The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
P. L. Morselli - One of the best experts on this subject based on the ideXlab platform.
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Alpidem lack of sedative effect on psychomotor performance in therapeutic doses
Human Psychopharmacology-clinical and Experimental, 1993Co-Authors: P Rosenzweig, S Warrington, A Patat, V Ascalone, L Bergougnan, P. L. MorselliAbstract:This is a randomised, double blind, cross-over, placebo-controlled study carried out in 12 healthy young male volunteers. It consisted of six test days separated by two week wash-out periods. The objective was to compare the potential sedative effects of 3 single oral doses of Alpidem (50 mg, 100 mg and 200 mg) versus diazepam (10 mg and 15 mg). Pharmacodynamics were assessed by objective psychometric tests (critical flicker fusion, choice-reaction time, manual dexterity, digit span) and subjective evaluation (visual analogue scales) before then 2 h, 4 h, 8 h and 24 h post-dose. Alpidem in dosages of 50 mg and 100 mg did not impair alertness or psychomotor performance; with 200 mg, psychometric tests and visual analogue scales demonstrated sedative effects 2 h post-dose. In contrast, diazepam in a therapeutic dosage (10 and 15 mg) produced similar impairments of vigilance and psychomotor performance as Alpidem 200 mg, indicating a lack of dissociation between anxiolytic and sedative effects.
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effects of Alpidem in anxious elderly outpatients a double blind placebo controlled trial
Clinical Neuropharmacology, 1992Co-Authors: L Frattola, P Priore, R Piolti, S Bassi, M G Albizzati, C Borghi, B M Cesana, M S Bottani, P. L. MorselliAbstract:The efficacy and safety of Alpidem, a new anxiolytic imidazopyridine, were compared with those of placebo in anxious elderly patients (65-80 years) by means of a randomized, double-blind, parallel group study. Following a 7-day "placebo run-in," 40 anxious patients were randomized to receive either Alpidem or placebo. Daily doses ranging from 75 to 150 mg (25-50 mg t.i.d.) were administered for 3 weeks. Hamilton Rating Scale for Anxiety (HRSA), State Trait Anxiety Inventory (STAI-X1), Visual Analogue Scale (VAS), and Clinical Global Impression (CGI) were used on days 0, 3, 7, 14, and 21 for assessing efficacy. Psychomotor and mnesic performances were evaluated at the same time by means of the Digit Symbol Substitution Test (DSST), the Grunberger's test for fine motor coordination, and the Hawie's test for immediate memory. Possible adverse events were also recorded during the five visits. The anxiolytic efficacy of Alpidem was significantly (p < 0.01) superior to that of placebo in all the rating scales adopted. The anxiolytic action was clearly evident from day 7. For most of the patients the active dose was 25 mg t.i.d. No relevant adverse effects were observed in both groups. No impairment of psychomotor and mnesic performances could be observed in the Alpidem group. Alpidem is a new interesting anxiolytic drug for anxious elderly patients because it appears remarkably safe and, at effective doses, it does not impair psychomotor performances and cognitive functions.
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Comparative pharmacokinetic profile of two imidazopyridine drugs: zolpidem and Alpidem.
Drug Metabolism Reviews, 1992Co-Authors: A. Durand, J P Thénot, G. Bianchetti, P. L. MorselliAbstract:(1992). Comparative Pharmacokinetic Profile of Two Imidazopyridine Drugs: Zolpidem and Alpidem. Drug Metabolism Reviews: Vol. 24, No. 2, pp. 239-266.
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the disposition and pharmacokinetics of Alpidem a new anxiolytic in the rat
Drug Metabolism and Disposition, 1991Co-Authors: D Garrigougadenne, A. Durand, J P Thénot, P. L. MorselliAbstract:The autoradiographic distribution, disposition, biliary excretion, and pharmacokinetics of Alpidem in Sprague-Dawley rats were evaluated after iv or oral administration. Following i.v. administration, autoradiography showed that radioactivity was preferentially localized in lipid-rich tissues including central nervous system structures. After a 3-mg.kg-1 i.v. or oral dose of [14C]Alpidem, more than 80% of the radioactivity were excreted in the feces over a 6-day period. Biliary excretion of radioactivity in vigile rats, about 74% of the dose over a 7-hr period after either iv or oral administration, showed that Alpidem was well absorbed. The absolute bioavailability (13%) data indicated a high first-pass effect. Plasma pharmacokinetic parameters of Alpidem were as follows: Vd = 5 liter.kg-1, Cl = 2.2 liter.h-1.kg-1, and terminal t 1/2 beta = 1.2-1.7 hr. Three metabolites with a pharmacological activity similar to that of Alpidem were detected in plasma. They were eliminated from the central compartment with half-lives comparable to that of the parent drug. Alpidem crossed the blood-brain barrier following either i.v. or oral administration, resulting in cerebral levels 2.5 to 4 times greater than the plasma levels. Alpidem was eliminated from the central nervous system according a biphasic process with a t 1/2 alpha comparable in plasma and brain. Alpidem represented 94 and 63% of cerebral radioactivity 5 min after i.v. and oral administration, respectively. Two out of the three active plasma metabolites were detected in the brain.
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clