus monkey brain. [11C]RGH-1756 was rather homogenously distributed in brain and the regional binding potential (BP) values ranged between 0.17 and 0.48. Pretreatment with unlabelled RGH-1756 decreased radioligand binding to the level of the cerebellum in most brain areas. The regional BP values were lower after intravenous injection of a higher mass of RGH-1756, indicating saturable binding of [11C]RGH-1756. The D2/D3 antagonist raclopride partly inhibited the binding of [11C]RGH-1756 in several brain areas, including the striatum, mesencephalon and neocortex, whereas the 5HT(1A) antagonist WAY-100635 had no evident effect on [11C]RGH-1756 binding. Despite the promising binding characteristics of RGH-1756 in vitro the present PET-study indicates that [11C]RGH-1756 provides a low signal for specific binding to the D3 receptor in vivo. One explanation is that the favorable binding characteristics of RGH-1756 in vitro are not manifested in vivo. Alternatively, the results may support the hypothesis that the dopamine-D3 receptors are indeed occupied to a high extent by dopamine in vivo and thus not available for radioligand binding.

Efficacy of Massachusetts and 793B Vaccines Against Infectious Bronchitis Moroccan-Italy 02 Virus in Specific-Pathogen-Free Chickens and Commercial Broilers.

PubMed

Belkasmi, Sakhia F Z; Fellahi, Siham; Umar, Sajid; Delpont, Mattias; Delverdier, Maxence; Lucas, Marie-Noëlle; Bleuart, Céline; Kichou, Faouzi; Nassik, Saâdia; Guerin, Jean-Luc; Fihri, Ouafaa Fassi; Ducatez, Mariette F; El Houadfi, Mohammed

2017-12-01

The ability of commercial vaccines H120 and 4/91 to protect against Moroccan-Italy 02 infectious bronchitis virus (Mor-It02) was investigated in specific-pathogen-free (SPF) chickens and commercial broiler chickens. Commercial broiler chicks (Experiment 1) were vaccinated at the hatchery with H120 vaccine at Day 1, and challenged at Day 21 with 10 4 50% egg-infective dose (EID 50 ) of Mor-It02. All chicks were observed daily for clinical signs attributable to Mor-It02 infection during the 10 days postchallenge (pc). At 5 and 10 days pc, chicks were humanely sacrificed for necropsy examination, and tissues were collected for histopathology evaluation. To better understand the findings on commercial broilers, day-old SPF chicks were divided into five groups in a second experiment: Group Mass/4-91, vaccinated with H120 and 4/91 respectively at Days 1 and 15 of age; Group Mass/Mass, vaccinated by H120 at Days 1 and 15; Group Mass, vaccinated with H120 at Day 1; Group NV, kept unvaccinated; and Group NC, kept as a negative control (unchallenged). At Day 24 of age, Groups Mass/4-91, Mass/Mass, Mass, and NV were challenged with 10 4 EID 50 of Mor-It02. In both experiments, blood samples were collected at different periods for serologic analyses. Oropharyngeal swabs were collected for virus detection by reverse-transcription PCR. In Experiments 1 and 2, respiratory signs started as early as 24 hr pc and maximum severity was observed on Days 3 and 4 pc. The viral shedding rate was significantly lower in Group Mass/4-91 compared to other challenged groups. Serologic analysis in both experiments showed that the sera of challenged group exhibited significantly higher antibody titers than sera collected before challenge. Histopathologic investigations in SPF birds showed deciliation and hyperplasia in Group NV and less-pronounced lesions in Groups Mass/Mass and Mass. In commercial broilers vaccinated with H120 alone, hyperplasia and deciliation were observed in 90% of the tracheas. These experiments illustrated that Mor-It02 is pathogenic for chickens and a combination of live H120 and 4/91 vaccines given respectively at Day 1 and Day 15 of age confer a good protection against Mor-It02.

Preclinical Characterization of 18F-MK-6240, a Promising PET Tracer for In Vivo Quantification of Human Neurofibrillary Tangles.

PubMed

Hostetler, Eric D; Walji, Abbas M; Zeng, Zhizhen; Miller, Patricia; Bennacef, Idriss; Salinas, Cristian; Connolly, Brett; Gantert, Liza; Haley, Hyking; Holahan, Marie; Purcell, Mona; Riffel, Kerry; Lohith, Talakad G; Coleman, Paul; Soriano, Aileen; Ogawa, Aimie; Xu, Serena; Zhang, Xiaoping; Joshi, Elizabeth; Della Rocca, Joseph; Hesk, David; Schenk, David J; Evelhoch, Jeffrey L

2016-10-01

A PET tracer is desired to help guide the discovery and development of disease-modifying therapeutics for neurodegenerative diseases characterized by neurofibrillary tangles (NFTs), the predominant tau pathology in Alzheimer disease (AD). We describe the preclinical characterization of the NFT PET tracer 18 F-MK-6240. In vitro binding studies were conducted with 3 H-MK-6240 in tissue slices and homogenates from cognitively normal and AD human brain donors to evaluate tracer affinity and selectivity for NFTs. Immunohistochemistry for phosphorylated tau was performed on human brain slices for comparison with 3 H-MK-6240 binding patterns on adjacent brain slices. PET studies were performed with 18 F-MK-6240 in monkeys to evaluate tracer kinetics and distribution in the brain. 18 F-MK-6240 monkey PET studies were conducted after dosing with unlabeled MK-6240 to evaluate tracer binding selectivity in vivo. The 3 H-MK-6240 binding pattern was consistent with the distribution of phosphorylated tau in human AD brain slices. 3 H-MK-6240 bound with high affinity to human AD brain cortex homogenates containing abundant NFTs but bound poorly to amyloid plaque-rich, NFT-poor AD brain homogenates. 3 H-MK-6240 showed no displaceable binding in the subcortical regions of human AD brain slices and in the hippocampus/entorhinal cortex of non-AD human brain homogenates. In monkey PET studies, 18 F-MK-6240 displayed rapid and homogeneous distribution in the brain. The 18 F-MK-6240 volume of distribution stabilized rapidly, indicating favorable tracer kinetics. No displaceable binding was observed in self-block studies in rhesus monkeys, which do not natively express NFTs. Moderate defluorination was observed as skull uptake. 18 F-MK-6240 is a promising PET tracer for the in vivo quantification of NFTs in AD patients. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Evaluation of [11C]TAZA for amyloid β plaque imaging in postmortem human Alzheimer's disease brain region and whole body distribution in rodent PET/CT.

PubMed

Pan, Min-Liang; Mukherjee, Meenakshi T; Patel, Himika H; Patel, Bhavin; Constantinescu, Cristian C; Mirbolooki, M Reza; Liang, Christopher; Mukherjee, Jogeshwar

2016-04-01

Alzheimer's disease (AD) is a neurodegenerative disease characterized by Aβ plaques in the brain. The aim of this study was to evaluate the effectiveness of a novel radiotracer, 4-[(11) C]methylamino-4'-N,N-dimethylaminoazobenzene ([(11)C]TAZA), for binding to Aβ plaques in postmortem human brain (AD and normal control (NC)). Radiosyntheses of [(11)C]TAZA, related [(11)C]Dalene ((11)C-methylamino-4'-dimethylaminostyrylbenzene), and reference [(11)C]PIB were carried out using [(11)C]methyltriflate prepared from [(11) C]CO(2) and purified using HPLC. In vitro binding affinities were carried out in human AD brain homogenate with Aβ plaques labeled with [(3) H]PIB. In vitro autoradiography studies with the three radiotracers were performed on hippocampus of AD and NC brains. PET/CT studies were carried out in normal rats to study brain and whole body distribution. The three radiotracers were produced in high radiochemical yields (>40%) and had specific activities >37 GBq/μmol. TAZA had an affinity, K(i) = 0.84 nM and was five times more potent than PIB. [(11)C]TAZA bound specifically to Aβ plaques present in AD brains with gray matter to white matter ratios >20. [(11)C]TAZA was displaced by PIB (>90%), suggesting similar binding site for [(11)C]TAZA and [(11)C]PIB. [(11)C]TAZA exhibited slow kinetics of uptake in the rat brain and whole body images showed uptake in interscapular brown adipose tissue (IBAT). Binding in brain and IBAT were affected by preinjection of atomoxetine, a norepinephrine transporter blocker. [(11)C]TAZA exhibited high binding to Aβ plaques in human AD hippocampus. Rat brain kinetics was slow and peripheral binding to IBAT needs to be further evaluated. © 2016 Wiley Periodicals, Inc.

Autoradiographic analysis of the in vivo distribution of 3H-imipramine and 3H-desipramine in brain: Comparison to in vitro binding patterns

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duncan, G.E.; Paul, I.A.; Fassberg, J.B.

1991-03-01

Using high resolution autoradiographic techniques, the distribution of radioactivity in forebrain and brainstem was assessed after 4 injection of 3H-impramine or 3H-desipramine. Results were compared with regional binding of the drugs to brain sections in vitro. Similar topographic binding of 3H-imipramine and 3H-desipramine was observed in vitro among brain regions, except in the paraventricular nucleus of the hypothalamus and locus coeruleus, where binding was greater for 3H-desipramine. For both 3H-desipramine and 3H-imipramine, some brain regions that exhibited high binding in vitro also showed high accumulation after in vivo injection. However, certain regions that contained high densities of binding sites formore » the antidepressant drugs as measured by in vitro binding showed very low accumulation of radioactivity after in vivo treatment. Such regions included the dentate gyrus of the hippocampus, layer 1 of piriform cortex, caudate-putamen, pontine and midbrain central gray, and cerebellar granular layer. Compared to in vitro binding of the drugs, the distribution of imipramine and desipramine in vivo appears more anatomically selective. For imipramine, primary sites of action in vivo, as indicated by the topographic distribution in brain, appear to be the locus coeruleus, hippocampus, lateral septal nucleus, and amygdala. For desipramine, the greatest accumulation in vivo was found in the locus coeruleus, paraventricular nucleus of the hypothalamus, and anterior thalamic nuclei.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sawada, Y.; Kawai, R.; McManaway, M.

(3H)Cyclofoxy (CF: 17-cyclopropylmethyl-3,14-dihydroxy-4,5-alpha-epoxy-6-beta-fluoromorp hinan) is an opioid antagonist with affinity to both mu and kappa subtypes that was synthesized for quantitative evaluation of opioid receptor binding in vivo. Two sets of experiments in rats were analyzed. The first involved determining the metabolite-corrected blood concentration and tissue distribution of CF in brain 1 to 60 min after i.v. bolus injection. The second involved measuring brain washout for 15 to 120 s following intracarotid artery injection of CF. A physiologically based model and a classical compartmental pharmacokinetic model were compared. The models included different assumptions for transport across the blood-brain barrier (BBB);more » estimates of nonspecific tissue binding and specific binding to a single opiate receptor site were found to be essentially the same with both models. The nonspecific binding equilibrium constant varied modestly in different brain structures (Keq = 3-9), whereas the binding potential (BP) varied over a much broader range (BP = 0.6-32). In vivo estimates of the opioid receptor dissociation constant were similar for different brain structures (KD = 2.1-5.2 nM), whereas the apparent receptor density (Bmax) varied between 1 (cerebellum) and 78 (thalamus) pmol/g of brain. The receptor dissociation rate constants in cerebrum (k4 = 0.08-0.16 min-1; koff = 0.16-0.23 min-1) and brain vascular permeability (PS = 1.3-3.4 ml/min/g) are sufficiently high to achieve equilibrium conditions within a reasonable period of time. Graphical analysis of the data is inappropriate due to the high tissue-loss rate constant for CF in brain. From these findings, CF should be a very useful opioid receptor ligand for the estimation of the receptor binding parameters in human subjects using (18F)CF and positron emission tomography.« less

Regional variation in wood modulus of elasticity (stiffness) and modulus of rupture (strength) of planted loblolly pine in the United States

Treesearch

Antony Finto; Lewis Jordan; Laurence R. Schimleck; Alexander Clark; Ray A. Souter; Richard F. Daniels

2011-01-01

Modulus of elasticity (MOE), modulus of rupture (MOR), and specific gravity (SG) are important properties for determining the end-use and value of a piece of lumber. This study addressed the variation in MOE, MOR, and SG with physiographic region, tree height, and wood type. Properties were measured from two static bending samples (dimensions 25.4 mm × 25.4 mm × 406.4...

Silver-mordenite for radiologic gas capture from complex streams. Dual catalytic CH 3I decomposition and I confinement

DOE PAGES

Nenoff, Tina M.; Rodriguez, Mark A.; Soelberg, Nick R.; ...

2014-05-09

The selective capture of radiological iodine ( 129I) is a persistent concern for safe nuclear energy. In these nuclear fuel reprocessing scenarios, the gas streams to be treated are extremely complex, containing several distinct iodine-containing molecules amongst a large variety of other species. Silver-containing mordenite (MOR) is a longstanding benchmark for radioiodine capture, reacting with molecular iodine (I 2) to form AgI. However the mechanisms for organoiodine capture is not well understood. Here we investigate the capture of methyl iodide from complex mixed gas streams by combining chemical analysis of the effluent gas stream with in depth characterization of themore » recovered sorbent. Tools applied include infrared spectroscopy, thermogravimetric analysis with mass spectrometry, micro X-ray fluorescence, powder X-ray diffraction analysis, and pair distribution function analysis. Moreover, the MOR zeolite catalyzes decomposition of the methyl iodide through formation of surface methoxy species (SMS), which subsequently reacts with water in the mixed gas stream to form methanol, and with methanol to form dimethyl ether, which are both detected downstream in the effluent. The liberated iodine reacts with Ag in the MOR pore to the form subnanometer AgI clusters, smaller than the MOR pores, suggesting that the iodine is both physically and chemically confined within the zeolite.« less

Rice straw-wood particle composite for sound absorbing wooden construction materials.

PubMed

Yang, Han-Seung; Kim, Dae-Jun; Kim, Hyun-Joong

2003-01-01

In this study, rice straw-wood particle composite boards were manufactured as insulation boards using the method used in the wood-based panel industry. The raw material, rice straw, was chosen because of its availability. The manufacturing parameters were: a specific gravity of 0.4, 0.6, and 0.8, and a rice straw content (10/90, 20/80, and 30/70 weight of rice straw/wood particle) of 10, 20, and 30 wt.%. A commercial urea-formaldehyde adhesive was used as the composite binder, to achieve 140-290 psi of bending modulus of rupture (MOR) with 0.4 specific gravity, 700-900 psi of bending MOR with 0.6 specific gravity, and 1400-2900 psi of bending MOR with a 0.8 specific gravity. All of the composite boards were superior to insulation board in strength. Width and length of the rice straw particle did not affect the bending MOR. The composite boards made from a random cutting of rice straw and wood particles were the best and recommended for manufacturing processes. Sound absorption coefficients of the 0.4 and 0.6 specific gravity boards were higher than the other wood-based materials. The recommended properties of the rice straw-wood particle composite boards are described, to absorb noises, preserve the temperature of indoor living spaces, and to be able to partially or completely substitute for wood particleboard and insulation board in wooden constructions.

Moringa oleifera Lam.: Protease activity against blood coagulation cascade

PubMed Central

Satish, A; Sairam, Sudha; Ahmed, Faiyaz; Urooj, Asna

2012-01-01

Background: The present study evaluated the protease activity of aqueous extracts of Moringa oleifera (Moringaceae) leaf (MOL) and root (MOR). Materials and Methods: Protease activity was assayed using casein, human plasma clot and human fibrinogen as substrates. Results: Caseinolytic activity of MOL was significantly higher (P ≤ 0.05) than that of MOR. Similar observations were found in case of human plasma clot hydrolyzing activity, wherein MOL caused significantly higher (P ≤ 0.05) plasma clot hydrolysis than MOR. Zymographic techniques were used to detect proteolytic enzymes following electrophoretic separation in gels. Further, both the extracts exhibited significant procoagulant activity as reflected by a significant decrease (P ≤ 0.05) in recalcification time, accompanied by fibrinogenolytic and fibrinolytic activities; clotting time was decreased from 180 ± 10 sec to 119 ± 8 sec and 143 ± 10 sec by MOL and MOR, respectively, at a concentration of 2.5 mg/mL. Fibrinogenolytic (human fibrinogen) and fibrinolytic activity (human plasma clot) was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), plate method and colorimetric method. Zymographic profile indicated that both the extracts exerted their procoagulant activity by selectively hydrolyzing Aα and Bβ subunits of fibrinogen to form fibrin clot, thereby exhibiting fibrinogenolytic activity. However, prolonged incubation resulted in degradation of the formed fibrin clot, suggesting fibrinolytic like activity. Conclusions: These findings support the traditional usage of M. oleifera extracts for wound healing. PMID:22224061

Moringa oleifera Lam.: Protease activity against blood coagulation cascade.

PubMed

Satish, A; Sairam, Sudha; Ahmed, Faiyaz; Urooj, Asna

2012-01-01

The present study evaluated the protease activity of aqueous extracts of Moringa oleifera (Moringaceae) leaf (MOL) and root (MOR). Protease activity was assayed using casein, human plasma clot and human fibrinogen as substrates. Caseinolytic activity of MOL was significantly higher (P ≤ 0.05) than that of MOR. Similar observations were found in case of human plasma clot hydrolyzing activity, wherein MOL caused significantly higher (P ≤ 0.05) plasma clot hydrolysis than MOR. Zymographic techniques were used to detect proteolytic enzymes following electrophoretic separation in gels. Further, both the extracts exhibited significant procoagulant activity as reflected by a significant decrease (P ≤ 0.05) in recalcification time, accompanied by fibrinogenolytic and fibrinolytic activities; clotting time was decreased from 180 ± 10 sec to 119 ± 8 sec and 143 ± 10 sec by MOL and MOR, respectively, at a concentration of 2.5 mg/mL. Fibrinogenolytic (human fibrinogen) and fibrinolytic activity (human plasma clot) was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), plate method and colorimetric method. Zymographic profile indicated that both the extracts exerted their procoagulant activity by selectively hydrolyzing Aα and Bβ subunits of fibrinogen to form fibrin clot, thereby exhibiting fibrinogenolytic activity. However, prolonged incubation resulted in degradation of the formed fibrin clot, suggesting fibrinolytic like activity. These findings support the traditional usage of M. oleifera extracts for wound healing.

Identification and characterization of MOR-CP, a cysteine protease induced by ozone and developmental senescence in maize (Zea mays L.) leaves.

PubMed

Ahmad, Rafiq; Zuily-Fodil, Yasmine; Passaquet, Chantal; Bethenod, Olivier; Roche, Romain; Repellin, Anne

2014-08-01

Among the different classes of endoproteases, cysteine proteases are consistently associated with senescence, defense signaling pathways and cellular responses to abiotic stresses. The objectives of this work were to study the effects of various concentrations of ozone on gene expression and enzymatic activity for papain-like cysteine proteases (PLCPs), in the leaves of maize plants grown under field conditions. Leaves from ranks 12 and 10 (cob leaf) were harvested regularly over a long-term artificial ozone fumigation experiment (50 d). Tissues were tested for transcriptional and activity changes concerning cysteine proteases, using qRT-PCR for the newly identified ozone-responsive PLCP gene (Mor-CP) and synthetic oligopeptide Boc-Val-Leu-Lys-AMC as a PLCP-specific substrate, respectively. Results showed that developmental senescence induced a significant and progressive rise in CP activity, only in the older leaves 10 and had no effect on Mor-CP gene expression levels. On the other hand, ozone dramatically enhanced Mor-CP mRNA levels and global PLCP enzymatic activity in leaves 12 and 10, particularly toward the end of the treatment. Ozone impact was more pronounced in the older leaves 10. Together, these observations concurred to conclude that ozone stress enhances natural senescence processes, such as those related to proteolysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Distinct Mu, Delta, and Kappa Opioid Receptor Mechanisms Underlie Low Sociability and Depressive-Like Behaviors During Heroin Abstinence

PubMed Central

Lutz, Pierre-Eric; Ayranci, Gulebru; Chu-Sin-Chung, Paul; Matifas, Audrey; Koebel, Pascale; Filliol, Dominique; Befort, Katia; Ouagazzal, Abdel-Mouttalib; Kieffer, Brigitte L

2014-01-01

Addiction is a chronic disorder involving recurring intoxication, withdrawal, and craving episodes. Escaping this vicious cycle requires maintenance of abstinence for extended periods of time and is a true challenge for addicted individuals. The emergence of depressive symptoms, including social withdrawal, is considered a main cause for relapse, but underlying mechanisms are poorly understood. Here we establish a mouse model of protracted abstinence to heroin, a major abused opiate, where both emotional and working memory deficits unfold. We show that delta and kappa opioid receptor (DOR and KOR, respectively) knockout mice develop either stronger or reduced emotional disruption during heroin abstinence, establishing DOR and KOR activities as protective and vulnerability factors, respectively, that regulate the severity of abstinence. Further, we found that chronic treatment with the antidepressant drug fluoxetine prevents emergence of low sociability, with no impact on the working memory deficit, implicating serotonergic mechanisms predominantly in emotional aspects of abstinence symptoms. Finally, targeting the main serotonergic brain structure, we show that gene knockout of mu opioid receptors (MORs) in the dorsal raphe nucleus (DRN) before heroin exposure abolishes the development of social withdrawal. This is the first result demonstrating that intermittent chronic MOR activation at the level of DRN represents an essential mechanism contributing to low sociability during protracted heroin abstinence. Altogether, our findings reveal crucial and distinct roles for all three opioid receptors in the development of emotional alterations that follow a history of heroin exposure and open the way towards understanding opioid system-mediated serotonin homeostasis in heroin abuse. PMID:24874714

Low expression of D2R and Wntless correlates with high motivation for heroin.

PubMed

Tacelosky, Diana M; Alexander, Danielle N; Morse, Megan; Hajnal, Andras; Berg, Arthur; Levenson, Robert; Grigson, Patricia S

2015-12-01

Drug overdose now exceeds car accidents as the leading cause of accidental death in the United States. Of those drug overdoses, a large percentage of the deaths are due to heroin and/or pharmaceutical overdose, specifically misuse of prescription opioid analgesics. It is imperative, then, that we understand the mechanisms that lead to opioid abuse and addiction. The rewarding actions of opioids are mediated largely by the mu-opioid receptor (MOR), and signaling by this receptor is modulated by various interacting proteins. The neurotransmitter dopamine also contributes to opioid reward, and opioid addiction has been linked to reduced expression of dopamine D2 receptors (D2R) in the brain. That said, it is not known if alterations in the expression of these proteins relate to drug exposure and/or to the "addiction-like" behavior exhibited for the drug. Here, we held total drug self-administration constant across acquisition and showed that reduced expression of the D2R and the MOR interacting protein, Wntless, in the medial prefrontal cortex was associated with greater addiction-like behavior for heroin in general and with a greater willingness to work for the drug in particular. In contrast, reduced expression of the D2R in the nucleus accumbens and hippocampus was correlated with greater seeking during signaled nonavailability of the drug. Taken together, these data link reduced expression of both the D2R and Wntless to the explicit motivation for the drug rather than to differences in total drug intake per se. (c) 2015 APA, all rights reserved).

Fluctuations in [11C]SB207145 PET Binding Associated with Change in Threat-Related Amygdala Reactivity in Humans

PubMed Central

Fisher, Patrick MacDonald; Haahr, Mette Ewers; Jensen, Christian Gaden; Frokjaer, Vibe Gedsoe; Siebner, Hartwig Roman; Knudsen, Gitte Moos

2015-01-01

Serotonin critically affects the neural processing of emotionally salient stimuli, including indices of threat; however, how alterations in serotonin signaling contribute to changes in brain function is not well understood. Recently, we showed in a placebo-controlled study of 32 healthy males that brain serotonin 4 receptor (5-HT4) binding, assessed with [11C]SB207145 PET, was sensitive to a 3-week intervention with the selective serotonin reuptake inhibitor fluoxetine, supporting it as an in vivo model for fluctuations in central serotonin levels. Participants also underwent functional magnetic resonance imaging while performing a gender discrimination task of fearful, angry, and neutral faces. This offered a unique opportunity to evaluate whether individual fluctuations in central serotonin levels, indexed by change in [11C]SB207145 binding, predicted changes in threat-related reactivity (ie, fear and angry vs neutral faces) within a corticolimbic circuit including the amygdala and medial prefrontal and anterior cingulate cortex. We observed a significant association such that decreased brain-wide [11C]SB207145 binding (ie, increased brain serotonin levels) was associated with lower threat-related amygdala reactivity, whereas intervention group status did not predict change in corticolimbic reactivity. This suggests that in the healthy brain, interindividual responses to pharmacologically induced and spontaneously occurring fluctuations in [11C]SB207145 binding, a putative marker of brain serotonin levels, affect amygdala reactivity to threat. Our finding also supports that change in brain [11C]SB207145 binding may be a relevant marker for evaluating neurobiological mechanisms underlying sensitivity to threat and serotonin signaling. PMID:25560201

Comparison of (/sup 3/H)nicotine and (/sup 3/H)acetylcholine binding in mouse brain: regional distribution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sershen, H.; Reith, M.E.; Hashim, A.

1985-06-01

In a continuing study of nicotine binding sites, the authors determined the relative amount of nicotine binding and acetylcholine binding in various brain regions of C57/BL and of DBA mice. Although midbrain showed the highest and cerebellum the lowest binding for both (/sup 3/H)nicotine and (/sup 3/H)acetylcholine, the ratio of nicotine to acetylcholine binding showed a three-fold regional variation. Acetylcholine inhibition of (/sup 3/H)nicotine binding indicated that a portion of nicotine binding was not inhibited by acetylcholine. These results indicate important differences between the binding of (+/-)-(/sup 3/H)nicotine and that of (/sup 3/H)acetylcholine.

Characterization and localization of arginine vasotocin receptors in the brain and kidney of an amphibian

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boyd, S.K.

1987-01-01

Because arginine vasotocin (AVT) activates male sexual behaviors in the rough-skinned newt (Taricha granulosa), quantitative autoradiography with radiolabeled arginine vasopressin (/sup 3/H-AVP) was used to localize and characterize putative AVT receptors in the brain of this amphibian. Binding of /sup 3/H-AVP to sites within the medial pallium was saturable, specific, reversible, of high affinity and low capacity. These binding sites appear to represent authentic central nervous system receptors for AVT. Furthermore, ligand specificity for the binding sites in this amphibian differs from that reported for AVP binding sites in rat brains. Dense concentrations of specific binding sites were located inmore » the olfactory nerve as it entered the olfactory bulb within the medial pallium, dorsal pallium, and amygdala pars lateralis of the telencephalon, and in the tegmental region of the medulla. Concentrations of binding sites differed significantly among various brain regions. A comparison of male and female newts collected during the breeding season revealed no sexual dimorphism. These areas may represent site(s) of action where AVT elicits sexual behaviors in male T. granulosa.« less

Role of S fimbriae in Escherichia coli K1 binding to brain microvascular endothelial cells in vitro and penetration into the central nervous system in vivo.

PubMed

Wang, Ying; Wen, Zhang Guang; Kim, Kwang Sik

2004-12-01

Bacterial binding to host cell surface is considered an important initial step in the pathogenesis of many infectious diseases including meningitis. Previous studies using a laboratory Escherichia coli (E. coli) strain HB101 possessing a recombinant plasmid carrying the cloned S fimbriae gene cluster have shown that S fimbriae are the major contributor to binding to bovine brain microvascular endothelial cells (BMEC) for HB101. Our present study, however, revealed that S fimbriae did not play a major role for E. coli K1's binding to human BMEC in vitro and crossing of the blood-brain barrier in vivo. This was shown by our demonstration that E. coli K1 strain and its S fimbriae-operon deletion mutant exhibited similar rates of binding to human BMEC and similar rates of penetration into the central nervous system in the experimental hematogenous meningitis model. Studies are needed to identify major determinants of E. coli K1 contributing to BMEC binding and subsequent crossing of the blood-brain barrier in vivo.

High Tech High School Interns Develop a Mid-Ocean Ridge Database for Research and Education

NASA Astrophysics Data System (ADS)

Staudigel, D.; Delaney, R.; Staudigel, H.; Koppers, A. A.; Miller, S. P.

2004-12-01

Mid-ocean ridges (MOR) represent one of the most important geographical and geological features on planet Earth. MORs are the locations where plates spread apart, they are the locations of the majority of the Earths' volcanoes that harbor some of the most extreme life forms. These concepts attract much research, but mid-ocean ridges are still effectively underrepresented in the Earth science class rooms. As two High Tech High School students, we began an internship at Scripps to develop a database for mid-ocean ridges as a resource for science and education. This Ridge Catalog will be accessible via http://earthref.org/databases/RC/ and applies a similar structure, design and data archival principle as the Seamount Catalog under EarthRef.org. Major research goals of this project include the development of (1) an archival structure for multibeam and sidescan data, standard bathymetric maps (including ODP-DSDP drill site and dredge locations) or any other arbitrary digital objects relating to MORs, and (2) to compile a global data set for some of the most defining characteristics of every ridge segment including ridge segment length, depth and azimuth and half spreading rates. One of the challenges included the need of making MOR data useful to the scientist as well as the teacher in the class room. Since the basic structure follows the design of the Seamount Catalog closely, we could move our attention to the basic data population of the database. We have pulled together multibeam data for the MOR segments from various public archives (SIOExplorer, SIO-GDC, NGDC, Lamont), and pre-processed it for public use. In particular, we have created individual bathymetric maps for each ridge segment, while merging the multibeam data with global satellite bathymetry data from Smith & Sandwell (1997). The global scale of this database will give it the ability to be used for any number of applications, from cruise planning to data

Temperatures and cooling rates recorded in REE in coexisting pyroxenes in ophiolitic and abyssal peridotites

NASA Astrophysics Data System (ADS)

Dygert, Nick; Liang, Yan

2015-06-01

Mantle peridotites from ophiolites are commonly interpreted as having mid-ocean ridge (MOR) or supra-subduction zone (SSZ) affinity. Recently, an REE-in-two-pyroxene thermometer was developed (Liang et al., 2013) that has higher closure temperatures (designated as TREE) than major element based two-pyroxene thermometers for mafic and ultramafic rocks that experienced cooling. The REE-in-two-pyroxene thermometer has the potential to extract meaningful cooling rates from ophiolitic peridotites and thus shed new light on the thermal history of the different tectonic regimes. We calculated TREE for available literature data from abyssal peridotites, subcontinental (SC) peridotites, and ophiolites around the world (Alps, Coast Range, Corsica, New Caledonia, Oman, Othris, Puerto Rico, Russia, and Turkey), and augmented the data with new measurements for peridotites from the Trinity and Josephine ophiolites and the Mariana trench. TREE are compared to major element based thermometers, including the two-pyroxene thermometer of Brey and Köhler (1990) (TBKN). Samples with SC affinity have TREE and TBKN in good agreement. Samples with MOR and SSZ affinity have near-solidus TREE but TBKN hundreds of degrees lower. Closure temperatures for REE and Fe-Mg in pyroxenes were calculated to compare cooling rates among abyssal peridotites, MOR ophiolites, and SSZ ophiolites. Abyssal peridotites appear to cool more rapidly than peridotites from most ophiolites. On average, SSZ ophiolites have lower closure temperatures than abyssal peridotites and many ophiolites with MOR affinity. We propose that these lower temperatures can be attributed to the residence time in the cooling oceanic lithosphere prior to obduction. MOR ophiolites define a continuum spanning cooling rates from SSZ ophiolites to abyssal peridotites. Consistent high closure temperatures for abyssal peridotites and the Oman and Corsica ophiolites suggests hydrothermal circulation and/or rapid cooling events (e.g., normal faulting, unroofing) control the late thermal histories of peridotites from transform faults and slow and fast spreading centers with or without a crustal section.

High-silica Rocks from Oceans, Arcs and Ophiolites: What Can They Tell Us About Ophiolite Origins?

NASA Astrophysics Data System (ADS)

Perfit, M. R.; Lundstrom, C.; Wanless, V. D.

2015-12-01

Although the volumes of high-silica rocks in submarine oceanic and supra-subduction zone environments are not well constrained, their common occurrence, field relations and compositions have led to various hypotheses suggesting that silicic intrusions (plagiogranites) in ophiolites formed by similar processes to high-silica volcanic rocks at mid-ocean ridge (MOR) or island arc environments. Geochemical attributes of andesite-rhyolite suites from MOR (East Pacific Rise, Juan de Fuca Ridge, Galapagos Spreading Center, Pacific-Antarctic Rise) and back-arc basins (Manus Basin, Lau Basin, East Scotia Ridge) show both similarities and differences to plagiogranitic suites (qtz. diorite-tonalite-trondhjemite) from ophiolites (Troodos and Semail). Both suites are commonly attributed to: extreme (>90%) fractional crystallization of basaltic melts; fractional crystallization coupled with assimilation of hydrated oceanic crust (AFC); or partial melting of preexisting crust. Normalized incompatible trace element patterns show either highly elevated, relatively flat patterns with negative Eu and Sr anomalies similar to high silica volcanics or have complimentary patterns with low abundance, more depleted patterns with positive Eu and Sr anomalies. None of the mechanisms, however, provide a consistent explanation for the compositional and isotopic variations that are observed among plagiogranites. In fact, ophiolitic plagiogranites can have at least two petrogenetic signatures - one indicative of a MORB parent and another that has been related to later, off-axis formation associated with supra-subduction zone magmatism. Based on thermal gradient experiments, the systematic changes in Fe and Si stable isotope ratios with differentiation observed in ophiolite and MOR high-silica suites may result from melt-mineral reactions within a temperature gradient near the boundaries of MOR magma lenses. Comparative major element, trace element and isotopic data will be presented from MOR, BAB and ophiolites to address questions of their origins. Although the mechanism(s) by which plagiogranite bodies form and their relationship to andesitic to rhyolitic lavas still remains enigmatic geochemical comparisons between them provide important clues toward understanding their petrotectonic origins.

Increased risk of advanced neoplasms among asymptomatic siblings of patients with colorectal cancer.

PubMed

Ng, Siew C; Lau, James Y W; Chan, Francis K L; Suen, Bing Yee; Leung, Wai-Keung; Tse, Yee Kit; Ng, Simon S M; Lee, Janet F Y; To, Ka-Fai; Wu, Justin C Y; Sung, Joseph J Y

2013-03-01

Colorectal cancer (CRC) is the second-most common cancer in Hong Kong. Relatives of patients with CRC have an increased risk of colorectal neoplasm. We assessed the prevalence of advanced neoplasms among asymptomatic siblings of patients with CRC. Patients with CRC were identified from the Prince of Wales Hospital CRC Surgery Registry from 2001 to 2011. Colonoscopies were performed for 374 siblings of patients (age, 52.6 ± 7.4 y) and 374 age- and sex-matched siblings of healthy subjects who had normal colonoscopies and did not have a family history of CRC (controls, 52.7 ± 7.4 y). We identified individuals with advanced neoplasms (defined as cancers or adenomas of at least 10 mm in diameter, high-grade dysplasia, with villous or tubulovillous characteristics). The prevalence of advanced neoplasms was 7.5% among siblings of patients and 2.9% among controls (matched odds ratio [mOR], 3.07; 95% confidence interval [CI], 1.5-6.3; P = .002). The prevalence of adenomas larger than 10 mm was higher among siblings of patients than in controls (5.9% vs 2.1%; mOR, 3.34; 95% CI, 1.45-7.66; P = .004), as was the presence of colorectal adenomas (31.0% vs 18.2%; mOR, 2.19; 95% CI, 1.52-3.17; P < .001). Six cancers were detected among siblings of patients; no cancers were detected in controls. The prevalence of advanced neoplasms among siblings of patients was higher when their index case was female (mOR, 4.95; 95% CI, 1.81-13.55) and had distally located CRC (mOR, 3.10; 95% CI, 1.34-7.14). In Hong Kong, siblings of patients with CRC have a higher prevalence of advanced neoplasms, including CRC, than siblings of healthy individuals. Screening is indicated in this high-risk population. ClinicalTrials.gov number: NCT00164944. Copyright © 2013 AGA Institute. Published by Elsevier Inc. All rights reserved.

Characterization of ( sup 3 H)alprazolam binding to central benzodiazepine receptors

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCabe, R.T.; Mahan, D.R.; Smith, R.B.

1990-10-01

The binding of the triazolobenzodiazepine ({sup 3}H)alprazolam was studied to characterize the in vitro interactions with benzodiazepine receptors in membrane preparations of rat brain. Studies using nonequilibrium and equilibrium binding conditions for ({sup 3}H)alprazolam resulted in high specific to nonspecific (signal to noise) binding ratios. The binding of ({sup 3}H)alprazolam was saturable and specific with a low nanomolar affinity for benzodiazepine receptors in the rat brain. The Kd was 4.6 nM and the Bmax was 2.6 pmol/mg protein. GABA enhanced ({sup 3}H)alprazolam binding while several benzodiazepine receptor ligands were competitive inhibitors of this drug. Compounds that bind to other receptormore » sites had a very weak or negligible effect on ({sup 3}H)alprazolam binding. Alprazolam, an agent used as an anxiolytic and in the treatment of depression, acts in vitro as a selective and specific ligand for benzodiazepine receptors in the rat brain. The biochemical binding profile does not appear to account for the unique therapeutic properties which distinguish this compound from the other benzodiazepines in its class.« less

Mechanisms of extracellular signal-regulated kinase/cAMP response element-binding protein/brain-derived neurotrophic factor signal transduction pathway in depressive disorder☆

PubMed Central

Wang, Hongyan; Zhang, Yingquan; Qiao, Mingqi

2013-01-01

The extracellular signal-regulated kinase/cAMP response element-binding protein/brain-derived neurotrophic factor signal transduction pathway plays an important role in the mechanism of action of antidepressant drugs and has dominated recent studies on the pathogenesis of depression. In the present review we summarize the known roles of extracellular signal-regulated kinase, cAMP response element-binding protein and brain-derived neurotrophic factor in the pathogenesis of depression and in the mechanism of action of antidepressant medicines. The extracellular signal-regulated kinase/cAMP response element-binding protein/brain-derived neurotrophic factor pathway has potential to be used as a biological index to help diagnose depression, and as such it is considered as an important new target in the treatment of depression. PMID:25206732

Renilla luciferase reporter assay to study 3'UTR-driven posttranscriptional regulations of OPRM1.

PubMed

Vincelli, Gabriele; Bedini, Andrea

2015-01-01

The regulation of MOR expression at the level of mRNA is relevant for its role in pain transmission and in other functions involving opioid receptors. Recently, the role of the 3'UTR in the posttranscriptional regulation of MOR expression has been highlighted. Here we describe a Renilla luciferase reporter assay for the study of the effect of any selective treatment on the 3'UTR-dependent regulation of OPRM1 in a model of glial cells.

Proceedings of Military Operations Research Symposia (Index) Volume 3. 31st through 40th inclusive

DTIC Science & Technology

1980-11-01

Rist Prize, 35th MORS) 35-75 Couch Jr. and William H Newhart Jr), Designing to system performance/cost/effectiveness, 32-9 Benedict Frank C. Tactical...George L (with Creighton W Cook), Design -to- of threat-oriented ordnance for combat. (Rist Prize. cest: fact or fantasy. 32-125 35th MORS) 35-75...1 Cook Creighton IV (with George L Arnold). Design -to- performance in military vehicles. 35-92 cost: fact or fantasy. 32-125 Dixon Thomas E (with Rif

Inhibition of [11C]mirtazapine binding by alpha2-adrenoceptor antagonists studied by positron emission tomography in living porcine brain.

PubMed

Smith, Donald F; Dyve, Suzan; Minuzzi, Luciano; Jakobsen, Steen; Munk, Ole L; Marthi, Katalin; Cumming, Paul

2006-06-15

We have developed [(11)C]mirtazapine as a ligand for PET studies of antidepressant binding in living brain. However, previous studies have determined neither optimal methods for quantification of [(11)C]mirtazapine binding nor the pharmacological identity of this binding. To obtain that information, we have now mapped the distribution volume (V(d)) of [(11)C]mirtazapine relative to the arterial input in the brain of three pigs, in a baseline condition and after pretreatment with excess cold mirtazapine (3 mg/kg). Baseline V(d) ranged from 6 ml/ml in cerebellum to 18 ml/ml in frontal cortex, with some evidence for a small self-displaceable binding component in the cerebellum. Regional binding potentials (pBs) obtained by a constrained two-compartment model, using the V(d) observation in cerebellum, were consistently higher than pBs obtained by other arterial input or reference tissue methods. We found that adequate quantification of pB was obtained using the simplified reference tissue method. Concomitant PET studies with [(15)O]-water indicated that mirtazapine challenge increased CBF uniformly in cerebellum and other brain regions, supporting the use of this reference tissue for calculation of [(11)C]mirtazapine pB. Displacement by mirtazapine was complete in the cerebral cortex, but only 50% in diencephalon, suggesting the presence of multiple binding sites of differing affinities in that tissue. Competition studies with yohimbine and RX 821002 showed decreases in [(11)C]mirtazapine pB throughout the forebrain; use of the multireceptor version of the Michaelis-Menten equation indicated that 42% of [(11)C]mirtazapine binding in cortical regions is displaceable by yohimbine. Thus, PET studies confirm that [(11)C]mirtazapine affects alpha(2)-adrenoceptor binding sites in living brain. (c) 2006 Wiley-Liss, Inc.

Pharmacological evaluation of an [(123)I] labelled imidazopyridine-3-acetamide for the study of benzodiazepine receptors.

PubMed

Mattner, Filomena; Mardon, Karine; Loc'h, Christian; Katsifis, Andrew

2006-06-13

In vitro binding of the iodinated imidazopyridine, N',N'-dimethyl-6-methyl-(4'-[(123)I]iodophenyl)imidazo[1,2-a]pyridine-3-acetamide [(123)I]IZOL to benzodiazepine binding sites on brain cortex, adrenal and kidney membranes is reported. Saturation experiments showed that [(123)I]IZOL, bound to a single class of binding site (n(H)=0.99) on adrenal and kidney mitochondrial membranes with a moderate affinity (K(d)=30 nM). The density of binding sites was 22+/-6 and 1.2+/-0.4 pmol/mg protein on adrenal and kidney membranes, respectively. No specific binding was observed in mitochondrial-synaptosomal membranes of brain cortex. In biodistribution studies in rats, the highest uptake of [(123)I]IZOL was found 30 min post injection in adrenals (7.5% ID/g), followed by heart, kidney, lung (1% ID/g) and brain (0.12% ID/g), consistent with the distribution of peripheral benzodiazepine binding sites. Pre-administration of unlabelled IZOL and the specific PBBS drugs, PK 11195 and Ro 5-4864 significantly reduced the uptake of [(123)I]IZOL by 30% (p<0.05) in olfactory bulbs and by 51-86% (p<0.01) in kidney, lungs, heart and adrenals, while it increased by 30% to 50% (p<0.01) in the rest of the brain and the blood. Diazepam, a mixed CBR-PBBS drug, inhibited the uptake in kidney, lungs, heart, adrenals and olfactory bulbs by 32% to 44% (p<0.01) but with no effect on brain uptake and in blood concentration. Flumazenil, a central benzodiazepine drug and haloperidol (dopamine antagonist/sigma receptor drug) displayed no effect in [(123)I]IZOL in peripheral organs and in the brain. [(123)I]IZOL may deserve further development for imaging selectively peripheral benzodiazepine binding sites.

Epidemic leptospirosis associated with pulmonary hemorrhage-Nicaragua, 1995.

PubMed

Trevejo, R T; Rigau-Pérez, J G; Ashford, D A; McClure, E M; Jarquín-González, C; Amador, J J; de los Reyes, J O; Gonzalez, A; Zaki, S R; Shieh, W J; McLean, R G; Nasci, R S; Weyant, R S; Bolin, C A; Bragg, S L; Perkins, B A; Spiegel, R A

1998-11-01

In October 1995, epidemic "hemorrhagic fever," without jaundice or renal manifestations, was reported in rural Nicaragua following heavy flooding; 2259 residents were evaluated for nonmalarial febrile illnesses (cumulative incidence, 6.1%) and 15 (0.7%) died with pulmonary hemorrhage. A case-control study found that case-patients were more likely than controls to have ever walked in creeks (matched odds ratio [MOR], 15.0; 95% confidence interval [CI], 1.7-132.3), have household rodents (MOR, 10.4; 95% CI, 1.1-97.1), or own dogs with titers >/=400 to Leptospira species (MOR, 23.4; 95% CI, 3.6-infinity). Twenty-six of 51 case-patients had serologic or postmortem evidence of acute leptospirosis. Leptospira species were isolated from case-patients and potential animal reservoirs. This leptospirosis epidemic likely resulted from exposure to flood waters contaminated by urine from infected animals, particularly dogs. Leptospirosis should be included in the differential diagnosis for nonmalarial febrile illness, particularly during periods of flooding or when pulmonary hemorrhage occurs.

Controlled Synthesis of Pt Nanowires with Ordered Large Mesopores for Methanol Oxidation Reaction

NASA Astrophysics Data System (ADS)

Zhang, Chengwei; Xu, Lianbin; Yan, Yushan; Chen, Jianfeng

2016-08-01

Catalysts for methanol oxidation reaction (MOR) are at the heart of key green-energy fuel cell technology. Nanostructured Pt materials are the most popular and effective catalysts for MOR. Controlling the morphology and structure of Pt nanomaterials can provide opportunities to greatly increase their activity and stability. Ordered nanoporous Pt nanowires with controlled large mesopores (15, 30 and 45 nm) are facilely fabricated by chemical reduction deposition from dual templates using porous anodic aluminum oxide (AAO) membranes with silica nanospheres self-assembled in the channels. The prepared mesoporous Pt nanowires are highly active and stable electrocatalysts for MOR. The mesoporous Pt nanowires with 15 nm mesopores exhibit a large electrochemically active surface area (ECSA, 40.5 m2 g-1), a high mass activity (398 mA mg-1) and specific activity (0.98 mA cm-2), and a good If/Ib ratio (1.15), better than the other mesoporous Pt nanowires and the commercial Pt black catalyst.

Cholera Epidemic Associated with Consumption of Unsafe Drinking Water and Street-Vended Water—Eastern Freetown, Sierra Leone, 2012

PubMed Central

Nguyen, Von D.; Sreenivasan, Nandini; Lam, Eugene; Ayers, Tracy; Kargbo, David; Dafae, Foday; Jambai, Amara; Alemu, Wondimagegnehu; Kamara, Abdul; Islam, M. Sirajul; Stroika, Steven; Bopp, Cheryl; Quick, Robert; Mintz, Eric D.; Brunkard, Joan M.

2014-01-01

During 2012, Sierra Leone experienced a cholera epidemic with 22,815 reported cases and 296 deaths. We conducted a matched case-control study to assess risk factors, enrolling 49 cases and 98 controls. Stool specimens were analyzed by culture, polymerase chain reaction (PCR), and pulsed-field gel electrophoresis (PFGE). Conditional logistic regression found that consuming unsafe water (matched odds ratio [mOR]: 3.4; 95% confidence interval [CI]: 1.1, 11.0), street-vended water (mOR: 9.4; 95% CI: 2.0, 43.7), and crab (mOR: 3.3; 95% CI: 1.03, 10.6) were significant risk factors for cholera infection. Of 30 stool specimens, 13 (43%) showed PCR evidence of toxigenic Vibrio cholerae O1. Six specimens yielded isolates of V. cholerae O1, El Tor; PFGE identified a pattern previously observed in seven countries. We recommended ensuring the quality of improved water sources, promoting household chlorination, and educating street vendors on water handling practices. PMID:24470563

Cholera epidemic associated with consumption of unsafe drinking water and street-vended water--Eastern Freetown, Sierra Leone, 2012.

PubMed

Nguyen, Von D; Sreenivasan, Nandini; Lam, Eugene; Ayers, Tracy; Kargbo, David; Dafae, Foday; Jambai, Amara; Alemu, Wondimagegnehu; Kamara, Abdul; Islam, M Sirajul; Stroika, Steven; Bopp, Cheryl; Quick, Robert; Mintz, Eric D; Brunkard, Joan M

2014-03-01

During 2012, Sierra Leone experienced a cholera epidemic with 22,815 reported cases and 296 deaths. We conducted a matched case-control study to assess risk factors, enrolling 49 cases and 98 controls. Stool specimens were analyzed by culture, polymerase chain reaction (PCR), and pulsed-field gel electrophoresis (PFGE). Conditional logistic regression found that consuming unsafe water (matched odds ratio [mOR]: 3.4; 95% confidence interval [CI]: 1.1, 11.0), street-vended water (mOR: 9.4; 95% CI: 2.0, 43.7), and crab (mOR: 3.3; 95% CI: 1.03, 10.6) were significant risk factors for cholera infection. Of 30 stool specimens, 13 (43%) showed PCR evidence of toxigenic Vibrio cholerae O1. Six specimens yielded isolates of V. cholerae O1, El Tor; PFGE identified a pattern previously observed in seven countries. We recommended ensuring the quality of improved water sources, promoting household chlorination, and educating street vendors on water handling practices.

Graphene-cobaltite-Pd hybrid materials for use as efficient bifunctional electrocatalysts in alkaline direct methanol fuel cells.

PubMed

Sharma, Chandra Shekhar; Awasthi, Rahul; Singh, Ravindra Nath; Sinha, Akhoury Sudhir Kumar

2013-12-14

Hybrid materials comprising of Pd, MCo2O4 (where M = Mn, Co or Ni) and graphene have been prepared for use as efficient bifunctional electrocatalysts in alkaline direct methanol fuel cells. Structural and electrochemical characterizations were carried out using X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, chronoamperometry and cyclic, CO stripping, and linear sweep voltammetries. The study revealed that all the three hybrid materials are active for both methanol oxidation (MOR) and oxygen reduction (ORR) reactions in 1 M KOH. However, the Pd-MnCo2O4/GNS hybrid electrode exhibited the greatest MOR and ORR activities. This active hybrid electrode has also outstanding stability under both MOR and ORR conditions, while Pt- and other Pd-based catalysts undergo degradation under similar experimental conditions. The Pd-MnCo2O4/GNS hybrid catalyst exhibited superior ORR activity and stability compared to even Pt in alkaline solutions.

Mars observer radio science (MORS) observations in polar regions

NASA Technical Reports Server (NTRS)

Simpson, Richard A.

1992-01-01

MORS observations will focus on two major areas of study: (1) the gravity field of Mars and its interpretation in terms of internal structure and history and (2) the structure of the atmosphere, with emphasis on both temperature-pressure profiles of the background atmosphere and small scale inhomogeneities resulting from turbulence. Scattering of cm wavelength radio signals from Mars' surface at highly oblique angles will also be studied during the primary mission; nongrazing scattering experiments may be possible during an extended mission. During the MORS primary mission, measurements of the spacecraft distance and velocity with respect to Earth based tracking stations will be used to develop models of the global gravity field. The improvement in knowledge of the gravity field will be especially evident in polar regions. The spatial and temporal coverage of atmospheric radio occultation measurements are determined by the geometry of the spacecraft orbit and the direction to the Earth. Profiles of atmospheric temperature and pressure will extend from the surface to altitudes of 50 to 70 km.

Binding of (/sup 3/H)forskolin to solubilized preparations of adenylate cyclase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nelson, C.A.; Seamon, K.B.

1988-01-01

The binding of (/sup 3/H)forskolin to proteins solubilized from bovine brain membranes was studied by precipitating proteins with polyethylene glycol and separating (/sup 3/H)forskolin bound to protein from free (/sup 3/H)forskolin by rapid filtration. The K/sub d/ for (/sup 3/H)forskolin binding to solubilized proteins was 14 nM which was similar to that for (/sup 3/H)forskolin binding sites in membranes from rat brain and human platelets. Forskolin analogs competed for (/sup 3/H)forskolin binding sites with the same rank potency in both brain membranes and in proteins solubilized from brain membranes. (/sup 3/H)forskolin bound to proteins solubilized from membranes with a Bmaxmore » of 38 fmolmg protein which increased to 94 fmolmg protein when GppNHp was included in the binding assay. In contrast, GppNHp had no effect on (/sup 3/H)forskolin binding to proteins solubilized from membranes preactivated with GppNHp. Solubilized adenylate cyclase from non-preactivated membranes had a basal activity of 130 pmolmgmin which was increased 7-fold by GppNHp. In contrast, adenylate cyclase from preactivated membranes had a basal activity of 850 pmolmgmin which was not stimulated by GppNHp or forskolin« less

The role of metals in mammalian olfaction of low molecular weight organosulfur compounds

PubMed Central

Block, Eric; Batista, Victor S.; Matsunami, Hiroaki; Zhuang, Hanyi; Ahmed, Lucky

2017-01-01

While suggestions concerning the possible role of metals in olfaction and taste date back 50 years, only recently has it been possible to confirm these proposals with experiments involving individual olfactory receptors (ORs). A detailed discussion of recent experimental results demonstrating the key role of metals in enhancing the response of human and other vertebrate ORs to specific odorants is presented against the backdrop of our knowledge of how the sense of smell functions both at the molecular and whole animal levels. This review emphasizes the role of metals in the detection of low molecular weight thiols, sulfides, and other organosulfur compounds, including those found in strong-smelling animal excretions and plant volatiles, and those used in gas odorization. Alternative theories of olfaction are described, with evidence favoring the modified “shape” theory. The use of quantum mechanical/molecular modeling (QM/MM), site-directed mutagenesis and saturation-transfer-difference (STD) NMR is discussed, providing support for biological studies of mouse and human receptors, MOR244-3 and OR OR2T11, respectively. Copper is bound at the active site of MOR244-3 by cysteine and histidine, while cysteine, histidine and methionine are involved with OR2T11. The binding pockets of these two receptors are found in different locations in the three-dimensional seven transmembrane models. Another recently deorphaned human olfactory receptor, OR2M3, highly selective for a thiol from onions, and a broadly-tuned thiol receptor, OR1A1, are also discussed. Other topics covered include the effects of nanoparticles and heavy metal toxicants on vertebrate and fish ORs, intranasal zinc products and the loss of smell (anosmia). PMID:28471462

Opiorphin causes a panicolytic-like effect in rat panic models mediated by μ-opioid receptors in the dorsal periaqueductal gray.

PubMed

Maraschin, Jhonatan Christian; Rangel, Marcel Pereira; Bonfim, Antonio Joaquim; Kitayama, Mariana; Graeff, Frederico Guilherme; Zangrossi, Hélio; Audi, Elisabeth Aparecida

2016-02-01

Reported evidence indicates that endogenous opioid peptides regulate the expression of escape behavior in rats, a panic-related defensive response, through μ-opioid receptors (MORs) in the dorsal periaqueductal gray (dPAG). These peptides are rapidly catabolized by degrading enzymes, including neutral endopeptidase (NEP) and aminopeptidase N (APN). Opiorphin is a peptide inhibitor of both NEP and APN and potentiates the action of endogenous enkephalins. This study evaluated the effects of intravenous and intra-dPAG administration of opiorphin on escape responses in the elevated T-maze and in a dPAG electrical stimulation test in rats. We also evaluated the involvement of MORs in the effects of opiorphin using the selective MOR antagonist CTOP. A dose of 2.0 mg/kg, i.v., of opiorphin impaired escape performance in both tests. Similar effects were observed with intra-dPAG administration of 5.0 nmol of opiorphin. Local pretreatment with 1.0 nmol CTOP antagonized the anti-escape effects of intra-dPAG opiorphin in both tests, as well as the effect of systemically administered opiorphin (2.0 mg/kg, i.v.) in the electrical stimulation test. These results indicate that opiorphin has an antipanic-like effect that is mediated by MORs in the dPAG. They may open new perspectives for the development of opiorphin analogues with greater bioavailability and physicochemical characteristics in the pursuit of new medications for the treatment of panic disorder. Copyright © 2015 Elsevier Ltd. All rights reserved.

Blockade of neuronal dopamine D2 receptor attenuates morphine tolerance in mice spinal cord.

PubMed

Dai, Wen-Ling; Xiong, Feng; Yan, Bing; Cao, Zheng-Yu; Liu, Wen-Tao; Liu, Ji-Hua; Yu, Bo-Yang

2016-12-22

Tolerance induced by morphine remains a major unresolved problem and significantly limits its clinical use. Recent evidences have indicated that dopamine D2 receptor (D2DR) is likely to be involved in morphine-induced antinociceptive tolerance. However, its exact effect and molecular mechanism remain unknown. In this study we examined the effect of D2DR on morphine antinociceptive tolerance in mice spinal cord. Chronic morphine treatment significantly increased levels of D2DR in mice spinal dorsal horn. And the immunoreactivity of D2DR was newly expressed in neurons rather than astrocytes or microglia both in vivo and in vitro. Blockade of D2DR with its antagonist (sulpiride and L-741,626, i.t.) attenuated morphine antinociceptive tolerance without affecting basal pain perception. Sulpiride (i.t.) also down-regulated the expression of phosphorylation of NR1, PKC, MAPKs and suppressed the activation of astrocytes and microglia induced by chronic morphine administration. Particularly, D2DR was found to interact with μ opioid receptor (MOR) in neurons, and chronic morphine treatment enhanced the MOR/D2DR interactions. Sulpiride (i.t.) could disrupt the MOR/D2DR interactions and attenuate morphine tolerance, indicating that neuronal D2DR in the spinal cord may be involved in morphine tolerance possibly by interacting with MOR. These results may present new opportunities for the treatment and management of morphine-induced antinociceptive tolerance which often observed in clinic.

The noradrenergic component in tapentadol action counteracts μ-opioid receptor-mediated adverse effects on adult neurogenesis.

PubMed

Meneghini, Vasco; Cuccurazzu, Bruna; Bortolotto, Valeria; Ramazzotti, Vera; Ubezio, Federica; Tzschentke, Thomas M; Canonico, Pier Luigi; Grilli, Mariagrazia

2014-05-01

Opiates were the first drugs shown to negatively impact neurogenesis in the adult mammalian hippocampus. Literature data also suggest that norepinephrine is a positive modulator of hippocampal neurogenesis in vitro and in vivo. On the basis of these observations, we investigated whether tapentadol, a novel central analgesic combining μ-opioid receptor (MOR) agonism with norepinephrine reuptake inhibition (NRI), may produce less inhibition of hippocampal neurogenesis compared with morphine. When tested in vitro, morphine inhibited neuronal differentiation, neurite outgrowth, and survival of adult mouse hippocampal neural progenitors and their progeny, via MOR interaction. By contrast, tapentadol was devoid of these adverse effects on cell survival and reduced neurite outgrowth and the number of newly generated neurons only at nanomolar concentrations where the MOR component is predominant. On the contrary, at higher (micromolar) concentrations, tapentadol elicited proneurogenic and antiapoptotic effects via activation of β2 and α2 adrenergic receptors, respectively. Altogether, these data suggest that the noradrenergic component in tapentadol has the potential to counteract the adverse MOR-mediated effects on hippocampal neurogenesis. As a proof of concept, we showed that reboxetine, an NRI antidepressant, counteracted both antineurogenic and apoptotic effects of morphine in vitro. In line with these observations, chronic tapentadol treatment did not negatively affect hippocampal neurogenesis in vivo. In light of the increasing long-term use of opiates in chronic pain, in principle, the tapentadol combined mechanism of action may result in less or no reduction in adult neurogenesis compared with classic opiates.

Odorant responsiveness of embryonic mouse olfactory sensory neurons expressing the odorant receptors S1 or MOR23.

PubMed

Lam, Rebecca S; Mombaerts, Peter

2013-07-01

The mammalian olfactory system has developed some functionality by the time of birth. There is behavioral and limited electrophysiological evidence for prenatal olfaction in various mammalian species. However, there have been no reports, in any mammalian species, of recordings from prenatal olfactory sensory neurons (OSNs) that express a given odorant receptor (OR) gene. Here we have performed patch-clamp recordings from mouse OSNs that express the OR gene S1 or MOR23, using the odorous ligands 2-phenylethyl alcohol or lyral, respectively. We found that, out of a combined total of 20 OSNs from embryos of these two strains at embryonic day (E)16.5 or later, all responded to a cognate odorous ligand. By contrast, none of six OSNs responded to the ligand at E14.5 or E15.5. The kinetics of the odorant-evoked electrophysiological responses of prenatal OSNs are similar to those of postnatal OSNs. The S1 and MOR23 glomeruli in the olfactory bulb are formed postnatally, but the axon terminals of OSNs expressing these OR genes may be synaptically active in the olfactory bulb at embryonic stages. The upper limit of the acquisition of odorant responsiveness for S1 and MOR23 OSNs at E16.5 is consistent with the developmental expression patterns of components of the olfactory signaling pathway. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Site of anticonvulsant action on sodium channels: autoradiographic and electrophysiological studies in rat brain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Worley, P.F.; Baraban, J.M.

1987-05-01

The anticonvulsants phenytoin and carbamazepine interact allosterically with the batrachotoxin binding site of sodium channels. In the present study, we demonstrate an autoradiographic technique to localize the batrachotoxin binding site on sodium channels in rat brain using (/sup 3/H)batrachotoxinin-A 20-alpha-benzoate (BTX-B). Binding of (/sup 3/H)BTX-B to brain sections is dependent on potentiating allosteric interactions with scorpion venom and is displaced by BTX-B (Kd approximately 200 nM), aconitine, veratridine, and phenytoin with the same rank order of potencies as described in brain synaptosomes. The maximum number of (/sup 3/H)BTX-B binding sites in forebrain sections also agrees with biochemical determinations. Autoradiographic localizationsmore » indicate that (/sup 3/H)BTX-B binding sites are not restricted to cell bodies and axons but are present in synaptic zones throughout the brain. For example, a particularly dense concentration of these sites in the substantia nigra is associated with afferent terminals of the striatonigral projection. By contrast, myelinated structures possess much lower densities of binding sites. In addition, we present electrophysiological evidence that synaptic transmission, as opposed to axonal conduction, is preferentially sensitive to the action of aconitine and veratridine. Finally, the synaptic block produced by these sodium channel activators is inhibited by phenytoin and carbamazepine at therapeutic anticonvulsant concentrations.« less

Modulation of [3H]DAGO binding by substance P (SP) and SP fragments in the mouse brain and spinal cord via MU1 interactions.

PubMed

Krumins, S A; Kim, D C; Seybold, V S; Larson, A A

1989-01-01

Binding of [3H]DAGO to fresh, frozen or beta-funaltrexamine (beta-FNA) pretreated membranes of mouse brain and spinal cord was extensively studied using substance P (SP) or SP fragments as potential competitors and/or modulators. The objective was to determine whether SP exerts its analgesic effect by interacting with mu opioid receptors. The affinity of DAGO was reduced and binding capacity was increased in the presence of SP or the N-terminal SP fragments SP(1-9) and SP(1-4) but not the C-terminal SP fragment SP(5-11). Because sub-nanomolar concentrations of SP or N-terminal SP fragments displaced [3H] DAGO binding to a minor but detectable degree, it is suggested that SP interacts with mu 1 sites through its N-terminus portion. The effect of SP on DAGO binding was less in the spinal cord compared to the rest of the brain. Modulation of DAGO binding by SP was enhanced in the brain after pretreatment of membranes with the narcotic antagonist beta-FNA. These results suggest a novel mechanism for the analgesic action of SP.

The behavioral and neural binding phenomena during visuomotor integration of angry facial expressions.

PubMed

Coll, Sélim Yahia; Ceravolo, Leonardo; Frühholz, Sascha; Grandjean, Didier

2018-05-02

Different parts of our brain code the perceptual features and actions related to an object, causing a binding problem, in which the brain has to integrate information related to an event without any interference regarding the features and actions involved in other concurrently processed events. Using a paradigm similar to Hommel, who revealed perception-action bindings, we showed that emotion could bind with motor actions when relevant, and in specific conditions, irrelevant for the task. By adapting our protocol to a functional Magnetic Resonance Imaging paradigm we investigated, in the present study, the neural bases of the emotion-action binding with task-relevant angry faces. Our results showed that emotion bound with motor responses. This integration revealed increased activity in distributed brain areas involved in: (i) memory, including the hippocampi; (ii) motor actions with the precentral gyri; (iii) and emotion processing with the insula. Interestingly, increased activations in the cingulate gyri and putamen, highlighted their potential key role in the emotion-action binding, due to their involvement in emotion processing, motor actions, and memory. The present study confirmed our previous results and point out for the first time the functional brain activity related to the emotion-action association.

Nicotinic Cholinergic Receptor Binding Sites in the Brain: Regulation in vivo

NASA Astrophysics Data System (ADS)

Schwartz, Rochelle D.; Kellar, Kenneth J.

1983-04-01

Tritiated acetylcholine was used to measure binding sites with characteristics of nicotinic cholinergic receptors in rat brain. Regulation of the binding sites in vivo was examined by administering two drugs that stimulate nicotinic receptors directly or indirectly. After 10 days of exposure to the cholinesterase inhibitor diisopropyl fluorophosphate, binding of tritiated acetylcholine in the cerebral cortex was decreased. However, after repeated administration of nicotine for 10 days, binding of tritiated acetylcholine in the cortex was increased. Saturation analysis of tritiated acetylcholine binding in the cortices of rats treated with diisopropyl fluorophosphate or nicotine indicated that the number of binding sites decreased and increased, respectively, while the affinity of the sites was unaltered.

2-(/sup 125/I)iodomelatonin binding sites in hamster brain membranes: pharmacological characteristics and regional distribution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duncan, M.J.; Takahashi, J.S.; Dubocovich, M.L.

1988-05-01

Studies in a variety of seasonally breeding mammals have shown that melatonin mediates photoperiodic effects on reproduction. Relatively little is known, however, about the site(s) or mechanisms of action of this hormone for inducing reproductive effects. Although binding sites for (3H)melatonin have been reported previously in bovine, rat, and hamster brain, the pharmacological selectivity of these sites was never demonstrated. In the present study, we have characterized binding sites for a new radioligand, 2-(125I)iodomelatonin, in brains from a photoperiodic species, the Syrian hamster. 2-(125I)Iodomelatonin labels a high affinity binding site in hamster brain membranes. Specific binding of 2-(125I)iodomelatonin is rapid,more » stable, saturable, and reversible. Saturation studies demonstrated that 2-(125I)iodomelatonin binds to a single class of sites with an affinity constant (Kd) of 3.3 +/- 0.5 nM and a total binding capacity (Bmax) of 110.2 +/- 13.4 fmol/mg protein (n = 4). The Kd value determined from kinetic analysis (3.1 +/- 0.9 nM; n = 5) was very similar to that obtained from saturation experiments. Competition experiments showed that the relative order of potency of a variety of indoles for inhibition of 2-(125I)iodomelatonin binding site to hamster brain membranes was as follows: 6-chloromelatonin greater than or equal to 2-iodomelatonin greater than N-acetylserotonin greater than or equal to 6-methoxymelatonin greater than or equal to melatonin greater than 6-hydroxymelatonin greater than or equal to 6,7-dichloro-2-methylmelatonin greater than 5-methoxytryptophol greater than 5-methoxytryptamine greater than or equal to 5-methoxy-N,N-dimethyltryptamine greater than N-acetyltryptamine greater than serotonin greater than 5-methoxyindole (inactive).« less

The stability of copper oxo species in zeolite frameworks

DOE PAGES

Vilella, Laia; Studt, Felix

2016-03-07

Cu-exchanged zeolites are promising heterogeneous catalysts, as they provide a confined environment to carry out highly selective reactions. Furthermore, the knowledge of how the zeolite framework and the location of Al atoms therein affect the adsorption of copper species is still not well understood. In this work, DFT was used to investigate the adsorption of potential Cu oxo active species suggested in the literature [Cu(η 2-O 2), Cu(µ-O)Cu, and Cu 2O 2] into zeolites with different pore sizes and shapes (AFI, CHA, TON, MOR, and MFI). The calculations revealed that both monomeric and dimeric Cu oxo species bind strongly tomore » the O atoms of the lattice. For the monometallic species similar adsorption energies are obtained with the different zeolite frameworks, whereas an optimum Al–Al distance is required for the dimeric species.« less

Tactics for preclinical validation of receptor-binding radiotracers

PubMed Central

Lever, Susan Z.; Fan, Kuo-Hsien; Lever, John R.

2016-01-01

Introduction Aspects of radiopharmaceutical development are illustrated through preclinical studies of [125I]-(E)-1-(2-(2,3-dihydrobenzofuran-5-yl)ethyl)-4-(iodoallyl)piperazine ([125I]-E-IA- BF-PE-PIPZE), a radioligand for sigma-1 (σ1) receptors, coupled with examples from the recent literature. Findings are compared to those previously observed for [125I]-(E)-1-(2-(2,3-dimethoxy-5-yl)ethyl)-4-(iodoallyl)piperazine ([125I]-E-IA-DM-PE-PIPZE). Methods Syntheses of E-IA-BF-PE-PIPZE and [125I]-E-IA-BF-PE-PIPZE were accomplished by standard methods. In vitro receptor binding studies and autoradiography were performed, and binding potential was predicted. Measurements of lipophilicity and protein binding were obtained. In vivo studies were conducted in mice to evaluate radioligand stability, as well as specific binding to σ1 sites in brain, brain regions and peripheral organs in the presence and absence of potential blockers. Results E-IA-BF-PE-PIPZE exhibited high affinity and selectivity for σ1 receptors (Ki = 0.43 ± 0.03 nM, σ2 / σ1 = 173). [125I]-E-IA-BF-PE-PIPZE was prepared in good yield and purity, with high specific activity. Radioligand binding provided dissociation (koff) and association (kon) rate constants, along with a measured Kd of 0.24 ± 0.01 nM and Bmax of 472 ± 13 fmol / mg protein. The radioligand proved suitable for quantitative autoradiography in vitro using brain sections. Moderate lipophilicity, Log D7.4 2.69 ± 0.28, was determined, and protein binding was 71 ± 0.3%. In vivo, high initial whole brain uptake, > 6% injected dose / g, cleared slowly over 24 h. Specific binding represented 75% to 93% of total binding from 15 min to 24 h. Findings were confirmed and extended by regional brain biodistribution. Radiometabolites were not observed in brain (1%). Conclusions Substitution of dihydrobenzofuranylethyl for dimethoxyphenethyl increased radioligand affinity for σ1 receptors by 16-fold. While high specific binding to σ1 receptors was observed for both radioligands in vivo, [125I]-E-IA-BF-PE-PIPZE displayed much slower clearance kinetics than [125I]-E-IA-DM-PE-PIPZE. Thus, minor structural modifications of σ1 receptor radioligands lead to major differences in binding properties in vitro and in vivo. PMID:27755986

Low concentrations of ethanol do not affect radioligand binding to the delta-subunit-containing GABAA receptors in the rat brain.

PubMed

Mehta, Ashok K; Marutha Ravindran, C R; Ticku, Maharaj K

2007-08-24

In the present study, we investigated the co-localization pattern of the delta subunit with other subunits of GABA(A) receptors in the rat brain using immunoprecipitation and Western blotting techniques. Furthermore, we investigated whether low concentrations of ethanol affect the delta-subunit-containing GABA(A) receptor assemblies in the rat brain using radioligand binding to the rat brain membrane homogenates as well as to the immunoprecipitated receptor assemblies. Our results revealed that delta subunit is not co-localized with gamma(2) subunit but it is associated with the alpha(1), alpha(4) or alpha(6), beta(2) and/or beta(3) subunit(s) of GABA(A) receptors in the rat brain. Ethanol (1-50 mM) neither affected [(3)H]muscimol (3 nM) binding nor diazepam-insensitive [(3)H]Ro 15-4513 (2 nM) binding in the rat cerebellum and cerebral cortex membranes. However, a higher concentration of ethanol (500 mM) inhibited the binding of these radioligands to the GABA(A) receptors partially in the rat cerebellum and cerebral cortex. Similarly, ethanol (up to 50 mM) did not affect [(3)H]muscimol (15 nM) binding to the immunoprecipitated delta-subunit-containing GABA(A) receptor assemblies in the rat cerebellum and hippocampus but it inhibited the binding partially at a higher concentration (500 mM). These results suggest that the native delta-subunit-containing GABA(A) receptors do not play a major role in the pharmacology of clinically relevant low concentrations of ethanol.

Enterprise Cloud Architecture for Chinese Ministry of Railway

NASA Astrophysics Data System (ADS)

Shan, Xumei; Liu, Hefeng

Enterprise like PRC Ministry of Railways (MOR), is facing various challenges ranging from highly distributed computing environment and low legacy system utilization, Cloud Computing is increasingly regarded as one workable solution to address this. This article describes full scale cloud solution with Intel Tashi as virtual machine infrastructure layer, Hadoop HDFS as computing platform, and self developed SaaS interface, gluing virtual machine and HDFS with Xen hypervisor. As a result, on demand computing task application and deployment have been tackled per MOR real working scenarios at the end of article.

Amyloid tracers detect multiple binding sites in Alzheimer's disease brain tissue.

PubMed

Ni, Ruiqing; Gillberg, Per-Göran; Bergfors, Assar; Marutle, Amelia; Nordberg, Agneta

2013-07-01

Imaging fibrillar amyloid-β deposition in the human brain in vivo by positron emission tomography has improved our understanding of the time course of amyloid-β pathology in Alzheimer's disease. The most widely used amyloid-β imaging tracer so far is (11)C-Pittsburgh compound B, a thioflavin derivative but other (11)C- and (18)F-labelled amyloid-β tracers have been studied in patients with Alzheimer's disease and cognitively normal control subjects. However, it has not yet been established whether different amyloid tracers bind to identical sites on amyloid-β fibrils, offering the same ability to detect the regional amyloid-β burden in the brains. In this study, we characterized (3)H-Pittsburgh compound B binding in autopsied brain regions from 23 patients with Alzheimer's disease and 20 control subjects (aged 50 to 88 years). The binding properties of the amyloid tracers FDDNP, AV-45, AV-1 and BF-227 were also compared with those of (3)H-Pittsburgh compound B in the frontal cortices of patients with Alzheimer's disease. Saturation binding studies revealed the presence of high- and low-affinity (3)H-Pittsburgh compound B binding sites in the frontal cortex (K(d1): 3.5 ± 1.6 nM; K(d2): 133 ± 30 nM) and hippocampus (K(d1):5.6 ± 2.2 nM; K(d2): 181 ± 132 nM) of Alzheimer's disease brains. The relative proportion of high-affinity to low-affinity sites was 6:1 in the frontal cortex and 3:1 in the hippocampus. One control showed both high- and low-affinity (3)H-Pittsburgh compound B binding sites (K(d1): 1.6 nM; K(d2): 330 nM) in the cortex while the others only had a low-affinity site (K(d2): 191 ± 70 nM). (3)H-Pittsburgh compound B binding in Alzheimer's disease brains was higher in the frontal and parietal cortices than in the caudate nucleus and hippocampus, and negligible in the cerebellum. Competitive binding studies with (3)H-Pittsburgh compound B in the frontal cortices of Alzheimer's disease brains revealed high- and low-affinity binding sites for BTA-1 (Ki: 0.2 nM, 70 nM), florbetapir (1.8 nM, 53 nM) and florbetaben (1.0 nM, 65 nM). BF-227 displaced 83% of (3)H-Pittsburgh compound B binding, mainly at a low-affinity site (311 nM), whereas FDDNP only partly displaced (40%). We propose a multiple binding site model for the amyloid tracers (binding sites 1, 2 and 3), where AV-45 (florbetapir), AV-1 (florbetaben), and Pittsburgh compound B, all show nanomolar affinity for the high-affinity site (binding site 1), as visualized by positron emission tomography. BF-227 shows mainly binding to site 3 and FDDNP shows only some binding to site 2. Different amyloid tracers may provide new insight into the pathophysiological mechanisms in the progression of Alzheimer's disease.

[Molecular organization of glutamate-sensitive chemoexcitatory membranes of nerve cells. Comparative analysis of glutamate-binding membrane proteins from the cerebral cortex of rats and humans].

PubMed

Dambinova, S A; Gorodinskiĭ, A I; Lekomtseva, T M; Koreshonkov, O N

1987-10-01

The kinetics of 3H-L-glutamate binding to human brain synaptic membranes revealed the existence of one type of binding sites with Kd and Vmax comparable with those for freshly isolated rat brain membranes. The fraction of glutamate-binding proteins (GBP) was shown to contain three components with Mr of 14, 60 and 280 kD whose stoichiometry is specific for human and rat brain. All fractions were found to bind the radiolabeled neurotransmitter and to dissociate into subunits with Mr of 14 kD after treatment with-potent detergents (with the exception of the 56-60 kD component). Study of association-dissociation of GBP protein subunits by high performance liquid chromatography confirmed the hypothesis on the oligomeric structure of glutamate receptors which are made up of low molecular weight glycoprotein-lipid subunits and which form ionic channels by way of repeated association. Despite the similarity of antigen determinants in the active center of glutamate receptors from human and rat brain, it was assumed that the stoichiometry of structural organization of receptor subunits isolated from different sources is different. The functional role of structural complexity of human brain glutamate receptors is discussed.

B2-kinin receptors in the dorsal periaqueductal gray are implicated in the panicolytic-like effect of opiorphin.

PubMed

Sestile, Caio César; Maraschin, Jhonatan Christian; Rangel, Marcel Pereira; Santana, Rosangela Getirana; Zangrossi, Hélio; Graeff, Frederico Guilherme; Audi, Elisabeth Aparecida

2017-10-03

Reported results have shown that the pentapeptide opiorphin inhibits oligopeptidases that degrade brain neuropeptides, and has analgesic and antidepressant effects in experimental animals, without either tolerance or dependency after chronic administration. In a previous study we showed that opiorphin has a panicolytic-like effect in the dorsal periaqueductal gray (dPAG) electrical stimulation test (EST), mediated by the μ-opioid receptor (MOR). This study further analyzes the mechanism of opiorphin panicolytic action, using the EST and drug injection inside the dPAG. The obtained results showed that blockade of the 5-HT 1A receptors with WAY-100635 did not change the escape-impairing effect of opiorphin, and combined injection of sub-effective doses of opiorphin and the 5-HT 1A -agonist 8-OH-DPAT did not have a significant anti-escape effect. In contrast, the anti-escape effect of opiorphin was antagonized by pretreatment with the kinin B2 receptor blocker HOE-140, and association of sub-effective doses of opiorphin and bradykinin caused a significant anti-escape effect. The anti-escape effect of bradykinin was not affected by previous administration of WAY-100635. Therefore, the anti-escape effect of opiorphin in the dPAG seems to be mediated by endogenous bradykinin, acting on kinin B2 receptors, which previous results have shown to interact synergistically with MOR in the dPAG to restrain escape in two animal models of panic. Chemical compounds: Opiorphin (PubChem CID: 25195667); WAY100635 maleate salt (PubChem CID: 11957721); 8-OH-DPAT hydrobromide (PubChem CID: 6917794); Bradykinin (PubChem CID: 439201); HOE-140 (Icatibant) (PubChem CID: 6918173). Copyright © 2017 Elsevier Inc. All rights reserved.

The influence of μ-opioid and noradrenaline reuptake inhibition in the modulation of pain responsive neurones in the central amygdala by tapentadol in rats with neuropathy

PubMed Central

Gonçalves, Leonor; Friend, Lauren V.; Dickenson, Anthony H.

2015-01-01

Treatments for neuropathic pain are either not fully effective or have problematic side effects. Combinations of drugs are often used. Tapentadol is a newer molecule that produces analgesia in various pain models through two inhibitory mechanisms, namely central μ-opioid receptor (MOR) agonism and noradrenaline reuptake inhibition. These two components interact synergistically, resulting in levels of analgesia similar to opioid analgesics such as oxycodone and morphine, but with more tolerable side effects. The right central nucleus of the amygdala (CeA) is critical for the lateral spinal ascending pain pathway, regulates descending pain pathways and is key in the emotional-affective components of pain. Few studies have investigated the pharmacology of limbic brain areas in pain models. Here we determined the actions of systemic tapentadol on right CeA neurones of animals with neuropathy and which component of tapentadol contributes to its effect. Neuronal responses to multimodal peripheral stimulation of animals with spinal nerve ligation or sham surgery were recorded before and after two doses of tapentadol. After the higher dose of tapentadol either naloxone or yohimbine were administered. Systemic tapentadol resulted in dose-dependent decrease in right CeA neuronal activity only in neuropathy. Both naloxone and yohimbine reversed this effect to an extent that was modality selective. The interactions of the components of tapentadol are not limited to the synergy between the MOR and α2-adrenoceptors seen at spinal levels, but are seen at this supraspinal site where suppression of responses may relate to the ability of the drug to alter affective components of pain. PMID:25576174

Alterations in opioid inhibition cause widespread nociception but do not affect anxiety-like behavior in oral cancer mice.

PubMed

Ye, Yi; Bernabé, Daniel G; Salvo, Elizabeth; Viet, Chi T; Ono, Kentaro; Dolan, John C; Janal, Malvin; Aouizerat, Brad E; Miaskowski, Christine; Schmidt, Brian L

2017-11-05

Widespread pain and anxiety are commonly reported in cancer patients. We hypothesize that cancer is accompanied by attenuation of endogenous opioid-mediated inhibition, which subsequently causes widespread pain and anxiety. To test this hypothesis we used a mouse model of oral squamous cell carcinoma (SCC) in the tongue. We found that mice with tongue SCC exhibited widespread nociceptive behaviors in addition to behaviors associated with local nociception that we reported previously. Tongue SCC mice exhibited a pattern of reduced opioid receptor expression in the spinal cord; intrathecal administration of respective mu (MOR), delta (DOR), and kappa (KOR) opioid receptor agonists reduced widespread nociception in mice, except for the fail flick assay following administration of the MOR agonist. We infer from these findings that opioid receptors contribute to widespread nociception in oral cancer mice. Despite significant nociception, mice with tongue SCC did not differ from sham mice in anxiety-like behaviors as measured by the open field assay and elevated maze. No significant differences in c-Fos staining were found in anxiety-associated brain regions in cancer relative to control mice. No correlation was found between nociceptive and anxiety-like behaviors. Moreover, opioid receptor agonists did not yield a statistically significant effect on behaviors measured in the open field and elevated maze in cancer mice. Lastly, we used an acute cancer pain model (injection of cancer supernatant into the mouse tongue) to test whether adaptation to chronic pain is responsible for the absence of greater anxiety-like behavior in cancer mice. No changes in anxiety-like behavior were observed in mice with acute cancer pain. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Effects of calcium and magnesium ions on the interaction of corticosterone with rat brain cytosol receptor(s).

PubMed

Nakai, T; Ueda, M; Takeda, R

1978-01-01

The apparent maximum corticosterone binding (B max) with rat brain cytosol and the apparent dissociation constant of this steroid-receptor binding (Kd) estimated with a Scatchard plot was 2.9 X 10(-13) moles/mg cytosol protein and 4.0 X 10(-9) M, respectively. When increasing amounts of CaCl2 or MgCl2 up to 5.0 mM were added, a specific [3H] corticosterone binding increased 4-fold by CaCl2 at concentrations of 1.0-2.0 mM and 1.5-fold by MgCl2 at concentrations of 0.5-5.0 mM. The addition of MnCl2 and KCl did not affect this binding. Binding of corticosterone with rat brain cytosol receptor(s) were decreased by increasing amounts of EGTA and complete inhibition was observed at concentrations equal to and greater than 2.5 mM. Inhibition of this binding by EDTA was less than by EGTA. Either theophylline or dibutyryl cyclic AMP had no effect on this binding.

Differences between high-affinity forskolin binding sites in dopamine-riche and other regions of rat brain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poat, J.A.; Cripps, H.E.; Iversen, L.L.

1988-05-01

Forskolin labelled with (/sup 3/H) bound to high- and low-affinity sites in the rat brain. The high-affinity site was discretely located, with highest densities in the striatum, nucleus accumbens, olfactory tubercule, substantia nigra, hippocampus, and the molecular layers of the cerebellum. This site did not correlate well with the distribution of adenylate cyclase. The high-affinity striatal binding site may be associated with a stimulatory guanine nucleotide-binding protein. Thus, the number of sites was increased by the addition of Mg/sup 2 +/ and guanylyl imidodiphosphate. Cholera toxin stereotaxically injected into rat striatum increased the number of binding sites, and no furthermore » increase was noted following the subsequent addition of guanyl nucleotide. High-affinity forskolin binding sites in non-dopamine-rich brain areas (hippocampus and cerebullum) were modulated in a qualitatively different manner by guanyl nucleotides. In these areas the number of binding sites was significantly reduced by the addition of guanyl nucleotide. These results suggest that forskolin may have a potential role in identifying different functional/structural guanine nucleotide-binding proteins.« less

Regulatory consequences of neuronal ELAV-like protein binding to coding and non-coding RNAs in human brain

PubMed Central

Scheckel, Claudia; Drapeau, Elodie; Frias, Maria A; Park, Christopher Y; Fak, John; Zucker-Scharff, Ilana; Kou, Yan; Haroutunian, Vahram; Ma'ayan, Avi

2016-01-01

Neuronal ELAV-like (nELAVL) RNA binding proteins have been linked to numerous neurological disorders. We performed crosslinking-immunoprecipitation and RNAseq on human brain, and identified nELAVL binding sites on 8681 transcripts. Using knockout mice and RNAi in human neuroblastoma cells, we showed that nELAVL intronic and 3' UTR binding regulates human RNA splicing and abundance. We validated hundreds of nELAVL targets among which were important neuronal and disease-associated transcripts, including Alzheimer's disease (AD) transcripts. We therefore investigated RNA regulation in AD brain, and observed differential splicing of 150 transcripts, which in some cases correlated with differential nELAVL binding. Unexpectedly, the most significant change of nELAVL binding was evident on non-coding Y RNAs. nELAVL/Y RNA complexes were specifically remodeled in AD and after acute UV stress in neuroblastoma cells. We propose that the increased nELAVL/Y RNA association during stress may lead to nELAVL sequestration, redistribution of nELAVL target binding, and altered neuronal RNA splicing. DOI: http://dx.doi.org/10.7554/eLife.10421.001 PMID:26894958

High-affinity cannabinoid binding site in brain: A possible marijuana receptor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nye, J.S.

The mechanism by which delta{sup 9} tetrahydrocannabinol (delta{sup 9}THC), the major psychoactive component of marijuana or hashish, produces its potent psychological and physiological effects is unknown. To find receptor binding sites for THC, we designed a water-soluble analog for use as a radioligand. 5{prime}-Trimethylammonium-delta{sup 8}THC (TMA) is a positively charged analog of delta-{sup 8}THC modified on the 5{prime} carbon, a portion of the molecule not important for its psychoactivity. We have studied the binding of ({sup 3}H)-5{prime}-trimethylammonium-delta-{sup 8}THC (({sup 3}H)TMA) to rat neuronal membranes. ({sup 3}H)TMA binds saturably and reversibly to brain membranes with high affinity to apparently one classmore » of sites. Highest binding site density occurs in brain, but several peripheral organs also display specific binding. Detergent solubilizes the sites without affecting their pharmacologial properties. Molecular sieve chromatography reveals a bimodal peak of ({sup 3}H)TMA binding activity of approximately 60,000 daltons apparent molecular weight.« less

Calcitonin: regional distribution of the hormone and its binding sites in the human brain and pituitary.

PubMed

Fischer, J A; Tobler, P H; Kaufmann, M; Born, W; Henke, H; Cooper, P E; Sagar, S M; Martin, J B

1981-12-01

Immunoreactive calcitonin (CT), indistinguishable from human CT-(1-32) and its sulfoxide, has been identified in extracts of the hypothalamus, the pituitary, and the thyroid obtained from human subjects at autopsy. DCT concentrations were highest in a region encompassing the posterior hypothalamus, the median eminence, and the pituitary; intermediate in the substantia nigra, the anterior hypothalamus, the globus pallidus, and the inferior colliculus; and low in the caudate nucleus, the hippocampus, the amygdala, and the cerebral and cerebellar cortices. Specific CT binding measured with 125I-labeled salmon CT was highest in homogenates of the posterior hypothalamus and the median eminence, shown to contain the highest concentrations of endogenous CT in the brain; CT binding was less than 12% of hypothalamic binding in all of the other regions of the brain examined and was negligible in the pituitary. Half-maximal binding was achieved with 0.1 nM nonradioactive salmon CT-(1-32), and the binding was directed to structural or conformational sites, or both, in the COOH-terminal half of salmon CT. The rank order of the inhibition of the binding by CT from different species and analogues of the human hormone was the same as in receptors on a human lymphoid cell line (Moran, J., Hunziker, W. & Fischer, J. A. (1978) Proc. Natl. Acad. Sci. USA 75, 3984-3988). The functional role of CT and of its binding sites in the brain remains to be elucidated.

An autoradiographic analysis of cholinergic receptors in mouse brain after chronic nicotine treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pauly, J.R.; Marks, M.J.; Gross, S.D.

1991-09-01

Quantitative autoradiographic procedures were used to examine the effects of chronic nicotine infusion on the number of central nervous system nicotinic cholinergic receptors. Female DBA mice were implanted with jugular cannulas and infused with saline or various doses of nicotine (0.25, 0.5, 1.0 or 2.0 mg/kg/hr) for 10 days. The animals were then sacrificed and the brains were removed and frozen in isopentane. Cryostat sections were collected and prepared for autoradiographic procedures as previously described. Nicotinic cholinergic receptors were labeled with L-(3H)nicotine or alpha-(125I)bungarotoxin; (3H)quinuclidinyl benzilate was used to measure muscarinic cholinergic receptor binding. Chronic nicotine infusion increased the numbermore » of sites labeled by (3H)nicotine in most brain areas. However, the extent of the increase in binding as well as the dose-response curves for the increase were widely different among brain regions. After the highest treatment dose, binding was increased in 67 of 86 regions measured. Septal and thalamic regions were most resistant to change. Nicotinic binding measured by alpha-(125I)bungarotoxin also increased after chronic treatment, but in a less robust fashion. At the highest treatment dose, only 26 of 80 regions were significantly changes. Muscarinic binding was not altered after chronic nicotine treatment. These data suggest that brain regions are not equivalent in the mechanisms that regulate alterations in nicotinic cholinergic receptor binding after chronic nicotine treatment.« less

Serotonin 2A receptor agonist binding in the human brain with [11C]Cimbi-36

PubMed Central

Ettrup, Anders; da Cunha-Bang, Sophie; McMahon, Brenda; Lehel, Szabolcs; Dyssegaard, Agnete; Skibsted, Anine W; Jørgensen, Louise M; Hansen, Martin; Baandrup, Anders O; Bache, Søren; Svarer, Claus; Kristensen, Jesper L; Gillings, Nic; Madsen, Jacob; Knudsen, Gitte M

2014-01-01

[11C]Cimbi-36 was recently developed as a selective serotonin 2A (5-HT2A) receptor agonist radioligand for positron emission tomography (PET) brain imaging. Such an agonist PET radioligand may provide a novel, and more functional, measure of the serotonergic system and agonist binding is more likely than antagonist binding to reflect 5-HT levels in vivo. Here, we show data from a first-in-human clinical trial with [11C]Cimbi-36. In 29 healthy volunteers, we found high brain uptake and distribution according to 5-HT2A receptors with [11C]Cimbi-36 PET. The two-tissue compartment model using arterial input measurements provided the most optimal quantification of cerebral [11C]Cimbi-36 binding. Reference tissue modeling was feasible as it induced a negative but predictable bias in [11C]Cimbi-36 PET outcome measures. In five subjects, pretreatment with the 5-HT2A receptor antagonist ketanserin before a second PET scan significantly decreased [11C]Cimbi-36 binding in all cortical regions with no effects in cerebellum. These results confirm that [11C]Cimbi-36 binding is selective for 5-HT2A receptors in the cerebral cortex and that cerebellum is an appropriate reference tissue for quantification of 5-HT2A receptors in the human brain. Thus, we here describe [11C]Cimbi-36 as the first agonist PET radioligand to successfully image and quantify 5-HT2A receptors in the human brain. PMID:24780897

Characterization of angiotensin-binding sites in the bovine adrenal and the rat brain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rogulja, I.

1989-01-01

The first study was designed to determine whether systemically administered MSG affects neurons in the CVOs that are potentially important in mediating angiotensin-dependent responses. Rats were pretreated with MSG and the receptors for angiotensin II were assayed by radioligand binding in brain homogenates from the septum anteroventral third ventricular region (AV3V) and the thalamus/hypothalamus region using {sup 125}I-angiotensin II as the radioligand. The results of this experiment indicate that systematically administered MSG in the rat significantly reduced the number (Bmax) of Ang II receptors in a tissue sample which contained both extra blood-brain barrier organs as well as tissue withinmore » the blood-brain barrier with no change in the affinity (Kd) of the binding sites. The second chapter reports the successful solubilization of bovine adrenal {sup 125}I Ang II and {sup 125}I Sar{sup 1},Ile{sup 8}-Ang II binding sites with the detergent CHAPS. The results of our studies indicate the presence of two angiotensin binding sites. The one site is specific for naturally occurring angiotensins as well as sarcosine-1 substituted angiotensin analogues. The other site which can be optimally stabilized be re-addition of 0.3% CHAPS into the incubation assay binds sarcosine-1 substituted angiotensins exclusively. Hydrophobic interaction chromatography experiments suggest that these sites, possibly, represent distinct proteins. The third chapter discusses the successful solubilization and partial characterization of the rat brain angiotensin receptor.« less

Identification of a botulinum C3-like enzyme in bovine brain that catalyzes ADP-ribosylation of GTP-binding proteins.

PubMed

Maehama, T; Takahashi, K; Ohoka, Y; Ohtsuka, T; Ui, M; Katada, T

1991-06-05

A novel enzyme activity was found in bovine brain cytosol that transfers the ADP-ribosyl moiety of NAD to proteins with Mr values of 22,000 and 25,000. The substrates were the same GTP-binding proteins serving as the substrate of an ADP-ribosyltransferase C3 which was produced by a type C strain of Clostridium botulinum. The brain enzyme was partially purified from the cytosol and had a molecular mass of approximately 20,000 on a gel filtration column. The brain endogenous enzyme displayed unique properties similar to those observed with botulinum C3 enzyme. The enzyme activity was markedly stimulated by a protein factor that had been initially found in the cytosol as an activator for botulinum C3-catalyzed ADP-ribosylation (Ohtsuka, T., Nagata, K., Iiri, T., Nozawa, Y., Ueno, K., Ui, M., and Katada, T. (1989) J. Biol. Chem. 264, 15000-15005). The activity of the brain enzyme was also affected by certain types of detergents or phospholipids. The substrate of the brain enzyme was specific for GTP-binding proteins serving as the substrate of botulinum C3 enzyme; the alpha-subunits of trimeric GTP-binding proteins which served as the substrate of cholera or pertussis toxin were not ADP-ribosylated by the endogenous enzyme. Thus, this is the first report showing an endogenous enzyme in mammalian cells that catalyzes ADP-ribosylation of small molecular weight GTP-binding proteins.

Animal-related factors associated with moderate-to-severe diarrhea in children younger than five years in western Kenya: A matched case-control study.

PubMed

Conan, Anne; O'Reilly, Ciara E; Ogola, Eric; Ochieng, J Benjamin; Blackstock, Anna J; Omore, Richard; Ochieng, Linus; Moke, Fenny; Parsons, Michele B; Xiao, Lihua; Roellig, Dawn; Farag, Tamer H; Nataro, James P; Kotloff, Karen L; Levine, Myron M; Mintz, Eric D; Breiman, Robert F; Cleaveland, Sarah; Knobel, Darryn L

2017-08-01

Diarrheal disease remains among the leading causes of global mortality in children younger than 5 years. Exposure to domestic animals may be a risk factor for diarrheal disease. The objectives of this study were to identify animal-related exposures associated with cases of moderate-to-severe diarrhea (MSD) in children in rural western Kenya, and to identify the major zoonotic enteric pathogens present in domestic animals residing in the homesteads of case and control children. We characterized animal-related exposures in a subset of case and control children (n = 73 pairs matched on age, sex and location) with reported animal presence at home enrolled in the Global Enteric Multicenter Study in western Kenya, and analysed these for an association with MSD. We identified potentially zoonotic enteric pathogens in pooled fecal specimens collected from domestic animals resident at children's homesteads. Variables that were associated with decreased risk of MSD were washing hands after animal contact (matched odds ratio [MOR] = 0.2; 95% CI 0.08-0.7), and presence of adult sheep that were not confined in a pen overnight (MOR = 0.1; 0.02-0.5). Variables that were associated with increased risk of MSD were increasing number of sheep owned (MOR = 1.2; 1.0-1.5), frequent observation of fresh rodent excreta (feces/urine) outside the house (MOR = 7.5; 1.5-37.2), and participation of the child in providing water to chickens (MOR = 3.8; 1.2-12.2). Of 691 pooled specimens collected from 2,174 domestic animals, 159 pools (23%) tested positive for one or more potentially zoonotic enteric pathogens (Campylobacter jejuni, C. coli, non-typhoidal Salmonella, diarrheagenic E. coli, Giardia, Cryptosporidium, or rotavirus). We did not find any association between the presence of particular pathogens in household animals, and MSD in children. Public health agencies should continue to promote frequent hand washing, including after animal contact, to reduce the risk of MSD. Future studies should address specific causal relations of MSD with sheep and chicken husbandry practices, and with the presence of rodents.

Ca isotope fractionation and Sr/Ca partitioning associated with anhydrite formation at mid-ocean ridge hydrothermal systems: An experimental approach

NASA Astrophysics Data System (ADS)

Syverson, D. D.; Scheuermann, P.; Pester, N. J.; Higgins, J. A.; Seyfried, W. E., Jr.

2016-12-01

The elemental and isotopic mass balance of Ca and Sr between seawater and basalt at mid-ocean ridge (MOR) hydrothermal systems is an integrated reflection of the various physiochemical processes, which induce chemical exchange, in the subseafloor. Specifically, the processes of anhydrite precipitation and recrystallization are recognized to be important controls on governing the Ca and Sr elemental and isotope compositions of high temperature vent fluids, however, few experimental data exist to constrain these geochemical effects. Thus, to better understand the associated Sr/Ca partitioning and Ca isotope fractionation and rate of exchange between anhydrite and dissolved constituents, anhydrite precipitation and recrystallization experiments were performed at 175, 250, and 350°C and 500 bar at chemical conditions indicative of active MOR hydrothermal systems. The experimental data suggest that upon entrainment of seawater into MOR hydrothermal systems, anhydrite will precipitate rapidly and discriminate against the heavy isotopes of Ca (Δ44/40Ca(Anh-Fluid) = -0.68 - -0.25 ‰), whereas Sr/Ca partitioning depends on the saturation state of the evolving hydrothermal fluid with respect to anhydrite at each PTX (KD(Anh-Fluid) = 1.24 - 0.55). Coupling experimental constraints with the temperature gradient inferred for high temperature MOR hydrothermal systems in the oceanic crust, data suggest that the Ca isotope and Sr elemental composition of anhydrite formed near the seafloor will be influenced by disequilibrium effects, while, at higher temperatures further into the oceanic crust, anhydrite will be representative of equilibrium Sr/Ca partitioning and Ca isotope fractionation conditions. These experimental observations are consistent with analyzed Sr/Ca and Ca isotope compositions of anhydrites and vent fluids sampled from modern MOR hydrothermal systems1,2 and can be used to further constrain the geochemical effects of hydrothermal circulation in the oceanic crust throughout Earth's history. 1 Tivey, M. K. Generation of Seafloor Hydrothermal Deposits. Oceanography 20, 50-66 (2007).2 Amini, M. et al. Calcium isotope (δ44/40Ca) fractionation along hydrothermal pathways, Logatchev field (Mid-Atlantic Ridge, 14°45'N). Geochimica et Cosmochimica Acta 72, 4107-4122 (2008).

Automatic Black-Box Model Order Reduction using Radial Basis Functions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stephanson, M B; Lee, J F; White, D A

Finite elements methods have long made use of model order reduction (MOR), particularly in the context of fast freqeucny sweeps. In this paper, we discuss a black-box MOR technique, applicable to a many solution methods and not restricted only to spectral responses. We also discuss automated methods for generating a reduced order model that meets a given error tolerance. Numerical examples demonstrate the effectiveness and wide applicability of the method. With the advent of improved computing hardware and numerous fast solution techniques, the field of computational electromagnetics are progressed rapidly in terms of the size and complexity of problems thatmore » can be solved. Numerous applications, however, require the solution of a problem for many different configurations, including optimization, parameter exploration, and uncertainly quantification, where the parameters that may be changed include frequency, material properties, geometric dimensions, etc. In such cases, thousands of solutions may be needed, so solve times of even a few minutes can be burdensome. Model order reduction (MOR) may alleviate this difficulty by creating a small model that can be evaluated quickly. Many MOR techniques have been applied to electromagnetic problems over the past few decades, particularly in the context of fast frequency sweeps. Recent works have extended these methods to allow more than one parameter and to allow the parameters to represent material and geometric properties. There are still limitations with these methods, however. First, they almost always assume that the finite element method is used to solve the problem, so that the system matrix is a known function of the parameters. Second, although some authors have presented adaptive methods (e.g., [2]), the order of the model is often determined before the MOR process begins, with little insight about what order is actually needed to reach the desired accuracy. Finally, it not clear how to efficiently extend most methods to the multiparameter case. This paper address the above shortcomings be developing a method that uses a block-box approach to the solution method, is adaptive, and is easily extensible to many parameters.« less

The Impact of Radiation Oncologists on the Early Adoption of Hypofractionated Radiation Therapy for Early-Stage Breast Cancer.

PubMed

Boero, Isabel J; Gillespie, Erin F; Hou, Jiayi; Paravati, Anthony J; Kim, Ellen; Einck, John P; Yashar, Catheryn; Mell, Loren K; Murphy, James D

2017-03-01

Despite multiple randomized trials showing the efficacy of hypofractionated radiation therapy in early-stage breast cancer, the United States has been slow to adopt this treatment. The goal of this study was to evaluate the impact of individual radiation oncologists on the early adoption of hypofractionated radiation therapy for early-stage breast cancer. We identified 22,233 Medicare beneficiaries with localized breast cancer that was diagnosed from 2004 to 2011 who underwent breast-conserving surgery with adjuvant radiation. Multilevel, multivariable logistic models clustered by radiation oncologist and geographic practice area were used to determine the impact of the provider and geographic region on the likelihood of receiving hypofractionated compared with standard fractionated radiation therapy while controlling for a patient's clinical and demographic covariates. Odds ratios (OR) describe the impact of demographic or clinical covariates, and the median OR (MOR) describes the relative impact of the individual radiation oncologist and geographic region on the likelihood of undergoing hypofractionated radiation therapy. Among the entire cohort, 2333 women (10.4%) were treated with hypofractionated radiation therapy, with unadjusted rates ranging from 0.0% in the bottom quintile of radiation oncologists to 30.4% in the top quintile. Multivariable analysis found that the individual radiation oncologist (MOR 3.08) had a greater impact on the use of hypofractionation than did geographic region (MOR 2.10) or clinical and demographic variables. The impact of the provider increased from the year 2004 to 2005 (MOR 2.82) to the year 2010 to 2011 (MOR 3.16) despite the publication of long-term randomized trial results in early 2010. Male physician and radiation oncologists treating the highest volume of breast cancer patients were less likely to perform hypofractionation (P<.05). The individual radiation oncologist strongly influenced the likelihood of a patient's receiving hypofractionated radiation therapy, and this trend increased despite the publication of long-term data showing equivalence to standard fractionation. Future research should focus on physician-related factors that influence this decision. Copyright © 2016 Elsevier Inc. All rights reserved.

Sex Differences in Serotonin 1 Receptor Binding in Rat Brain

NASA Astrophysics Data System (ADS)

Fischette, Christine T.; Biegon, Anat; McEwen, Bruce S.

1983-10-01

Male and female rats exhibit sex differences in binding by serotonin 1 receptors in discrete areas of the brain, some of which have been implicated in the control of ovulation and of gonadotropin release. The sex-specific changes in binding, which occur in response to the same hormonal (estrogenic) stimulus, are due to changes in the number of binding sites. Castration alone also affects the number of binding sites in certain areas. The results lead to the conclusion that peripheral hormones modulate binding by serotonin 1 receptors. The status of the serotonin receptor system may affect the reproductive capacity of an organism and may be related to sex-linked emotional disturbances in humans.

Binding Sequences for RdgB, a DNA Damage-Responsive Transcriptional Activator, and Temperature-Dependent Expression of Bacteriocin and Pectin Lyase Genes in Pectobacterium carotovorum subsp. carotovorum▿ †

PubMed Central

Yamada, Kazuteru; Kaneko, Jun; Kamio, Yoshiyuki; Itoh, Yoshifumi

2008-01-01

Pectobacterium carotovorum subsp. carotovorum strain Er simultaneously produces the phage tail-like bacteriocin carotovoricin (Ctv) and pectin lyase (Pnl) in response to DNA-damaging agents. The regulatory protein RdgB of the Mor/C family of proteins activates transcription of pnl through binding to the promoter. However, the optimal temperature for the synthesis of Ctv (23°C) differs from that for synthesis of Pnl (30°C), raising the question of whether RdgB directly activates ctv transcription. Here we report that RdgB directly regulates Ctv synthesis. Gel mobility shift assays demonstrated RdgB binding to the P0, P1, and P2 promoters of the ctv operons, and DNase I footprinting determined RdgB-binding sequences (RdgB boxes) on these and on the pnl promoters. The RdgB box of the pnl promoter included a perfect 7-bp inverted repeat with high binding affinity to the regulator (Kd [dissociation constant] = 150 nM). In contrast, RdgB boxes of the ctv promoters contained an imperfect inverted repeat with two or three mismatches that consequently reduced binding affinity (Kd = 250 to 350 nM). Transcription of the rdgB and ctv genes was about doubled at 23°C compared with that at 30°C. In contrast, the amount of pnl transcription tripled at 30°C. Thus, the inverse synthesis of Ctv and Pnl as a function of temperature is apparently controlled at the transcriptional level, and reduced rdgB expression at 30°C obviously affected transcription from the ctv promoters with low-affinity RdgB boxes. Pathogenicity toward potato tubers was reduced in an rdgB knockout mutant, suggesting that the RdgAB system contributes to the pathogenicity of this bacterium, probably by activating pnl expression. PMID:18689515

A comparative study of dietary curcumin, nanocurcumin, and other classical amyloid-binding dyes for labeling and imaging of amyloid plaques in brain tissue of 5×-familial Alzheimer's disease mice.

PubMed

Maiti, Panchanan; Hall, Tia C; Paladugu, Leela; Kolli, Nivya; Learman, Cameron; Rossignol, Julien; Dunbar, Gary L

2016-11-01

Deposition of amyloid beta protein (Aβ) is a key component in the pathogenesis of Alzheimer's disease (AD). As an anti-amyloid natural polyphenol, curcumin (Cur) has been used as a therapy for AD. Its fluorescent activity, preferential binding to Aβ, as well as structural similarities with other traditional amyloid-binding dyes, make it a promising candidate for labeling and imaging of Aβ plaques in vivo. The present study was designed to test whether dietary Cur and nanocurcumin (NC) provide more sensitivity for labeling and imaging of Aβ plaques in brain tissues from the 5×-familial AD (5×FAD) mice than the classical Aβ-binding dyes, such as Congo red and Thioflavin-S. These comparisons were made in postmortem brain tissues from the 5×FAD mice. We observed that Cur and NC labeled Aβ plaques to the same degree as Aβ-specific antibody and to a greater extent than those of the classical amyloid-binding dyes. Cur and NC also labeled Aβ plaques in 5×FAD brain tissues when injected intraperitoneally. Nanomolar concentrations of Cur or NC are sufficient for labeling and imaging of Aβ plaques in 5×FAD brain tissue. Cur and NC also labeled different types of Aβ plaques, including core, neuritic, diffuse, and burned-out, to a greater degree than other amyloid-binding dyes. Therefore, Cur and or NC can be used as an alternative to Aβ-specific antibody for labeling and imaging of Aβ plaques ex vivo and in vivo. It can provide an easy and inexpensive means of detecting Aβ-plaque load in postmortem brain tissue of animal models of AD after anti-amyloid therapy.

Characterization of kappa 1 and kappa 2 opioid binding sites in frog (Rana esculenta) brain membrane preparation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benyhe, S.; Varga, E.; Hepp, J.

1990-09-01

The distribution and properties of frog brain kappa-opioid receptor subtypes differ not only from those of the guinea pig brain, but also from that of the rat brain. In guinea pig cerebellum the kappa 1 is the dominant receptor subtype, frog brain contains mainly the kappa 2 subtype, and the distribution of the rat brain subtypes is intermediate between the two others. In competition experiments it has been established that ethylketocyclazocine and N-cyclopropylmethyl-norazidomorphine, which are nonselective kappa-ligands, have relatively high affinities to frog brain membranes. The kappa 2 ligands (Met5)enkephalin-Arg6-Phe7 and etorphine also show high affinities to the frog brain.more » Kappa 1 binding sites measured in the presence of 5 microM/D-Ala2-Leu5/enkephalin represent 25-30% of (3H)ethylketocyclazocine binding in frog brain membranes. The kappa 2 subtype in frog brain resembles more to the mu subtype than the delta subtype of opioid receptors, but it differs from the mu subtype in displaying low affinity toward beta-endorphin and /D-Ala2-(Me)Phe4-Gly5-ol/enkephalin (DAGO). From our data it is evident that the opioid receptor subtypes are already present in the amphibian brain but the differences among them are less pronounced than in mammalian brain.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zukin, R.S.; Eghbali, M.; Olive, D.

{kappa} opioid receptors ({kappa} receptors) have been characterized in homogenates of guinea pig and rat brain under in vitro binding conditions. {kappa} receptors were labeled by using the tritiated prototypic {kappa} opioid ethylketocyclazocine under conditions in which {mu} and {delta} opioid binding was suppressed. In the case of guinea pig brain membranes, a single population of high-affinity {kappa} opioid receptor sites was observed. In contrast, in the case of rat brain, two populations of {kappa} sites were observed. To test the hypothesis that the high- and low-affinity {kappa} sites represent two distinct {kappa} receptor subtypes, a series of opioids weremore » tested for their abilities to compete for binding to the two sites. U-69,593 and Cambridge 20 selectively displaced the high-affinity {kappa} site in both guinea pig and rat tissue, but were inactive at the rat-brain low-affinity site. Other {kappa} opioid drugs competed for binding to both sites, but with different rank orders of potency. Quantitative light microscopy in vitro autoradiography was used to visualize the neuroanatomical pattern of {kappa} receptors in rat and guinea pig brain. The distribution patterns of the two {kappa} receptor subtypes of rat brain were clearly different. Collectively, these data provide direct evidence for the presence of two {kappa} receptor subtypes; the U-69,593-sensitive, high-affinity {kappa}{sub 1} site predominates in guinea pig brain, and the U-69,593-insensitive, low-affinity {kappa}{sub 2} site predominates in rat brain.« less

The effects of para-chloromercuribenzoic acid and different oxidative and sulfhydryl agents on a novel, non-AT1, non-AT2 angiotensin binding site identified as neurolysin

PubMed Central

Santos, Kira L.; Vento, Megan A; Wright, John W.; Speth, Robert C.

2013-01-01

A novel, non-AT1, non-AT2 brain binding site for angiotensin peptides that is unmasked by p-chloromercuribenzoate (PCMB) has been identified as a membrane associated variant of neurolysin. The ability of different organic and inorganic oxidative and sulfhydryl reactive agents to unmask or inhibit 125I-Sar1Ile8 angiotensin II (SI-Ang II) binding to this site was presently examined. In tissue membranes from homogenates of rat brain and testis incubated in assay buffer containing losartan (10 μM) and PD123319 (10 μM) plus 100 μM PCMB, 5 of the 39 compounds tested inhibited 125I-SI Ang II binding in brain and testis. Mersalyl acid, mercuric chloride (HgCl2) and silver nitrate (AgNO3) most potently inhibited 125I-SI Ang II binding with IC50’s ~1–20 μM This HgCl2 inhibition was independent of any interaction of HgCl2 with angiotensin II (Ang II) based on the lack of effect of HgCl2 on the dipsogenic effects of intracerebroventricularly administered Ang II and 125I-SI Ang II binding to AT1 receptors in the liver. Among sulfhydryl reagents, cysteamine and reduced glutathione (GSH), but not oxidized glutathione (GSSG) up to 1 mM, inhibited PCMB-unmasked 125I-SI Ang II binding in brain and testis. Thimerosal and 4-hydroxymercuribenzoate moderately inhibited PCMB-unmasked 125I-SI Ang II binding in brain and testis at 100 μM; however, they also unmasked non-AT1, non-AT2 binding independent of PCMB. 4-hydroxybenzoic acid did not promote 125 I-SI Ang II binding to this binding site indicating that only specific organomercurial compounds can unmask the binding site. The common denominator for all of these interacting substances is the ability to bind to protein cysteine sulfur. Comparison of cysteines between neurolysin and the closely related enzyme thimet oligopeptidase revealed an unconserved cysteine (cys650, based on the full length variant) in the proposed ligand binding channel (Brown et al., 2001) [1] near the active site of neurolysin. It is proposed that the mercuric ion in PCMB and closely related organomercurial compounds binds to cys650, while the acidic anion forms an ionic bond with a nearby arginine or lysine along the channel to effect a conformational change in neurolysin that promotes Ang II binding. PMID:23511333

Recent advances in the development of 14-alkoxy substituted morphinans as potent and safer opioid analgesics.

PubMed

Spetea, M; Schmidhammer, H

2012-01-01

Morphine and other opioid morphinans produce analgesia primarily through μ opioid receptors (MORs), which mediate beneficial but also non-beneficial actions. There is a continued search for efficacious opioid analgesics with reduced complications. The cornerstone in the development of 14-alkoxymorphinans as novel analgesic drugs was the synthesis of the highly potent MOR agonist 14-O-methyloxymorphone. This opioid showed high antinociceptive potency but also the adverse effects associated with morphine type compounds. Further developments represent the introduction of a methyl and benzyl group at position 5 of 14-O-methyloxymorphone leading to the strong opioid analgesics 14-methoxymetopon and its 5-benzyl analogue, which exhibited less pronounced side effects than morphine although interacting selectively with MORs. Introduction of arylalkyl substituents such as phenylpropoxy in position 14 led to a series of extremely potent antinociceptive agents with enhanced affinities at all three opioid receptor types. During the past years, medicinal chemistry and opioid research focused increasingly on exploring the therapeutic potential of peripheral opioid receptors by peripheralization of opioids in order to minimize the occurrence of centrally-mediated side effects. Strategies to reduce penetration to the central nervous system (CNS) include chemical modifications that increase hydrophilicity. Zwitterionic 6-amino acid conjugates of 14-Oalkyloxymorphones were developed in an effort to obtain opioid agonists that have limited access to the CNS. These compounds show high antinociceptive potency by interacting with peripheral MORs. Opioid drugs with peripheral site of action represent an important target for the treatment of severe and chronic pain without the adverse actions of centrally acting opioids.

Magma Plumbing System at a Young Back-Arc Spreading Center: The Marsili Volcano, Southern Tyrrhenian Sea

NASA Astrophysics Data System (ADS)

Trua, T.; Marani, M. P.; Gamberi, F.

2018-01-01

Although spreading rate is commonly taken as a proxy for decompression mantle melting at mid-ocean ridges (MORs), magmatism at back-arc spreading centers (BASCs) is further influenced by the subduction-related flux melting of the mantle. These regions consequently show a diversity of crustal structures, lava compositions, and morphologies not typically found in MORs. Here we investigate the crustal plumbing system of the small-scale, Marsili back-arc spreading center of the Southern Tyrrhenian Sea using plagioclase data from a wide spectrum of lavas (basalts to andesites) dredged from its summit and flanks. We employ petrological modeling to identify the plagioclase populations carried in the individual lavas, allocate them to plausible magmatic components present within the plumbing system, and trace the processes occurring during magma ascent to the surface. The properties of the system, such as mush porosity and abundance of the melt bodies, vary from one magma extraction zone to another along the BASC, evidencing the local variability of melt supply conditions. The plagioclase crystals document a range of relationships with the host lavas, indicating magma extraction from a composite, vertically extensive mush and melt-lens system resembling that of MORs. At the same time, however, in small BASCs, such as in the case of the Marsili Basin, crustal accretion and resulting morphology are significantly influenced by the three-dimensional setting of the basin margins. This is an important deviation from the conventional model based on the linear continuity and essentially two-dimensional framework of MORs.

Reversible Opening of the Blood-Brain Barrier by Anti-Bacterial Antibodies

NASA Astrophysics Data System (ADS)

Tuomanen, Elaine I.; Prasad, Sudha M.; George, Jonathan S.; Hoepelman, Andy I. M.; Ibsen, Per; Heron, Iver; Starzyk, Ruth M.

1993-08-01

The leukocyte adhesion molecule CR3 (CD11b/CD18, Mac-1) promotes leukocyte transmigration into tissues by engaging an unknown cognate ligand on the surface of vascular endothelial cells. Filamentous hemagglutinin (FHA), an adhesin of the bacterium Bordetella pertussis, binds to CR3. We hypothesized that FHA mimics the native ligand for the CR3 integrin on endothelial cells and predicted that anti-FHA antibodies should bind to endothelial cells, interfere with leukocyte recruitment, and induce endothelial permeability. Anti-FHA monoclonal antibodies bound to cerebral microvessels in sections from human brain and upon intravenous injection into rabbits. Antibody binding correlated with the ability to recognize two polypeptides in extracts of human cerebral vessels that were also bound by CD18. In vivo, antibody binding not only interfered with transmigration of leukocytes into cerebrospinal fluid but also induced a dose-dependent reversible increase in blood-brain barrier permeability sufficient to improve delivery of intravenously administered therapeutic agents to brain parenchyma.

Evidence that a synthetic amyloid-ß oligomer-binding peptide (ABP) targets amyloid-ß deposits in transgenic mouse brain and human Alzheimer's disease brain.

PubMed

Chakravarthy, Balu; Ito, Shingo; Atkinson, Trevor; Gaudet, Chantal; Ménard, Michel; Brown, Leslie; Whitfield, James

2014-03-14

The synthetic ~5 kDa ABP (amyloid-ß binding peptide) consists of a region of the 228 kDa human pericentrioloar material-1 (PCM-1) protein that selectively and avidly binds in vitro Aβ1-42 oligomers, believed to be key co-drivers of Alzheimer's disease (AD), but not monomers (Chakravarthy et al., (2013) [3]). ABP also prevents Aß1-42 from triggering the apoptotic death of cultured human SHSY5Y neuroblasts, likely by sequestering Aß oligomers, suggesting that it might be a potential AD therapeutic. Here we support this possibility by showing that ABP also recognizes and binds Aβ1-42 aggregates in sections of cortices and hippocampi from brains of AD transgenic mice and human AD patients. More importantly, ABP targets Aβ1-42 aggregates when microinjected into the hippocampi of the brains of live AD transgenic mice. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

A robust computational technique for model order reduction of two-time-scale discrete systems via genetic algorithms.

PubMed

Alsmadi, Othman M K; Abo-Hammour, Zaer S

2015-01-01

A robust computational technique for model order reduction (MOR) of multi-time-scale discrete systems (single input single output (SISO) and multi-input multioutput (MIMO)) is presented in this paper. This work is motivated by the singular perturbation of multi-time-scale systems where some specific dynamics may not have significant influence on the overall system behavior. The new approach is proposed using genetic algorithms (GA) with the advantage of obtaining a reduced order model, maintaining the exact dominant dynamics in the reduced order, and minimizing the steady state error. The reduction process is performed by obtaining an upper triangular transformed matrix of the system state matrix defined in state space representation along with the elements of B, C, and D matrices. The GA computational procedure is based on maximizing the fitness function corresponding to the response deviation between the full and reduced order models. The proposed computational intelligence MOR method is compared to recently published work on MOR techniques where simulation results show the potential and advantages of the new approach.

Mesoporous graphene-like nanobowls as Pt electrocatalyst support for highly active and stable methanol oxidation

NASA Astrophysics Data System (ADS)

Yan, Zaoxue; He, Guoqiang; Jiang, Zhifeng; Wei, Wei; Gao, Lina; Xie, Jimin

2015-06-01

Mesoporous graphene-like nanobowls (GLBs) with high surface area of 1091 m2 g-1, high pore volume of 2.7 cm3 g-1 and average pore diameter of 9.8 nm are synthesized through template method. The GLBs with inherent excellent electrical conductivity and chemical inertia show the properties of well mass transfer, poison resistance and stable loading of smaller Pt particles. Therefore, the Pt/GLB catalyst shows much higher activity and stability than that of commercial Pt/C (TKK) for methanol oxidation reaction (MOR). Therein, the peak current density on Pt/GLB (2075 mA mgPt-1) for MOR is 2.87 times that of commercial Pt/C (723 mA mgPt-1); and the onset potential for the MOR on the former is negatively shifted about 160 mV compared with that on the latter. The catalytic performances of the Pt/GLB are also better than those of the Pt loading on mesoporous amorphous carbon nanobowls (Pt/BLC), indicating promotion effect of graphite on Pt catalytic performance.

Mordenite/Nafion and analcime/Nafion composite membranes prepared by spray method for improved direct methanol fuel cell performance

NASA Astrophysics Data System (ADS)

Prapainainar, Paweena; Du, Zehui; Kongkachuichay, Paisan; Holmes, Stuart M.; Prapainainar, Chaiwat

2017-11-01

The aim of this work was to improve proton exchange membranes (PEMs) used in direct methanol fuel cells (DMFCs). A membrane with a high proton conductivity and low methanol permeability was required. Zeolite filler in Nafion (NF matrix) composite membranes were prepared using two types of zeolite, mordenite (MOR) and analcime (ANA). Spray method was used to prepare the composite membranes, and properties of the membranes were investigated: mechanical properties, solubility, water and methanol uptake, ion-exchange capacity (IEC), proton conductivity, methanol permeability, and DMFC performance. It was found that MOR filler showed higher performance than ANA. The MOR/Nafion composite membrane gave better properties than ANA/Nafion composite membrane, including a higher proton conductivity and a methanol permeability that was 2-3 times lower. The highest DMFC performance (10.75 mW cm-2) was obtained at 70 °C and with 2 M methanol, with a value 1.5 times higher than that of ANA/Nafion composite membrane and two times higher than that of commercial Nafion 117 (NF 117).

Pulmonary Tuberculosis Is Associated With Biomass Fuel Use Among Rural Women in Pakistan: An Age- and Residence-Matched Case-Control Study.

PubMed

Rabbani, Unaib; Sahito, Ambreen; Nafees, Asaad Ahmed; Kazi, Ambreen; Fatmi, Zafar

2017-04-01

Facility-based, age- and residential area-matched case-control study was conducted in Sindh, Pakistan to determine association between biomass fuel use for cooking and pulmonary tuberculosis (TB). Cases were women with pulmonary TB, and controls were those suffering from other diseases. Current users of biomass fuel were at higher risk of pulmonary TB (adjusted matched odds ratio [mOR] = 3.0; 95% CI = 1.1-4.9) compared with nonusers. In comparison with former biomass users (women not using biomass for >10 years), recent biomass users (women who switched from biomass to nonbiomass ≤10 years ago), and current (lifetime) users were at a higher risk in a dose-response manner (adjusted mOR = 2.8, 95% CI = 0.9-8.2 and adjusted mOR = 3.9, 95% CI = 1.4-10.7, respectively). Population attributable fraction for TB related to biomass fuel use was 40.6% (95% CI = 35.5%-45.7%). This study strengthens the evidence that biomass fuel use for cooking is associated with pulmonary TB and risk increases with duration of exposure.

Morin Flavonoid Adsorbed on Mesoporous Silica, a Novel Antioxidant Nanomaterial

PubMed Central

Arriagada, Francisco; Correa, Olosmira; Günther, Germán; Nonell, Santi; Mura, Francisco; Olea-Azar, Claudio

2016-01-01

Morin (2´,3, 4´,5,7-pentahydroxyflavone) is a flavonoid with several beneficial health effects. However, its poor water solubility and it sensitivity to several environmental factors avoid its use in applications like pharmaceutical and cosmetic. In this work, we synthetized morin-modified mesoporous silica nanoparticles (AMSNPs-MOR) as useful material to be used as potential nanoantioxidant. To achieve this, we characterized its adsorption kinetics, isotherm and the antioxidant capacity as hydroxyl radical (HO•) scavenger and singlet oxygen (1O2) quencher. The experimental data could be well fitted with Langmuir, Freundlich and Temkin isotherm models, besides the pseudo-second order kinetics model. The total quenching rate constant obtained for singlet oxygen deactivation by AMSNPs-MOR was one order of magnitude lower than the morin rate constant reported previously in neat solvents and lipid membranes. The AMSNPs-MOR have good antioxidant properties by itself and exhibit a synergic effect with morin on the antioxidant property against hydroxyl radical. This effect, in the range of concentrations studied, was increased when the amount of morin adsorbed increased. PMID:27812111

Activation of the mu-opiate receptor by Vitex agnus-castus methanol extracts: implication for its use in PMS.

PubMed

Webster, D E; Lu, J; Chen, S-N; Farnsworth, N R; Wang, Z Jim

2006-06-30

The dried ripe fruit of Vitex agnus-castus L. (VAC) is widely used for the treatment of premenstrual syndrome (PMS). A previous study reported that extracts of VAC showed affinity to opiate receptors; however, functional activity was not determined. We tested two different VAC extracts in receptor binding and functional assays. Our objectives were: (1) to confirm the opiate affinity; (2) to rule out interference by free fatty acids (FFA); (3) to determine the mode of action of VAC at the mu-opiate receptor. Methanol extracts of VAC were prepared either before (VAC-M1) or after (VAC-M2) extraction with petroleum ether to remove fatty acids. Both extracts showed significant affinities to the mu-opiate receptor, as indicated by the concentration-dependent displacement of [3H]DAMGO binding in Chinese hamster ovary (CHO)-human mu-opiate receptor (hMOR) cells. The IC50 values were estimated to be 159.8 microg/ml (VAC-M1) and 69.5 microg/ml (VAC-M2). Since the defatted extract not only retained, but exhibited a higher affinity (p<0.001), it argued against significant interference by fatty acids. In an assay to determine receptor activation, VAC-M1 and VAC-M2 stimulated [35S]GTPgammaS binding by 41 and 61% (p<0.001), respectively. These results suggested for the first time that VAC acted as an agonist at the mu-opiate receptor, supporting its beneficial action in PMS.

A designed recombinant fusion protein for targeted delivery of siRNA to the mouse brain.

PubMed

Haroon, Mohamed Mohamed; Dar, Ghulam Hassan; Jeyalakshmi, Durga; Venkatraman, Uthra; Saba, Kamal; Rangaraj, Nandini; Patel, Anant Bahadur; Gopal, Vijaya

2016-04-28

RNA interference represents a novel therapeutic approach to modulate several neurodegenerative disease-related genes. However, exogenous delivery of siRNA restricts their transport into different tissues and specifically into the brain mainly due to its large size and the presence of the blood-brain barrier (BBB). To overcome these challenges, we developed here a strategy wherein a peptide known to target specific gangliosides was fused to a double-stranded RNA binding protein to deliver siRNA to the brain parenchyma. The designed fusion protein designated as TARBP-BTP consists of a double-stranded RNA-binding domain (dsRBD) of human Trans Activation response element (TAR) RNA Binding Protein (TARBP2) fused to a brain targeting peptide that binds to monosialoganglioside GM1. Conformation-specific binding of TARBP2 domain to siRNA led to the formation of homogenous serum-stable complex with targeting potential. Further, uptake of the complex in Neuro-2a, IMR32 and HepG2 cells analyzed by confocal microscopy and fluorescence activated cell sorting, revealed selective requirement of GM1 for entry. Remarkably, systemic delivery of the fluorescently labeled complex (TARBP-BTP:siRNA) in ΑβPP-PS1 mouse model of Alzheimer's disease (AD) led to distinctive localization in the cerebral hemisphere. Further, the delivery of siRNA mediated by TARBP-BTP led to significant knockdown of BACE1 in the brain, in both ΑβPP-PS1 mice and wild type C57BL/6. The study establishes the growing importance of fusion proteins in delivering therapeutic siRNA to brain tissues. Copyright © 2016 Elsevier B.V. All rights reserved.

Downregulation of Brain Phosphodiesterase Type IV Measured with 11C-(R)-Rolipram Positron Emission Tomography in Major Depressive Disorder

PubMed Central

Fujita, Masahiro; Hines, Christina S.; Zoghbi, Sami S.; Mallinger, Alan G.; Dickstein, Leah P.; Liow, Jeih-San; Zhang, Yi; Pike, Victor W.; Drevets, Wayne C.; Innis, Robert B.; Zarate, Carlos A.

2012-01-01

Background Phosphodiesterase type IV (PDE4), an important component of the cyclic adenosine monophosphate (cAMP) cascade, selectively metabolizes cAMP in the brain to the inactive monophosphate. Basic studies suggest that PDE4 mediates the effects of several antidepressants. This study sought to quantify the binding of 11C-(R)-rolipram, a PDE4 inhibitor, as an indirect measure of this enzyme’s activity in the brain of individuals with major depressive disorder (MDD) compared with healthy control subjects. Methods 11C-(R)-Rolipram brain positron emission tomography scans were performed in 28 unmedicated MDD subjects and 25 age- and gender-matched healthy control subjects. Patients were moderately depressed and about one half were treatment-naive. 11C-(R)-Rolipram binding in the brain was measured using arterial 11C-(R)-rolipram levels to correct for the influence of cerebral blood flow. Results Major depressive disorder subjects showed a widespread, approximately 20% reduction in 11C-(R)-rolipram binding (p = .002), which was not caused by different volumes of gray matter. Decreased rolipram binding of similar magnitudes was observed in most brain areas. Rolipram binding did not correlate with the severity of depressive or anxiety symptoms. Conclusions This study is the first to demonstrate that brain levels of PDE4, a critical enzyme that regulates cAMP, are decreased in unmedicated individuals with MDD in vivo. These results are in line with human postmortem and rodent studies demonstrating downregulation of the cAMP cascade in MDD and support the hypothesis that agents such as PDE4 inhibitors, which increase activity within the cAMP cascade, may have antidepressant effects. PMID:22677471

N-isopropyl-(/sup 123/I)p-iodoamphetamine: single-pass brain uptake and washout; binding to brain synaptosomes; and localization in dog and monkey brain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Winchell, H.S.; Horst, W.D.; Braun, L.

1980-10-01

The kinetics of N-isopropyl-p-(/sup 123/I)iodoamphetamine in rat brains were determined by serial measurements of brain uptake index (BUI) after intracarotid injection; also studied were its effects on amine uptake and release in rat's brain cortical synaptosomes; and its in vivo distribution in the dog and monkey. No specific localization in brain nuclei of the dog was seen, but there was progressive accumulation in the eyes. Rapid initial brain uptake in the ketamine-sedated monkey was noted, and further slow brain uptake occurred during the next 20 min but without retinal localization. High levels of brain activity were maintained for several hours.more » The quantitative initial single-pass clearance of the agent in the brain suggests its use in evaluation of regional brain perfusion. Its interaction with brain amine-binding sites suggests its possible application in studies of cerebral amine metabolism.« less

Development and accuracy of a multipoint method for measuring visibility.

PubMed

Tai, Hongda; Zhuang, Zibo; Sun, Dongsong

2017-10-01

Accurate measurements of visibility are of great importance in many fields. This paper reports a multipoint visibility measurement (MVM) method to measure and calculate the atmospheric transmittance, extinction coefficient, and meteorological optical range (MOR). The relative errors of atmospheric transmittance and MOR measured by the MVM method and traditional transmissometer method are analyzed and compared. Experiments were conducted indoors, and the data were simultaneously processed. The results revealed that the MVM can effectively improve the accuracy under different visibility conditions. The greatest improvement of accuracy was 27%. The MVM can be used to calibrate and evaluate visibility meters.

Special issue on Military Operations Research Society (MORS) Symposium (80th): Expanding the Boundaries of National Security Analysis (Phalanx: The Bulletin of Military Operations Research. Volume 45, Number 2, June 2012)

DTIC Science & Technology

2012-06-01

brianmccue@alum.mit.edu Letters to the Editor, John Willis, Augustine Consulting, Inc., jwillis@aciedge.com Modeling and Simulation , James N. Bexfield, FS, OSD...concepts that are now being applied to modern analytical thinking. The tuto- rials are free to MORS members and $75 for the day for nonmembers. The...Overview of Agent- based Modeling and Simulation and Complex Adaptive Systems •  Visual Data Analysis •  Analyzing Combat Identification •  Guidelines for

CLEAR: Communications Link Expert Assistance Resource

NASA Technical Reports Server (NTRS)

Hull, Larry G.; Hughes, Peter M.

1987-01-01

Communications Link Expert Assistance Resource (CLEAR) is a real time, fault diagnosis expert system for the Cosmic Background Explorer (COBE) Mission Operations Room (MOR). The CLEAR expert system is an operational prototype which assists the MOR operator/analyst by isolating and diagnosing faults in the spacecraft communication link with the Tracking and Data Relay Satellite (TDRS) during periods of realtime data acquisition. The mission domain, user requirements, hardware configuration, expert system concept, tool selection, development approach, and system design were discussed. Development approach and system implementation are emphasized. Also discussed are system architecture, tool selection, operation, and future plans.

Anatomical location of LPA1 activation and LPA phospholipid precursors in rodent and human brain.

PubMed

González de San Román, Estibaliz; Manuel, Iván; Giralt, María Teresa; Chun, Jerold; Estivill-Torrús, Guillermo; Rodríguez de Fonseca, Fernando; Santín, Luis Javier; Ferrer, Isidro; Rodríguez-Puertas, Rafael

2015-08-01

Lysophosphatidic acid (LPA) is a signaling molecule that binds to six known G protein-coupled receptors: LPA1 -LPA6 . LPA evokes several responses in the CNS, including cortical development and folding, growth of the axonal cone and its retraction process. Those cell processes involve survival, migration, adhesion proliferation, differentiation, and myelination. The anatomical localization of LPA1 is incompletely understood, particularly with regard to LPA binding. Therefore, we have used functional [(35) S]GTPγS autoradiography to verify the anatomical distribution of LPA1 binding sites in adult rodent and human brain. The greatest activity was observed in myelinated areas of the white matter such as corpus callosum, internal capsule and cerebellum. MaLPA1 -null mice (a variant of LPA1 -null) lack [(35) S]GTPγS basal binding in white matter areas, where the LPA1 receptor is expressed at high levels, suggesting a relevant role of the activity of this receptor in the most myelinated brain areas. In addition, phospholipid precursors of LPA were localized by MALDI-IMS in both rodent and human brain slices identifying numerous species of phosphatides and phosphatidylcholines. Both phosphatides and phosphatidylcholines species represent potential LPA precursors. The anatomical distribution of these precursors in rodent and human brain may indicate a metabolic relationship between LPA and LPA1 receptors. Lysophosphatidic acid (LPA) is a signaling molecule that binds to six known G protein-coupled receptors (GPCR), LPA1 to LPA6 . LPA evokes several responses in the central nervous system (CNS), including cortical development and folding, growth of the axonal cone and its retraction process. We used functional [(35) S]GTPγS autoradiography to verify the anatomical distribution of LPA1 -binding sites in adult rodent and human brain. The distribution of LPA1 receptors in rat, mouse and human brains show the highest activity in white matter myelinated areas. The basal and LPA-evoked activities are abolished in MaLPA1 -null mice. The phospholipid precursors of LPA are localized by MALDI-IMS. The anatomical distribution of LPA precursors in rodent and human brain suggests a relationship with functional LPA1 receptors. © 2015 International Society for Neurochemistry.

Long-term Immunogenicity of Elosulfase Alfa in the Treatment of Morquio A Syndrome: Results From MOR-005, a Phase III Extension Study.

PubMed

Long, Brian; Tompkins, Troy; Decker, Celeste; Jesaitis, Lynne; Khan, Shahid; Slasor, Peter; Harmatz, Paul; O'Neill, Charles A; Schweighardt, Becky

2017-01-01

Elosulfase alfa is an enzyme replacement therapy for the treatment of Morquio A syndrome (mucopolysaccharidosis IVA), a lysosomal storage disorder caused by a deficiency of the enzyme N-acetylgalactose-amine-6-sulfatase. We previously reported immunogenicity data from our 24-week placebo-controlled Phase III study, MOR-004. Here, we report the long-term immunogenicity profile of elosulfase alfa from MOR-005, the Phase III extension trial to assess potential correlations between antidrug antibodies and efficacy and safety profile outcomes throughout 120 weeks of treatment. The long-term immunogenicity of elosulfase alfa was evaluated in patients with Morquio A syndrome in an open-label extension study for a total of 120 weeks. All patients received 2.0 mg/kg elosulfase alfa either weekly or every other week before establishment of 2.0 mg/kg/wk as the recommended dose, at which time all patients received weekly treatment. Efficacy measures were compared with those from the MOR-004 baseline, enabling analysis of changes over 120 weeks. The primary efficacy measure was the change from baseline in 6-minute walk test. Secondary measures included changes from baseline in 3-minute stair climb test and normalized urine keratan sulfate, a pharmacodynamic metric. All patients treated with elosulfase alfa developed antidrug total antibodies (TAb) by week 24 of MOR-004. In the extension study, all patients, including those who had previously received placebo, were TAb positive by study week 36 (MOR-005 week 12). All patients remained TAb positive throughout the study, and TAb titers were similar across treatment groups at week 120. Nearly all patients tested positive for neutralizing antibodies (NAb) at least once, with incidence of NAb positivity peaking at 85.9% at study week 36, then steadily declining to 66.0% at study week 120. In all treatment groups, mean urine keratan sulfate remained below treatment-naive baseline despite the presence of antidrug antibodies. No relationship was observed between TAb titers or NAb positivity and changes in urine keratan sulfate, 6-minute walk test, or 3-minute stair climb test from baseline to week 120. No consistent associations were detected between antidrug antibodies and the occurrence of hypersensitivity adverse events or anaphylaxis over the course of the study. Immunogenicity results from this long-term study are consistent with previously reported 24-week results. Despite the sustained presence of antidrug antibodies, elosulfase alfa was well tolerated, and patients continued to benefit from treatment through week 120. No associations were detected between higher TAb titers or NAb positivity and reduced treatment effect or worsened safety profile measures. ClinicalTrials.gov identifier: NCT01415427. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Preferential reduction of binding of sup 125 I-iodopindolol to beta-1 adrenoceptors in the amygdala of rat after antidepressant treatments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ordway, G.A.; Gambarana, C.; Tejani-Butt, S.M.

1991-05-01

This study utilized quantitative receptor autoradiography to examine the effects of repeated administration of antidepressants to rats on the binding of the beta adrenoceptor antagonist, {sup 125}I-iodopindolol ({sup 125}I-IPIN) to either beta-1 or beta-2 adrenoceptors in various regions of brain. Antidepressants were selected to represent various chemical and pharmacological classes including tricyclic compounds (desipramine and protriptyline), monoamine oxidase inhibitors (clorgyline, phenelzine and tranylcypromine), atypical antidepressants (mianserin and trazodone) and selective inhibitors of the uptake of serotonin (citalopram and sertraline). Additionally, rats were treated with various psychotropic drugs that lack antidepressant efficacy (cocaine, deprenyl, diazepam and haloperidol). Repeated treatment of ratsmore » with desipramine, protriptyline, clorgyline, phenelzine, tranylcypromine or mianserin reduced the binding of {sup 125}I-IPIN to beta-1 adrenoceptors in many brain areas. Only in the basolateral and lateral nuclei of the amygdala did all six of these antidepressants significantly reduce {sup 125}I-IPIN binding to beta-1 adrenoceptors. In these amygdaloid nuclei, the magnitude of the reduction in the binding of {sup 125}I-IPIN caused by each of these drugs was comparable to or greater than the reduction in binding produced in any other region of brain. Reductions of binding of {sup 125}I-IPIN after antidepressant treatments were not consistently observed in the cortex, the area of brain examined most often in homogenate binding studies. Only the monoamine oxidase inhibitors caused reductions in the binding of {sup 125}I-IPIN to beta-2 adrenoceptors, and this effect was generally localized to the amygdala and hypothalamus.« less

Influence of alcoholism and cholesterol on TSPO binding in brain: PET [11C]PBR28 studies in humans and rodents.

PubMed

Kim, Sung Won; Wiers, Corinde E; Tyler, Ryan; Shokri-Kojori, Ehsan; Jang, Yeon Joo; Zehra, Amna; Freeman, Clara; Ramirez, Veronica; Lindgren, Elsa; Miller, Gregg; Cabrera, Elizabeth A; Stodden, Tyler; Guo, Min; Demiral, Şükrü B; Diazgranados, Nancy; Park, Luke; Liow, Jeih-San; Pike, Victor; Morse, Cheryl; Vendruscolo, Leandro F; Innis, Robert B; Koob, George F; Tomasi, Dardo; Wang, Gene-Jack; Volkow, Nora D

2018-05-03

Neuroinflammation appears to contribute to neurotoxicity observed with heavy alcohol consumption. To assess whether chronic alcohol results in neuroinflammation we used PET and [ 11 C]PBR28, a ligand that binds to the 18-kDa translocator protein (TSPO), to compare participants with an alcohol use disorder (AUD: n = 19) with healthy controls (HC: n = 17), and alcohol-dependent (n = 9) with -nondependent rats (n = 10). Because TSPO is implicated in cholesterol's transport for steroidogenesis, we investigated whether plasma cholesterol levels influenced [ 11 C]PBR28 binding. [ 11 C]PBR28 binding did not differ between AUD and HC. However, when separating by TSPO genotype rs6971, we showed that medium-affinity binders AUD participants showed lower [ 11 C]PBR28 binding than HC in regions of interest (whole brain, gray and white matter, hippocampus, and thalamus), but no group differences were observed in high-affinity binders. Cholesterol levels inversely correlated with brain [ 11 C]PBR28 binding in combined groups, due to a correlation in AUD participants. In rodents, we observed no differences in brain [ 11 C]PBR28 uptake between alcohol-dependent and -nondependent rats. These findings, which are consistent with two previous [ 11 C]PBR28 PET studies, may indicate lower activation of microglia in AUD, whereas failure to observe alcohol effects in the rodent model indicate that species differences do not explain the discrepancy with prior rodent autoradiographic studies reporting increases in TSPO binding with chronic alcohol. However, reduced binding in AUD participants could also reflect competition from endogenous TSPO ligands such as cholesterol; and since the rs6971 polymorphism affects the cholesterol-binding domain of TSPO this could explain why differences were observed only in medium-affinity binders.

Localization and characterization of (/sup 3/H)desmethylimipramine binding sites in rat brain by quantitative autoradiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biegon, A.; Rainbow, T.C.

1983-05-01

The high affinity binding sites for the antidepressant desmethlyimipramine (DMI) have been localized in rat brain by quantitative autoradiography. There are high concentrations of binding sites in the locus ceruleus, the anterior ventral thalamus, the ventral portion of the bed nucleus of the stria terminalis, the paraventricular and the dorsomedial nuclei of the hypothalamus. The distribution of DMI binding sites is in striking accord with the distribution of norepinephrine terminals. Pretreatment of rats with the neurotoxin 6-hydroxydopamine, which causes a selective degeneration of catecholamine terminals, results in 60 to 90% decrease in DMI binding. These data support the idea thatmore » high affinity binding sites for DMI are located on presynaptic noradrenergic terminals.« less

[3H]N-METHYLSCOPOLAMINE BINDING TO HEART ATRIUM AND FOUR BRAIN REGIONS FROM THE MALLARD (ANAS PLATYRHNCHOS)

EPA Science Inventory

Neurotransmitter receptor research has blossomed in the past decade in the human health sciences. owever, little attention has been given to this line of investigation by environmental scientists. n this study, binding characteristics of membrane preparations from four brain regi...

Synthesis and receptor binding studies of (+/-)1-iodo-MK-801

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, D.J.; Ciliax, B.J.; Van Dort, M.E.

1989-06-01

The glutamate analogue N-methyl-D-aspartate (NMDA) binds to a subset of glutamate receptors that are coupled to a voltage-sensitive cation channel. This NMDA-linked channel is the likely binding locus of the potent anticonvulsant MK-801. To develop single-photon emission computed tomography (SPECT) probes of this brain channel, we synthesized (+/)1-iodo-MK-801 and (+/-)1-({sup 125}I)iodo-MK-801. The effect of (+/-)1-iodo-MK-801 on ligand binding to the NMDA-linked glutamate receptor site was assessed using a rat brain homogenate assay. (+/-)1-Iodo-MK-801 displaced the dissociative anesthetic ligand ({sup 3}H)N-(1-(2-thienyl)cyclohexyl)piperidine (({sup 3}H)TCP) binding with an IC50 of 1 microM, which is a 10-fold lower binding affinity than that of (+/-)MK-801.more » In in vivo autoradiographic studies, (+/-)MK-801 failed to block selective uptake of (+/-)1-iodo-MK-801 in rat brain. These results suggest that (+/-)1-iodo-MK-801 may not be a suitable ligand for mapping NMDA-linked glutamate receptor channels.« less

Ropizine concurrently enhances and inhibits ( sup 3 H) dextromethorpan binding to different structures of the guinea pig brain: Autoradiographic evidence for multiple binding sites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Canoll, P.D.; Smith, P.R.; and Musacchio, J.M.

1990-01-01

Ropizine produces a simultaneous enhancement and inhibition of ({sup 3}H) dextromethorphan (DM) high-affinity binding to different areas of the guinea pig brain. These results imply that there are two distinct types of high-affinity ({sup 3}H)DM binding sites, which are present in variable proportions in different brain structures. The ropizine-enhances ({sup 3}H)DM binding type was preferentially inhibited by (+)-pentazocine. This is consistent with the presumption that the (+)-pentazocine-sensitive site is identical with the common site for DM and 3-(-3-Hydroxphenyl)-N-(1-propyl)piperidine ((+)-3-PPP). The second binding type, which is inhibited by ropizine and is not so sensitive to (+){minus} pentazocine, has not been fullymore » characterized. This study demonstrates that the biphasic effects to ropizine are due, at least in part, to the effects of ropizine on two different types of ({sup 3}H)DM binding sites. However, this study does not rule out that the common DM/(+)-3-PPP site also might be inhibited by higher concentrations of ropizine.« less

Aging-induced changes in brain regional serotonin receptor binding: Effect of Carnosine.

PubMed

Banerjee, S; Poddar, M K

2016-04-05

Monoamine neurotransmitter, serotonin (5-HT) has its own specific receptors in both pre- and post-synapse. In the present study the role of carnosine on aging-induced changes of [(3)H]-5-HT receptor binding in different brain regions in a rat model was studied. The results showed that during aging (18 and 24 months) the [(3)H]-5-HT receptor binding was reduced in hippocampus, hypothalamus and pons-medulla with a decrease in their both Bmax and KD but in cerebral cortex the [(3)H]-5-HT binding was increased with the increase of its only Bmax. The aging-induced changes in [(3)H]-5-HT receptor binding with carnosine (2.0 μg/kg/day, intrathecally, for 21 consecutive days) attenuated in (a) 24-month-aged rats irrespective of the brain regions with the attenuation of its Bmax except hypothalamus where both Bmax and KD were significantly attenuated, (b) hippocampus and hypothalamus of 18-month-aged rats with the attenuation of its Bmax, and restored toward the [(3)H]-5-HT receptor binding that observed in 4-month-young rats. The decrease in pons-medullary [(3)H]-5-HT binding including its Bmax of 18-month-aged rats was promoted with carnosine without any significant change in its cerebral cortex. The [(3)H]-5-HT receptor binding with the same dosages of carnosine in 4-month-young rats (a) increased in the cerebral cortex and hippocampus with the increase in their only Bmax whereas (b) decreased in hypothalamus and pons-medulla with a decrease in their both Bmax and KD. These results suggest that carnosine treatment may (a) play a preventive role in aging-induced brain region-specific changes in serotonergic activity (b) not be worthy in 4-month-young rats in relation to the brain regional serotonergic activity. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

A Lipoprotein Receptor Cluster IV Mutant Preferentially Binds Amyloid-β and Regulates Its Clearance from the Mouse Brain*

PubMed Central

Sagare, Abhay P.; Bell, Robert D.; Srivastava, Alaka; Sengillo, Jesse D.; Singh, Itender; Nishida, Yoichiro; Chow, Nienwen; Zlokovic, Berislav V.

2013-01-01

Soluble low density lipoprotein receptor-related protein-1 (sLRP1) binds ∼70% of amyloid β-peptide (Aβ) in human plasma. In Alzheimer disease (AD) and individuals with mild cognitive impairment converting to AD, plasma sLRP1 levels are reduced and sLRP1 is oxidized, which results in diminished Aβ peripheral binding and higher levels of free Aβ in plasma. Experimental studies have shown that free circulating Aβ re-enters the brain and that sLRP1 and/or its recombinant wild type cluster IV (WT-LRPIV) prevent Aβ from entering the brain. Treatment of Alzheimer APPsw+/0 mice with WT-LRPIV has been shown to reduce brain Aβ pathology. In addition to Aβ, LRPIV binds multiple ligands. To enhance LRPIV binding for Aβ relative to other LRP1 ligands, we generated a library of LRPIV-derived fragments and full-length LRPIV variants with glycine replacing aspartic acid residues 3394, 3556, and 3674 in the calcium binding sites. Compared with WT-LRPIV, a lead LRPIV-D3674G mutant had 1.6- and 2.7-fold higher binding affinity for Aβ40 and Aβ42 in vitro, respectively, and a lower binding affinity for other LRP1 ligands (e.g. apolipoprotein E2, E3, and E4 (1.3–1.8-fold), tissue plasminogen activator (2.7-fold), matrix metalloproteinase-9 (4.1-fold), and Factor Xa (3.8-fold)). LRPIV-D3674G cleared mouse endogenous brain Aβ40 and Aβ42 25–27% better than WT-LRPIV. A 3-month subcutaneous treatment of APPsw+/0 mice with LRPIV-D3674G (40 μg/kg/day) reduced Aβ40 and Αβ42 levels in the hippocampus, cortex, and cerebrospinal fluid by 60–80% and improved cerebral blood flow responses and hippocampal function at 9 months of age. Thus, LRPIV-D3674G is an efficient new Aβ clearance therapy. PMID:23580652

Receptor-mediated transcytosis of cyclophilin B through the blood-brain barrier.

PubMed

Carpentier, M; Descamps, L; Allain, F; Denys, A; Durieux, S; Fenart, L; Kieda, C; Cecchelli, R; Spik, G

1999-07-01

Cyclophilin B (CyPB) is a cyclosporin A (CsA)-binding protein mainly located in intracellular vesicles and secreted in biological fluids. In previous works, we demonstrated that CyPB interacts with T lymphocytes and enhances in vitro cellular incorporation and activity of CsA. In addition to its immunosuppressive activity, CsA is able to promote regeneration of damaged peripheral nerves. However, the crossing of the drug from plasma to neural tissue is restricted by the relative impermeability of the blood-brain barrier. To know whether CyPB might also participate in the delivery of CsA into the brain, we have analyzed the interactions of CyPB with brain capillary endothelial cells. First, we demonstrated that CyPB binds to two types of binding sites present at the surface of capillary endothelial cells from various species of tissues. The first type of binding sites (K(D) = 300 nM; number of sites = 3 x 10(6)) is related to interactions with negatively charged compounds such as proteoglycans. The second type of binding sites, approximately 50,000 per cell, exhibits a higher affinity for CyPB (K(D) = 15 nM) and is involved in an endocytosis process, indicating it might correspond to a functional receptor. Finally, the use of an in vitro model of blood-brain barrier allowed us to demonstrate that CyPB is transcytosed by a receptor-mediated pathway (flux = 16.5 fmol/cm2/h). In these conditions, CyPB did not significantly modify the passage of CsA, indicating that it is unlikely to provide a pathway for CsA brain delivery.

QSAR, molecular docking studies of thiophene and imidazopyridine derivatives as polo-like kinase 1 inhibitors

NASA Astrophysics Data System (ADS)

Cao, Shandong

2012-08-01

The purpose of the present study was to develop in silico models allowing for a reliable prediction of polo-like kinase inhibitors based on a large diverse dataset of 136 compounds. As an effective method, quantitative structure activity relationship (QSAR) was applied using the comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). The proposed QSAR models showed reasonable predictivity of thiophene analogs (Rcv2=0.533, Rpred2=0.845) and included four molecular descriptors, namely IC3, RDF075m, Mor02m and R4e+. The optimal model for imidazopyridine derivatives (Rcv2=0.776, Rpred2=0.876) was shown to perform good in prediction accuracy, using GATS2m and BEHe1 descriptors. Analysis of the contour maps helped to identify structural requirements for the inhibitors and served as a basis for the design of the next generation of the inhibitor analogues. Docking studies were also employed to position the inhibitors into the polo-like kinase active site to determine the most probable binding mode. These studies may help to understand the factors influencing the binding affinity of chemicals and to develop alternative methods for prescreening and designing of polo-like kinase inhibitors.

Neuromedin N: high affinity interaction with brain neurotensin receptors and rapid inactivation by brain synaptic peptidases.

PubMed

Checler, F; Vincent, J P; Kitabgi, P

1986-07-31

Neuromedin N (NN) is a novel neurotensin (NT)-like hexapeptide recently isolated from porcine spinal cord. NN competitively inhibited the binding of monoiodinated [Trp11]NT to rat brain synaptic membranes with a 19-fold lower potency than NT. In the presence of 1 mM 1,10-phenanthroline or 10 microM bestatin, the potency of NN relative to NT was increased about 5-fold. NN was readily degraded by rat brain synaptic membranes, and NN-(2-6) was the major degradation product. NN-(2-6) did not bind to NT receptors at concentrations up to 1 microM whether or not peptidase inhibitors were present in the binding assay. The rate of degradation by synaptic membranes was nearly 2.5 times higher for NN than for NT. NN degradation by membranes was totally prevented by 1,10-phenanthroline and markedly inhibited by bestatin. The presence of NN in the central nervous system, its high potency to interact with brain NT receptors and its rapid inactivation by brain synaptic peptidases make it a potential neurotransmitter candidate acting at the NT receptor.

Autoradiographic analysis of tritiated imipramine binding in the human brain post mortem: effects of suicide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gross-Isseroff, R.; Israeli, M.; Biegon, A.

In vitro quantitative autoradiography of high-affinity tritiated imipramine binding sites was performed on brains of 12 suicide victims and 12 matched controls. Region-specific differences in imipramine binding were found between the two groups. Thus, the pyramidal and molecular layers of the cornu ammoni hippocampal fields and the hilus of the dentate gyrus exhibited 80%, 60%, and 90% increases in binding in the suicide group, respectively. The postcentral cortical gyrus, insular cortex, and claustrum had 45%, 28%, and 75% decreases in binding in the suicide group, respectively. No difference in imipramine binding was observed in prefrontal cortical regions, in the basalmore » ganglia, and in mesencephalic nuclei. No sex and postmortem delay effects on imipramine binding were found. Imipramine binding was positively correlated with age, the effect of age being most pronounced in portions of the basal ganglia and temporal cortex.« less

Substance P receptors in brain stem respiratory centers of the rat: regulation of NK1 receptors by hypoxia.

PubMed

Mazzone, S B; Hinrichsen, C F; Geraghty, D P

1997-09-01

Substance P (SP) is a key neurotransmitter involved in the brain stem integration of carotid body chemoreceptor reflexes. In this study, the characteristics and location of SP receptors in the rat brain stem and their regulation by hypoxia were investigated using homogenate radioligand binding and quantitative autoradiography. Specific binding of [125I] Bolton-Hunter SP (BHSP) to brain stem homogenates was saturable (approximately 0.3 nM) and to a single class of high-affinity sites (K(d), 0.16 nM; maximum density of binding sites, 0.43 fmol/mg wet weight tissue). The order of potency of agonists for inhibition of BHSP binding was SP > [Sar9Met(O2)11]SP > neurokinin A > septide > neurokinin B > [Nle10]-neurokinin A(4-10) = senktide, and for nonpeptide antagonists, RP 67580 > CP-96,345 > RP 68651 = CP-96,344, consistent with binding to NK1 receptors. The effect of single and multiple, 5-min bouts of hypoxia (8.5% O2/91.5% N2) on BHSP binding was investigated using quantitative autoradiography. Binding sites were localized to the lateral, medial and commissural nucleus of the solitary tract (NTS), the hypoglossal nucleus, central gray and the spinal trigeminal tract and nucleus (Sp5 and nSp5, respectively). Five min after a single bout of hypoxia, the density of BHSP binding sites had decreased significantly (P < .05) in the medial NTS (-33%) and lateral NTS (-24%) when compared to normoxic controls. However, the normal receptor complement was restored within 60 min of the hypoxic challenge. In the Sp5, a significant decrease (P < .05) in binding was observed 5 min after hypoxia which was still apparent after 60 min. In contrast, the density of BHSP binding sites in the hypoglossal nucleus decreased slowly and was significantly lower (P < .05) than normoxic controls 60 min after hypoxia. Five min after repetitive hypoxia (3 x 5 min bouts), BHSP binding in the NTS was reduced by more than 40%. Studies in homogenates showed that the affinity of SP for BHSP binding sites was not affected by repetitive hypoxia (K(d)s, normoxic, 0.27 nM; hypoxic, 0.24 nM). These data suggest that afferent input from carotid body chemoreceptors may dynamically regulate NK1 receptors in several brain stem nuclei that are intimately involved in stimulating ventilation during hypoxia, and that the time-course of receptor turnover may differ from region to region in the brain stem. The temporary loss of NK1 receptors in the NTS may partly explain why adequate ventilation is often not maintained during hypoxia.

Panicolytic-like action of bradykinin in the dorsal periaqueductal gray through μ-opioid and B2-kinin receptors.

PubMed

Sestile, Caio César; Maraschin, Jhonatan Christian; Gama, Vanessa Scalco; Zangrossi, Hélio; Graeff, Frederico Guilherme; Audi, Elisabeth Aparecida

2017-09-01

A wealth of evidence has shown that opioid and kinin systems may control proximal defense in the dorsal periaqueductal gray matter (dPAG), a critical panic-associated area. Studies with drugs that interfere with serotonin-mediated neurotransmission suggest that the μ-opioid receptor (MOR) synergistically interacts with the 5-HT 1A receptor in the dPAG to inhibit escape, a panic-related behavior. A similar inhibitory effect has also been reported after local administration of bradykinin (BK), which is blocked by the non-selective opioid receptor antagonist naloxone. The latter evidence, points to an interaction between BK and opioids in the dPAG. We further explored the existence of this interaction through the dPAG electrical stimulation model of panic. We also investigated whether intra-dPAG injection of captopril, an inhibitor of the angiotensin-converting enzyme (ACE) that also degrades BK, causes a panicolytic-like effect. Our results showed that intra-dPAG injection of BK inhibited escape performance in a dose-dependent way, and this panicolytic-like effect was blocked by the BK type 2 receptor (B2R) antagonist HOE-140, and by the selective MOR antagonist CTOP. Conversely, the panicolytic-like effect caused by local administration of the selective MOR agonist DAMGO was antagonized by pre-treatment with either CTOP or HOE-140, indicating cross-antagonism between MOR and B2R. Finally, intra-dPAG injection of captopril also impaired escape in a dose-dependent way, and this panicolytic-like effect was blocked by pretreatment with HOE-140, suggesting mediation by endogenous BK. The panicolytic-like effect of captopril indicates that the use of ACE inhibitors in the clinical management of panic disorder may be worth exploring. Copyright © 2017 Elsevier Ltd. All rights reserved.

Single-Dose Adductor Canal Block With Local Infiltrative Analgesia Compared With Local Infiltrate Analgesia After Total Knee Arthroplasty: A Randomized, Double-Blind, Placebo-Controlled Trial.

PubMed

Nader, Antoun; Kendall, Mark C; Manning, David W; Beal, Matthew; Rahangdale, Rohit; Dekker, Robert; De Oliveira, Gildasio S; Kamenetsky, Eric; McCarthy, Robert J

A single-dose adductor canal block can provide postoperative analgesia for patients undergoing total knee arthroplasty (TKA). The purpose of this study was to assess postoperative opioid consumption after ultrasound-guided single-injection bupivacaine compared with saline adductor canal block for patients undergoing TKA. After institutional review board approval, written informed consent was obtained from patients (>18 years old) undergoing elective TKA. Subjects were randomized into 2 groups as follows: adductor canal blockade with 10 mL of bupivacaine 0.25% with epinephrine 1:300,000 or 10 mL of normal saline. All patients received a periarticular infiltration mixture intraoperatively with scheduled and patient requested oral and IV analgesics postoperatively for breakthrough pain. Personnel blinded to group allocation recorded pain scores and opioid consumption every 6 hours. Pain burden, area under the numeric rating score for pain, was calculated for 36 hours. The primary outcome was postoperative IV/IM morphine (mg morEq) consumption at 36 hours after surgery. Forty (28 women/12 men) subjects were studied. Postoperative opioid consumption was reduced in the bupivacaine 48 (39 to 61) mg morEq compared with saline 60 (49 to 85) mg morEq, difference -12 (-33 to -2) mg morEq (P = 0.03). Pain burden at rest was decreased in the bupivacaine 71 (37 to 120) score · hours compared with saline 131 (92 to 161) score · hours, difference -60 (-93 to -14) score · hours (P = 0.009). Adductor canal blockade with bupivacaine 0.25% with epinephrine 1:300,000 effectively reduces pain and opioid requirement in the postoperative period after TKA. Adductor canal blockade is an effective pain management adjunct for patients undergoing TKA.

μ-Opioid Receptor Trafficking on Inhibitory Synapses in the Rat Brainstem

PubMed Central

Browning, Kirsteen N.; Kalyuzhny, Alexander E.; Travagli, R. Alberto

2011-01-01

Whole-cell recordings were made from identified gastric-projecting rat dorsal motor nucleus of the vagus (DMV) neurons. The amplitude of evoked IPSCs (eIPSCs) was unaffected by perfusion with met-enkephalin (ME) or by μ-, δ-, or κ-opioid receptor selective agonists, namely d-Ala2-N-Me-Phe4-Glycol5-enkephalin (DAMGO), cyclic [d-Pen2-d-Pen5]-enkephalin, or trans-3,4-dichloro-N-methyl-N-[2-(1-pyrolytinil)-cyclohexyl]-benzeneacetamide methane sulfonate (U50,488), respectively. Brief incubation with the adenylate cyclase activator forskolin or the nonhydrolysable cAMP analog 8-bromo-cAMP, thyrotropin releasing hormone, or cholecystokinin revealed the ability of ME and DAMGO to inhibit IPSC amplitude; this inhibition was prevented by pretreatment with the μ-opioid receptor (MOR1) selective antagonist d-Phe-Cys-Tyr-d-Trp-Orn-Thr-Pen-Thr-NH2. Conversely, incubation with the adenylate cyclase inhibitor dideoxyadenosine, with the protein kinase A (PKA) inhibitor N-[2-(p-Bromocinnamyl-amino)ethyl]-5-isoquinolinesulfonamide dihydrochloride (H89), or with the Golgi-disturbing agent brefeldin A, blocked the ability of forskolin to facilitate the inhibitory actions of ME. Immunocytochemical experiments revealed that under control conditions, MOR1 immunoreactivity (MOR1-IR) was colocalized with glutamic acid decarboxylase (GAD)-IR in profiles apposing DMV neurons only after stimulation of the cAMP–PKA pathway. Pretreatment with H89 or brefeldin A or incubation at 4°C prevented the forskolin-mediated insertion of MOR1 on GAD-IR-positive profiles. These results suggest that the cAMP–PKA pathway regulates trafficking of μ-opioid receptors into the cell surface of GABAergic nerve terminals. By consequence, the inhibitory actions of opioid peptides in the dorsal vagal complex may depend on the state of activation of brainstem vagal circuits. PMID:15317860

Improved silicon carbide for advanced heat engines

NASA Technical Reports Server (NTRS)

Whalen, T. J.; Winterbottom, W. L.

1986-01-01

Work performed to develop silicon carbide materials of high strength and to form components of complex shape and high reliability is described. A beta-SiC powder and binder system was adapted to the injection molding process and procedures and process parameters developed capable of providing a sintered silicon carbide material with improved properties. The initial effort has been to characterize the baseline precursor materials (beta silicon carbide powder and boron and carbon sintering aids), develop mixing and injection molding procedures for fabricating test bars, and characterize the properties of the sintered materials. Parallel studies of various mixing, dewaxing, and sintering procedures have been carried out in order to distinguish process routes for improving material properties. A total of 276 MOR bars of the baseline material have been molded, and 122 bars have been fully processed to a sinter density of approximately 95 percent. The material has a mean MOR room temperature strength of 43.31 ksi (299 MPa), a Weibull characteristic strength of 45.8 ksi (315 MPa), and a Weibull modulus of 8.0. Mean values of the MOR strengths at 1000, 1200, and 14000 C are 41.4, 43.2, and 47.2 ksi, respectively. Strength controlling flaws in this material were found to consist of regions of high porosity and were attributed to agglomerates originating in the initial mixing procedures. The mean stress rupture lift at 1400 C of five samples tested at 172 MPa (25 ksi) stress was 62 hours and at 207 MPa (30 ksi) stress was 14 hours. New fluid mixing techniques have been developed which significantly reduce flaw size and improve the strength of the material. Initial MOR tests indicate the strength of the fluid-mixed material exceeds the baseline property by more than 33 percent.

An urban, water-borne outbreak of diarrhoea and shigellosis in a district town in eastern India.

PubMed

Saha, T; Murhekar, M; Hutin, Y J; Ramamurthy, T

2009-01-01

In September 2007, the Gayeshpur municipality reported a cluster of cases with diarrhoea. We aimed to identify the causative agent and the source of the disease. We defined a case as the occurrence of diarrhoea (> 3 loose stools/day) with fever or bloody stools in a resident of Gayeshpur in September-October 2007. We asked healthcare facilities to report cases, collected stool specimens from patients, constructed an epidemic curve, drew a map and calculated the incidence by age and sex. We also conducted a matched case-control study (58 in each group), calculated matched odds ratio (MOR) and population attributable fraction (PAF), as well as assessed the environment. We identified 461 cases (attack rate: 46/1000 population) and isolated Shigella flexneri (serotype 2a and 3a) from 3 of 4 stool specimens. The attack rate was higher among females (52/1000) and those in the age group of 45-59 years (71/1000). The outbreak started on 22 September, peaked multiple times and subsided on 12 October 2007. Cases were clustered distal to a leaking pipeline that crossed an open drain to intermittently supply non-chlorinated water to taps. The 58 cases and 58 controls were matched for age and sex. Drinking tap water (MOR: 10; 95% CI: 3-32; PAF: 89%), washing utensils in tap water (MOR: 3.7; 95% CI: 1.2-11.3) and bathing in tap water (MOR: 3.5; 95% CI: 1.1-11) were associated with the illness. This outbreak of diarrhoea and Shigella flexneri dysentery was caused by contamination of tap water and subsided following repair of the pipeline. We recommended regular chlorination of the water and maintenance of pipelines.

Analysis of radar images of the active volcanic zone at Krafla, Iceland: The effects of look azimuth biasing

NASA Technical Reports Server (NTRS)

Garvin, J. B.; Williams, R. S., Jr.

1989-01-01

The geomorphic expression of Mid-Ocean-Ridge (MOR) volcanism in a subaerial setting occurs uniquely on Earth in Iceland, and the most recent MOR eruptive activity has been concentrated in the Northeastern Volcanic Zone in an area known as Krafla. Within the Krafla region are many of the key morphologic elements of MOR-related basaltic volcanism, as well as volcanic explosion craters, subglacial lava shields, tectonic fissure swarms known as gjar, and basaltic-andesite flows with well developed ogives (pressure-ridges). The objective was to quantify the degree to which the basic volcanic and structural features can be mapped from directional SAR imagery as a function of the look azimuth. To accomplish this, the current expression of volcanic and tectonic constructs was independently mapped within the Krafla region on the E, W, and N-looking SAR images, as well as from SPOT Panchromatic imagery acquired in 1987. The initial observations of the E, W, and N images indicates that fresh a'a lava surfaces are extremely radar bright (rough at 3 cm to meter scales) independent of look direction; this suggests that these flows do not have strong flow direction related structures at meter and cm scales, which is consistent with typical Icelandic a'a lava surfaces in general. The basic impression from a preliminary analysis of the effects of look azimuth biasing on interpretation of the geology of an active MOR volcanic zone is that up to 30 percent of the diagnostic features can be missed at any given look direction, but that having two orthogonal look direction images is probably sufficient to prevent gross misinterpretation.

Increased morbidity odds ratio of primary liver cancer and cirrhosis of the liver among vinyl chloride monomer workers

PubMed Central

Du C., L.; Wang, J. D.

1998-01-01

OBJECTIVES: To determine if there is an increased risk of admission to hospital for various diseases among vinyl chloride monomer (VCM) workers. METHODS: 2224 workers with occupational exposure to VCM were identified for occurrence of disease based on a search of hospital computer files on labour insurance. These data were compared with those of workers manufacturing optical equipment and motorcycles from 1 January 1985 to 31 March 1994. Cardiovascular and cerebrovascular diseases were used as reference diseases, and the age adjusted morbidity odds ratio (MOR) was calculated. RESULTS: A significantly increased risk of admission to hospital among VCM workers due to primary liver cancer (MOR 4.5-6.5), cirrhosis of the liver (MOR 1.7- 2.1), and other chronic diseases (MOR 1.5-2.0) was found. There were eight cases of primary liver cancer, all with heavy previous exposure to VCM. Another four cases of hepatoma in polyvinyl chloride (PVC) workers were found in the death registry. Ten out of 11 cases of hepatoma, with detailed medical information, were carriers of hepatitis B virus. The average latent period (20 years) was not different from other studies. Alternative agents of primary liver cancer were largely ruled out, suggesting that the combination of hepatitis B and VCM may lead to primary liver cancer. CONCLUSION: There is an increased risk of primary liver cancer in workers exposed to VCM, although the incomplete coverage of the Labor Insurance Bureau data warrants cautious interpretation of the results. Further study exploring the synergistic effects of VCM and hepatitis B is also indicated.   PMID:9849539

Spinal Endomorphin 2 Antinociception and the Mechanisms That Produce It Are Both Sex- and Stage of Estrus Cycle–Dependent in Rats

PubMed Central

Liu, Nai-Jiang; Gintzler, Alan R.

2014-01-01

Endomorphin 2 (EM2) is the predominant endogenous mu-opioid receptor (MOR) ligand in the spinal cord. Given its endogenous presence, antinociceptive responsiveness to the intrathecal application of EM2 most likely reflects its ability to modulate nociception when released in situ. In order to explore the physiological pliability of sex-dependent differences in spinal MOR-mediated antinociception, we investigated the antinociception produced by intrathecal EM2 in male, proestrus female, and diestrus female rats. Antinociception was reflected by changes in tail flick latency to radiant heat. In females, the spinal EM2 antinociceptive system oscillated between analgesically active and inactive states. During diestrus, when circulating estrogens are low, spinal EM2 antinociceptive responsiveness was minimal. In contrast, during proestrus, when circulating estrogens are high, spinal EM2 antinociception was robust and comparable in magnitude to that manifest by males. Furthermore, in proestrus females, spinal EM2 antinociception required spinal dynorphin and kappaopioid receptor activation, concomitant with MOR activation. This is required for neither spinal EM2 antinociception in males nor the antinociception elicited in proestrus females by spinal sufentanil or [d-Ala2,N-methyl-Phe4,Gly-ol5]-enkephalin, which are prototypic MOR-selective nonpeptide and peptide agonists, respectively. These results reveal that spinal EM2 antinociception and the signaling mechanisms used to produce it fundamentally differ in males and females. Perspective The inability to mount spinal EM2 antinociception during defined stages of the estrus (and presumably menstrual) cycle and impaired transition from spinal EM2 analgesically nonresponsive to responsive physiological states could be causally associated with the well-documented greater severity and frequency of chronic intractable pain syndromes in women vs men. PMID:24084000

Association Between Occupational Exposures and Sarcoidosis: An Analysis From Death Certificates in the United States, 1988-1999.

PubMed

Liu, Hongbo; Patel, Divya; Welch, Alison M; Wilson, Carla; Mroz, Margaret M; Li, Li; Rose, Cecile S; Van Dyke, Michael; Swigris, Jeffrey J; Hamzeh, Nabeel; Maier, Lisa A

2016-08-01

Sarcoidosis is a disease that is associated with occupational and environmental antigens, in the setting of a susceptible host. The aim of this study was to examine the association between sarcoidosis mortality and previously reported occupational exposures based on sex and race. The decedents enrolled in this study were derived from United States death certificates from 1988-1999. Cause of death was coded according to ICD-9 and ICD-10. The usual occupation was coded with Bureau of the Census Occupation Codes. Mortality odds ratio (MOR) were determined and multiple Poisson regression were performed to evaluate the independent exposure effects after adjustment for age, sex, race and other occupational exposures. Of the 7,118,535 decedents in our study, 3,393 were identified as sarcoidosis-related, including 1,579 identified as sarcoidosis being the underlying cause of death. The sarcoidosis-related MOR of any occupational exposure was 1.52 (95% CI, 1.35-1.71). Women with any exposure demonstrated an increased MOR compared to women without (MOR 1.65, 95% CI, 1.45-1.89). The mortality risk was significantly elevated in those with employment involving metal working, health care, teaching, sales, banking, and administration. Higher sarcoidosis-related mortality risks associated with specific exposures were noted in women vs men and blacks vs whites. Findings of prior occupations and risk of sarcoidosis were verified using sarcoidosis mortality rates. There were significant differences in risk for sarcoidosis mortality by occupational exposures based on sex and race. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Aging, estradiol and time of day differentially affect serotonin transporter binding in the central nervous system of female rats.

PubMed

Krajnak, Kristine; Rosewell, Katherine L; Duncan, Marilyn J; Wise, Phyllis M

2003-11-14

Estrogen-related changes in serotonergic neuronal transmission, including changes in the number of serotonin transporter (SERT) binding sites, have been cited as a possible cause for changes in mood, memory and sleep that occur during the menopausal transition. However, both aging and estradiol regulate SERT binding sites in the brain. The goal of this experiment was to determine how aging and estrogen interact to regulate SERT levels in the forebrain of young and reproductively senescent female Sprague-Dawley rats using [3H]paroxetine. The density of specific [3H]paroxetine binding in various brain regions was compared in young (2-4 months) and reproductively senescent (10-12 months) female rats at three times of day. In most brain regions examined, estrogen and aging independently increased the number of [3H]paroxetine binding sites. The only region that displayed a reduction in [3H]paroxetine binding with age was the suprachiasmatic nucleus (SCN). Time of day influenced [3H]paroxetine binding in the SCN and the paraventricular thalamus (PVT), two regions known to be involved in the regulation of circadian rhythms. Aging and/or estrogen also altered the pattern of binding in these regions. Thus, based on the results of this study, we conclude that aging and estrogen both act to regulate SERT binding sites in the forebrain of female rats, and that this regulation is region specific.

In Vivo [11C]Dihydrotetrabenazine ([11C]DTBZ) Binding in Rat Striatum: Sensitivity to Dopamine Concentrations

PubMed Central

Kilbourn, Michael R.; Butch, Elizabeth R.; Desmond, Timothy; Sherman, Phillip; Harris, Paul E.; Frey, Kirk A.

2009-01-01

Introduction The sensitivity of the in vivo binding of [11C]dihydrotetrabenazine ([11C]DTBZ) and [11C]methylphenidate ([11C]MPH) to their respective targets, the vesicular monoamine transporter (VMAT2) and the neuronal membrane dopamine transporter (DAT), after alterations of endogenous levels of dopamine were examined in the rat brain. Methods In vivo binding of [11C]DTBZ and [11C]MPH were determined using a bolus+infusion protocol. In vitro numbers of VMAT2 binding sites were determined by autoradiography. Results Repeated dosing with α-methyl-p-tyrosine (AMPT) at doses that significantly (−75%) depleted brain tissue dopamine levels resulted in increased (+36%) in vivo [11C]DTBZ binding to VMAT2 in the striatum. The increase in binding could be completely reversed by treatment with L-DOPA/benserazide to restore dopamine levels. There were no changes in total numbers of VMAT2 binding sites as measured using in vitro autoradiography. No changes were observed for in vivo [11C]MPH binding to the DAT in the striatum following AMPT pretreatment. Conclusion These results indicate that large reductions of dopamine concentrations in the rat brain can produce modest but significant changes in binding of radioligands to the VMAT2, which can be reversed by repleneshment of dopamine using exogenous L-DOPA. PMID:20122661

Use of a benzimidazole derivative BF-188 in fluorescence multispectral imaging for selective visualization of tau protein fibrils in the Alzheimer's disease brain.

PubMed

Harada, Ryuichi; Okamura, Nobuyuki; Furumoto, Shozo; Yoshikawa, Takeo; Arai, Hiroyuki; Yanai, Kazuhiko; Kudo, Yukitsuka

2014-02-01

Selective visualization of amyloid-β and tau protein deposits will help to understand the pathophysiology of Alzheimer's disease (AD). Here, we introduce a novel fluorescent probe that can distinguish between these two deposits by multispectral fluorescence imaging technique. Fluorescence spectral analysis was performed using AD brain sections stained with novel fluorescence compounds. Competitive binding assay using [(3)H]-PiB was performed to evaluate the binding affinity of BF-188 for synthetic amyloid-β (Aβ) and tau fibrils. In AD brain sections, BF-188 clearly stained Aβ and tau protein deposits with different fluorescence spectra. In vitro binding assays indicated that BF-188 bound to both amyloid-β and tau fibrils with high affinity (K i  < 10 nM). In addition, BF-188 showed an excellent blood-brain barrier permeability in mice. Multispectral imaging with BF-188 could potentially be used for selective in vivo imaging of tau deposits as well as amyloid-β in the brain.

Binding characteristics of [125I]Bolton-Hunter [Sar9,Met(O2)11]substance P, a new selective radioligand for the NK1 receptor.

PubMed

Lew, R; Geraghty, D P; Drapeau, G; Regoli, D; Burcher, E

1990-08-02

The selective tachykinin agonist [Sar9,Met(O2)11]substance P (Sar-SP) was radioiodinated with [125I]Bolton-Hunter reagent and the product [125I]Bolton-Hunter-[Sar9,Met(O)2)11]SP (BHSar-SP) purified using reverse phase HPLC. Autoradiographic studies showed dense specific binding of BHSar-SP over the rat submandibular gland and over several regions in rat brain, with very low nonspecific binding, identical with the pattern of binding sites seen in a parallel study with [125I]Bolton-Hunter SP (BHSP). In homogenate binding experiments, BHSar-SP bound with high affinity to a single site in membranes from rat brain (KD 261 pM) and rat submandibular gland (KD 105 pM). Comparative values for BHSP were 495 and 456 pM, i.e. of two and four fold lower affinity than BHSar-SP. Association of BHSar-SP to membranes from brain (k+1 3.7 x 10(9) M-1 min-1) was faster than to membranes from salivary gland (k+1 5.6 x 10(8) M-1 min-1). In competition studies, BHSar-SP was displaced from salivary gland membranes by substance P (SP) approximately physalaemin greater than or equal to Sar-SP approximately SP-(3-11) greater than SP-(5-11) much greater than neurokinin A (NKA) approximately eledoisin = kassinin = SP-methyl ester greater than or equal to neurokinin B (NKB) much greater than [Nle10]NKA-(4-10) greater than [MePhe7]NKB-(4-10). In brain membranes, the rank potency order was SP greater than Sar-SP greater than or equal to physalaemin greater than SP-(3-11) greater than SP-(5-11) greater than NKA greater than or equal to eledoisin much greater than NKB greater than kassinin greater than SP-methyl ester: however [MePhe7]NKB-(4-10) and [Nle10]NKA-(4-10) were ineffective competitors at concentrations up to 1 microM. Both binding patterns are consistent with BHSar-SP binding to an NK1 site. With the exception of SP, Sar-SP, SP-(3-11) and physalaemin, all competitors were 5 to 54 times less potent at BHSar-SP binding sites in brain than in salivary gland. These data reveal some differences in characteristics of NK1 binding sites in brain and submandibular gland. Although of higher affinity, BHSar-SP does not appear greatly more selective than BHSP in its ability to define NK1 binding sites.

Expression pattern of the type 1 sigma receptor in the brain and identity of critical anionic amino acid residues in the ligand-binding domain of the receptor.

PubMed

Seth, P; Ganapathy, M E; Conway, S J; Bridges, C D; Smith, S B; Casellas, P; Ganapathy, V

2001-07-25

The type 1 sigma receptor (sigmaR1) has been shown to participate in a variety of functions in the central nervous system. To identify the specific regions of the brain that are involved in sigmaR1 function, we analyzed the expression pattern of the receptor mRNA in the mouse brain by in situ hybridization. SigmaR1 mRNA was detectable primarily in the cerebral cortex, hippocampus, and Purkinje cells of cerebellum. To identify the critical anionic amino acid residues in the ligand-binding domain of sigmaR1, we employed two different approaches: chemical modification of anionic amino acid residues and site-directed mutagenesis. Chemical modification of anionic amino acids in sigmaR1 with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide reduced the ligand-binding activity markedly. Since it is known that a splice variant of this receptor which lacks exon 3 does not have the ability to bind sigma ligands, the ligand-binding domain with its critical anionic amino acid residues is likely to be present in or around the region coded by exon 3. Therefore, each of the anionic amino acids in this region was mutated individually and the influence of each mutation on ligand binding was assessed. These studies have identified two anionic amino acids, D126 and E172, that are obligatory for ligand binding. Even though the ligand-binding function was abolished by these two mutations, the expression of these mutants was normal at the protein level. These results show that sigmaR1 is expressed at high levels in specific areas of the brain that are involved in memory, emotion and motor functions. The results also provide important information on the chemical nature of the ligand-binding site of sigmaR1 that may be of use in the design of sigmaR1-specific ligands with potential for modulation of sigmaR1-related brain functions.

Multimodal Imaging of Alzheimer Pathophysiology in the Brain's Default Mode Network

DOE PAGES

Shin, Jonghan; Kepe, Vladimir; Small, Gary W.; ...

2011-01-01

The spatial correlations between the brain's default mode network (DMN) and the brain regions known to develop pathophysiology in Alzheimer's disease (AD) have recently attracted much attention. In this paper, we compare results of different functional and structural imaging modalities, including MRI and PET, and highlight different patterns of anomalies observed within the DMN. Multitracer PET imaging in subjects with and without dementia has demonstrated that [C-11]PIB- and [F-18]FDDNP-binding patterns in patients with AD overlap within nodes of the brain's default network including the prefrontal, lateral parietal, lateral temporal, and posterior cingulate cortices, with the exception of the medial temporalmore » cortex (especially, the hippocampus) where significant discrepancy between increased [F-18]FDDNP binding and negligible [C-11]PIB-binding was observed. [F-18]FDDNP binding in the medial temporal cortex—a key constituent of the DMN—coincides with both the presence of amyloid and tau pathology, and also with cortical areas with maximal atrophy as demonstrated by T1-weighted MR imaging of AD patients.« less

Preclinical Evaluation of [(18)F]THK-5105 Enantiomers: Effects of Chirality on Its Effectiveness as a Tau Imaging Radiotracer.

PubMed

Tago, Tetsuro; Furumoto, Shozo; Okamura, Nobuyuki; Harada, Ryuichi; Adachi, Hajime; Ishikawa, Yoichi; Yanai, Kazuhiko; Iwata, Ren; Kudo, Yukitsuka

2016-04-01

Noninvasive imaging of tau and amyloid-β pathologies would facilitate diagnosis of Alzheimer's disease (AD). Recently, we have developed [(18)F]THK-5105 for selective detection of tau pathology by positron emission tomography (PET). The purpose of this study was to clarify biological properties of optically pure [(18)F]THK-5105 enantiomers. Binding for tau aggregates in AD brain section was evaluated by autoradiography (ARG). In vitro binding assays were performed to evaluate the binding properties of enantiomers for AD brain homogenates. The pharmacokinetics in the normal mouse brains was assessed by ex vivo biodistribution assay The ARG of enantiomers showed the high accumulation of radioactivity corresponding to the distribution of tau deposits. In vitro binding assays revealed that (S)-[(18)F]THK-5105 has slower dissociation from tau than (R)-[(18)F]THK-5105. Biodistribution assays indicated that (S)-[(18)F]THK-5105 eliminated faster from the mouse brains and blood compared with (R)-[(18)F]THK-5105. (S)-[(18)F]THK-5105 could be more suitable than (R)-enantiomer for a tau imaging agent.

Alternative Polyadenylation in Glioblastoma Multiforme and Changes in Predicted RNA Binding Protein Profiles

PubMed Central

Shao, Jiaofang; Zhang, Jing; Zhang, Zengming; Jiang, Huawei; Lou, Xiaoyan; Foltz, Gregory; Lan, Qing; Huang, Qiang

2013-01-01

Abstract Alternative polyadenylation (APA) is widely present in the human genome and plays a key role in carcinogenesis. We conducted a comprehensive analysis of the APA products in glioblastoma multiforme (GBM, one of the most lethal brain tumors) and normal brain tissues and further developed a computational pipeline, RNAelements (http://sysbio.zju.edu.cn/RNAelements/), using covariance model from known RNA binding protein (RBP) targets acquired by RNA Immunoprecipitation (RIP) analysis. We identified 4530 APA isoforms for 2733 genes in GBM, and found that 182 APA isoforms from 148 genes showed significant differential expression between normal and GBM brain tissues. We then focused on three genes with long and short APA isoforms that show inconsistent expression changes between normal and GBM brain tissues. These were myocyte enhancer factor 2D, heat shock factor binding protein 1, and polyhomeotic homolog 1 (Drosophila). Using the RNAelements program, we found that RBP binding sites were enriched in the alternative regions between the first and the last polyadenylation sites, which would result in the short APA forms escaping regulation from those RNA binding proteins. To the best of our knowledge, this report is the first comprehensive APA isoform dataset for GBM and normal brain tissues. Additionally, we demonstrated a putative novel APA-mediated mechanism for controlling RNA stability and translation for APA isoforms. These observations collectively lay a foundation for novel diagnostics and molecular mechanisms that can inform future therapeutic interventions for GBM. PMID:23421905

Local oxytocin expression and oxytocin receptor binding in the male rat brain is associated with aggressiveness.

PubMed

Calcagnoli, Federica; de Boer, Sietse F; Beiderbeck, Daniela I; Althaus, Monika; Koolhaas, Jaap M; Neumann, Inga D

2014-03-15

We recently demonstrated in male wild-type Groningen rats that enhancing brain oxytocin (OXT) levels acutely produces marked pro-social explorative and anti-aggressive effects. Moreover, these pharmacologically-induced changes are moderated by the individual's aggressive phenotype, suggesting an inverse relationship between aggressiveness and tonic endogenous OXT signaling properties. Aim of the present study was to verify the hypothesis that variations in OXT expression and/or OXT receptor (OXTR) binding in selected brain regions are associated with different levels or forms of aggression. To this end, male resident wild-type Groningen rats that repeatedly contested and dominated intruder conspecifics were categorized as being low aggressive, highly aggressive or excessively aggressive. Their brains were subsequently collected and quantified for OXT mRNA expression and OXTR binding levels. Our results showed that OXT mRNA expression in the hypothalamic paraventricular nucleus (PVN), but not in the supraoptic nucleus (SON), negatively correlates with the level of offensiveness. In particular, the excessively aggressive group showed a significantly lower OXT mRNA expression in the PVN as compared to both low and highly aggressive groups. Further, the excessively aggressive animals showed the highest OXTR binding in the central amygdala (CeA) and bed nucleus of the stria terminalis (BNST). These findings demonstrate that male rats with excessively high levels and abnormal forms of aggressive behavior have diminished OXT transcription and enhanced OXTR binding capacities in specific nodes of the social behavioral brain circuitry. Copyright © 2014 Elsevier B.V. All rights reserved.

Purification of a benzodiazepine from bovine brain and detection of benzodiazepine-like immunoreactivity in human brain.

PubMed Central

Sangameswaran, L; Fales, H M; Friedrich, P; De Blas, A L

1986-01-01

An endogenous brain substance that binds to the central-type benzodiazepine receptors with agonist properties is present in both rat and bovine brains. This substance has been purified to homogeneity from bovine brain by immunoaffinity chromatography on immobilized monoclonal anti-benzodiazepine antibody followed by gel filtration on Sephadex G-25 and two reversed-phase HPLC steps. The purified substance was characterized as the benzodiazepine N-desmethyldiazepam (nordiazepam). The techniques used for the identification were mass spectrometry, HPLC, spectrophotometry, benzodiazepine receptor binding, and immunological techniques. Benzodiazepine-like immunoreactivity was also found in all the human brains tested, including six brains that had been stored in paraffin since 1940, fifteen years before the first synthesis of benzodiazepines. These results show that benzodiazepine-like molecules of natural origin--and possibly benzodiazepines themselves--are present in human and other mammalian brains. Images PMID:3024172

Positron Emission Tomography of Brain β-Amyloid and Tau Levels in Adults With Down Syndrome

PubMed Central

Nelson, Linda D.; Siddarth, Prabha; Kepe, Vladimir; Scheibel, Kevin E.; Huang, S. C.; Barrio, Jorge R.; Small, Gary W.

2012-01-01

Objectives To determine the neuropathological load in the living brain of nondemented adults with Down syndrome using positron emission tomography with 2-(1-{6-[(2-fluorine 18–labeled fluoroethyl)methylamino]-2-napthyl}ethylidene) malononitrile ([18F]FDDNP) and to assess the influence of age and cognitive and behavioral functioning. For reference, [18F]FDDNP binding values and patterns were compared with those from patients with Alzheimer disease and cognitively intact control participants. Design Cross-sectional clinical study. Participants Volunteer sample of 19 persons with Down syndrome without dementia (mean age, 36.7 years), 10 patients with Alzheimer disease (mean age, 66.5 years), and 10 controls (mean age, 43.8 years). Main Outcome Measures Binding of [18F]FDDNP in brain regions of interest, including the parietal, medial temporal, lateral temporal, and frontal lobes and posterior cingulate gyrus, and the average of all regions (global binding). Results The [18F]FDDNP binding values were higher in all brain regions in the Down syndrome group than in controls. Compared with the Alzheimer disease group, the Down syndrome group had higher [18F]FDDNP binding values in the parietal and frontal regions, whereas binding levels in other regions were comparable. Within the Down syndrome group, age correlated with [18F]FDDNP binding values in all regions except the posterior cingulate, and several measures of behavioral dysfunction showed positive correlations with global, frontal, parietal, and posterior cingulate [18F]FDDNP binding. Conclusions Consistent with neuropathological findings from postmortem studies, [18F]FDDNP positron emission tomography shows high binding levels in Down syndrome comparable to Alzheimer disease and greater levels than in members of a control group. The positive associations between [18F]FDDNP binding levels and age as well as behavioral dysfunction in Down syndrome are consistent with the age-related progression of Alzheimer-type neuropathological findings in this population. PMID:21670401

Autoradiographic localization of sigma receptor binding sites in guinea pig and rat central nervous system with (+)3H-3-(3-hydroxyphenyl)-N-(1-propyl)piperidine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gundlach, A.L.; Largent, B.L.; Snyder, S.H.

1986-06-01

(+)3H-3-PPP ((+)3H-3-(3-Hydroxyphenyl)-N-(1-propyl)-piperidine) binds with high affinity to brain membranes with a pharmacological profile consistent with that of sigma receptors. The distribution of (+)3H-3-PPP binding sites in brain and spinal cord of both guinea pig and rat has been determined by in vitro autoradiography with binding densities quantitated by computer-assisted densitometry. (+)3H-3-PPP binding to slide-mounted brain sections is saturable and displays high affinity and a pharmacological specificity very similar to sites labeled in homogenates. (+)3H-3-PPP binding sites are heterogeneously distributed. Highest concentrations of binding sites occur in spinal cord, particularly the ventral horn and dorsal root ganglia; the pons-medulla, associated withmore » the cranial nerve and pontine nuclei and throughout the brain stem reticular formation; the cerebellum, over the Purkinje cell layer; the midbrain, particularly the central gray and red nucleus; and hippocampus, over the pyramidal cell layer. Lowest levels are seen in the basal ganglia and parts of the thalamus, while all other areas, including hypothalamus and cerebral cortex, exhibit moderate grain densities. Quinolinic acid-induced lesions of the hippocampus indicate that (+)3H-3-PPP labels hippocampal pyramidal cells and granule cells in the dentate gyrus. Intrastriatal injection of ibotenic acid dramatically reduces (+)3H-3-PPP binding in this area, while injection of 6-hydroxydopamine produces a relatively slight decrease. The distribution of (+)3H-3-PPP binding sites does not correlate with the receptor distribution of any recognized neurotransmitter or neuropeptide, including dopamine. However, there is a notable similarity between the distribution of (+)3H-3-PPP sites and high-affinity binding sites for psychotomimetic opioids, such as the benzomorphan (+)SKF 10,047.« less

Lack of effect of reserpine-induced dopamine depletion on the binding of the dopamine-D3 selective radioligand, [11C]RGH-1756.

PubMed

Sóvágó, Judit; Farde, Lars; Halldin, Christer; Schukin, Evgenij; Schou, Magnus; Laszlovszky, István; Kiss, Béla; Gulyás, Balázs

2005-10-15

The effect of reserpine induced dopamine depletion on the binding of the putative dopamine-D3 receptor ligand, [(11)C]RGH-1756 was examined in the monkey brain with positron emission tomography (PET). In a previous series of experiments, we have made an attempt to selectively label D3 receptors in the monkey brain using [(11)C]RGH-1756. Despite high selectivity and affinity of RGH-1756 in vitro, [(11)C]RGH-1756 displayed only low specific binding to D3 receptors in vivo. The aim of the present study was to examine whether low specific binding of [(11)C]RGH-1756 is caused by insufficient in vivo affinity of the ligand, or by high physiological occupancy of D3 receptors by endogenous dopamine (DA). PET experiments were performed in three monkeys under baseline conditions and after administration of reserpine (0.5 mg/kg). The results of the baseline measurements corresponded well to our earlier observations with [(11)C]RGH-1756. Reserpine caused no evident change in the regional distribution of [(11)C]RGH-1756 in the monkey brain, and no conspicuous regional accumulation of activity could be observed. After reserpine treatment there was no evident increase of specific binding and binding potential (BP) of [(11)C]RGH-1756. The lack of increased [(11)C]RGH-1756 binding after reserpine treatment indicates that competition with endogenous DA is not the predominant reason for the failure of the radioligand to label D3 receptors. Therefore, the low binding of [(11)C]RGH-1756 could largely be explained by the need for very high affinity of radioligand for D3 receptors in vivo, to obtain a suitable signal for the minute densities of D3 receptors expressed in the primate brain.

Cultured bovine brain capillary endothelial cells (BBCEC) - a blood-brain barrier model for studying the binding and internalization of insulin and insulin-like growth factor 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keller, B.T.; Borchardt, R.T.

1987-05-01

Cultured bovine brain capillary endothelial cells (BBCEC) have previously been reported by their laboratory as a working model for studying nutrient and drug transport and metabolism at the blood-brain barrier. In the present study, they have utilized this culture system to investigate the binding and internalization of (/sup 125/I)-labelled insulin (INS) and insulin-like growth factor 1(IGF-1) by BBCEC. After 2 hrs at 23/sup 0/C, the specific binding of INS and IGF-1 was 1.6% and 13.6%, respectively. At 37/sup 0/C, the maximum specific binding was 0.9% for INS and 5.8% for IGF-1. Using an acid-wash technique to assess peptide internalization, itmore » was observed that, at 37/sup 0/C, approximately 60% of the bound INS rapidly became resistant to acid treatment, a value which was constant over 2 hr. With IGF-1, a similar proportion of the bound material, 62%, became resistant by 30 min, but subsequently decreased to 45% by 2 hr. Scatchard analysis of competitive binding studies indicated the presence of two binding sites for each protein, having K/sub d/'s of 0.82 nM and 19.2 nM for INS and 0.39 nM and 3.66 nM for IGF-1. Little change in the amount of INS binding was observed over a four-day interval as the cultures became a confluent monolayer. The present report of binding and internalization of these proteins suggests that the BBCEC may utilize a receptor-mediated process to internalize and/or transport (transcytosis) INS and IGF-1 from the circulation.« less

Age and sex differences in oxytocin and vasopressin V1a receptor binding densities in the rat brain: focus on the social decision-making network.

PubMed

Smith, Caroline J W; Poehlmann, Max L; Li, Sara; Ratnaseelan, Aarane M; Bredewold, Remco; Veenema, Alexa H

2017-03-01

Oxytocin (OT) and vasopressin (AVP) regulate various social behaviors via activation of the OT receptor (OTR) and the AVP V1a receptor (V1aR) in the brain. Social behavior often differs across development and between the sexes, yet our understanding of age and sex differences in brain OTR and V1aR binding remains incomplete. Here, we provide an extensive analysis of OTR and V1aR binding density throughout the brain in juvenile and adult male and female rats, with a focus on regions within the social decision-making network. OTR and V1aR binding density were higher in juveniles than in adults in regions associated with reward and socio-spatial memory and higher in adults than in juveniles in key regions of the social decision-making network and in cortical regions. We discuss possible implications of these shifts in OTR and V1aR binding density for the age-specific regulation of social behavior. Furthermore, sex differences in OTR and V1aR binding density were less numerous than age differences. The direction of these sex differences was region-specific for OTR but consistently higher in females than in males for V1aR. Finally, almost all sex differences in OTR and V1aR binding density were already present in juveniles and occurred in regions with denser binding in adults compared to juveniles. Possible implications of these sex differences for the sex-specific regulation of behavior, as well potential underlying mechanisms, are discussed. Overall, these findings provide an important framework for testing age- and sex-specific roles of OTR and V1aR in the regulation of social behavior.

Influence of volatile anesthetics on muscarinic receptor adenylate cyclase coupling in brain and heart

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anthony, B.L.

In the present study, the influence of four volatile anesthetics (enflurane, isoflurane, diethyl ether, and chloroform) on (1) muscarinic receptor binding parameters and (2) muscarnic regulation of adenylate cyclase activity was examined using membranes isolated from rat brain and heart. Membranes were equilibrated with each of the four anesthetics for 30 minutes and then during the binding assay. The data obtained can be summarized as follows: (1) volatile anesthetics increased receptor affinity for a radiolabeled antagonists, ({sup 3}H)N-methylscopolamine (({sup 3}H)MS), by decreasing its rate of dissociation in brain stem, but not in cardiac, membranes, (2) volatile anesthetics decreased high affinitymore » ({sup 3}H)Oxotremorine-M binding, (3) volatile anesthetics depressed or eliminated the guanine nucleotide sensitivity of agonist binding. The influence of volatile anesthetics on muscarinic regulation of adenylate cyclase enzyme activity was studied using {alpha}({sup 32}P)ATP as the substrate.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewis, M.E.; Khachaturian, H.; Watson, S.J.

Using adjacent section autoradiography-immunocytochemistry, the distribution of (TH)naloxone binding sites was studied in relation to neuronal systems containing (Leu)enkephalin, dynorphin A, or beta-endorphin immunoreactivity in rat brain. Brain sections from formaldehyde-perfused rats show robust specific binding of (TH)naloxone, the pharmacological (mu-like) properties of which appear unaltered. In contrast, specific binding of the delta ligand (TH)D-Ala2,D-Leu5-enkephalin was virtually totally eliminated as a result of formaldehyde perfusion. Using adjacent section analysis, the authors have noted associations between (TH)naloxone binding sites and one, two, or all three opioid systems in different brain regions; however, in some areas, no apparent relationship could be observed.more » Within regions, the relationship was complex. The complexity of the association between (TH)naloxone binding sites and the multiple opioid systems, and previous reports of co-localization of mu and kappa receptors in rat brain, are inconsistent with a simple-one-to-one relationship between a given opioid precursor and opioid receptor subtype. Instead, since differential processing of the three precursors gives rise to peptides of varying receptor subtype potencies and selectivities, the multiple peptide-receptor relationships may point to a key role of post-translational processing in determining the physiological consequences of opioid neurotransmission.« less

High occupancy of sigma-1 receptors in the human brain after single oral administration of fluvoxamine: a positron emission tomography study using [11C]SA4503.

PubMed

Ishikawa, Masatomo; Ishiwata, Kiichi; Ishii, Kenji; Kimura, Yuichi; Sakata, Muneyuki; Naganawa, Mika; Oda, Keiichi; Miyatake, Ryousuke; Fujisaki, Mihisa; Shimizu, Eiji; Shirayama, Yukihiko; Iyo, Masaomi; Hashimoto, Kenji

2007-10-15

Sigma-1 receptors might be implicated in the pathophysiology of psychiatric diseases, as well as in the mechanisms of action of some selective serotonin reuptake inhibitors (SSRIs). Among the several SSRIs, fluvoxamine has the highest affinity for sigma-1 receptors (Ki = 36 nM), whereas paroxetine shows low affinity (Ki = 1893 nM). The present study was undertaken to examine whether fluvoxamine binds to sigma-1 receptors in living human brain. A dynamic positron emission tomography (PET) data acquisition using the selective sigma-1 receptor ligand [(11)C]SA4503 was performed with arterial blood sampling to evaluate quantitatively the binding of [(11)C]SA4503 to sigma-1 receptors in 15 healthy male volunteers. Each subject had two PET scans before and after randomly receiving a single dose of either fluvoxamine (50, 100, 150, or 200 mg) or paroxetine (20 mg). The binding potential of [(11)C]SA4503 in 9 regions of the brain was calculated by a 2-tissue 3-compartment model. In addition, we examined the effects of functional polymorphisms of the sigma-1 receptor (SIGMAR1) gene on the binding potential of [(11)C]SA4503. Fluvoxamine bound to sigma-1 receptors in all brain regions in a dose-dependent manner, whereas paroxetine did not bind to sigma-1 receptors. However, there was no association between the SIGMAR1 gene polymorphism GC-241-240TT and binding potential. The study demonstrated that fluvoxamine bound to sigma-1 receptors in living human brain at therapeutic doses. These findings suggest that sigma-1 receptors may play an important role in the mechanism of action of fluvoxamine.

Preclinical Evaluation of 18F-JNJ64349311, a Novel PET Tracer for Tau Imaging.

PubMed

Declercq, Lieven; Rombouts, Frederik; Koole, Michel; Fierens, Katleen; Mariën, Jonas; Langlois, Xavier; Andrés, José Ignacio; Schmidt, Mark; Macdonald, Gregor; Moechars, Diederik; Vanduffel, Wim; Tousseyn, Thomas; Vandenberghe, Rik; Van Laere, Koen; Verbruggen, Alfons; Bormans, Guy

2017-06-01

In this study, we have synthesized and evaluated 18 F-JNJ64349311, a tracer with high affinity for aggregated tau (inhibition constant value, 8 nM) and high (≥500×) in vitro selectivity for tau over β-amyloid, in comparison with the benchmark compound 18 F-AV1451 ( 18 F-T807) in mice, rats, and a rhesus monkey. Methods: In vitro binding characteristics were determined for Alzheimer's disease, progressive supranuclear palsy, and corticobasal degeneration patient brain tissue slices using autoradiography studies. Ex vivo biodistribution studies were performed in mice. Radiometabolites were quantified in the brain and plasma of mice and in the plasma of a rhesus monkey using high-performance liquid chromatography. Dynamic small-animal PET studies were performed in rats and a rhesus monkey to evaluate tracer pharmacokinetics in the brain. Results: Mouse biodistribution studies showed moderate initial brain uptake and rapid brain washout. Radiometabolite analyses after injection of 18 F-JNJ64349311 in mice showed the presence of a polar radiometabolite in plasma, but not in the brain. Semiquantitative autoradiography studies on postmortem tissue sections of human Alzheimer's disease brains showed highly displaceable binding to tau-rich regions. No specific binding was, however, found on human progressive supranuclear palsy and corticobasal degeneration brain slices. Small-animal PET scans of Wistar rats revealed moderate initial brain uptake (SUV, ∼1.5 at 1 min after injection) and rapid brain washout. Gradual bone uptake was, however, also observed. Blocking and displacement did not affect brain time-activity curves, suggesting no off-target specific binding of the tracer in the healthy rat brain. A small-animal PET scan of a rhesus monkey revealed moderate initial brain uptake (SUV, 1.9 at 1 min after injection) with a rapid washout. In the monkey, no bone uptake was detected during the 120-min scan. Conclusion: This biologic evaluation suggests that 18 F-JNJ64349311 is a promising tau PET tracer candidate, with a favorable pharmacokinetic profile, as compared with 18 F-AV1451. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

In vitro sensitivity of cholinesterases and [3H]oxotremorine-M binding in heart and brain of adult and aging rats to organophosphorus anticholinesterases.

PubMed

Mirajkar, Nikita; Pope, Carey N

2008-10-15

Organophosphorus (OP) insecticides elicit toxicity via acetylcholinesterase inhibition, allowing acetylcholine accumulation and excessive stimulation of cholinergic receptors. Some OP insecticides bind to additional macromolecules including butyrylcholinesterase and cholinergic receptors. While neurotoxicity from OP anticholinesterases has been extensively studied, effects on cardiac function have received less attention. We compared the in vitro sensitivity of acetylcholinesterase, butyrylcholinesterase and [(3)H]oxotremorine-M binding to muscarinic receptors in the cortex and heart of adult (3 months) and aging (18 months) rats to chlorpyrifos, methyl parathion and their active metabolites chlorpyrifos oxon and methyl paraoxon. Using selective inhibitors, the great majority of cholinesterase in brain was defined as acetylcholinesterase, while butyrylcholinesterase was the major cholinesterase in heart, regardless of age. In the heart, butyrylcholinesterase was markedly more sensitive than acetylcholinesterase to inhibition by chlorpyrifos oxon, and butyrylcholinesterase in tissues from aging rats was more sensitive than enzyme from adults, possibly due to differences in A-esterase mediated detoxification. Relatively similar differences were noted in brain. In contrast, acetylcholinesterase was more sensitive than butyrylcholinesterase to methyl paraoxon in both heart and brain, but no age-related differences were noted. Both oxons displaced [(3)H]oxotremorine-M binding in heart and brain of both age groups in a concentration-dependent manner. Chlorpyrifos had no effect but methyl parathion was a potent displacer of binding in heart and brain of both age groups. Such OP and age-related differences in interactions with cholinergic macromolecules may be important because of potential for environmental exposures to insecticides as well as the use of anticholinesterases in age-related neurological disorders.

IN VITRO SENSITIVITY OF CHOLINESTERASES AND [3H]OXOTREMORINE-M BINDING IN HEART AND BRAIN OF ADULT AND AGING RATS TO ORGANOPHOSPHORUS ANTICHOLINESTERASES

PubMed Central

Mirajkar, Nikita; Pope, Carey N.

2008-01-01

Organophosphorus (OP) insecticides elicit toxicity via acetylcholinesterase inhibition, allowing acetylcholine accumulation and excessive stimulation of cholinergic receptors. Some OP insecticides bind to additional macromolecules including butyrylcholinesterase and cholinergic receptors. While neurotoxicity from OP anticholinesterases has been extensively studied, effects on cardiac function have received less attention. We compared the in vitro sensitivity of acetylcholinesterase, butyrylcholinesterase and [3H]oxotremorine-M binding to muscarinic receptors in the cortex and heart of adult (3 months) and aging (18 months) rats to chlorpyrifos, methyl parathion and their active metabolites chlorpyrifos oxon and methyl paraoxon. Using selective inhibitors, the great majority of cholinesterase in brain was defined as acetylcholinesterase, while butyrylcholinesterase was the major cholinesterase in heart, regardless of age. In the heart, butyrylcholinesterase was markedly more sensitive than acetylcholinesterase to inhibition by chlorpyrifos oxon, and butyrylcholinesterase in tissues from aging rats was more sensitive than enzyme from adults, possibly due to differences in A-esterase mediated detoxification. Relatively similar differences were noted in brain. In contrast, acetylcholinesterase was more sensitive than butyrylcholinesterase to methyl paraoxon in both heart and brain, but no age-related differences were noted. Both oxons displaced [3H]oxotremorine-M binding in heart and brain of both age groups in a concentration-dependent manner. Chlorpyrifos had no effect but methyl parathion was a potent displacer of binding in heart and brain of both age groups. Such OP and age-related differences in interactions with cholinergic macromolecules may be important because of potential for environmental exposures to insecticides as well as the use of anticholinesterases in age-related neurological disorders. PMID:18761328

Biomolecular characterization and protein sequences of the Campanian hadrosaur B. canadensis.

PubMed

Schweitzer, Mary H; Zheng, Wenxia; Organ, Chris L; Avci, Recep; Suo, Zhiyong; Freimark, Lisa M; Lebleu, Valerie S; Duncan, Michael B; Vander Heiden, Matthew G; Neveu, John M; Lane, William S; Cottrell, John S; Horner, John R; Cantley, Lewis C; Kalluri, Raghu; Asara, John M

2009-05-01

Molecular preservation in non-avian dinosaurs is controversial. We present multiple lines of evidence that endogenous proteinaceous material is preserved in bone fragments and soft tissues from an 80-million-year-old Campanian hadrosaur, Brachylophosaurus canadensis [Museum of the Rockies (MOR) 2598]. Microstructural and immunological data are consistent with preservation of multiple bone matrix and vessel proteins, and phylogenetic analyses of Brachylophosaurus collagen sequenced by mass spectrometry robustly support the bird-dinosaur clade, consistent with an endogenous source for these collagen peptides. These data complement earlier results from Tyrannosaurus rex (MOR 1125) and confirm that molecular preservation in Cretaceous dinosaurs is not a unique event.

Synthesis of new opioid derivatives with a propellane skeleton and their pharmacologies: Part 5, novel pentacyclic propellane derivatives with a 6-amide side chain.

PubMed

Nakajima, Ryo; Yamamoto, Naoshi; Hirayama, Shigeto; Iwai, Takashi; Saitoh, Akiyoshi; Nagumo, Yasuyuki; Fujii, Hideaki; Nagase, Hiroshi

2015-10-01

We designed and synthesized pentacyclic propellane derivatives with a 6-amide side chain to afford compounds with higher MOR/KOR ratio and lower sedative effects than nalfurafine. The obtained etheno-bridged derivative with a β-amide side chain, YNT-854, showed a higher MOR/KOR ratio than nalfurafine. YNT-854 also exhibited a higher dose ratio between the sedative effect and the analgesic effect than observed with nalfurafine, which may guide the future design of useful analgesics with a weaker sedative effect than nalfurafine. Copyright © 2015 Elsevier Ltd. All rights reserved.

Influence of model order reduction methods on dynamical-optical simulations

NASA Astrophysics Data System (ADS)

Störkle, Johannes; Eberhard, Peter

2017-04-01

In this work, the influence of model order reduction (MOR) methods on optical aberrations is analyzed within a dynamical-optical simulation of a high precision optomechanical system. Therefore, an integrated modeling process and new methods have to be introduced for the computation and investigation of the overall dynamical-optical behavior. For instance, this optical system can be a telescope optic or a lithographic objective. In order to derive a simplified mechanical model for transient time simulations with low computational cost, the method of elastic multibody systems in combination with MOR methods can be used. For this, software tools and interfaces are defined and created. Furthermore, mechanical and optical simulation models are derived and implemented. With these, on the one hand, the mechanical sensitivity can be investigated for arbitrary external excitations and on the other hand, the related optical behavior can be predicted. In order to clarify these methods, academic examples are chosen and the influences of the MOR methods and simulation strategies are analyzed. Finally, the systems are investigated with respect to the mechanical-optical frequency responses, and in conclusion, some recommendations for the application of reduction methods are given.

Model Order Reduction of Aeroservoelastic Model of Flexible Aircraft

NASA Technical Reports Server (NTRS)

Wang, Yi; Song, Hongjun; Pant, Kapil; Brenner, Martin J.; Suh, Peter

2016-01-01

This paper presents a holistic model order reduction (MOR) methodology and framework that integrates key technological elements of sequential model reduction, consistent model representation, and model interpolation for constructing high-quality linear parameter-varying (LPV) aeroservoelastic (ASE) reduced order models (ROMs) of flexible aircraft. The sequential MOR encapsulates a suite of reduction techniques, such as truncation and residualization, modal reduction, and balanced realization and truncation to achieve optimal ROMs at grid points across the flight envelope. The consistence in state representation among local ROMs is obtained by the novel method of common subspace reprojection. Model interpolation is then exploited to stitch ROMs at grid points to build a global LPV ASE ROM feasible to arbitrary flight condition. The MOR method is applied to the X-56A MUTT vehicle with flexible wing being tested at NASA/AFRC for flutter suppression and gust load alleviation. Our studies demonstrated that relative to the fullorder model, our X-56A ROM can accurately and reliably capture vehicles dynamics at various flight conditions in the target frequency regime while the number of states in ROM can be reduced by 10X (from 180 to 19), and hence, holds great promise for robust ASE controller synthesis and novel vehicle design.

Proposal for Laser Cooling of Alkaline Earth Monoalkoxide Free Radicals

NASA Astrophysics Data System (ADS)

Baum, Louis; Kozyryev, Ivan; Matsuda, Kyle; Doyle, John M.

2016-05-01

Cold samples of polyatomic molecules will open new avenues in physics, chemistry, and quantum science. Non-diagonal Franck-Condon factors, technically challenging wavelengths, and the lack of strong electronic transitions inhibit direct laser cooling of nonlinear molecules. We identify a scheme for optical cycling in certain molecules with six or more atoms. Replacing hydrogen in alcohols with an alkaline earth metal (M) leads to alkaline earth monoalkoxide free radicals (MOR), which have favorable properties for laser cooling. M-O bond is very ionic, so the metal orbitals are slightly affected by the nature of R on the ligand. Diagonal Franck-Condon factors, laser accessible transitions, and a small hyperfine structure make MOR molecules suitable for laser cooling. We explore a scheme for optical cycling on the A - X transition of SrOCH3 . Molecules lost to dark vibrational states will be repumped on the B - X transition. Extension to larger species is possible through expansion of the R group since transitions involve the promotion of the metal-centered nonbonding valence electron. We will detail our estimations of the Franck-Condon factors, simulations of the cooling process and describe progress towards the Doppler cooling of MOR polyatomics.

Three dimensional graphene foam supported platinum-ruthenium bimetallic nanocatalysts for direct methanol and direct ethanol fuel cell applications

NASA Astrophysics Data System (ADS)

Kung, Chih-Chien; Lin, Po-Yuan; Xue, Yuhua; Akolkar, Rohan; Dai, Liming; Yu, Xiong; Liu, Chung-Chiun

2014-06-01

A novel composite material of hierarchically structured platinum-ruthenium (PtRu) nanoparticles grown on large surface area three dimensional graphene foam (3D GF) is reported. 3D GF was incorporated with PtRu bimetallic nanoparticles as an electrochemical nanocatalyst for methanol and ethanol oxidation. PtRu/3D GF nanocatalyst showed a higher tolerance to poisoning by CO and exhibited improved catalytic activity for both methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR). Cyclic voltammetry (CV) results and long-term cycling stability tests demonstrated that GF provided a promising platform for the development of electrochemical nanocatalysts. Specifically, PtRu/3D GF nanocatalyst showed excellent catalytic activity toward MOR and EOR compared with PtRu/Graphene (Commercial graphene), PtRu/C (Vulcan XC-72R carbon), and PtRu alone. The crystal size of PtRu on 3D GF was reduced to 3.5 nm and its active surface area was enhanced to 186.2 m2 g-1. Consequently, the MOR and EOR rates were nearly doubled on PtRu/3D GF compared to those on PtRu/Graphene.

β-Arrestins: Regulatory Role and Therapeutic Potential in Opioid and Cannabinoid Receptor-Mediated Analgesia

PubMed Central

Bohn, Laura M.

2016-01-01

Pain is a complex disorder with neurochemical and psychological components contributing to the severity, the persistence, and the difficulty in adequately treating the condition. Opioid and cannabinoids are two classes of analgesics that have been used to treat pain for centuries and are arguably the oldest of “pharmacological” interventions used by man. Unfortunately, they also produce several adverse side effects that can complicate pain management. Opioids and cannabinoids act at G protein-coupled receptors (GPCRs), and much of their effects are mediated by the mu-opioid receptor (MOR) and cannabinoid CB1 receptor (CB1R), respectively. These receptors couple to intracellular second messengers and regulatory proteins to impart their biological effects. In this chapter, we review the role of the intracellular regulatory proteins, β-arrestins, in modulating MOR and CB1R and how they influence the analgesic and side-effect profiles of opioid and cannabinoid drugs in vivo. This review of the literature suggests that the development of opioid and cannabinoid agonists that bias MOR and CB1R toward G protein signaling cascades and away from β-arrestin interactions may provide a novel mechanism by which to produce analgesia with less severe adverse effects. PMID:24292843

PtRu nanoparticles embedded in nitrogen doped carbon with highly stable CO tolerance and durability

NASA Astrophysics Data System (ADS)

Ling, Ying; Yang, Zehui; Yang, Jun; Zhang, Yunfeng; Zhang, Quan; Yu, Xinxin; Cai, Weiwei

2018-02-01

As is well known, the lower durability and sluggish methanol oxidation reaction (MOR) of PtRu alloy electrocatalyst blocks the commercialization of direct methanol fuel cells (DMFCs). Here, we design a new PtRu electrocatalyst, with highly stable CO tolerance and durability, in which the PtRu nanoparticles are embedded in nitrogen doped carbon layers derived from carbonization of poly(vinyl pyrrolidone). The newly fabricated electrocatalyst exhibits no loss in electrochemical surface area (ECSA) and MOR activity after potential cycling from 0.6-1.0 V versus reversible hydrogen electrode, while commercial CB/PtRu retains only 50% of its initial ECSA. Meanwhile, due to the same protective layers, the Ru dissolution is decelerated, resulting in stable CO tolerance. Methanol oxidation reaction (MOR) testing indicates that the activity of newly fabricated electrocatalyst is two times higher than that of commercial CB/PtRu, and the fuel cell performance of the embedded PtRu electrocatalyst was comparable to that of commercial CB/PtRu. The embedded PtRu electrocatalyst is applicable in real DMFC operation. This study offers important and useful information for the design and fabrication of durable and CO tolerant electrocatalysts.

Mu-opioid receptors modulate the stability of dendritic spines

PubMed Central

Liao, Dezhi; Lin, Hang; Law, Ping Yee; Loh, Horace H.

2005-01-01

Opioids classically regulate the excitability of neurons by suppressing synaptic GABA release from inhibitory neurons. Here, we report a role for opioids in modulating excitatory synaptic transmission. By activating ubiquitously clustered μ-opioid receptor (MOR) in excitatory synapses, morphine caused collapse of preexisting dendritic spines and decreased synaptic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors. Meanwhile, the opioid antagonist naloxone increased the density of spines. Chronic treatment with morphine decreased the density of dendritic spines even in the presence of Tetrodotoxin, a sodium channel blocker, indicating that the morphine's effect was not caused by altered activity in neural network through suppression of GABA release. The effect of morphine on dendritic spines was absent in transgenic mice lacking MORs and was blocked by CTOP (D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-ThrNH2), a μ-receptor antagonist. These data together with others suggest that endogenous opioids and/or constitutive activity of MORs participate in maintaining normal morphology and function of spines, challenging the classical model of opioids. Abnormal alteration of spines may occur in drug addiction when opioid receptors are overactivated by exogenous opiates. PMID:15659552

Odorant responses of olfactory sensory neurons expressing the odorant receptor MOR23: A patch clamp analysis in gene-targeted mice

PubMed Central

Grosmaitre, Xavier; Vassalli, Anne; Mombaerts, Peter; Shepherd, Gordon M.; Ma, Minghong

2006-01-01

A glomerulus in the mammalian olfactory bulb receives axonal inputs from olfactory sensory neurons (OSNs) that express the same odorant receptor (OR). Glomeruli are generally thought to represent functional units of olfactory coding, but there are no data on the electrophysiological properties of OSNs that express the same endogenous OR. Here, using patch clamp recordings in an intact epithelial preparation, we directly measured the transduction currents and receptor potentials from the dendritic knobs of mouse OSNs that express the odorant receptor MOR23 along with the green fluorescent protein. All of the 53 cells examined responded to lyral, a known ligand for MOR23. There were profound differences in response kinetics, particularly in the deactivation phase. The cells were very sensitive to lyral, with some cells responding to as little as 10 nM. The dynamic range was unexpectedly broad, with threshold and saturation in individual cells often covering three log units of lyral concentration. The potential causes and biological significance of this cellular heterogeneity are discussed. Patch clamp recording from OSNs that express a defined OR provides a powerful approach to investigate the sensory inputs to individual glomeruli. PMID:16446455

Odorant responses of olfactory sensory neurons expressing the odorant receptor MOR23: a patch clamp analysis in gene-targeted mice.

PubMed

Grosmaitre, Xavier; Vassalli, Anne; Mombaerts, Peter; Shepherd, Gordon M; Ma, Minghong

2006-02-07

A glomerulus in the mammalian olfactory bulb receives axonal inputs from olfactory sensory neurons (OSNs) that express the same odorant receptor (OR). Glomeruli are generally thought to represent functional units of olfactory coding, but there are no data on the electrophysiological properties of OSNs that express the same endogenous OR. Here, using patch clamp recordings in an intact epithelial preparation, we directly measured the transduction currents and receptor potentials from the dendritic knobs of mouse OSNs that express the odorant receptor MOR23 along with the green fluorescent protein. All of the 53 cells examined responded to lyral, a known ligand for MOR23. There were profound differences in response kinetics, particularly in the deactivation phase. The cells were very sensitive to lyral, with some cells responding to as little as 10 nM. The dynamic range was unexpectedly broad, with threshold and saturation in individual cells often covering three log units of lyral concentration. The potential causes and biological significance of this cellular heterogeneity are discussed. Patch clamp recording from OSNs that express a defined OR provides a powerful approach to investigate the sensory inputs to individual glomeruli.

Prevalence of heroin markers in urine for pain management patients.

PubMed

Knight, Julie; Puet, Brandi L; DePriest, Anne; Heltsley, Rebecca; Hild, Cheryl; Black, David L; Robert, Timothy; Caplan, Yale H; Cone, Edward J

2014-10-01

Surveys of current trends indicate heroin abuse is associated with nonmedical use of pain relievers. Consequently, there is an interest in evaluating the presence of heroin-specific markers in chronic pain patients who are prescribed controlled substances. A total of 926,084 urine specimens from chronic pain patients were tested for heroin/diacetylmorphine (DAM), 6-acetylmorphine (6AM), 6-acetylcodeine (6AC), codeine (COD), and morphine (MOR). Heroin and markers were analyzed using liquid chromatography tandem mass spectrometry (LC-MS-MS). Opiates were analyzed following hydrolysis using LC-MS-MS. The prevalence of heroin use was 0.31%, as 2871 were positive for one or more heroin-specific markers including DAM, 6AM, or 6AC (a known contaminant of illicit heroin). Of these, 1884 were additionally tested for the following markers of illicit drug use: 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), methamphetamine (MAMP), 11-nor-9-carboxy-Δ(9)-tetracannabinol (THCCOOH), and benzoylecgonine (BZE); 654 (34.7%) had positive findings for one or more of these analytes. The overall prevalence of heroin markers were as follows: DAM 1203 (41.9%), 6AM 2570 (89.5%), 6AC 1082 (37.7%). MOR was present in 2194 (76.4%) and absent (

Animal-related factors associated with moderate-to-severe diarrhea in children younger than five years in western Kenya: A matched case-control study

PubMed Central

Conan, Anne; O’Reilly, Ciara E.; Ogola, Eric; Ochieng, J. Benjamin; Blackstock, Anna J.; Omore, Richard; Ochieng, Linus; Moke, Fenny; Parsons, Michele B.; Xiao, Lihua; Roellig, Dawn; Farag, Tamer H.; Nataro, James P.; Kotloff, Karen L.; Levine, Myron M.; Mintz, Eric D.; Breiman, Robert F.; Cleaveland, Sarah

2017-01-01

Background Diarrheal disease remains among the leading causes of global mortality in children younger than 5 years. Exposure to domestic animals may be a risk factor for diarrheal disease. The objectives of this study were to identify animal-related exposures associated with cases of moderate-to-severe diarrhea (MSD) in children in rural western Kenya, and to identify the major zoonotic enteric pathogens present in domestic animals residing in the homesteads of case and control children. Methodology/Principal findings We characterized animal-related exposures in a subset of case and control children (n = 73 pairs matched on age, sex and location) with reported animal presence at home enrolled in the Global Enteric Multicenter Study in western Kenya, and analysed these for an association with MSD. We identified potentially zoonotic enteric pathogens in pooled fecal specimens collected from domestic animals resident at children’s homesteads. Variables that were associated with decreased risk of MSD were washing hands after animal contact (matched odds ratio [MOR] = 0.2; 95% CI 0.08–0.7), and presence of adult sheep that were not confined in a pen overnight (MOR = 0.1; 0.02–0.5). Variables that were associated with increased risk of MSD were increasing number of sheep owned (MOR = 1.2; 1.0–1.5), frequent observation of fresh rodent excreta (feces/urine) outside the house (MOR = 7.5; 1.5–37.2), and participation of the child in providing water to chickens (MOR = 3.8; 1.2–12.2). Of 691 pooled specimens collected from 2,174 domestic animals, 159 pools (23%) tested positive for one or more potentially zoonotic enteric pathogens (Campylobacter jejuni, C. coli, non-typhoidal Salmonella, diarrheagenic E. coli, Giardia, Cryptosporidium, or rotavirus). We did not find any association between the presence of particular pathogens in household animals, and MSD in children. Conclusions and significance Public health agencies should continue to promote frequent hand washing, including after animal contact, to reduce the risk of MSD. Future studies should address specific causal relations of MSD with sheep and chicken husbandry practices, and with the presence of rodents. PMID:28783751

Effects of sea-level changes on mid-ocean ridge magmatism and implications for emission rates of carbon.

NASA Astrophysics Data System (ADS)

Cerpa, N.; Katz, R. F.; Keller, T.

2017-12-01

Glacial cycles move water between ice sheets and the ocean, and hence cause regional pressure changes in the solid Earth. The rate of sea-level (SL) change during this cycle is comparable to the rate of mantle upwelling beneath mid-ocean ridges (MORs), and hence we expect the induced pressure variations to modify the rate and depth of silicate melting. SL variations may therefore induce changes in the supply and composition of magma at MORs, which could affect the flux of carbon into the climate system. Likewise, the trace-element geochemistry of magmas tapped by ridge volcanism may vary during these cycles due to variations in melt flux. Such variations may have been recorded by sediment-hosted volcanic glass fragments [Ferguson et al., 2017]. We investigate these questions using computational models of melt production and transport in which volatiles participate in the thermodynamics of melting. Published models of the effect of SL on MORs predict up to 10% variation in carbon emission rates for absolute changes in SL of 50-100 m with possible lag times of several tens of kyrs [Burley et al., 2015; Hasenclever et al., 2017]. A major assumption of those models is that water and carbon are passive, incompatible elements. But small concentrations of those volatiles affect the solidus of mantle peridotite and increase the volume of upper mantle undergoing partial melting. Hence the current predictions of variation in MOR carbon emission might be an underestimate. Moreover, published models neglect the effects of volatiles on melt transport. Recents studies have demonstrated that volatiles can induce channelized transport [Keller and Katz 2016], potentially affecting the rate at which carbon is extracted from the mantle. In this study, we investigate the interplay between SL variations, melting, and segregation of volatile-rich melts. We use two-phase magma/mantle dynamics coupled to melting models that treat water and carbon dioxide as thermodynamic components. We compare models of equilibrium and disequilibrium melting to assess the influence of reaction kinetics on magma productivity at MORs during SL variations. Our calculations provide new estimates of the lag and amplitude of carbon emissions during glacial cycles. We address the impact of SL variations on the trace-element composition of magmas.

Distribution of lacosamide in the rat brain assessed by in vitro slice technique.

PubMed

Gáll, Zsolt; Vancea, Szende

2018-01-01

Lacosamide is a newer anticonvulsant and is the only one that enhances the slow inactivation of voltage gated sodium channels. It is also claimed to have disease-modifying potential, but its pharmacokinetic properties have been much less discussed in the literature. In rats, lacosamide shows restricted distribution to tissues, and the brain-to-plasma partition coefficient (K p ) is only 0.553. In this study, the brain disposition of lacosamide was evaluated in rat brains, and its neuropharmacokinetic parameters (i.e., protein binding and intracellular accumulation) were assessed using in vitro methods. Brain slice experiments and brain homogenate binding studies were performed for several drugs acting on the central nervous system, and drugs were assayed by using a liquid chromatography-mass spectrometry system. By applying a combined approach, it was found that (1) the unbound volume of distribution in the brain for lacosamide (V u,brain  = 1.37) was lower than that of other classical anticonvulsants; (2) the unbound fraction of lacosamide in the brain (0.899) was slightly lower than its unbound fraction in plasma (0.96); (3) the unbound intracellular-to-extracellular concentration ratio of lacosamide was 1.233, meaning that lacosamide was accumulated in the intracellular space because of its physicochemical properties and zwitterionic structure; and (4) the unbound brain-to-plasma concentration ratio of lacosamide was lower than the total brain-to-plasma concentration ratio (K p,uu,brain  = 0.42 vs. K p  = 0.553). In conclusion, the limited brain distribution of lacosamide is not related to its nonspecific protein-binding capacity; rather, an active transport mechanism across the blood-brain barrier may be involved, which reduces the anticonvulsant and/or antiepileptogenic actions of this drug.

Pharmacological characterization of the cloned kappa opioid receptor as a kappa 1b subtype.

PubMed

Lai, J; Ma, S W; Zhu, R H; Rothman, R B; Lentes, K U; Porreca, F

1994-10-27

Substantial pharmacological evidence in vitro and in vivo has suggested the existence of subtypes of the kappa opioid receptor. Quantitative radioligand binding techniques resolved the presence of two high affinity binding sites for the kappa 1 ligand [3H]U69,593 in mouse brain membranes, termed kappa 1a and kappa 1b, respectively. Whereas the kappa 1a site has high affinity for fedotozine and oxymorphindole and low affinity for bremazocine and alpha-neoendorphin, site kappa 1b has high affinity for bremazocine and alpha-neoendorphin and low affinity for fedotozine and oxymorphindole. CI-977 and U69,593 bind equally well at both sites. To determine the relationship between these kappa 1 receptor subtypes and the recently cloned mouse kappa 1 receptor (KOR), we examined [3H]U69,593 binding to the KOR in stably transfected cells (KORCHN-8). Competition of [3H]U69,593 binding to the KOR by bremazocine, alpha-neoendorphin, fedotozine and oxymorphindole resolved a single class of binding sites at which these agents had binding affinities similar to that of the kappa 1b site present in mouse brain. These results suggest that the cloned KOR corresponds to the kappa 1 site in mouse brain defined as kappa 1b.

Biochemical study of prolactin binding sites in Xenopus laevis brain and choroid plexus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muccioli, G.; Guardabassi, A.; Pattono, P.

1990-03-01

The occurrence of prolactin binding sites in some brain structures (telencephalon, ventral hypothalamus, myelencephalon, hypophysis, and choroid plexus) from Xenopus laevis (anuran amphibian) was studied by the in vitro biochemical technique. The higher binding values were obtained at the level of the choroid plexus and above all of the hypothalamus. On the bases of hormonal specificity and high affinity, these binding sites are very similar to those of prolactin receptors of classical target tissues as well as of those described by us in other structures from Xenopus. To our knowledge, the present results provide the first demonstration of the occurrencemore » of prolactin specific binding sites in Xenopus laevis choroid plexus cells.« less

BINDING, SPATIAL ATTENTION AND PERCEPTUAL AWARENESS

PubMed Central

Robertson, Lynn C.

2012-01-01

The world is experienced as a unified whole, but sensory systems do not deliver it to the brain in this way. Signals from different sensory modalities are initially registered in separate brain areas —even within a modality, features of the sensory mosaic such as colour, size, shape and motion are fragmented and registered in specialized areas of the cortex. How does this information become bound together in experience? Findings from the study of abnormal binding — for example, after stroke — and unusual binding — as in synaesthesia — might help us to understand the cognitive and neural mechanisms that contribute to solving this ‘binding problem’. PMID:12563280

Distinct binding of PET ligands PBB3 and AV-1451 to tau fibril strains in neurodegenerative tauopathies

PubMed Central

Ono, Maiko; Sahara, Naruhiko; Kumata, Katsushi; Ji, Bin; Ni, Ruiqing; Koga, Shunsuke; Dickson, Dennis W.; Trojanowski, John Q.; Lee, Virginia M-Y.; Yoshida, Mari; Hozumi, Isao; Yoshiyama, Yasumasa; van Swieten, John C.; Nordberg, Agneta; Suhara, Tetsuya; Zhang, Ming-Rong; Higuchi, Makoto

2017-01-01

Abstract Diverse neurodegenerative disorders are characterized by deposition of tau fibrils composed of conformers (i.e. strains) unique to each illness. The development of tau imaging agents has enabled visualization of tau lesions in tauopathy patients, but the modes of their binding to different tau strains remain elusive. Here we compared binding of tau positron emission tomography ligands, PBB3 and AV-1451, by fluorescence, autoradiography and homogenate binding assays with homologous and heterologous blockades using tauopathy brain samples. Fluorescence microscopy demonstrated intense labelling of non-ghost and ghost tangles with PBB3 and AV-1451, while dystrophic neurites were more clearly detected by PBB3 in brains of Alzheimer’s disease and diffuse neurofibrillary tangles with calcification, characterized by accumulation of all six tau isoforms. Correspondingly, partially distinct distributions of autoradiographic labelling of Alzheimer’s disease slices with 11C-PBB3 and 18F-AV-1451 were noted. Neuronal and glial tau lesions comprised of 4-repeat isoforms in brains of progressive supranuclear palsy, corticobasal degeneration and familial tauopathy due to N279K tau mutation and 3-repeat isoforms in brains of Pick’s disease and familial tauopathy due to G272V tau mutation were sensitively detected by PBB3 fluorescence in contrast to very weak AV-1451 signals. This was in line with moderate 11C-PBB3 versus faint 18F-AV-1451 autoradiographic labelling of these tissues. Radioligand binding to brain homogenates revealed multiple binding components with differential affinities for 11C-PBB3 and 18F-AV-1451, and higher availability of binding sites on progressive supranuclear palsy tau deposits for 11C-PBB3 than 18F-AV-1451. Our data indicate distinct selectivity of PBB3 compared to AV-1451 for diverse tau fibril strains. This highlights the more robust ability of PBB3 to capture wide-range tau pathologies. PMID:28087578

Heart type fatty acid binding protein (H-FABP) is decreased in brains of patients with Down syndrome and Alzheimer's disease.

PubMed

Cheon, M S; Kim, S H; Fountoulakis, M; Lubec, G

2003-01-01

Fatty acid binding proteins (FABPs) are thought to play a role in the binding, targeting and transport of long-chain fatty acids, and at least three types of FABPs are found in human brain; heart type (H)-FABP, brain type (B)-FABP and epidermal type (E)-FABP. Although all three FABPs could be involved in normal brain function in prenatal and postnatal life, a neurobiological role of FABPs in neurodegenerative diseases has not been reported yet. These made us evaluate the protein levels of FABPs in brains from patients with Down syndrome (DS) and Alzheimer's disease (AD) and fetal cerebral cortex with DS using two-dimensional (2-D) gel electrophoresis with subsequent matrix-assisted laser desorption ionization mass spectroscopy (MALDI-MS) identification and specific software for quantification of proteins. In adult brain, B-FABP was significantly increased in occipital cortex of DS, and H-FABP was significantly decreased in DS (frontal, occipital and parietal cortices) and AD (frontal, temporal, occipital and parietal cortices). In fetal brain, B-FABP and epidermal E-FABP levels were comparable in controls and DS. We conclude that aberrant expression of FABPs, especially H-FABP may alter membrane fluidity and signal transduction, and consequently could be involved in cellular dysfunction in neurodegenerative disorders.

Multiple sclerosis: Presence of serum antibodies to lipids and predominance of cholesterol recognition.

PubMed

Jurewicz, Anna; Domowicz, Malgorzata; Galazka, Grazyna; Raine, Cedric S; Selmaj, Krzysztof

2017-10-01

A lot of available data on lipid immunology in multiple sclerosis (MS) have been derived from studies using synthetic lipids, therefore the role of lipids in the immunopathogenesis of MS remains poorly defined. The present study on the lipid response in MS was performed on native lipids from autopsied brain tissue. For this, lipid fractions (n = 9) were prepared from MS (n = 3) and control (n = 2) white matter according to the Folch procedure and were characterized depending on their solubility in chloroform/methanol. TLC showed that, in brain from MS cases, neutral lipids were rich in cholesterol and cholesterol esters while lipids from control brains displayed a predominance of phospholipids. MS serum IgG and IgM were found to bind to MS brain lipid fractions with a higher efficacy (p < 0.05) than the control serum. F(ab) 2 fractionation revealed that MS serum IgG binding depended on a specific antibody-type of recognition. Pre-adsorption of serum with cholesterol, galactocerebrosides, sulfitides, and phosphatidylinositol prior to ELISA with MS brain lipids, showed that cholesterol diminished IgG and IgM binding up to 70%. Experiments with synthetic lipids confirmed the predominance of cholesterol binding by MS serum. Our results demonstrate that IgG and IgM fractions from MS serum specifically and predominantly recognize native cholesterol and cholesterol esters isolated from the brain tissue of patients with MS. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

FABP-1 gene ablation impacts brain endocannabinoid system in male mice.

PubMed

Martin, Gregory G; Chung, Sarah; Landrock, Danilo; Landrock, Kerstin K; Huang, Huan; Dangott, Lawrence J; Peng, Xiaoxue; Kaczocha, Martin; Seeger, Drew R; Murphy, Eric J; Golovko, Mikhail Y; Kier, Ann B; Schroeder, Friedhelm

2016-08-01

Liver fatty acid-binding protein (FABP1, L-FABP) has high affinity for and enhances uptake of arachidonic acid (ARA, C20:4, n-6) which, when esterified to phospholipids, is the requisite precursor for synthesis of endocannabinoids (EC) such as arachidonoylethanolamide (AEA) and 2-arachidonoylglycerol (2-AG). The brain derives most of its ARA from plasma, taking up ARA and transporting it intracellularly via cytosolic fatty acid-binding proteins (FABPs 3,5, and 7) localized within the brain. In contrast, the much more prevalent cytosolic FABP1 is not detectable in the brain but is instead highly expressed in the liver. Therefore, the possibility that FABP1 outside the central nervous system may regulate brain AEA and 2-AG was examined in wild-type (WT) and FABP1 null (LKO) male mice. LKO increased brain levels of AA-containing EC (AEA, 2-AG), correlating with increased free and total ARA in brain and serum. LKO also increased brain levels of non-ARA that contain potentiating endocannabinoids (EC*) such as oleoyl ethanolamide (OEA), PEA, 2-OG, and 2-PG. Concomitantly, LKO decreased serum total ARA-containing EC, but not non-ARA endocannabinoids. LKO did not elicit these changes in the brain EC and EC* as a result of compensatory up-regulation of brain protein levels of enzymes in EC synthesis (NAPEPLD, DAGLα) or cytosolic EC chaperone proteins (FABPs 3, 5, 7, SCP-2, HSP70), or cannabinoid receptors (CB1, TRVP1). These data show for the first time that the non-CNS fatty acid-binding protein FABP1 markedly affected brain levels of both ARA-containing endocannabinoids (AEA, 2-AG) as well as their non-ARA potentiating endocannabinoids. Fatty acid-binding protein-1 (FABP-1) is not detectable in brain but instead is highly expressed in liver. The possibility that FABP1 outside the central nervous system may regulate brain endocannabinoids arachidonoylethanolamide (AEA) and 2-arachidonoylglycerol (2-AG) was examined in wild-type (WT) and FABP-1 null (LKO) male mice. LKO increased brain levels of arachidonic acid-containing endocannabinoids (AEA, 2-AG), correlating with increased free and total arachidonic acid in brain and serum. Read the Editorial Highlight for this article on page 371. © 2016 International Society for Neurochemistry.

Characterization of nicotine binding in mouse brain and comparison with the binding of alpha-bungarotoxin and quinuclidinyl benzilate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marks, M.J.; Collins, A.C.

1982-11-01

The binding of (/sup 3/H)nicotine to mouse brain has been measured and subsequently compared with the binding of (/sup 125/I)alpha-bungarotoxin (alpha-BTX) and L-(/sup 3/H)quinuclidinyl benzilate (QNB). The binding of nicotine was saturable, reversible, and stereospecific. Although the rates of association and dissociation of nicotine were temperature-dependent, the incubation temperature had no effect on either KD or Bmax. Nicotine binding was unaffected by the addition of NaCl, KCl, CaCl/sub 2/, or MgSO/sub 4/ to the incubation medium. Nicotinic cholinergic agonists were potent inhibitors of nicotine binding; however, nicotinic antagonists were poor inhibitors. The regional distribution of binding was not uniform: midbrainmore » and striatum contained the highest number of receptors, whereas cerebellum had the fewest. Differences in site densities, regional distribution, inhibitor potencies, and thermal denaturation indicated that nicotine binding was not the same as either QNB or alpha-BTX binding, and therefore that receptors for nicotine may represent a unique population of cholinergic receptors.« less

In vivo detection of amyloid plaques in the mouse brain using the near-infrared fluorescence probe THK-265.

PubMed

Okamura, Nobuyuki; Mori, Masanori; Furumoto, Shozo; Yoshikawa, Takeo; Harada, Ryuichi; Ito, Satoshi; Fujikawa, Yosuke; Arai, Hiroyuki; Yanai, Kazuhiko; Kudo, Yukitsuka

2011-01-01

Noninvasive detection of amyloid-β (Aβ) deposits in the brain would be beneficial for an early and presymptomatic diagnosis of Alzheimer's disease (AD). We developed THK-265 as a candidate near-infrared fluorescence (NIRF) probe for the in vivo detection of amyloid deposits in the brain. The maximal emission wavelength of THK-265 was greater than 650nm and it showed high quantum yield and molar absorption coefficients. A fluorescence binding assay showed its high binding affinity to Aβ fibrils (Kd = 97 nM). THK-265 clearly stained amyloid plaques in AD neocortical brain sections and showed a moderate log p value (1.8). After intravenous administration of THK-265 in amyloid-β protein precursor (AβPP) transgenic mice, amyloid deposits in the brain were clearly labeled with THK-265. Furthermore, in vivo NIRF imaging demonstrated significantly higher fluorescence intensity in the brains of AβPP transgenic mice than in those of wild-type mice. As THK-265 showed profound hyperchromic effect upon binding to Aβ fibrils, good discrimination between AβPP transgenic and wild-type mice was demonstrated even early after THK-265 administration. Furthermore, the fluorescence intensity of THK-265 correlated with amyloid plaque burden in the brains of AβPP transgenic mice. These findings strongly support the usefulness of THK-265 as an NIRF imaging probe for the noninvasive measurement of brain amyloid load.

A study of silver species on silver-exchanged ETS-10 and mordenite by XRD, SEM and solid-state 109Ag, 29Si and 27AI NMR spectroscopy.

PubMed

Liu, Yan; Chen, Fu; Wasylishen, Roderick E; Xu, Zhenghe; Sawada, James; Kuznicki, Steven M

2012-08-01

Silver zeolites, especially Ag-ETS-10 and Ag-mordenite, actively bind xenon and iodine, two prime contaminants common to nuclear accidents. The evolution of silver species on silver exchanged ETS-10 (Ag/ETS-10) and mordenite (Ag/Mor) has been investigated by exposing the materials to a series of activation conditions in Ar, air and H2. The samples were characterized by XRD, SEM and solid-state 109Ag, 29Si and 27AI MAS NMR. The silver reduction and structural evolution have been illustrated by those techniques. The effectiveness of one sample of each type of sieve was tested for its ability to trap mercury from a gas stream. However, the results from this study demonstrate that the adsorption characteristics of silver-loaded sieves cannot necessarily be predicted using a full complement of structural characterization techniques, which highlights the importance of understanding the formation and nature of silver species on molecular sieves.

Fab MOR03268 triggers absorption shift of a diagnostic dye via packaging in a solvent-shielded Fab dimer interface.

PubMed

Hillig, Roman C; Urlinger, Stefanie; Fanghänel, Jörg; Brocks, Bodo; Haenel, Cornelia; Stark, Yvonne; Sülzle, Detlev; Svergun, Dmitri I; Baesler, Siegfried; Malawski, Guido; Moosmayer, Dieter; Menrad, Andreas; Schirner, Michael; Licha, Kai

2008-03-14

Molecular interactions between near-IR fluorescent probes and specific antibodies may be exploited to generate novel smart probes for diagnostic imaging. Using a new phage display technology, we developed such antibody Fab fragments with subnanomolar binding affinity for tetrasulfocyanine, a near-IR in vivo imaging agent. Unexpectedly, some Fabs induced redshifts of the dye absorption peak of up to 44 nm. This is the largest shift reported for a biological system so far. Crystal structure determination and absorption spectroscopy in the crystal in combination with microcalorimetry and small-angle X-ray scattering in solution revealed that the redshift is triggered by formation of a Fab dimer, with tetrasulfocyanine being buried in a fully closed protein cavity within the dimer interface. The derived principle of shifting the absorption peak of a symmetric dye via packaging within a Fab dimer interface may be transferred to other diagnostic fluorophores, opening the way towards smart imaging probes that change their wavelength upon interaction with an antibody.

Long-Term Effect of Docosahexaenoic Acid Feeding on Lipid Composition and Brain Fatty Acid-Binding Protein Expression in Rats

PubMed Central

Elsherbiny, Marwa E.; Goruk, Susan; Monckton, Elizabeth A.; Richard, Caroline; Brun, Miranda; Emara, Marwan; Field, Catherine J.; Godbout, Roseline

2015-01-01

Arachidonic (AA) and docosahexaenoic acid (DHA) brain accretion is essential for brain development. The impact of DHA-rich maternal diets on offspring brain fatty acid composition has previously been studied up to the weanling stage; however, there has been no follow-up at later stages. Here, we examine the impact of DHA-rich maternal and weaning diets on brain fatty acid composition at weaning and three weeks post-weaning. We report that DHA supplementation during lactation maintains high DHA levels in the brains of pups even when they are fed a DHA-deficient diet for three weeks after weaning. We show that boosting dietary DHA levels for three weeks after weaning compensates for a maternal DHA-deficient diet during lactation. Finally, our data indicate that brain fatty acid binding protein (FABP7), a marker of neural stem cells, is down-regulated in the brains of six-week pups with a high DHA:AA ratio. We propose that elevated levels of DHA in developing brain accelerate brain maturation relative to DHA-deficient brains. PMID:26506385

In vivo and in vitro changes in neurochemical parameters related to mercury concentrations from specific brain regions of polar bears (Ursus maritimus).

PubMed

Krey, Anke; Kwan, Michael; Chan, Hing Man

2014-11-01

Mercury (Hg) has been detected in polar bear brain tissue, but its biological effects are not well known. Relationships between Hg concentrations and neurochemical enzyme activities and receptor binding were assessed in the cerebellum, frontal lobes, and occipital lobes of 24 polar bears collected from Nunavik (Northern Quebec), Canada. The concentration-response relationship was further studied with in vitro experiments using pooled brain homogenate of 12 randomly chosen bears. In environmentally exposed brain samples, there was no correlative relationship between Hg concentration and cholinesterase (ChE) activity or muscarinic acetylcholine receptor (mAChR) binding in any of the 3 brain regions. Monoamine oxidase (MAO) activity in the occipital lobe showed a negative correlative relationship with total Hg concentration. In vitro experiments, however, demonstrated that Hg (mercuric chloride and methylmercury chloride) can inhibit ChE and MAO activities and muscarinic mAChR binding. These results show that Hg can alter neurobiochemical parameters but the current environmental Hg exposure level does have an effect on the neurochemistry of polar bears from northern Canada. © 2014 SETAC.

Characterization of [(3)H]harmane binding to rat whole brain membranes.

PubMed

Anderson, N J; Robinson, E S J; Husbands, S M; Delagrange, P; Nutt, D J; Hudson, A L

2003-12-01

This study investigates the binding of [(3)H]harmane to rat whole brain homogenates. Saturation studies revealed [(3)H]harmane labels a single, saturable, high-capacity population with high affinity. All the test compounds displaced [(3)H]harmane completely and in an apparently monophasic manner. The displacement profile of the test ligands indicated labeling of MAO-A. Given the high level of MAO-A binding, it is unlikely that a low-capacity I(2) site would be distinguishable from the total [(3)H]harmane population.

Fatty Acid Binding Proteins Expressed at the Human Blood-Brain Barrier Bind Drugs in an Isoform-Specific Manner.

PubMed

Lee, Gordon S; Kappler, Katharina; Porter, Christopher J H; Scanlon, Martin J; Nicolazzo, Joseph A

2015-10-01

To examine the expression of fatty acid binding proteins (FABPs) at the human blood-brain barrier (BBB) and to assess their ability to bind lipophilic drugs. mRNA and protein expression of FABP subtypes in immortalized human brain endothelial (hCMEC/D3) cells were examined by RT-qPCR and Western blot, respectively. FABPs that were found in hCMEC/D3 cells (hFABPs) were recombinantly expressed and purified from Escherichia coli C41(DE3) cells. Drug binding to these hFABPs was assessed using a fluorescence assay, which measured the ability of a panel of lipophilic drugs to displace the fluorescent probe compound 1-anilinonaphthalene-8-sulfonic acid (ANS). hFABP3, 4 and 5 were expressed in hCMEC/D3 cells at the mRNA and protein level. The competitive ANS displacement assay demonstrated that, in general, glitazones preferentially bound to hFABP5 (Ki: 1.0-28 μM) and fibrates and fenamates preferentially bound to hFABP4 (Ki: 0.100-17 μM). In general, lipophilic drugs appeared to show weaker affinities for hFABP3 relative to hFABP4 and hFABP5. No clear correlation was observed between the molecular structure or physicochemical properties of the drugs and their ability to displace ANS from hFABP3, 4 and 5. hFABP3, 4 and 5 are expressed at the human BBB and bind differentially to a diverse range of lipophilic drugs. The unique expression and binding patterns of hFABPs at the BBB may therefore influence drug disposition into the brain.

The tau positron-emission tomography tracer AV-1451 binds with similar affinities to tau fibrils and monoamine oxidases.

PubMed

Vermeiren, Céline; Motte, Philippe; Viot, Delphine; Mairet-Coello, Georges; Courade, Jean-Philippe; Citron, Martin; Mercier, Joël; Hannestad, Jonas; Gillard, Michel

2018-02-01

Lilly/Avid's AV-1451 is one of the most advanced tau PET tracers in the clinic. Although results obtained in Alzheimer's disease patients are compelling, discrimination of tracer uptake in healthy individuals and patients with supranuclear palsy (PSP) is less clear as there is substantial overlap of signal in multiple brain regions. Moreover, accurate quantification of [ 18 F]AV-1451 uptake in Alzheimer's disease may not be possible. The aim of the present study was to characterize the in vitro binding of AV-1451 to understand and identify potential off-target binding that could explain the poor discrimination observed in PSP patients. [ 3 H]AV-1451 and AV-1451 were characterized in in vitro binding assays using recombinant and native proteins/tissues from postmortem samples of controls and Alzheimer's disease and PSP patients. [ 3 H]AV-1451 binds to multiple sites with nanomolar affinities in brain homogenates and to tau fibrils isolated from Alzheimer's disease or PSP patients. [ 3 H]AV-1451 also binds with similarly high affinities in brain homogenates devoid of tau pathology. This unexpected binding was demonstrated to be because of nanomolar affinities of [ 3 H]AV-1451 for monoamine oxidase A and B enzymes. High affinity of AV-1451 for monoamine oxidase proteins may limit its utility as a tau PET tracer in PSP and Alzheimer's disease because of high levels of monoamine oxidase expression in brain regions also affected by tau deposition, especially if monoamine oxidase levels change over time or with a treatment intervention. © 2017 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and Movement Disorder Society.

Sigma opiates and certain antipsychotic drugs mutually inhibit (+)-[3H] SKF 10,047 and [3H]haloperidol binding in guinea pig brain membranes.

PubMed Central

Tam, S W; Cook, L

1984-01-01

The relationship between binding of antipsychotic drugs and sigma psychotomimetic opiates to binding sites for the sigma agonist (+)-[3H]SKF 10,047 (N-allylnormetazocine) and to dopamine D2 sites was investigated. In guinea pig brain membranes, (+)-[3H]SKF 10,047 bound to a single class of sites with a Kd of 4 X 10(-8) M and a Bmax of 333 fmol/mg of protein. This binding was different from mu, kappa, or delta opiate receptor binding. It was inhibited by opiates that produce psychotomimetic activities but not by opiates that lack such activities. Some antipsychotic drugs inhibited (+)-[3H]SKF 10,047 binding with high to moderate affinities in the following order of potency: haloperidol greater than perphenazine greater than fluphenazine greater than acetophenazine greater than trifluoperazine greater than molindone greater than or equal to pimozide greater than or equal to thioridazine greater than or equal to chlorpromazine greater than or equal to triflupromazine. However, there were other antipsychotic drugs such as spiperone and clozapine that showed low affinity for the (+)-[3H]SKF 10,047 binding sites. Affinities of antipsychotic drugs for (+)-[3H]SKF 10,047 binding sites did not correlate with those for [3H]spiperone (dopamine D2) sites. [3H]-Haloperidol binding in whole brain membranes was also inhibited by the sigma opiates pentazocine, cyclazocine, and (+)-SKF 10,047. In the striatum, about half of the saturable [3H]haloperidol binding was to [3H]spiperone (D2) sites and the other half was to sites similar to (+)-[3H]SKF 10,047 binding sites. PMID:6147851

Considerations in the Development of Reversibly Binding PET Radioligands for Brain Imaging

PubMed Central

Pike, Victor W.

2017-01-01

The development of reversibly binding radioligands for imaging brain proteins in vivo, such as enzymes, neurotransmitter transporters, receptors and ion channels, with positron emission tomography (PET) is keenly sought for biomedical studies of neuropsychiatric disorders and for drug discovery and development, but is recognized as being highly challenging at the medicinal chemistry level. This article aims to compile and discuss the main considerations to be taken into account by chemists embarking on programs of radioligand development for PET imaging of brain protein targets. PMID:27087244

Anatomical Location of LPA1 Activation and LPA Phospholipid Precursors in Rodent and Human Brain

PubMed Central

González de San Román, E; Manuel, I; Giralt, MT; Chun, J; Estivill-Torrús, G; Rodriguez de Fonseca, F; Santín, LJ; Ferrer, I; Rodriguez-Puertas, R

2016-01-01

Lysophosphatidic acid (LPA) is a signaling molecule that binds to six known G protein-coupled receptors (GPCRs): LPA1–LPA6. LPA evokes several responses in the CNS including cortical development and folding, growth of the axonal cone and its retraction process. Those cell processes involve survival, migration, adhesion proliferation, differentiation and myelination. The anatomical localization of LPA1 is incompletely understood, particularly with regard to LPA binding. Therefore, we have used functional [35S]GTPγS autoradiography to verify the anatomical distribution of LPA1 binding sites in adult rodent and human brain. The greatest activity was observed in myelinated areas of the white matter such as corpus callosum, internal capsule and cerebellum. MaLPA1-null mice (a variant of LPA1-null) lack [35S]GTPγS basal binding in white matter areas, where the LPA1 receptor is expressed at high levels, suggesting a relevant role of the activity of this receptor in the most myelinated brain areas. In addition, phospholipid precursors of LPA were localized by MALDI-IMS in both rodent and human brain slices identifying numerous species of phosphatides (PA) and phosphatidylcholines (PC). Both PA and PC species represent potential LPA precursors. The anatomical distribution of these precursors in rodent and human brain may indicate a metabolic relationship between LPA and LPA1 receptors. PMID:25857358

Evaluation of the antagonism of nicotine by mecamylamine and pempidine in the brain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, T.J.

1989-01-01

Antagonists have been crucial in the characterization of nicotine's pharmacology. Initial evidence for the existence of central nicotinic receptors was based on the fact that nicotine produced a number of behavioral effects that were antagonized by ganglionic blockers that crossed the blood-brain barrier, such as mecamylamine and pempidine. These compounds are thought to be noncompetitive antagonists due to the fact that they do not compete for agonist binding to brain homogenate in vitro. However, pharmacological evidence in support of noncompetitive antagonism is lacking. Dose-response curves for nicotine were determined in the presence of various doses of pempidine for depression ofmore » spontaneous activity and antinociception in mice. Pempidine was found to shift the dose response curves for these effects of nicotine in a manner consistent with noncompetitive antagonism. A number of mecamylamine analogs were investigated for antagonism of these central effects of nicotine as well. These studies revealed that the N-, 2-, and 3-methyls were crucial for optimal efficacy and potency and suggests that these compounds possess a specific mechanism of action, possibly involving a receptor. Furthermore, the structure-activity relationships for the mecamylamine analogs were found to be different than that previously reported for the agonists, suggesting that they do not act at the same site. The binding of ({sup 3} H)-L-nicotine and ({sup 3}H)-pempidine was studied in vitro to mouse brain homogentate and in situ to rat brain slices. The in situ binding of ({sup 3}H)-L-nicotine to rat brain slices was quantitated autoradiographically to discrete brain areas in the presence and absence of 1, 10 and 100 {mu}M nicotine and pempidine. Pempidine did not effectively displace ({sup 3}H)-L-nicotine binding.« less

Differential inhibition of [3H]-oxotremorine-M and [3H]-quinuclinidyl benzilate binding to muscarinic receptors in rat brain membranes with acetylcholinesterase inhibitors.

PubMed

Lockhart, B; Closier, M; Howard, K; Steward, C; Lestage, P

2001-04-01

The potential interaction of acetylcholinesterase inhibitors with cholinergic receptors may play a significant role in the therapeutic and/or side-effects associated with this class of compound. In the present study, the capacity of acetylcholinesterase inhibitors to interact with muscarinic receptors was assessed by their ability to displace both [3H]-oxotremorine-M and [3H]-quinuclinidyl benzilate binding in rat brain membranes. The [3H]-quinuclinidyl benzilate/[3H]-oxotremorine-M affinity ratios permitted predictions to be made of either the antagonist or agonist properties of the different compounds. A series of compounds, representative of the principal classes of acetylcholinesterase inhibitors, displaced [3H]-oxotremorine-M binding with high-to-moderate potency (ambenonium>neostigmine=pyridostigmine=tacrine>physostigmine> edrophonium=galanthamine>desoxypeganine) whereas only ambenonium and tacrine displaced [3H]-quinuclinidyl benzilate binding. Inhibitors such as desoxypeganine, parathion and gramine demonstrated negligible inhibition of the binding of both radioligands. Scatchard plots constructed from the inhibition of [3H]-oxotremorine-M binding in the absence and presence of different inhibitors showed an unaltered Bmax and a reduced affinity constant, indicative of potential competitive or allosteric mechanisms. The capacity of acetylcholinesterase inhibitors, with the exception of tacrine and ambenonium, to displace bound [3H]-oxotremorine-M in preference to [3H]quinuclinidyl benzilate predicts that the former compounds could act as potential agonists at muscarinic receptors. Moreover, the rank order for potency in inhibiting acetylcholinesterase (ambenonium>neostigmine=physostigmine =tacrine>pyridostigmine=edrophonium=galanthamine >desoxypeganine>parathion>gramine) indicated that the most effective inhibitors of acetylcholinesterase also displaced [3H]-oxotremorine-M to the greatest extent. The capacity of these inhibitors to displace [3H]-oxotremorine-M binding preclude their utilisation for the prevention of acetylcholine catabolism in rat brain membranes, the latter being required to estimate the binding of acetylcholine to [3H]-oxotremorine-M-labelled muscarinic receptors. However, fasciculin-2, a potent peptide inhibitor of acetylcholinesterase (IC50 24 nM), did prevent catabolism of acetylcholine in rat brain membranes with an atypical inhibition isotherm of [3H]-oxotremorine-M binding, thus permitting an estimation of the "global affinity" of acetylcholine (Ki 85 nM) for [3H]-oxotremorine-M-labelled muscarinic receptors in rat brain.

Examination of the Mechanism of Human Brain Aspartoacylase through the Binding of an Intermediate Analogue†‡

PubMed Central

Le Coq, Johanne; Pavlovsky, Alexander; Malik, Radhika; Sanishvili, Ruslan; Xu, Chengfu; Viola, Ronald E.

2009-01-01

Canavan disease is a fatal neurological disorder caused by the malfunctioning of a single metabolic enzyme, aspartoacylase, that catalyzes the deacetylation of N-acetyl-l-aspartate to produce l-aspartate and acetate. The structure of human brain aspartoacylase has been determined in complex with a stable tetrahedral intermediate analogue, N-phosphonomethyl-l-aspartate. This potent inhibitor forms multiple interactions between each of its heteroatoms and the substrate binding groups arrayed within the active site. The binding of the catalytic intermediate analogue induces the conformational ordering of several substrate binding groups, thereby setting up the active site for catalysis. The highly ordered binding of this inhibitor has allowed assignments to be made for substrate binding groups and provides strong support for a carboxypeptidase-type mechanism for the hydrolysis of the amide bond of the substrate, N-acetyl-l-aspartate. PMID:18293939

Examination of the mechanism of human brain aspartoacylase through the binding of an intermediate analogue.

PubMed

Le Coq, Johanne; Pavlovsky, Alexander; Malik, Radhika; Sanishvili, Ruslan; Xu, Chengfu; Viola, Ronald E

2008-03-18

Canavan disease is a fatal neurological disorder caused by the malfunctioning of a single metabolic enzyme, aspartoacylase, that catalyzes the deacetylation of N-acetyl-L-aspartate to produce L-aspartate and acetate. The structure of human brain aspartoacylase has been determined in complex with a stable tetrahedral intermediate analogue, N-phosphonomethyl-L-aspartate. This potent inhibitor forms multiple interactions between each of its heteroatoms and the substrate binding groups arrayed within the active site. The binding of the catalytic intermediate analogue induces the conformational ordering of several substrate binding groups, thereby setting up the active site for catalysis. The highly ordered binding of this inhibitor has allowed assignments to be made for substrate binding groups and provides strong support for a carboxypeptidase-type mechanism for the hydrolysis of the amide bond of the substrate, N-acetyl- l-aspartate.

Autoradiographic analysis of alpha 1-noradrenergic receptors in the human brain postmortem. Effect of suicide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gross-Isseroff, R.; Dillon, K.A.; Fieldust, S.J.

In vitro quantitative autoradiography of alpha 1-noradrenergic receptors, using tritiated prazosin as a ligand, was performed on 24 human brains postmortem. Twelve brains were obtained from suicide victims and 12 from matched controls. We found significant lower binding to alpha 1 receptors in several brain regions of the suicide group as compared with matched controls. This decrease in receptor density was evident in portions of the prefrontal cortex, as well as the temporal cortex and in the caudate nucleus. Age, sex, presence of alcohol, and time of death to autopsy did not affect prazosin binding, in our sample, as measuredmore » by autoradiography.« less

DAMGO binding to mouse brain membranes: influence of salts, guanine nucleotides, substance P, and substance P fragments.

PubMed

Krumins, S A; Kim, D C; Igwe, O J; Larson, A A

1993-01-01

Substance P (SP) appears to mediate many processes of the central nervous system, including pain. This report deals with modulation of opioid binding in the mouse brain by SP and SP fragments, as well as by salts and guanine nucleotides. Binding studies of the selective mu opioid receptor agonist [D-Ala2, MePhe4,Gly(ol)5]enkephalin (DAMGO) to mouse brain membrane preparations demonstrated that guanine nucleotide modulation of DAMGO binding affinity was modified by SP. However, SP had little or no influence on inhibition of DAMGO binding induced by salts, such as MgCl2, CaCl2, or NaCl. By replacing GTP with GppNHp, SP (0.1 nM) produced multiple affinity forms of the DAMGO receptor, while at a higher concentration (10 nM), SP lost its influence on DAMGO binding. Furthermore, 0.1 nM SP changed DAMGO binding parameters in a medium containing NaCl, CaCl2, and GppNHp such that the high- and low-affinity conformations of the receptor converted to a single site following the addition of SP to the incubation medium. While the C-terminal SP fragment SP(5-11) was without effect, the N-terminal SP fragments SP(1-9) and SP(1-7) appeared to imitate SP in modifying GppNHp-modulated DAMGO binding. These results suggest that SP functions as a modulator of opioid binding at the mu receptor and it appears that the N-terminus of SP plays a role in the modulatory process.

Effects of hypoxia-ischemia and MK-801 treatment on the binding of a phencyclidine analogue in the developing rat brain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silverstein, F.S.; McDonald, J.W. III; Bommarito, M.

1990-02-01

The phencyclidine analogue ({sup 3}H)(1-(2-thienyl)cyclohexyl)piperidine ({sup 3}H-TCP) binds to the ion channel associated with the N-methyl-D-aspartate receptor channel complex. In vitro autoradiography indicates that the distribution of {sup 3}H-TCP binding in brain closely parallels that of ({sup 3}H)glutamate binding to the N-methyl-D-aspartate receptor. In nine 7-day-old rats, an acute focal hypoxic-ischemic insult produced by unilateral carotid artery ligation and subsequent exposure to 8% oxygen acutely reduced {sup 3}H-TCP binding ipsilateral to the ligation by 30% in the CA1, by 27% in the CA3, by 26% in the dentate gyrus, and by 17% in the striatum compared with values from themore » contralateral hemisphere. In 10 littermates that received 1 mg/kg of the neuroprotective noncompetitive N-methyl-D-aspartate antagonist MK-801 immediately before hypoxic exposure, the regional distribution of {sup 3}H-TCP binding in hypoxic-ischemic brain was relatively preserved and there were no interhemispheric asymmetries in {sup 3}H-TCP binding densities. In addition, in three unoperated rats decapitated 24 hours after MK-801 treatment, {sup 3}H-TCP binding was reduced by 15-35%; similar bilateral suppression of {sup 3}H-TCP binding was detected in MK-801-treated ligates. Our data indicate that {sup 3}H-TCP autoradiography can be used to assay the efficacy of neuroprotective agents in this experimental model of perinatal stroke.« less

Fusion antibody for Alzheimer's disease with bidirectional transport across the blood-brain barrier and abeta fibril disaggregation.

PubMed

Boado, Ruben J; Zhang, Yufeng; Zhang, Yun; Xia, Chun-Fang; Pardridge, William M

2007-01-01

Delivery of monoclonal antibody therapeutics across the blood-brain barrier is an obstacle to the diagnosis or therapy of CNS disease with antibody drugs. The immune therapy of Alzheimer's disease attempts to disaggregate the amyloid plaque of Alzheimer's disease with an anti-Abeta monoclonal antibody. The present work is based on a three-step model of immune therapy of Alzheimer's disease: (1) influx of the anti-Abeta monoclonal antibody across the blood-brain barrier in the blood to brain direction, (2) binding and disaggregation of Abeta fibrils in brain, and (3) efflux of the anti-Abeta monoclonal antibody across the blood-brain barrier in the brain to blood direction. This is accomplished with the genetic engineering of a trifunctional fusion antibody that binds (1) the human insulin receptor, which mediates the influx from blood to brain across the blood-brain barrier, (2) the Abeta fibril to disaggregate amyloid plaque, and (3) the Fc receptor, which mediates the efflux from brain to blood across the blood-brain barrier. This fusion protein is a new antibody-based therapeutic for Alzheimer's disease that is specifically engineered to cross the human blood-brain barrier in both directions.

FABP-1 GENE ABLATION IMPACTS BRAIN ENDOCANNABINOID SYSTEM IN MALE MICE

PubMed Central

Martin, Gregory G.; Chung, Sarah; Landrock, Danilo; Landrock, Kerstin K.; Huang, Huan; Dangott, Lawrence J.; Peng, Xiaoxue; Kaczocha, Martin; Seeger, Drew R.; Murphy, Eric J.; Golovko, Mikhail Y.; Kier, Ann B.; Schroeder, Friedhelm

2016-01-01

Liver fatty acid binding protein (FABP1, L-FABP) has high affinity for and enhances uptake of arachidonic acid (ARA, C20:4, n-6) which, when esterified to phospholipids, is the requisite precursor for synthesis of endocannabinoids (EC) such as arachidonoylethanolamide (AEA) and 2-arachidonoylglycerol (2-AG). The brain derives most of its ARA from plasma, taking up ARA and transporting it intracellularly via cytosolic fatty acid binding proteins (FABPs 3,5, and 7) localized within the brain. In contrast, the much more prevalent cytosolic FABP1 is not detectable in the brain but is instead highly expressed in the liver. Therefore, the possibility that FABP1 outside the central nervous system may regulate brain AEA and 2-AG was examined in wild-type (WT) and FABP1 null (LKO) male mice. LKO increased brain levels of AA-containing EC (AEA, 2-AG), correlating with increased free and total ARA in brain and serum. LKO also increased brain levels of non-ARA that contain potentiating endocannabinoids (EC*) such as OEA, PEA, 2-OG, and 2-PG. Concomitantly, LKO decreased serum total ARA-containing EC, but not non-ARA endocannabinoids. LKO did not elicit these changes in the brain EC and EC* due to compensatory upregulation of brain protein levels of enzymes in EC synthesis (NAPEPLD, DAGLα) or cytosolic EC chaperone proteins (FABPs 3, 5, 7, SCP-2, HSP70), or cannabinoid receptors (CB1, TRVP1). These data show for the first time that the non-CNS fatty acid binding protein FABP1 markedly affected brain levels of both ARA-containing endocannabinoids (AEA, 2-AG) as well as their non-ARA potentiating endocannabinoids. PMID:27167970

Muscarinic cholinergic receptor binding: in vivo depiction using single photon emission computed tomography and radioiodinated quinuclidinyl benzilate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drayer, B.; Jaszczak, R.; Coleman, E.

1982-06-01

An attempt was made to characterize, in vivo, specific binding to the muscarinic cholinergic receptor in the calf using the radioiodinated ligand quinuclidinyl benzilate (/sup 123/I-OH-QNB) and single photon detection emission computed tomography (SPECT). The supratentorial brain activity was significantly increased after the intravenous infusion of /sup 123/I-OH-QNB as compared to free /sup 123/I. Scopolamine, a muscarinic cholinergic receptor antagonist, decreased the measured brain activity when infused prior to /sup 123/I-OH-QNB consistent with pharmacologic blockade of specific receptor binding. Quantitative in vitro tissue distribution studies obtained following SPECT imaging were consistent with regionally distinct specific receptor binding in the striatummore » and cortical gray matter, nonspecific binding in the cerebellum, and pharmacologic blockade of specific binding sites with scopolamine. Although /sup 123/I-OH-QNB is not the ideal radioligand, our limited success will hopefully encourage the development of improved binding probes for SPECT imaging and quantitation.« less

Rate constants of agonist binding to muscarinic receptors in rat brain medulla. Evaluation by competition kinetics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schreiber, G.; Henis, Y.I.; Sokolovsky, M.

The method of competition kinetics, which measures the binding kinetics of an unlabeled ligand through its effect on the binding kinetics of a labeled ligand, was employed to investigate the kinetics of muscarinic agonist binding to rat brain medulla pons homogenates. The agonists studied were acetylcholine, carbamylcholine, and oxotremorine, with N-methyl-4-(TH)piperidyl benzilate employed as the radiolabeled ligand. Our results suggested that the binding of muscarinic agonists to the high affinity sites is characterized by dissociation rate constants higher by 2 orders of magnitude than those of antagonists, with rather similar association rate constants. Our findings also suggest that isomerization ofmore » the muscarinic receptors following ligand binding is significant in the case of antagonists, but not of agonists. Moreover, it is demonstrated that in the medulla pons preparation, agonist-induced interconversion between high and low affinity bindings sites does not occur to an appreciable extent.« less

[Glutamate-binding membrane proteins from human platelets].

PubMed

Gurevich, V S; Popov, Iu G; Gorodinskiĭ, A I; Dambinova, S A

1991-09-01

Solubilization of the total membrane fraction of human platelets in a 2% solution of sodium deoxycholate and subsequent affinity chromatography on glutamate agarose resulted in two protein fractions possessing a glutamate-binding activity. As can be evidenced from radioligand binding data, the first fraction contains two types of binding sites (Kd1 = 1 microM, Bmax 1 = 100 pmol/mg of protein; Kd2 = 9.3 microMm Bmax2 = 395 pmol/mg of protein). The second fraction has only one type of binding sites (Kd = 1 microM, Bmax = = 110 pmol/mg of protein). SDS-PAAG electrophoresis revealed the presence in the first fraction of proteins with Mr of 14, 24, 56 and 155 kDa, whereas the second fraction was found to contain 14, 46, 71 and 155 kDa proteins. Solid phase immunoenzymatic analysis using poly- and monoclonal specific antibodies against mammalian brain glutamate-binding proteins revealed a marked immunochemical similarity of the isolated protein fractions with human brain synaptic membrane glutamate-binding proteins.

Nicotinic α4β2 receptor imaging agents. Part IV. Synthesis and biological evaluation of 3-(2-(S)-3,4-dehydropyrrolinyl methoxy)-5-(3'-¹⁸F-fluoropropyl)pyridine (¹⁸F-Nifrolene) using PET.

PubMed

Pichika, Rama; Kuruvilla, Sharon A; Patel, Narmisha; Vu, Kenny; Sinha, Sangamitra; Easwaramoorthy, Balu; Narayanan, Tanjore K; Shi, Bingzhi; Christian, Bradley; Mukherjee, Jogeshwar

2013-01-01

Imaging agents for nicotinic α4β2 receptors in the brain have been under way for studying various CNS disorders. Previous studies from our laboratories have reported the successful development of agonist, ¹⁸F-nifene. In attempts to develop potential antagonists, ¹⁸F-nifrolidine and ¹⁸F-nifzetidine were previously reported. Further optimization of these fluoropropyl derivatives has now been carried out resulting in 3-(2-(S)-3,4-dehydropyrrolinylmethoxy)-5-(3'-Fluoropropyl)pyridine (nifrolene) as a new high affinity agent for nicotinic α4β2 receptors. Nifrolene in rat brain homogenate assays--labeled with ³H-cytisine--exhibited a binding affinity of 0.36 nM. The fluorine-18 analog, ¹⁸F-nifrolene, was synthesized in approximately 10%-20% yield and specific activity was estimated to be >2000 Ci/mmol. Rat brain slices indicated selective binding to anterior thalamic nuclei, thalamus, subiculum, striata, cortex and other regions consistent with α4β2 receptor distribution. This selective binding was displaced >90% by 300 μM nicotine. Thalamus to cerebellum ratio (>10) was the highest for ¹⁸F-nifrolene with several other regions showing selective binding. In vivo rat PET studies exhibited rapid uptake of ¹⁸F-nifrolene in the brain with specific retention in the thalamus and other brain regions while clearing out from the cerebellum. Thalamus to cerebellum ratio value in the rat was >4. Administration of nicotine caused a rapid decline in the thalamic ¹⁸F-nifrolene suggesting reversible binding to nicotinic receptors. PET imaging studies of ¹⁸F-nifrolene in anesthetized rhesus monkey revealed highest binding in the thalamus followed by regions of the lateral cingulated and temporal cortex. Cerebellum showed the least binding. Thalamus to cerebellum ratio in the monkey brain was >3 at 120 min. These ratios of ¹⁸F-nifrolene are higher than measured for ¹⁸F-nifrolidine and ¹⁸F-nifzetidine. ¹⁸F-Nifrolene thus shows promise as a new PET imaging agent for α4β2 nAChR. Copyright © 2013 Elsevier Inc. All rights reserved.

Engineering endomorphin drugs: state of the art

PubMed Central

Lazarus, Lawrence H; Okada, Yoshio

2011-01-01

Importance of the field Although EM-1 (H-Tyr-Pro-Phe-Trp-NH2) and EM-2 (H-Tyr-Pro-Phe-Phe-NH2) are primarily considered agonists for the μ-opioid receptor (MOR), systematic alterations to specific residues provided antagonists and ligands with mixed μ/δ-opioid properties suitable for application to health related topics. Areas covered in this review This review attempts to succinctly provide insight on the development and bioactivity of endomorphin analogues during the past decade. Rational design approaches will focus on the engineering of endomorphin agonists, antagonists and mixed ligands for their application as a multi-target ligand. What the reader will gain While the application of endomorphins as antinociceptive agents and numerous biological endpoints were experimental delineated in laboratory animals and in vitro, clinical use is currently absent. However, structural alterations provide enhanced stability, formation of MOR antagonists or mixed and dual μ/δ-acting ligands could find considerable therapeutic potential. Take home message Aside from alleviating pain, EM analogues open new horizons in the treatment of medical syndromes involving neural reward mechanisms and extraneural regulation effects on homeostasis. Highly selective MOR antagonists may be promising to reduce inflammation, attenuate addiction to drugs and excess consumption of high caloric food, ameliorate alcoholism, affect the immune system and combat opioid bowel dysfunction. PMID:22214283

New Geochemical Analyses Reveal Crustal Accretionary Processes at The Overlapping Spreading Center Near 3 N East Pacific Rise

NASA Astrophysics Data System (ADS)

Smithka, I. N.; Perfit, M. R.

2013-12-01

Mid-ocean ridges (MORs) are the sites of oceanic lithosphere creation and construction. Ridge discontinuities are a global phenomenom but are not as well understood as ridge axes. Geochemical analyses provide insights into upper mantle processes since elements fractionate with melting and freezing as well as reside in material to retain source signature. Lavas collected from ridge discontinuities consist of greater chemical diversity and represent variations in source, melting parameters, and local crustal processes. The small overlapping spreading center (OSC) near the third parallel north on the East Pacific Rise has been superficially analyzed previously, but here we present new isotope analyses and expand our understanding of MOR processes and processes near OSCs. Initial analyses of lavas collected in 2000 on AHA-NEMO2 revealed normal MOR basalt trends in rare earth element enrichments as well as in major element concentrations. Crystal fractionation varies along the tips of both axes, with MgO and TiO2 concentrations increasing towards the OSC basin. Newly analyzed Sr, Nd, and Pb isotope ratios will further constrain the nature of geochemical diversity along axis. As the northern tip seems to be propagating and the southern tip dying, lavas collected from each may reflect two different underlying mantle melting and magma storage processes.

Isobolographic analysis of the opioid-opioid interactions in a tonic and a phasic mouse model of induced nociceptive pain.

PubMed

Miranda, Hugo F; Noriega, Viviana; Zanetta, Pilar; Prieto, Juan Carlos; Prieto-Rayo, Juan Carlos; Aranda, Nicolás; Sierralta, Fernando

2014-07-15

Opioids have been used for the management of pain and coadministration of two opioids may induce synergism. In a model of tonic pain, the acetic acid writhing test and in a phasic model, the hot plate, the antinociceptive interaction between fentanyl, methadone, morphine, and tramadol was evaluated. The potency of opioids in the writhing test compared to the hot plate assay was from 2.5 (fentanyl) to 15.5 (morphine) times, respectively. The ED50 was used in a fixed ratio for each of the six pairs of opioid combinations, which, resulted in a synergistic antinociception except for methadone/tramadol and fentanyl/tramadol which were additive, in the hot plate. The opioid antagonists naltrexone, naltrindole and nor-binaltorphimine, suggests that the synergism of morphine combinations are due to the activation of MOR subtypes with partially contribution of DOR and KOR, however fentanyl and methadone combinations are partially due to the activation of MOR and DOR subtypes and KOR lack of participation. The antinociceptive effects of tramadol combinations, are partially due to the activation of MOR, DOR and KOR opioid subtypes. These results suggets that effectiveness and magnitude of the interactions between opioids are dependent on pain stimulus intensity.

Isobolographic analysis of the opioid-opioid interactions in a tonic and a phasic mouse model of induced nociceptive pain

PubMed Central

2014-01-01

Background Opioids have been used for the management of pain and coadministration of two opioids may induce synergism. In a model of tonic pain, the acetic acid writhing test and in a phasic model, the hot plate, the antinociceptive interaction between fentanyl, methadone, morphine, and tramadol was evaluated. Results The potency of opioids in the writhing test compared to the hot plate assay was from 2.5 (fentanyl) to 15.5 (morphine) times, respectively. The ED50 was used in a fixed ratio for each of the six pairs of opioid combinations, which, resulted in a synergistic antinociception except for methadone/tramadol and fentanyl/tramadol which were additive, in the hot plate. The opioid antagonists naltrexone, naltrindole and nor-binaltorphimine, suggests that the synergism of morphine combinations are due to the activation of MOR subtypes with partially contribution of DOR and KOR, however fentanyl and methadone combinations are partially due to the activation of MOR and DOR subtypes and KOR lack of participation. The antinociceptive effects of tramadol combinations, are partially due to the activation of MOR, DOR and KOR opioid subtypes. Conclusion These results suggets that effectiveness and magnitude of the interactions between opioids are dependent on pain stimulus intensity. PMID:25017386

Electrocatalytic performance of Pt nanoparticles sputter-deposited on indium tin oxide toward methanol oxidation reaction: The particle size effect

NASA Astrophysics Data System (ADS)

Ting, Chao-Cheng; Chao, Chih-Hsuan; Tsai, Cheng Yu; Cheng, I.-Kai; Pan, Fu-Ming

2017-09-01

We sputter-deposited Pt nanoparticles with an average size ranging from 2.0 nm to 8.5 nm on the indium-tin oxide (ITO) glass substrate, and studied the effect of the size of Pt nanoparticles on electrocatalytic activity of the Pt/ITO electrode toward methanol oxidation reaction (MOR) in acidic solution. X-ray photoelectron spectroscopy (XPS) reveals an interfacial oxidized Pt layer present between Pt nanoparticles and the ITO substrate, which may modify the surface electronic structure of Pt nanoparticles and thus influences the electrocatalytic properties of the Pt catalyst toward MOR. According to electrochemical analyses, smaller Pt nanoparticles exhibit slower kinetics for CO electrooxidation and MOR. However, a smaller particle size enables better CO tolerance because the bifunctional mechanism is more effective on smaller Pt nanoparticles. The electrocatalytic activity decays rapidly for Pt nanoparticles with a size smaller than 3 nm and larger than 8 nm. The rapid activity decay is attributed to Pt dissolution for smaller nanoparticles and to CO poisoning for larger ones. Pt nanoparticles of 5-6 nm in size loaded on ITO demonstrate a greatly improved electrocatalytic activity and stability compared with those deposited on different substrates in our previous studies.

Functional Mu Opioid Receptor Polymorphism (OPRM1 A118G) Associated With Heroin Use Outcomes in Caucasian Males: A Pilot Study

PubMed Central

Woodcock, Eric A.; Lundahl, Leslie H.; Burmeister, Margit; Greenwald, Mark K.

2017-01-01

Background Heroin’s analgesic, euphoric and dependence-producing effects are primarily mediated by the mu opioid receptor (MOR). A single gene, OPRM1, encodes the MOR. The functional polymorphism A118G, located in exon 1 of the OPRM1 gene, results in anatomically-specific reductions in MOR expression, which may alter an individual’s response to heroin. In prior studies 118G (rare allele) carriers demonstrated significantly greater opioid tolerance, overdose vulnerability, and pain sensitivity than 118AA homozygotes. Those findings suggest OPRM1 genotype may impact characteristics of heroin use. Methods The present pilot study characterized the impact of OPRM1 genotype (rs1799971, 118G allele carriers vs. 118AA homozygotes) on heroin-use phenotypes associated with heroin dependence severity in a sample of male, Caucasian chronic heroin users (n = 86). Results Results indicate that 118G allele carriers reported significantly more heroin use-related consequences and heroin-quit attempts, and were more likely to have sought treatment for their heroin use than 118AA homozygotes. Conclusions These preliminary findings, consistent with extant data, illustrate a role for OPRM1 allelic variation on heroin use characteristics, and provide support for considering genotype in heroin treatment and relapse prevention. PMID:25911999

Challenges and Experiences of Building Multidisciplinary Datasets across Cultures

NASA Astrophysics Data System (ADS)

Jamiyansharav, K.; Laituri, M.; Fernandez-Gimenez, M.; Fassnacht, S. R.; Venable, N. B. H.; Allegretti, A. M.; Reid, R.; Baival, B.; Jamsranjav, C.; Ulambayar, T.; Linn, S.; Angerer, J.

2017-12-01

Efficient data sharing and management are key challenges to multidisciplinary scientific research. These challenges are further complicated by adding a multicultural component. We address the construction of a complex database for social-ecological analysis in Mongolia. Funded by the National Science Foundation (NSF) Dynamics of Coupled Natural and Human (CNH) Systems, the Mongolian Rangelands and Resilience (MOR2) project focuses on the vulnerability of Mongolian pastoral systems to climate change and adaptive capacity. The MOR2 study spans over three years of fieldwork in 36 paired districts (Soum) from 18 provinces (Aimag) of Mongolia that covers steppe, mountain forest steppe, desert steppe and eastern steppe ecological zones. Our project team is composed of hydrologists, social scientists, geographers, and ecologists. The MOR2 database includes multiple ecological, social, meteorological, geospatial and hydrological datasets, as well as archives of original data and survey in multiple formats. Managing this complex database requires significant organizational skills, attention to detail and ability to communicate within collective team members from diverse disciplines and across multiple institutions in the US and Mongolia. We describe the database's rich content, organization, structure and complexity. We discuss lessons learned, best practices and recommendations for complex database management, sharing, and archiving in creating a cross-cultural and multi-disciplinary database.

The ataxic mouse as a model for studying downbeat nystagmus.

PubMed

Stahl, John S; Thumser, Zachary C; Oommen, Brian S

2012-01-01

Downbeat nystagmus (DBN) is a common eye movement complication of cerebellar disease. Use of mice to study pathophysiology of vestibulocerebellar disease is increasing, but it is unclear if mice can be used to study DBN; it has not been reported in this species. We determined whether DBN occurs in the ataxic mutant tottering, which carries a mutation in the Cacna1a gene for P/Q calcium channels. Spontaneous DBN occurred only rarely, and its magnitude did not exhibit the relationship to head tilt seen in human patients. DBN during yaw rotation was more common and shares some properties with the tilt-independent, gaze-independent component of human DBN, but differs in its dependence on vision. Hyperactivity of otolith circuits responding to pitch tilts is hypothesized to contribute to the gaze-independent component of human DBN. Mutants exhibited hyperactivity of the tilt maculo-ocular reflex (tiltMOR) in pitch. The hyperactivity may serve as a surrogate for DBN in mouse studies. TiltMOR hyperactivity correlates with hyperdeviation of the eyes and upward deviation of the head during ambulation; these may be alternative surrogates. Muscimol inactivation of the cerebellar flocculus suggests a floccular role in the tiltMOR hyperactivity and provides insight into the rarity of frank DBN in ataxic mice.

The ataxic mouse as a model for studying downbeat nystagmus

PubMed Central

Stahl, John S.; Thumser, Zachary C.; Oommen, Brian S.

2016-01-01

Downbeat nystagmus (DBN) is a common eye movement complication of cerebellar disease. Use of mice to study pathophysiology of vestibulocerebellar disease is increasing, but it is unclear if mice can be used to study DBN; it has not been reported in this species. We determined whether DBN occurs in the ataxic mutant tottering, which carries a mutation in the Cacna1a gene for P/Q calcium channels. Spontaneous DBN occurred only rarely, and its magnitude did not exhibit the relationship to head tilt seen in human patients. DBN during yaw rotation was more common and shares some properties with the tilt-independent, gaze-independent component of human DBN, but differs in its dependence on vision. Hyperactivity of otolith circuits responding to pitch tilts is hypothesized to contribute to the gaze-independent component of human DBN. Mutants exhibited hyperactivity of the tilt maculo-ocular reflex (tiltMOR) in pitch. The hyperactivity may serve as a surrogate for DBN in mouse studies. TiltMOR hyperactivity correlates with hyperdeviation of the eyes and upward deviation of the head during ambulation; these may be alternative surrogates. Muscimol inactivation of the cerebellar flocculus suggests a floccular role in the tiltMOR hyperactivity and provides insight into the rarity of frank DBN in ataxic mice. PMID:23302704

Berberine Improves Intestinal Motility and Visceral Pain in the Mouse Models Mimicking Diarrhea-Predominant Irritable Bowel Syndrome (IBS-D) Symptoms in an Opioid-Receptor Dependent Manner

PubMed Central

Pan, Qiuhui; Fichna, Jakub; Zheng, Lijun; Wang, Kesheng; Yu, Zhen; Li, Yongyu; Li, Kun; Song, Aihong; Liu, Zhongchen; Song, Zhenshun; Kreis, Martin

2015-01-01

Background and Aims Berberine and its derivatives display potent analgesic, anti-inflammatory and anticancer activity. Here we aimed at characterizing the mechanism of action of berberine in the gastrointestinal (GI) tract and cortical neurons using animal models and in vitro tests. Methods The effect of berberine was characterized in murine models mimicking diarrhea-predominant irritable bowel syndrome (IBS-D) symptoms. Then the opioidantagonists were used to identify the receptors involved. Furthermore, the effect of berberineon opioid receptors expression was established in the mouse intestine and rat fetal cortical neurons. Results In mouse models, berberine prolonged GI transit and time to diarrhea in a dose-dependent manner, and significantly reduced visceral pain. In physiological conditions the effects of berberine were mediated by mu- (MOR) and delta- (DOR) opioidreceptors; hypermotility, excessive secretion and nociception were reversed by berberine through MOR and DOR-dependent action. We also found that berberine increased the expression of MOR and DOR in the mouse bowel and rat fetal cortical neurons. Conclusion Berberine significantly improved IBS-D symptoms in animal models, possibly through mu- and delta- opioid receptors. Berberine may become a new drug candidate for the successful treatment of IBS-D in clinical conditions. PMID:26700862

Increased mortality odds ratio of male liver cancer in a community contaminated by chlorinated hydrocarbons in groundwater

PubMed Central

Lee, L; Chung, C; Ma, Y; Wang, G; Chen, P; Hwang, Y; Wang, J

2003-01-01

Aims: To investigate the association between cancer mortality risk and exposure to chlorinated hydrocarbons in groundwater of a downstream community near a contaminated site. Methods: Death certificates inclusive for the years 1966–97 were collected from two villages in the vicinity of an electronics factory operated between 1970 and 1992. These two villages were classified into the downstream (exposed) village and the upstream (unexposed) according to groundwater flow direction. Exposure classification was validated by the contaminant levels in 49 residential wells measured with gas chromatography/mass spectrometry. Mortality odds ratios (MORs) for cancer were calculated with cardiovascular-cerebrovascular diseases as the reference diseases. Multiple logistic regressions were performed to estimate the effects of exposure and period after adjustment for age. Results: Increased MORs were observed among males for all cancer, and liver cancer for the periods after 10 years of latency, namely, 1980–89, and 1990–97. Adjusted MOR for male liver cancer was 2.57 (95% confidence interval 1.21 to 5.46) with a significant linear trend for the period effect. Conclusion: The results suggest a link between exposure to chlorinated hydrocarbons and male liver cancer risk. However, the conclusion is limited by lack of individual information on groundwater exposure and potential confounding factors. PMID:12709523

A receptor autoradiographic and in situ hybridization analysis of the distribution of the 5-ht7 receptor in rat brain.

PubMed Central

Gustafson, E. L.; Durkin, M. M.; Bard, J. A.; Zgombick, J.; Branchek, T. A.

1996-01-01

1. Receptor autoradiography and in situ hybridization histochemistry have been used to delineate the distribution of the 5-ht7 receptor and its mRNA in rat brain. Receptor autoradiographic studies were performed using [3H]-5-carboxamidotryptamine (5-CT) as the radioligand. The binding characteristics of the masking compounds were determined in Cos-7 cells transfected with a panel of 5-HT receptor subtype cDNAs, including the rat 5-ht7 cDNA. In situ hybridization studies were carried out with 35S-labelled oligonucleotide probes to the rat 5-ht7 mRNA. 2. Specific binding of [3H]-5-CT was observed in many areas of the rat brain. Following co-incubation with 1 microM ergotamine, this binding was completely eliminated. After addition of the masking ligands, [3H]-5-CT binding remained in layers 1-3 of cortex, septum, globus pallidus, thalamus, hypothalamus, centromedial amygdala, substantia nigra, periaquaductal gray, and superior colliculus. Addition of the antagonist, methiothepin, to the incubation regimen eliminated most of the remaining [3H]-5-CT binding in the brain, with the exception of the globus pallidus and substantia nigra. 3. The 5-ht7 mRNA was discretely localized in rat brain. The most intense hybridization signals were observed over the thalamus, the anterior hippocampal rudiment, and over the CA3 region of the hippocampus. Other regions containing hybridization signals included the septum, the hypothalamus, the centromedial amygdala and the periaquaductal gray. The regions exhibiting a modest receptor binding signal after methiothepin incubation, the globus pallidus and the substantia nigra, contained no 5-ht7 hybridization signals, suggesting a non-5-ht7 subtype in these two related structures. 4. The distribution of the 5-ht7 receptor and its mRNA is suggestive of multiple roles for this novel 5-HT receptor, within several brain systems. The limbic system (centromedial amygdala, anterior hippocampal rudiment, hypothalamus) is particularly well-represented, indicating a potential role for the 5-ht7 receptor in affective processes. Images Figure 2 Figure 3 Figure 4 PMID:8646411

sigma opiates and certain antipsychotic drugs mutually inhibit (+)-(/sup 3/H)SKF 10,047 and (/sup 3/H)haloperidol binding in guinea pig brain membranes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tam, S.W.; Cook, L.

1984-09-01

The relationship between binding of antipsychotic drugs and sigma psychotomimetic opiates to binding sites for the sigma agonist (+)-(/sup 3/H)SKF 10,047 (N-allylnormetazocine) and to dopamine D/sub 2/ sites was investigated. In guinea pig brain membranes, (+)-(/sup 3/H)SKF 10,047 bound to single class of sites with a K/sub d/ of 4 x 10/sup -8/ M and a B/sub max/ of 333 fmol/mg of protein. This binding was different from ..mu.., kappa, or delta opiate receptor binding. It was inhibited by opiates that produce psychotomimetic activities but not by opiates that lack such activities. Some antipsychotic drugs inhibited (+)-(/sup 3/H)SKF 10,047 bindingmore » with high to moderate affinities in the following order of potency: haloperidol > perphenazine > fluphenazine > acetophenazine > trifluoperazine > molindone greater than or equal to pimozide greater than or equal to thioridazine greater than or equal to chlorpromazine greater than or equal to triflupromazine. However, there were other antipsychotic drugs such as spiperone and clozapine that showed low affinity for the (+)-(/sup 3/H)SKF 10,047 binding sites. Affinities of antipsychotic drugs for (+)-(/sup 3/H)SKF 10,047 binding sites did not correlate with those for (/sup 3/H)spiperone (dopamine D/sub 2/) sites. (/sup 3/H)-Haloperidol binding in whole brain membranes was also inhibited by the sigma opiates pentazocine, cyclazocine, and (+)-(/sup 3/H)SKF 10,047. In the striatum, about half of the saturable (/sup 3/H)haloperidol binding was to (/sup 3/H)spiperone (D/sub 2/) sites and the other half was to sites similar to (+)-(/sup 3/H)SKF 10,047 binding sites. 15 references, 4 figures, 1 table.« less

Persistence of evolutionary memory: primordial six-transmembrane helical domain mu opiate receptors selectively linked to endogenous morphine signaling.

PubMed

Kream, Richard M; Sheehan, Melinda; Cadet, Patrick; Mantione, Kirk J; Zhu, Wei; Casares, Federico; Stefano, George B

2007-12-01

Biochemical, molecular and pharmacological evidence for two unique six-transmembrane helical (TMH) domain opiate receptors expressed from the micro opioid receptor (MOR) gene have been shown. Designated micro3 and micro4 receptors, both protein species are Class A rhodopsin-like members of the superfamily of G-protein coupled receptors but are selectively tailored to mediate the cellular regulatory effects of endogenous morphine and related morphinan alkaloids via stimulation of nitric oxide (NO) production and release. Both micro3 and micro4 receptors lack an amino acid sequence of approximately 90 amino acids that constitute the extracellular N-terminal and TMH1 domains and part of the first intracellular loop of the micro1 receptor, but retain the empirically defined ligand binding pocket distributed across conserved TMH2, TMH3, and TMH7 domains of the micro1 sequence. Additionally, the receptor proteins are terminated by unique intracellular C-terminal amino acid sequences that serve as putative coupling or docking domains required for constitutive NO synthase activation. Because the recognition profile of micro3 and micro4 receptors is restricted to rigid benzylisoquinoline alkaloids typified by morphine and its extended family of chemical congeners, it is hypothesized that conformational stabilization provided by interaction of extended extracellular N-terminal protein domains and the extracellular loops is required for binding of endogenous opioid peptides as well as synthetic flexible opiate alkaloids.

Peripheral antinociceptive effects of the cyclic endomorphin-1 analog c[YpwFG] in a mouse visceral pain model.

PubMed

Bedini, Andrea; Baiula, Monica; Gentilucci, Luca; Tolomelli, Alessandra; De Marco, Rossella; Spampinato, Santi

2010-11-01

We previously described a novel cyclic endomorphin-1 analog c[Tyr-D-Pro-D-Trp-Phe-Gly] (c[YpwFG]), acting as a mu-opioid receptor (MOR) agonist. This study reports that c[YpwFG] is more lipophilic and resistant to enzymatic hydrolysis than endomorphin-1 and produces preemptive antinociception in a mouse visceral pain model when injected intraperitoneally (i.p.) or subcutaneously (s.c.) before 0.6% acetic acid, employed to evoke abdominal writhing (i.p. ED(50)=1.24 mg/kg; s.c. ED(50)=2.13 mg/kg). This effect is reversed by the selective MOR antagonist β-funaltrexamine and by a high dose of the mu(1)-opioid receptor-selective antagonist naloxonazine. Conversely, the kappa-opioid receptor antagonist nor-binaltorphimine and the delta-opioid receptor antagonist naltrindole are ineffective. c[YpwFG] produces antinociception when injected i.p. after acetic acid (ED(50)=4.80 mg/kg), and only at a dose of 20mg/kg did it elicit a moderate antinociceptive response in the mouse, evaluated by the tail flick assay. Administration of a lower dose of c[YpwFG] (10mg/kg i.p.) apparently produces a considerable part of antinociception on acetic acid-induced writhes through peripheral opioid receptors as this action is fully prevented by i.p. naloxone methiodide, which does not readily cross the blood-brain barrier; whereas this opioid antagonist injected intracerebroventricularly (i.c.v.) is not effective. Antinociception produced by a higher dose of c[YpwFG] (20mg/kg i.p.) is partially reversed by naloxone methiodide i.c.v. administered. Thus, only at the dose of 20mg/kg c[YpwFG] can produce antinociception through both peripheral and central opioid receptors. In conclusion, c[YpwFG] displays sufficient metabolic stability to be effective after peripheral administration and demonstrates the therapeutic potential of endomorphin derivatives as novel analgesic agents to control visceral pain. Copyright © 2010 Elsevier Inc. All rights reserved.

Noble metals in mid-ocean ridge volcanism: A significant fractionation of gold with respect to platinum group metals

NASA Technical Reports Server (NTRS)

Crocket, James H.

1988-01-01

Hydrothermal precipitates, black smoker particulate, and massive sulphide dredge samples from the Explorer Ridge on the Juan de Fuca Plate and the TAG hydrothermal area on the Mid-Atlantic Ridge were analyzed for selected noble metals including Au, Ir and Pd by radiochemical neutron activation analysis. The preliminary results indicate that gold contents may reach the ppm range although values in the neighborhood of 100 to 200 ppb are more typical. The platinum group elements (PGE) represented by Ir and Pd are typically less than 0.02 ppb and less than 2 ppb respectively. These abundances represent a significant enrichment of gold relative to the PGE in comparison with average noble metal abundances in mid-ocean ridge basalts (MORB). A partial explanation of this distinctive fractionation can be found in the concepts of sulfur-saturation of basic magma in mid-ocean ridge (MOR) settings, and the origin of MOR hydrothermal fluids. Experimental and petrological data suggest that MORBs are sulfur-saturated at the time of magma generation and that an immiscible sulfide component remains in the mantle residue. Hence, MORBs are noble metal-poor, particularly with respect to PGE. Consequently, black smoker fluids can be expected to reflect the low Ir and Pd contents of the rock column. The average Au content of MORB is 1.3 ppb, and so the rock column is not significantly enriched in Au. The generation of fluids which precipitate solids with 200 ppb Au is apparently dependent on highly efficient fluid chemistry to mobilize Au from the rock column, high Au solubility in seawater hydrothermal fluids and efficient precipitation mechanisms to coprecipitate Au on Fe, Zn and Cu sulfides. Significant differences in these parameters appear to be the ultimate cause of the strong Au-PGE fractionation in the MOR setting. It does not appear from the current data base that MOR hydrothermal fluids are significant contributors to the Ir enrichment seen in Cretaceous-Tertiary boundary sediments.

Changes in Receipt of Cancer Screening in Medicare Beneficiaries Following the Affordable Care Act

PubMed Central

Kou, Tzuyung D.; Schluchter, Mark D.; Dor, Avi; Koroukian, Siran M.

2016-01-01

Background: The Affordable Care Act (ACA) removed copayments for screening mammography and colonoscopy in Medicare beneficiaries, but its clinical impact is unknown. Methods: Using a 5% random sample of Medicare claims from 2009 through 2012 in individuals age 70 years or older who were due for screening, we examined claims for screening mammography and screening or surveillance colonoscopy for two years prior to ACA (2009–2010) and two years post-ACA (2011–2012). Receipt of the procedures at the patient level was compared across years using generalized estimating equations. Statistical tests were two-sided. Results: Compared with 2009, we found an increase in mammography uptake during the ACA coverage period, with multivariable odds ratios (MOR) of 1.22 (95% confidence interval [CI] = 1.20 to 1.25, P < .001) for 2011 and 1.17 (95% CI = 1.15 to 1.20, P < .001) for 2012 and less change in 2010 (OR = 1.03, 95% CI = 1.01 to 1.05, P = .01). In contrast to mammography, uptake of screening or surveillance colonoscopy decreased in 2012 (MOR = 0.95, 95% CI = 0.92 to 0.98, P = .002) compared with 2009, with no change in 2010 (MOR = 1.01, 95% CI = 0.99 to 1.04, P = .47) or 2011 (MOR = 1.01, 95% CI = 0.99 to 1.04, P = .34). Other factors associated with procedure receipt included younger age and prior preventive health visits. In an analysis restricted to patients age 70 to 74 years, colonoscopy use increased slightly in 2011 but was unchanged in 2012, and the findings by year for mammography were consistent with the main analysis. Conclusions: Following ACA implementation with concomitant reduction in out-of-pocket expenditures, there was a statistically significant increment in mammography uptake but not colonoscopy. This suggests that affordability is a necessary but not sufficient facilitator of preventive services. PMID:26640244

Changes in Receipt of Cancer Screening in Medicare Beneficiaries Following the Affordable Care Act.

PubMed

Cooper, Gregory S; Kou, Tzuyung D; Schluchter, Mark D; Dor, Avi; Koroukian, Siran M

2016-05-01

The Affordable Care Act (ACA) removed copayments for screening mammography and colonoscopy in Medicare beneficiaries, but its clinical impact is unknown. Using a 5% random sample of Medicare claims from 2009 through 2012 in individuals age 70 years or older who were due for screening, we examined claims for screening mammography and screening or surveillance colonoscopy for two years prior to ACA (2009-2010) and two years post-ACA (2011-2012). Receipt of the procedures at the patient level was compared across years using generalized estimating equations. Statistical tests were two-sided. Compared with 2009, we found an increase in mammography uptake during the ACA coverage period, with multivariable odds ratios (MOR) of 1.22 (95% confidence interval [CI] = 1.20 to 1.25, P < .001) for 2011 and 1.17 (95% CI = 1.15 to 1.20, P < .001) for 2012 and less change in 2010 (OR = 1.03, 95% CI = 1.01 to 1.05, P = .01). In contrast to mammography, uptake of screening or surveillance colonoscopy decreased in 2012 (MOR = 0.95, 95% CI = 0.92 to 0.98, P = .002) compared with 2009, with no change in 2010 (MOR = 1.01, 95% CI = 0.99 to 1.04, P = .47) or 2011 (MOR = 1.01, 95% CI = 0.99 to 1.04, P = .34). Other factors associated with procedure receipt included younger age and prior preventive health visits. In an analysis restricted to patients age 70 to 74 years, colonoscopy use increased slightly in 2011 but was unchanged in 2012, and the findings by year for mammography were consistent with the main analysis. Following ACA implementation with concomitant reduction in out-of-pocket expenditures, there was a statistically significant increment in mammography uptake but not colonoscopy. This suggests that affordability is a necessary but not sufficient facilitator of preventive services. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Methane oxidation and attenuation of sulphur compounds in landfill top cover systems: Lab-scale tests.

PubMed

Raga, Roberto; Pivato, Alberto; Lavagnolo, Maria Cristina; Megido, Laura; Cossu, Raffaello

2018-03-01

In this study, a top cover system is investigated as a control for emissions during the aftercare of new landfills and for old landfills where biogas energy production might not be profitable. Different materials were studied as landfill cover system in lab-scale columns: mechanical-biological pretreated municipal solid waste (MBP); mechanical-biological pretreated biowaste (PB); fine (PBS f ) and coarse (PBS c ) mechanical-biological pretreated mixtures of biowaste and sewage sludge, and natural soil (NS). The effectiveness of these materials in removing methane and sulphur compounds from a gas stream was tested, even coupled with activated carbon membranes. Concentrations of CO 2 , CH 4 , O 2 , N 2 , H 2 S and mercaptans were analysed at different depths along the columns. Methane degradation was assessed using mass balance and the results were expressed in terms of methane oxidation rate (MOR). The highest maximum and mean MOR were observed for MBP (17.2gCH 4 /m 2 /hr and 10.3gCH 4 /m 2 /hr, respectively). Similar values were obtained with PB and PBS c . The lowest values of MOR were obtained for NS (6.7gCH 4 /m 2 /hr) and PBS f (3.6gCH 4 /m 2 /hr), which may be due to their low organic content and void index, respectively. Activated membranes with high load capacity did not seem to have an influence on the methane oxidation process: MBP coupled with 220g/m 2 and 360g/m 2 membranes gave maximum MOR of 16.5gCH 4 /m 2 /hr and 17.4gCH 4 /m 2 /hr, respectively. Activated carbon membranes proved to be very effective on H 2 S adsorption. Furthermore, carbonyl sulphide, ethyl mercaptan and isopropyl mercaptan seemed to be easily absorbed by the filling materials. Copyright © 2017. Published by Elsevier B.V.

Differences in adults' health and health behaviour between 16 European urban areas and the associations with socio-economic status and physical and social environment.

PubMed

de Gelder, Rianne; Koster, Emmy M; van Buren, Laurens P; van Ameijden, Erik J C; Harrison, Annie; Birt, Christopher A; Verma, Arpana

2017-05-01

With a growing proportion of the European population living in urban areas (UAs), exploring health in urban areas becomes increasingly important. The objective of this study is to assess the magnitude of differences in health and health behaviour between adults living in urban areas (UAs) across Europe. We also explored whether and to what extent such differences can be explained by socio-economic status (SES) and physical or social environment. Data were obtained from a cross-sectional questionnaire survey, performed between as part of the European Urban Health Indicator System Part 2 (EURO-URHIS 2) project. Using multi-level logistic regression analysis, UA differences in psychological distress, self-assessed health, overweight and obesity, daily smoking, binge drinking and physical exercise were assessed. Median Odds Ratios (MORs) were calculated to estimate the extent to which the observed variance is attributable to UA, individual-level SES (measured by perceived financial strains, education level and employment status) and/or characteristics of physical and social environment. The dataset included 14 022 respondents in 16 UAs within 9 countries. After correction for age and gender, all MORs, except that for daily smoking, indicated statistically significant UA health differences. SES indicators (partly) explained UA differences in psychological distress, decreasing the MOR from 1.43 [95% credible interval (Cr.I.) 1.27-1.67, baseline model], to 1.25 (95% Cr.I. 1.14-1.40, SES model): a reduction of 42%. Accounting for the quality of green areas reduced the MOR for psychological distress by an additional 40%, to 1.15 (95% Cr.I. 1.05-1.28). Our study showed large differences in health and health behaviour between European UAs. Reducing socio-economic disadvantage and improving the quality of the neighbourhood's green spaces may reduce UA differences in psychological distress. © The Author 2016. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Functional coupling between adenosine A1 receptors and G-proteins in rat and postmortem human brain membranes determined with conventional guanosine-5'-O-(3-[35S]thio)triphosphate ([35S]GTPγS) binding or [35S]GTPγS/immunoprecipitation assay.

PubMed

Odagaki, Yuji; Kinoshita, Masakazu; Ota, Toshio; Meana, J Javier; Callado, Luis F; Matsuoka, Isao; García-Sevilla, Jesús A

2018-06-01

Adenosine signaling plays a complex role in multiple physiological processes in the brain, and its dysfunction has been implicated in pathophysiology of neuropsychiatric diseases such as schizophrenia and affective disorders. In the present study, the coupling between adenosine A 1 receptor and G-protein was assessed by means of two [ 35 S]GTPγS binding assays, i.e., conventional filtration method and [ 35 S]GTPγS binding/immunoprecipitation in rat and human brain membranes. The latter method provides information about adenosine A 1 receptor-mediated Gα i-3 activation in rat as well as human brain membranes. On the other hand, adenosine-stimulated [ 35 S]GTPγS binding determined with conventional assay derives from functional activation of Gα i/o proteins (not restricted only to Gα i-3 ) coupled to adenosine A 1 receptors. The determination of adenosine concentrations in the samples used in the present study indicates the possibility that the assay mixture under our experimental conditions contains residual endogenous adenosine at nanomolar concentrations, which was also suggested by the results on the effects of adenosine receptor antagonists on basal [ 35 S]GTPγS binding level. The effects of adenosine deaminase (ADA) on basal binding also support the presence of adenosine. Nevertheless, the varied patterns of ADA discouraged us from adding ADA into assay medium routinely. The concentration-dependent increases elicited by adenosine were determined in 40 subjects without any neuropsychiatric disorders. The increases in %E max values determined by conventional assay according to aging and postmortem delay should be taken into account in future studies focusing on the effects of psychiatric disorders on adenosine A 1 receptor/G-protein interaction in postmortem human brain tissue.

Leptin receptor deficiency is associated with upregulation of cannabinoid 1 receptors in limbic brain regions.

PubMed

Thanos, Panayotis K; Ramalhete, Roberto C; Michaelides, Michael; Piyis, Yianni K; Wang, Gene-Jack; Volkow, Nora D

2008-09-01

Leptin receptor dysfunction results in overeating and obesity. Leptin regulates hypothalamic signaling that underlies the motivation to hyperphagia, but the interaction between leptin and cannabinoid signaling is poorly understood. We evaluated the role of cannabinoid 1 receptors (CB(1)R) in overeating and the effects of food deprivation on CB(1)R in the brain. One-month-old Zucker rats were divided into unrestricted and restricted (fed 70% of unrestricted rats) diet groups and maintained until adulthood (4 months). Levels of relative binding sites of CB(1)R (CB(1)R binding levels) were assessed using [(3)H] SR141716A in vitro autoradiography. These levels were higher (except cerebellum and hypothalamus) at 4 months than at 1 month of age. One month CB(1)R binding levels for most brain regions did not differ between Ob and Lean (Le) rats (except in frontal and cingulate cortices in Le and in the hypothalamus in Ob). Four month Ob rats had higher CB(1)R binding levels than Le in most brain regions and food restriction was associated with higher CB(1)R levels in all brain regions in Ob, but not in Le rats. CB(1)R binding levels increased between adolescence and young adulthood which we believe was influenced by leptin and food availability. The high levels of CB(1)R in Ob rats suggest that leptin's inhibition of food-intake is in part mediated by downregulation of CB(1)R and that leptin interferes with CB(1)R upregulation under food-deprivation conditions. These results are consistent with prior findings showing increased levels of endogenous cannabinoids in the Ob rats corroborating the regulation of cannabinoid signaling by leptin. Published 2008 Wiley-Liss, Inc.

Leptin Receptor Deficiency is Associated With Upregulation of Cannabinoid 1 Receptors in Limbic Brain Regions

PubMed Central

THANOS, PANAYOTIS K.; RAMALHETE, ROBERTO C.; MICHAELIDES, MICHAEL; PIYIS, YIANNI K.; WANG, GENE-JACK; VOLKOW, NORA D.

2009-01-01

Leptin receptor dysfunction results in overeating and obesity. Leptin regulates hypothalamic signaling that underlies the motivation to hyperphagia, but the interaction between leptin and cannabinoid signaling is poorly understood. We evaluated the role of cannabinoid 1 receptors (CB1R) in overeating and the effects of food deprivation on CB1R in the brain. One-month-old Zucker rats were divided into unrestricted and restricted (fed 70% of unrestricted rats) diet groups and maintained until adulthood (4 months). Levels of relative binding sites of CB1R (CB1R binding levels) were assessed using [3H] SR141716A in vitro autoradiography. These levels were higher (except cerebellum and hypothalamus) at 4 months than at 1 month of age. One month CB1R binding levels for most brain regions did not differ between Ob and Lean (Le) rats (except in frontal and cingulate cortices in Le and in the hypothalamus in Ob). Four month Ob rats had higher CB1R binding levels than Le in most brain regions and food restriction was associated with higher CB1R levels in all brain regions in Ob, but not in Le rats. CB1R binding levels increased between adolescence and young adulthood which we believe was influenced by leptin and food availability. The high levels of CB1R in Ob rats suggest that leptin's inhibition of food-intake is in part mediated by downregulation of CB1R and that leptin interferes with CB1R upregulation under food-deprivation conditions. These results are consistent with prior findings showing increased levels of endogenous cannabinoids in the Ob rats corroborating the regulation of cannabinoid signaling by leptin. PMID:18563836

A six-year longitudinal PET study of (+)-[11C]DTBZ binding to the VMAT2 in monkey brain.

PubMed

Kilbourn, Michael R; Koeppe, Robert A

2017-12-01

The longitudinal reproducibility of in vivo binding potential measures for [ 11 C]dihydrotetrabenazine ([ 11 C]DTBZ) binding to the vesicular monoamine transporter 2 (VMAT2) site in primate brain was examined using a unique dataset of repeated control PET imaging studies. Forty-one dynamic [ 11 C]DTBZ PET studies were completed in a single rhesus monkey. Imaging equipment (microPET P4), personnel, radiotracer characteristics (injected mass amounts, molar activity) and image data analysis (BP ND-Logan ) were consistent throughout the entire sequence of PET studies. Same day reproducibility of BP ND-Logan estimates of specific binding was very good (-3% and -7% changes) for two control-control sessions. Over the full 74 months, the average BP ND-Logan value for [ 11 C]DTBZ-PET studies was 4.19±0.52, for a variance of 12%. No age-dependent change in binding potentials was observed over the six-year period. If the technical variables associated with PET scanner are consistently maintained, including PET scanner, imaging procedures and radiotracer preparation, in vivo biochemistry can be reproducibly measured in the primate brain over a multi-year period of time. Copyright © 2017 Elsevier Inc. All rights reserved.

MeCP2 regulates Tet1-catalyzed demethylation, CTCF binding, and learning-dependent alternative splicing of the BDNF gene in Turtle

PubMed Central

Zheng, Zhaoqing; Ambigapathy, Ganesh; Keifer, Joyce

2017-01-01

MECP2 mutations underlying Rett syndrome cause widespread misregulation of gene expression. Functions for MeCP2 other than transcriptional are not well understood. In an ex vivo brain preparation from the pond turtle Trachemys scripta elegans, an intraexonic splicing event in the brain-derived neurotrophic factor (BDNF) gene generates a truncated mRNA transcript in naïve brain that is suppressed upon classical conditioning. MeCP2 and its partners, splicing factor Y-box binding protein 1 (YB-1) and methylcytosine dioxygenase 1 (Tet1), bind to BDNF chromatin in naïve but dissociate during conditioning; the dissociation correlating with decreased DNA methylation. Surprisingly, conditioning results in new occupancy of BDNF chromatin by DNA insulator protein CCCTC-binding factor (CTCF), which is associated with suppression of splicing in conditioning. Knockdown of MeCP2 shows it is instrumental for splicing and inhibits Tet1 and CTCF binding thereby negatively impacting DNA methylation and conditioning-dependent splicing regulation. Thus, mutations in MECP2 can have secondary effects on DNA methylation and alternative splicing. DOI: http://dx.doi.org/10.7554/eLife.25384.001 PMID:28594324

Deacetylation of forskolin catalyzed by bovine brain membranes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Selfe, S.; Storm, D.R.

1985-11-27

Radiolabeled forskolin, 7-(/sup 3/H-acetyl)-forskolin, was synthesized to explore interactions between forskolin and bovine brain membrane preparations. The radiolabeled derivative was chemically characterized, and found to be indistinquishable from unlabeled forskolin in its ability to stimulate bovine brain adenylate cyclase. Preliminary binding data demonstrated that binding of 7-(/sup 3/H-acetyl)-forskolin to membranes was concentration dependent. However, competition binding studies using a constant concentration of 7-(/sup 3/H-acetyl)-forskolin with increasing levels of unlabeled forskolin showed enhanced binding of the labeled derivative. This suggested that 7-(/sup 3/H-acetyl)-forskolin was degraded by membranes and protected by native forskolin. Incubation of forskolin with membranes and analysis of themore » products by thin layer chromatography and mass spectroscopy showed the formation of 7-desacetylforskolin. The deacetylation of forskolin was monitored by quantitating the release of (/sup 3/H)acetate from 7-(/sup 3/H-acetyl)-forskolin. The reaction was linear with time and protein concentration. These data illustrate that forskolin can be degraded by membranes and indicate that ligand binding studies using labeled forskolin and membrane preparations should be cautiously interpreted.« less

Low-Dose Cannabinoid Type 2 Receptor Agonist Attenuates Tolerance to Repeated Morphine Administration via Regulating μ-Opioid Receptor Expression in Walker 256 Tumor-Bearing Rats.

PubMed

Zhang, Mingyue; Wang, Kun; Ma, Min; Tian, Songyu; Wei, Na; Wang, Guonian

2016-04-01

Morphine is widely used in patients with moderate and severe cancer pain, whereas the development of drug tolerance remains a major problem associated with opioid use. Previous studies have shown that cannabinoid type 2 (CB2) receptor agonists induce morphine analgesia, attenuate morphine tolerance in normal and neuropathic pain animals, induce transcription of the μ-opioid receptor (MOR) gene in Jurkat T cells, and increase morphine analgesia in cancer pain animals. However, no studies of the effects of CB2 receptor agonists on morphine tolerance in cancer pain have been performed. Therefore, we investigated the effect of repeated intrathecal (IT) injection of the low-dose CB2 receptor agonist AM1241 on the development of morphine tolerance in walker 256 tumor-bearing rats. We also tested the influence of the CB2 receptor agonist AM1241 on MOR protein and messenger ribonucleic acid (mRNA) expression in the rat spinal cord and dorsal root ganglia (DRG). Walker 256 cells were implanted into the plantar region of each rat's right hindpaw. Tumor-bearing rats received IT injection of the CB2 receptor agonist AM1241 or antagonist AM630 with or without morphine subcutaneously twice daily for 8 days. Rats receiving drug vehicle only served as the control group. Mechanical paw withdrawal threshold and thermal paw withdrawal latency were assessed by a von Frey test and hot plate test 30 minutes after drug administration every day. MOR protein and mRNA expression in the spinal cord and DRG were detected after the last day (day 8) of drug administration via Western blot and real-time reverse transcription polymerase chain reaction. The data were analyzed via analysis of variance followed by Student t test with Bonferroni correction for multiple comparisons. Repeated morphine treatments reduced the mechanical withdrawal threshold and thermal latency. Coadministration of a nonanalgetic dose of the CB2 receptor agonist AM1241 with morphine significantly inhibited the development of morphine tolerance and increased the MOR protein expression in the spinal cord and DRG and mRNA expression in the spinal cord in tumor-bearing rats. Our findings indicate that IT injection of a nonanalgetic dose of a CB2 receptor agonist increased the analgesia effect and alleviated tolerance to morphine in tumor-bearing rats, potentially by regulating MOR expression in the spinal cord and DRG. This receptor may be a new target for prevention of the development of opioid tolerance in cancer pain.

Treatment of pruritus with topically applied opiate receptor antagonist.

PubMed

Bigliardi, Paul L; Stammer, Holger; Jost, Gerhard; Rufli, Theo; Büchner, Stanislaw; Bigliardi-Qi, Mei

2007-06-01

Pruritus is the most common and distressing skin symptom, and treatment of itch is a problem for thousands of people. The currently available therapies are not very effective. Therefore there is an urgent need to find new effective topical drugs against itching. We conducted two separate studies to evaluate the efficacy of topically applied naltrexone, an opioid receptor antagonist, in the treatment of severe pruritus. The objective of the first open study was to correlate the clinical efficacy of topically applied naltrexone in different pruritic skin disorders to a change of epidermal mu-opiate receptor (MOR) expression. The second study was a double-blind, placebo-controlled, crossover study on pruritus in atopic dermatitis. Initially we performed an open pilot study on 18 patients with different chronic pruritic disorders using a topical formulation of 1% naltrexone for 2 weeks. A punch biopsy was performed in 11 patients before and after the application of the naltrexone cream and the staining of epidermal MOR was measured. Subsequently, a randomized, placebo-controlled, crossover trial was performed with the same formulation. We included in this trial 40 patients with localized and generalized atopic dermatitis with severe pruritus. In the open study more than 70% of the patients using the 1% naltrexone cream experienced a significant reduction of pruritus. More interestingly, the topical treatment with naltrexone caused an increase of epidermal MOR staining. The regulation of the epidermal opioid receptor correlated with the clinical assessment. The placebo-controlled, crossover trial demonstrated clearly that the cream containing naltrexone had an overall 29.4% better effect compared with placebo. The formulation containing naltrexone required a median of 46 minutes to reduce the itch symptoms to 50%; the placebo, 74 minutes. We could only take biopsy specimens in 11 patients, which means that a satisfactory statistical analysis of the changes of epidermal MOR staining was not possible. In addition, there was an insufficient number of patients with nephrogenic pruritus and pruritic psoriasis to draw definitive conclusions. The placebo-controlled study showed a significant advantage of topically applied naltrexone over the placebo formulation. This finding is supported by the biopsy results from the open studies, showing a regulation of MOR expression in epidermis after treatment with topical naltrexone, especially in atopic dermatitis. These results clearly show potential for topically applied opioid receptor antagonist in the treatment of pruritus. The placebo formulation also had some antipruritic effects. This underlines the importance of rehydration therapy for dry skin in the treatment of pruritus.

Evaluation of [11C]metergoline as a PET radiotracer for 5HTR in nonhuman primates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hooker, J.M.; Hooker, J.M.; Kim, S.W.

2010-04-20

Metergoline, a serotonin receptor antagonist, was labeled with carbon-11 in order to evaluate its pharmacokinetics and distribution in non-human primates using positron emission tomography. [{sup 11}C]Metergoline had moderate brain uptake and exhibited heterogeneous specific binding, which was blocked by pretreatment with metergoline and altanserin throughout the cortex. Non-specific binding and insensitivity to changes in synaptic serotonin limit its potential as a PET radiotracer. However, the characterization of [{sup 11}C]metergoline pharmacokinetics and binding in the brain and peripheral organs using PET improves our understanding of metergoline drug pharmacology.

Endogenous dopamine (DA) modulates (3H)spiperone binding in vivo in rat brain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bischoff, S.; Krauss, J.; Grunenwald, C.

1991-01-01

(3H)spiperone (SPI) binding in vivo, biochemical parameters and behavior were measured after modulating DA levels by various drug treatments. DA releasers and uptake inhibitors increased SPI binding in rat striatum. In other brain areas, the effects were variable, but only the pituitary remained unaffected. Surprisingly, nomifensine decreased SPI binding in frontal cortex. The effects of these drugs were monitored by measuring DA, serotonin (5-HT) and their metabolites in the same rats. The increased SPI binding in striatum was parallel to the locomotor stimulation with the following rank order: amfonelic acid greater than nomifensine greater than D-amphetamine greater than or equalmore » to methylphenidate greater than amineptine greater than bupropion. Decreasing DA levels with reserpine or alpha-methyl-para-tyrosine reduced SPI binding by 45% in striatum only when both drugs were combined. In contrast, reserpine enhanced SPI binding in pituitary. Thus, the amount of releasable DA seems to modulate SPI binding characteristics. It is suggested that in vivo, DA receptors are submitted to dynamic regulation in response to changes in intrasynaptic concentrations of DA.« less

Scanpath memory binding: multiple read-out experiments

NASA Astrophysics Data System (ADS)

Stark, Lawrence W.; Privitera, Claudio M.; Yang, Huiyang; Azzariti, Michela; Ho, Yeuk F.; Chan, Angie; Krischer, Christof; Weinberger, Adam

1999-05-01

The scanpath theory proposed that an internal spatial- cognitive model controls perception and the active looking eye movements, EMs, of the scanpath sequence. Evidence for this came from new quantitative methods, experiments with ambiguous figures and visual imagery and from MRI studies, all on cooperating human subjects. Besides recording EMs, we introduce other experimental techniques wherein the subject must depend upon memory bindings as in visual imagery, but may call upon other motor behaviors than EMs to read-out the remembered patterns. How is the internal model distributed and operationally assembled. The concept of binding speaks to the assigning of values for the model and its execution in various parts of the brain. Current neurological information helps to localize different aspects of the spatial-cognitive model in the brain. We suppose that there are several levels of 'binding' -- semantic or symbolic binding, structural binding for the spatial locations of the regions-of-interest and sequential binding for the dynamic execution program that yields the sequence of EMs. Our aim is to dissect out respective contributions of these different forms of binding.

Weak Lensing by Galaxy Clusters: from Pixels to Cosmology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gruen, Daniel

The story of the origin and evolution of our Universe is told, equivalently, by space-time itself and by the structures that grow inside of it. Clusters of galaxies are the frontier of bottom-up structure formation. They are the most massive objects to have collapsed at the present epoch. By that virtue, their abundance and structural parameters are highly sensitive to the composition and evolution of the Universe. The most common probe of cluster cosmology, abundance, uses samples of clusters selected by some observable. Applying a mass-observable relation (MOR), cosmological parameters can be constrained by comparing the sample to predicted clustermore » abundances as a function of observable and redshift. Arguably, however, cluster probes have not yet entered the era of per cent level precision cosmology. The primary reason for this is our imperfect understanding of the MORs. The overall normalization, the slope of mass vs. observable, the redshift evolution, and the degree and correlation of intrinsic scatters of observables at fixed mass have to be constrained for interpreting abundances correctly. Mass measurement of clusters by means of the differential deflection of light from background sources in their gravitational field, i.e. weak lensing, is a powerful approach for achieving this. This thesis presents new methods for and scientific results of weak lensing measurements of clusters of galaxies. The former include, on the data reduction side, (i) the correction of CCD images for non-linear effects due to the electric fields of accumulated charges and (ii) a method for masking artifact features in sets of overlapping images of the sky by comparison to the median image. Also, (iii) I develop a method for the selection of background galaxy samples based on their color and apparent magnitude that includes a new correction for contamination with cluster member galaxies. The main scientific results are the following. (i) For the Hubble Frontier Field cluster RXC J2248.7--4431 our lensing analysis constrains mass and concentration of the cluster halo and we confirm the large mass predicted by X-ray and Sunyaev-Zel’dovich (SZ) observations. The study of cluster members shows the relation of galaxy morphology to luminosity and environment. (ii) Our lensing mass measurements for 12 clusters are consistent with X-ray masses derived under the assumption of hydrostatic equilibrium of the intra-cluster gas. We confirm the MORs derived by the South Pole Telescope collaboration for the detection significance of the cluster SZ signal in their survey. We find discrepancies, however, with the Planck SZ MOR. We hypothesize that these are related either to a shallower slope of the MOR or a size-, redshift- or noise-dependent bias in SZ signal extraction. (iii) Finally, using a combination of simulations and theoretical models for the variation of cluster profiles at fixed mass, we find that the latter is a significant contribution to the uncertainty of cluster lensing mass measurements. A cosmic variance model, such as the one we develop, is necessary for MOR constraints to be accurate at the level required for future surveys.« less

Synthesis and Monkey-PET Study of (R)- and (S)-18F-Labeled 2-Arylbenzoheterocyclic Derivatives as Amyloid Probes with Distinctive in Vivo Kinetics.

PubMed

Yang, Yanping; Wang, Xuedan; Yang, Hui; Fu, Hualong; Zhang, Jinming; Zhang, Xiaojun; Dai, Jiapei; Zhang, Zhiyong; Lin, Chunping; Guo, Yuzhi; Cui, Mengchao

2016-11-07

This study describes an effective strategy to improve pharmacokinetics of Aβ imaging agents, offering a novel class of (R)- and (S)- 18 F-labeled 2-arylbenzoheterocyclic derivatives which bear an additional chiral hydroxyl group on the side chain. These ligands displayed binding abilities toward Aβ aggregates with K i values ranging from 3.2 to 195.6 nM. Chirality-related discrepancy was observed in biodistribution, and (S)-2-phenylbenzoxazole enantiomers exhibited vastly improved brain clearance with washout ratios higher than 20. Notably, (S)-[ 18 F]28 possessed high binding potency (K i = 7.6 nM) and exceptional brain kinetics (9.46% ID/g at 2 min, brain 2min /brain 60min = 27.8) that is superior to well-established [ 18 F]AV45. The excellent pharmacokinetics and low nonspecific binding of (S)-[ 18 F]28 were testified by dynamic PET/CT scans in monkey brains. In addition, (S)-[ 18 F]28 clearly labeled Aβ plaques both in vitro and ex vivo. These results might qualify (S)-[ 18 F]28 to detect Aβ plaques with high signal-to-noise ratio.

Chalcone Based Homodimeric PET Agent, 11C-(Chal)2DEA-Me, for Beta Amyloid Imaging: Synthesis and Bioevaluation.

PubMed

Chauhan, Kanchan; Tiwari, Anjani K; Chadha, Nidhi; Kaul, Ankur; Singh, Ajai Kumar; Datta, Anupama

2018-04-02

Homodimeric chalcone based 11 C-PET radiotracer, 11 C-(Chal) 2 DEA-Me, was synthesized, and binding affinity toward beta amyloid (Aβ) was evaluated. The computational studies revealed multiple binding of the tracer at the recognition sites of Aβ fibrils. The bivalent ligand 11 C-(Chal) 2 DEA-Me displayed higher binding affinity compared to the corresponding monomer, 11 C-Chal-Me, and classical Aβ agents. The radiolabeling yield with carbon-11 was 40-55% (decay corrected) with specific activity of 65-90 GBq/μmol. A significant ( p < 0.0001) improvement in the binding affinity of 11 C-(Chal) 2 DEA-Me with synthetic Aβ42 aggregates over the monomer, 11 C-Chal-Me, demonstrates the utility of the bivalent approach. The PET imaging and biodistribution data displayed suitable brain pharmacokinetics of both ligands with higher brain uptake in the case of the bivalent ligand. Metabolite analysis of healthy ddY mouse brain homogenates exhibited high stability of the radiotracers in the brain with >93% intact tracer at 30 min post injection. Both chalcone derivatives were fluorescent in nature and demonstrated significant changes in the emission properties after binding with Aβ42. The preliminary analysis indicates high potential of 11 C-(Chal) 2 DEA-Me as in vivo Aβ42 imaging tracer and highlights the significance of the bivalent approach to achieve a higher biological response for detection of early stages of amyloidosis.

Region-selective effects of neuroinflammation and antioxidant treatment on peripheral benzodiazepine receptors and NMDA receptors in the rat brain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biegon, A.; Alvarado, M.; Budinger, T.F.

2001-12-10

Following induction of acute neuroinflammation by intracisternal injection of endotoxin (lipopolysaccharide) in rats, quantitative autoradiography was used to assess the regional level of microglial activation and glutamate (NMDA) receptor binding. The possible protective action of the antioxidant phenyl-tert-butyl nitrone in this model was tested by administering the drug in the drinking water for 6 days starting 24 hours after endotoxin injection. Animals were killed 7 days post-injection and consecutive cryostat brain sections labeled with [3H]PK11195 as a marker of activated microglia and [125I]iodoMK801 as a marker of the open-channel, activated state of NMDA receptors. Lipopolysaccharide increased [3H]PK11195 binding in themore » brain, with the largest increases (2-3 fold) in temporal and entorhinal cortex, hippocampus, and substantia innominata. A significant (>50 percent) decrease in [125I]iodoMK801 binding was found in the same brain regions. Phenyl-tert-butyl nitrone treatment resulted in a partial inhibition ({approx}25 percent decrease) of the lipopolysaccharide-induced increase in [3H]PK11195 binding but completely reversed the lipopolysaccharide-induced decrease in [125I]iodoMK80 binding in the entorhinal cortex, hippocampus, and substantia innominata. Loss of NMDA receptor function in cortical and hippocampal regions may contribute to the cognitive deficits observed in diseases with a neuroinflammatory component, such as meningitis or Alzheimer's disease.« less

Short Nissl staining for incubated cryostat sections of the brain.

PubMed

Lindroos, O F

1991-01-01

Nissl stain often binds poorly to cryostat sections which have been incubated in solutions of radiolabeled ligands. Such incubation is used in receptor autoradiography of the brain when using the in vitro method. We have developed a rapid (16 min) modification of Nissl staining for sections that bind stain poorly, e.g., incubated sections. The method stains well sections which cannot be stained with other rapid Nissl staining methods.

Brain serotonin and dopamine transporter bindings in adults with high-functioning autism.

PubMed

Nakamura, Kazuhiko; Sekine, Yoshimoto; Ouchi, Yasuomi; Tsujii, Masatsugu; Yoshikawa, Etsuji; Futatsubashi, Masami; Tsuchiya, Kenji J; Sugihara, Genichi; Iwata, Yasuhide; Suzuki, Katsuaki; Matsuzaki, Hideo; Suda, Shiro; Sugiyama, Toshiro; Takei, Nori; Mori, Norio

2010-01-01

Autism is a neurodevelopmental disorder that is characterized by repetitive and/or obsessive interests and behavior and by deficits in sociability and communication. Although its neurobiological underpinnings are postulated to lie in abnormalities of the serotoninergic and dopaminergic systems, the details remain unknown. To determine the occurrence of changes in the binding of serotonin and dopamine transporters, which are highly selective markers for their respective neuronal systems. Using positron emission tomography, we measured the binding of brain serotonin and dopamine transporters in each individual with the radioligands carbon 11 ((11)C)-labeled trans-1,2,3,5,6,10-beta-hexahydro-6-[4-(methylthio)phenyl]pyrrolo-[2,1-a]isoquinoline ([(11)C](+)McN-5652) and 2beta-carbomethoxy-3-beta-(4-fluorophenyl)tropane ([(11)C]WIN-35,428), respectively. Statistical parametric mapping was used for between-subject analysis and within-subject correlation analysis with respect to clinical variables. Participants recruited from the community. Twenty men (age range, 18-26 years; mean [SD] IQ, 99.3 [18.1]) with autism and 20 age- and IQ-matched control subjects. Serotonin transporter binding was significantly lower throughout the brain in autistic individuals compared with controls (P < .05, corrected). Specifically, the reduction in the anterior and posterior cingulate cortices was associated with the impairment of social cognition in the autistic subjects (P < .05, corrected). A significant correlation was also found between repetitive and/or obsessive behavior and interests and the reduction of serotonin transporter binding in the thalamus (P < .05, corrected). In contrast, the dopamine transporter binding was significantly higher in the orbitofrontal cortex of the autistic group (P < .05, corrected in voxelwise analysis). In the orbitofrontal cortex, the dopamine transporter binding was significantly inversely correlated with serotonin transporter binding (r = -0.61; P = .004). The brains of autistic individuals have abnormalities in both serotonin transporter and dopamine transporter binding. The present findings indicate that the gross abnormalities in these neurotransmitter systems may underpin the neurophysiologic mechanism of autism. Our sample was not characteristic or representative of a typical sample of adults with autism in the community.

Surface tailored single walled carbon nanotubes as catalyst support for direct methanol fuel cell

NASA Astrophysics Data System (ADS)

Kireeti, Kota V. M. K.; Jha, Neetu

2017-10-01

A strategy for tuning the surface property of Single Walled Carbon Nanotubes (SWNTs) for enhanced methanol oxidation reaction (MOR) and oxygen reduction reaction (ORR) along with methanol tolerance is presented. The surface functionality is tailored using controlled acid and base treatment. Acid treatment leads to the attachment of carboxylic carbon (CC) fragments to SWNT making it hydrophilic (P3-SWNT). Base treatment of P3-SWNT with 0.05 M NaOH reduces the CCs and makes it hydrophobic (P33-SWNT). Pt catalyst supported on the P3-SWNT possesses enhanced MOR whereas that supported on P33-SWNT not only enhances ORR kinetics but also possess good tolerance towards methanol oxidation as verified by the electrochemical technique.

Regulation of the Adrenal Cortex Function During Stress

NASA Technical Reports Server (NTRS)

Soliman, K. F. A.

1978-01-01

A proposal to study the function of the adrenal gland in the rat during stress is presented. In the proposed project, three different phases of experimentation will be undertaken. The first phase includes establishment of the circadian rhythm of both brain amines and glucocoticoids, under normal conditions and under chronic and acute stressful conditions. The second phase includes the study of the pharmacokinetics of glucocorticoid binding under normal and stress conditions. The third phase includes brain uptake and binding under different experimental conditions. In the outlined experiments brain biogenic amines will be evaluated, adrenal functions will be measured and stress effect on those parameters will be studied. It is hoped that this investigation can explain some of the complex relationships between the brain neurotransmitter and adrenal function.

An interspecies comparison of mercury inhibition on muscarinic acetylcholine receptor binding in the cerebral cortex and cerebellum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Basu, Niladri; Department of Natural Resource Sciences, McGill University, Ste.-Anne-de-Bellevue, Quebec, H9X 3V9; Stamler, Christopher J.

2005-05-15

Mercury (Hg) is a ubiquitous pollutant that can disrupt neurochemical signaling pathways in mammals. It is well documented that inorganic Hg (HgCl{sub 2}) and methyl Hg (MeHg) can inhibit the binding of radioligands to the muscarinic acetylcholine (mACh) receptor in rat brains. However, little is known concerning this relationship in specific anatomical regions of the brain or in other species, including humans. The purpose of this study was to explore the inhibitory effects of HgCl{sub 2} and MeHg on [{sup 3}H]-quinuclidinyl benzilate ([{sup 3}H]-QNB) binding to the mACh receptor in the cerebellum and cerebral cortex regions from human, rat, mouse,more » mink, and river otter brain tissues. Saturation binding curves were obtained from each sample to calculate receptor density (B {sub max}) and ligand affinity (K {sub d}). Subsequently, samples were exposed to HgCl{sub 2} or MeHg to derive IC50 values and inhibition constants (K {sub i}). Results demonstrate that HgCl{sub 2} is a more potent inhibitor of mACh receptor binding than MeHg, and the receptors in the cerebellum are more sensitive to Hg-mediated mACh receptor inhibition than those in the cerebral cortex. Species sensitivities, irrespective of Hg type and brain region, can be ranked from most to least sensitive: river otter > rat > mink > mouse > humans. In summary, our data demonstrate that Hg can inhibit the binding [{sup 3}H]-QNB to the mACh receptor in a range of mammalian species. This comparative study provides data on interspecies differences and a framework for interpreting results from human, murine, and wildlife studies.« less

Sleep Deprivation Decreases [11C]Raclopride’s Binding to Dopamine D2/D3 Receptors in the Human Brain

PubMed Central

Volkow, Nora D.; Wang, Gene-Jack; Telang, Frank; Fowler, Joanna S.; Logan, Jean; Wong, Christopher; Ma, Jim; Pradhan, Kith; Tomasi, Dardo; Thanos, Peter K.; Ferré, Sergi; Jayne, Millard

2009-01-01

Sleep deprivation can markedly impair human performance contributing to accidents and poor productivity. The mechanisms underlying this impairment are not well understood but brain dopamine systems have been implicated. Here we test whether one night of sleep deprivation changes dopamine brain activity. We studied fifteen healthy subjects using positron emission tomography and [11C]raclopride (dopamine D2/3 receptor radioligand) and [11C]cocaine (dopamine transporter radioligand). Subjects were tested twice; after one night of rested sleep and after on night of sleep deprivation. [11C]Raclopride’s specific binding in striatum and thalamus were significantly reduced after sleep deprivation and the magnitude of this reduction correlated with increases in fatigue (tiredness and sleepiness) and with deterioration in cognitive performance (visual attention and working memory). In contrast sleep deprivation did not affect the specific binding of [11C]cocaine in striatum. Since [11C]raclopride competes with endogenous dopamine for binding to D2/D3 receptors, we interpret the decreases in binding to reflect dopamine increases with sleep deprivation. However, we can not rule out the possibility that decreased [11C]raclopride binding reflects decreases in receptor levels or affinity. Sleep deprivation did not affect dopamine transporters (target for most wake-promoting medications) and thus dopamine increases are likely to reflect increases in dopamine cell firing and/or release rather than decreases in dopamine reuptake. Inasmuch as dopamine-enhancing drugs increase wakefulness we postulate that dopamine increases after sleep deprivation is a mechanism by which the brain maintains arousal as the drive to sleep increases but one that is insufficient to counteract behavioral and cognitive impairment. PMID:18716203

Hyaluronate-binding proteins of murine brain.

PubMed

Marks, M S; Chi-Rosso, G; Toole, B P

1990-01-01

The distribution of hyaluronate-binding activity was determined in the soluble and membrane fractions derived from adult mouse brain by sonication in low-ionic-strength buffer. Approximately 60% of the total activity was recovered in the soluble fraction and 33% in membrane fractions. In both cases, the hyaluronate-binding activities were found to be of high affinity (KD = 10(-9) M), specific for hyaluronate, and glycoprotein in nature. Most of the hyaluronate-binding activity from the soluble fraction chromatographed in the void volume of Sepharose CL-4B and CL-6B. Approximately 50% of this activity was highly negatively charged, eluting from diethylaminoethyl (DEAE)-cellulose in 0.5 M NaCl, and contained chondroitin sulfate chains. This latter material also reacted with antibodies raised against cartilage link protein and the core protein of cartilage proteoglycan. Thus, the binding and physical characteristics of this hyaluronate-binding activity are consistent with those of a chondroitin sulfate proteoglycan aggregate similar to that found in cartilage. A 500-fold purification of this proteoglycan-like, hyaluronate-binding material was achieved by wheat germ agglutinin affinity chromatography, molecular sieve chromatography on Sepharose CL-6B, and ion exchange chromatography on DEAE-cellulose. Another class of hyaluronate-binding material (25-50% of that recovered) eluted from DEAE with 0.24 M NaCl; this material had the properties of a complex glycoprotein, did not contain chondroitin sulfate, and did not react with the antibodies against cartilage link protein and proteoglycan. Thus, adult mouse brain contains at least three different forms of hyaluronate-binding macromolecules. Two of these have properties similar to the link protein and proteoglycan of cartilage proteoglycan aggregates; the third is distinguishable from these entities.

Heterogeneity of binding of muscarinic receptor antagonists in rat brain homogenates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, J.H.; el-Fakahany, E.E.

1985-06-01

The binding properties of (-)-(/sup 3/H)quinuclidinyl benzilate and (/sup 3/H) N-methylscopolamine to muscarinic acetylcholine receptors have been investigated in rat brain homogenates. The binding of both antagonists demonstrated high affinity and saturability. Analysis of the binding data resulted in linear Scatchard plots. However, (-)-(/sup 3/H)quinuclidinyl benzilate showed a significantly higher maximal binding capacity than that of (/sup 3/H)N-methylscopolamine. Displacement of both ligands with several muscarinic receptor antagonists resulted in competition curves in accordance with the law of mass-action for quinuclidinyl benzilate, atropine and scopolamine. A similar profile was found for the quaternary ammonium analogs of atropine and scopolamine when (/supmore » 3/H)N-methylscopolamine was used to label the receptors. However, when these hydrophilic antagonists were used to displace (-)-(/sup 3/H) quinuclidinyl benzilate binding, they showed interaction with high- and low-affinity binding sites. On the other hand, the nonclassical muscarinic receptor antagonist, pirenzepine, was able to displace both ligands from two binding sites. The present data are discussed in terms of the relationship of this anomalous heterogenity of binding of these hydrophilic muscarinic receptor antagonists and the proposed M1 and M2 receptor subtypes.« less

Batrachotoxin Changes the Properties of the Muscarinic Receptor in Rat Brain and Heart: Possible Interaction(s) between Muscarinic Receptors and Sodium Channels

NASA Astrophysics Data System (ADS)

Cohen-Armon, Malca; Kloog, Yoel; Henis, Yoav I.; Sokolovsky, Mordechai

1985-05-01

The effects of Na+-channel activator batrachotoxin (BTX) on the binding properties of muscarinic receptors in homogenates of rat brain and heart were studied. BTX enhanced the affinity for the binding of the agonists carbamoylcholine and acetylcholine to the muscarinic receptors in brainstem and ventricle, but not in the cerebral cortex. Analysis of the data according to a two-site model for agonist binding indicated that the effect of BTX was to increase the affinity of the agonists to the high-affinity site. Guanyl nucleotides, known to induce interconversion of high-affinity agonist binding sites to the low-affinity state, canceled the effect of BTX on carbamoylcholine and acetylcholine binding. BTX had no effect on the binding of the agonist oxotremorine or on the binding of the antagonist [3H]-N-methyl-4-piperidyl benzilate. The local anesthetics dibucaine and tetracaine antagonized the effect of BTX on the binding of muscarinic agonists at concentrations known to inhibit the activation of Na+ channels by BTX. On the basis of these findings, we propose that in specific tissues the muscarinic receptors may interact with the BTX binding site (Na+ channels).

Imaging of VMAT2 binding sites in the brain by (18)F-AV-133: the effect of a pseudo-carrier.

PubMed

Zhu, Lin; Qiao, Hongwen; Lieberman, Brian P; Wu, Jingxiao; Liu, Yajing; Pan, Zhongyun; Ploessl, Karl; Choi, Seok Rye; Chan, Piu; Kung, Hank F

2012-10-01

Recently, 9-[(18)F]fluoropropyl-(+)-dihydrotetrabenazine ((18)F-AV-133) was reported as a new vesicular monoamine transporter (VMAT2) imaging agent for diagnosis of Parkinson's disease (PD). To shorten the preparation of (18)F-AV-133 and to make it more widely available, we evaluated a simple, rapid purification with a solid-phase extraction method (SPE) using an Oasis HLB cartridge instead of high pressure liquid chromatography (HPLC). The SPE method produced doses containing a pseudo-carrier, 9-hydroxypropyl-(+)-dihydrotetrabenazine (AV-149). To test the possible side effects of this pseudo-carrier, comparative dynamic PET scans of the brains of normal monkeys (2 each) and uni-laterally 6-OH-dopamine-lesioned PD monkeys (2 each) were performed using (18)F-AV-133 doses prepared by either SPE (containing pseudo-carrier) or HPLC (containing no pseudo-carrier). Autoradiographs of post mortem monkey brain sections were evaluated to confirm the relative (18)F-AV-133 uptake in the PD monkey brains and the effects of the pseudo-carrier on VMAT2 binding. The radiochemical purity of the (18)F-AV-133, whether prepared by SPE or by HPLC, was excellent (>99%). PET scans of normal and PD monkey brains showed an expected reduction of VMAT2 in the lesioned areas of the striatum. It was not affected by the presence of the pseudo-carrier, AV-149 (maximally 250 μg/dose). The reduced uptake in the striatum of the lesioned monkey brains was confirmed by autoradiography. Ex vivo inhibition studies of (18)F-AV-133 binding in rat brains, conducted with increasing amounts of AV-149, suggested that at the highest concentration (3.5mg/kg) the VMAT2 binding in the striatum was only moderately blocked (20% reduction). The pseudo-carrier, AV-149, did not affect the (18)F-AV-133/PET imaging of VMAT2 binding sites in normal or uni-laterally lesioned monkey brains. The new streamlined SPE purification method will enable (18)F-AV-133 to be widely available for routine clinical application in determining changes in monoamine neurons for patient with movement disorders or other psychiatric illnesses. Copyright © 2012 Elsevier Inc. All rights reserved.

The Relevance of AgRP Neuron-Derived GABA Inputs to POMC Neurons Differs for Spontaneous and Evoked Release

PubMed Central

2017-01-01

Hypothalamic agouti-related peptide (AgRP) neurons potently stimulate food intake, whereas proopiomelanocortin (POMC) neurons inhibit feeding. Whether AgRP neurons exert their orexigenic actions, at least in part, by inhibiting anorexigenic POMC neurons remains unclear. Here, the connectivity between GABA-releasing AgRP neurons and POMC neurons was examined in brain slices from male and female mice. GABA-mediated spontaneous IPSCs (sIPSCs) in POMC neurons were unaffected by disturbing GABA release from AgRP neurons either by cell type-specific deletion of the vesicular GABA transporter or by expression of botulinum toxin in AgRP neurons to prevent vesicle-associated membrane protein 2-dependent vesicle fusion. Additionally, there was no difference in the ability of μ-opioid receptor (MOR) agonists to inhibit sIPSCs in POMC neurons when MORs were deleted from AgRP neurons, and activation of the inhibitory designer receptor hM4Di on AgRP neurons did not affect sIPSCs recorded from POMC neurons. These approaches collectively indicate that AgRP neurons do not significantly contribute to the strong spontaneous GABA input to POMC neurons. Despite these observations, optogenetic stimulation of AgRP neurons reliably produced evoked IPSCs in POMC neurons, leading to the inhibition of POMC neuron firing. Thus, AgRP neurons can potently affect POMC neuron function without contributing a significant source of spontaneous GABA input to POMC neurons. Together, these results indicate that the relevance of GABAergic inputs from AgRP to POMC neurons is state dependent and highlight the need to consider different types of transmitter release in circuit mapping and physiologic regulation. SIGNIFICANCE STATEMENT Agouti-related peptide (AgRP) neurons play an important role in driving food intake, while proopiomelanocortin (POMC) neurons inhibit feeding. Despite the importance of these two well characterized neuron types in maintaining metabolic homeostasis, communication between these cells remains poorly understood. To provide clarity to this circuit, we made electrophysiological recordings from mouse brain slices and found that AgRP neurons do not contribute spontaneously released GABA onto POMC neurons, although when activated with channelrhodopsin AgRP neurons inhibit POMC neurons through GABA-mediated transmission. These findings indicate that the relevance of AgRP to POMC neuron GABA connectivity depends on the state of AgRP neuron activity and suggest that different types of transmitter release should be considered when circuit mapping. PMID:28667175

The Relevance of AgRP Neuron-Derived GABA Inputs to POMC Neurons Differs for Spontaneous and Evoked Release.

PubMed

Rau, Andrew R; Hentges, Shane T

2017-08-02

Hypothalamic agouti-related peptide (AgRP) neurons potently stimulate food intake, whereas proopiomelanocortin (POMC) neurons inhibit feeding. Whether AgRP neurons exert their orexigenic actions, at least in part, by inhibiting anorexigenic POMC neurons remains unclear. Here, the connectivity between GABA-releasing AgRP neurons and POMC neurons was examined in brain slices from male and female mice. GABA-mediated spontaneous IPSCs (sIPSCs) in POMC neurons were unaffected by disturbing GABA release from AgRP neurons either by cell type-specific deletion of the vesicular GABA transporter or by expression of botulinum toxin in AgRP neurons to prevent vesicle-associated membrane protein 2-dependent vesicle fusion. Additionally, there was no difference in the ability of μ-opioid receptor (MOR) agonists to inhibit sIPSCs in POMC neurons when MORs were deleted from AgRP neurons, and activation of the inhibitory designer receptor hM4Di on AgRP neurons did not affect sIPSCs recorded from POMC neurons. These approaches collectively indicate that AgRP neurons do not significantly contribute to the strong spontaneous GABA input to POMC neurons. Despite these observations, optogenetic stimulation of AgRP neurons reliably produced evoked IPSCs in POMC neurons, leading to the inhibition of POMC neuron firing. Thus, AgRP neurons can potently affect POMC neuron function without contributing a significant source of spontaneous GABA input to POMC neurons. Together, these results indicate that the relevance of GABAergic inputs from AgRP to POMC neurons is state dependent and highlight the need to consider different types of transmitter release in circuit mapping and physiologic regulation. SIGNIFICANCE STATEMENT Agouti-related peptide (AgRP) neurons play an important role in driving food intake, while proopiomelanocortin (POMC) neurons inhibit feeding. Despite the importance of these two well characterized neuron types in maintaining metabolic homeostasis, communication between these cells remains poorly understood. To provide clarity to this circuit, we made electrophysiological recordings from mouse brain slices and found that AgRP neurons do not contribute spontaneously released GABA onto POMC neurons, although when activated with channelrhodopsin AgRP neurons inhibit POMC neurons through GABA-mediated transmission. These findings indicate that the relevance of AgRP to POMC neuron GABA connectivity depends on the state of AgRP neuron activity and suggest that different types of transmitter release should be considered when circuit mapping. Copyright © 2017 the authors 0270-6474/17/377362-11$15.00/0.

Characterization of nicotine binding in mouse brain and comparison with the binding of alpha-bungarotoxin and quinuclidinyl benzilate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marks, M.J.; Collins, A.C.

1982-11-01

The binding of (/sup 3/H)nicotine to mouse brain has been measured and subsequently compared with the binding of (/sup 125/I)alpha-bungarotoxin (alpha-BTX) and L-(/sup 3/H)quinuclidinyl benzilate (QNB). The binding of nicotine was saturable, reversible, and stereospecific. The average KD and Bmax were 59 nM and 88 fmoles/mg of protein, respectively. Although the rates of association and dissociation of nicotine were temperature-dependent, the incubation temperature had no effect on either KD or Bmax. When measured at 20 degrees or 37 degrees, nicotine appeared to bind to a single class of binding sites, but a second, very low-affinity, binding site was observed atmore » 4 degrees. Nicotine binding was unaffected by the addition of NaCl, KCl, CaCl/sub 2/, or MgSO/sub 4/ to the incubation medium. Nicotinic cholinergic agonists were potent inhibitors of nicotine binding; however, nicotinic antagonists were poor inhibitors. The regional distribution of binding was not uniform: midbrain and striatum contained the highest number of receptors, whereas cerebellum had the fewest. Differences in site densities, regional distribution, inhibitor potencies, and thermal denaturation indicated that nicotine binding was not the same as either QNB or alpha-BTX binding, and therefore that receptors for nicotine may represent a unique population of cholinergic receptors.« less

LRP-mediated clearance of Abeta is inhibited by KPI-containing isoforms of APP.

PubMed

Moir, Robert D; Tanzi, Rudolph E

2005-04-01

The pathogenesis of Alzheimer's disease (AD) involves the abnormal accumulation and deposition of beta-amyloid in cerebral blood vessels and in the brain parenchyma. Critical in modulating beta-amyloid deposition in brain is the flux of Abeta across the blood brain barrier. The low-density lipoprotein receptor-related protein (LRP), is a large endocytic receptor that mediates the efflux of Abeta out of brain and into the periphery. The first step in the LRP-mediated clearance of Abeta involves the formation of a complex between Abeta and the LRP ligands apolipoprotein E (apoE) or alpha(2)-macroglobulin (alpha(2)M). The Abeta/chaperone complexes then bind to LRP via binding sites on apoE or alpha(2)M. The efflux of Abeta/chaperone complexes out of the neuropil and into the periphery may be attenuated by LRP-ligands that compete with apoE or alpha(2)M for LRP binding. LRP is also the cell surface receptor for Kunitz Protease Inhibitor (KPI) containing isoforms of Abeta's parent protein, the amyloid protein precursor (APP). Protein and mRNA levels of KPI-containing APP isoforms (APP-KPI) are elevated in AD brain and are associated with increased Abeta production. In this study we show that soluble non-amyloidogenic APP-KPI can also inhibit the uptake of Abeta/alpha(2)M in a cell culture model of LRP mediated Abeta clearance. Clearance of Abeta/apoE complexes was not inhibited by APP-KPI. Our findings are consistent with studies showing that apoE and alpha(2)M have discrete binding sites on LRP. Most significantly, our data suggests that the elevated levels of APP-KPI in AD brain may attenuate the clearance of Abeta, the proteins own amyloidogenic catabolic product.

Fluorophilia: Fluorophore-containing compounds adhere non-specifically to injured neurons

PubMed Central

Hawkins, Bridget E.; Frederickson, Christopher J.; DeWitt, Douglas S.; Prough, Donald S.

2012-01-01

Ionic (free) zinc (Zn2+) is implicated in apoptotic neuronal degeneration and death. In our attempt to examine the effects of Zn2+ in neurodegeneration following brain injury, we serendipitously discovered that injured neurons bind fluorescein moieties, either alone or as part of an indicator dye, in histologic sections. This phenomenon, that we have termed “fluorophilia”, is analogous to the ability of degenerating neuronal somata and axons to bind silver ions (argyrophilia — the basis of silver degeneration stains). To provide evidence that fluorophilia occurs in sections of brain tissue, we used a wide variety of indicators such as Fluoro-Jade (FJ), a slightly modified fluorescein sold as a marker for degenerating neurons; Newport Green, a fluorescein-containing Zn2+ probe; Rhod-5N, a rhodamine-containing Ca2+ probe; and plain fluorescein. All yielded remarkably similar staining of degenerating neurons in the traumatic brain-injured tissue with the absence of staining in our sham-injured brains. Staining of presumptive injured neurons by these agents was not modified when Zn2+ in the brain section was removed by prior chelation with EDTA or TPEN, whereas staining by a non-fluorescein containing Zn2+ probe, N-(6-methoxy-8-quinolyl)-p-toluenesulfonamide (TSQ), was suppressed by prior chelation. Thus, certain fluorophore-containing compounds nonspecifically stain degenerating neuronal tissue in histologic sections and may not reflect the presence of Zn2+. This may be of concern to researchers using indicator dyes to detect metals in brain tissue sections. Further experiments may be advised to clarify whether Zn2+-binding dyes bind more specifically in intact neurons in culture or organotypic slices. PMID:22137653

Sparteine monooxygenase in brain and liver: Identified by the dopamine uptake blocker ( sup 3 H)GBR-12935

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kalow, W.; Tyndale, R.F.; Niznik, H.B.

1990-02-26

P450IID6 (human sparteine monooxygenase) metabolizes many drugs including neuroleptics, antidepressants, and beta-blockers. The P450IID6 exists in human, bovine, rat and canine brains, but in very low quantities causing methodological difficulties in its assessment. Work with ({sup 3}H)GBR-12935; 1-(2-(diphenylmethoxy) ethyl)-4-(3-phenyl propyl) piperazine has shown that it binds a neuronal/hepatic protein with high affinity ({approximately}7nM) and a rank order of inhibitory potency suggesting that the binding protein is cytochrome P450IID6. The binding was used to predict that d-amphetamine and methamphetamine would interact with P450IID6. Inhibition studies indicated that these compounds were competitive inhibitors of P450IID6. Haloperidol (HAL) and it's metabolite hydroxy-haloperidol (RHAL)more » are both competitive inhibitors of P450IID6 activity and were found to inhibit ({sup 3}H)GBR-12935 binding. K{sub i} values of twelve compounds (known to interact with the DA transporter or P450IID6) for ({sup 3}H)GRB-12935 binding and P450IID6 activity. The techniques are now available for measurements of cytochrome P450IID6 in healthy and diseased brain/liver tissue using radio-receptor binding assay techniques with ({sup 3}H)GBR-12935.« less

A rapid solution-based method for determining the affinity of heroin hapten-induced antibodies to heroin, its metabolites, and other opioids.

PubMed

Torres, Oscar B; Duval, Alexander J; Sulima, Agnieszka; Antoline, Joshua F G; Jacobson, Arthur E; Rice, Kenner C; Alving, Carl R; Matyas, Gary R

2018-06-01

We describe for the first time a method that utilizes microscale thermophoresis (MST) technology to determine polyclonal antibody affinities to small molecules. Using a novel type of heterologous MST, we have accurately measured a solution-based binding affinity of serum antibodies to heroin which was previously impossible with other currently available methods. Moreover, this mismatch approach (i.e., using a cross-reactive hapten tracer) has never been reported in the literature. When compared with equilibrium dialysis combined with ultra-performance liquid chromatography/tandem mass spectrometry (ED-UPLC/MS/MS), this novel MST method yields similar binding affinity values for polyclonal antibodies to the major heroin metabolites 6-AM and morphine. Additionally, we herein report the method of synthesis of this novel cross-reactive hapten, MorHap-acetamide-a useful analog for the study of heroin hapten-antibody interactions. Using heterologous MST, we were able to determine the affinities, down to nanomolar accuracies, of polyclonal antibodies to various abused opioids. While optimizing this method, we further discovered that heroin is protected from serum esterase degradation by the presence of these antibodies in a concentration-dependent manner. Lastly, using affinity data for a number of structurally different opioids, we were able to dissect the moieties that are crucial to antibody binding. The novel MST method that is presented herein can be extended to the analysis of any ligand that is prone to degradation and can be applied not only to the development of vaccines to substances of abuse but also to the analysis of small molecule/protein interactions in the presence of serum. Graphical abstract Strategy for the determination of hapten-induced antibody affinities using Microscale thermophoresis.

Micromolar-Affinity Benzodiazepine Receptors Regulate Voltage-Sensitive Calcium Channels in Nerve Terminal Preparations

NASA Astrophysics Data System (ADS)

Taft, William C.; Delorenzo, Robert J.

1984-05-01

Benzodiazepines in micromolar concentrations significantly inhibit depolarization-sensitive Ca2+ uptake in intact nerve-terminal preparations. Benzodiazepine inhibition of Ca2+ uptake is concentration dependent and stereospecific. Micromolar-affinity benzodiazepine receptors have been identified and characterized in brain membrane and shown to be distinct from nanomolar-affinity benzodiazepine receptors. Evidence is presented that micromolar, and not nanomolar, benzodiazepine binding sites mediate benzodiazepine inhibition of Ca2+ uptake. Irreversible binding to micromolar benzodiazepine binding sites also irreversibly blocked depolarization-dependent Ca2+ uptake in synaptosomes, indicating that these compounds may represent a useful marker for identifying the molecular components of Ca2+ channels in brain. Characterization of benzodiazepine inhibition of Ca2+ uptake demonstrates that these drugs function as Ca2+ channel antagonists, because benzodiazepines effectively blocked voltage-sensitive Ca2+ uptake inhibited by Mn2+, Co2+, verapamil, nitrendipine, and nimodipine. These results indicate that micromolar benzodiazepine binding sites regulate voltage-sensitive Ca2+ channels in brain membrane and suggest that some of the neuronal stabilizing effects of micromolar benzodiazepine receptors may be mediated by the regulation of Ca2+ conductance.

Micromolar-affinity benzodiazepine receptors regulate voltage-sensitive calcium channels in nerve terminal preparations.

PubMed Central

Taft, W C; DeLorenzo, R J

1984-01-01

Benzodiazepines in micromolar concentrations significantly inhibit depolarization-sensitive Ca2+ uptake in intact nerve-terminal preparations. Benzodiazepine inhibition of Ca2+ uptake is concentration dependent and stereospecific. Micromolar-affinity benzodiazepine receptors have been identified and characterized in brain membrane and shown to be distinct from nanomolar-affinity benzodiazepine receptors. Evidence is presented that micromolar, and not nanomolar, benzodiazepine binding sites mediate benzodiazepine inhibition of Ca2+ uptake. Irreversible binding to micromolar benzodiazepine binding sites also irreversibly blocked depolarization-dependent Ca2+ uptake in synaptosomes, indicating that these compounds may represent a useful marker for identifying the molecular components of Ca2+ channels in brain. Characterization of benzodiazepine inhibition of Ca2+ uptake demonstrates that these drugs function as Ca2+ channel antagonists, because benzodiazepines effectively blocked voltage-sensitive Ca2+ uptake inhibited by Mn2+, Co2+, verapamil, nitrendipine, and nimodipine. These results indicate that micromolar benzodiazepine binding sites regulate voltage-sensitive Ca2+ channels in brain membrane and suggest that some of the neuronal stabilizing effects of micromolar benzodiazepine receptors may be mediated by the regulation of Ca2+ conductance. PMID:6328498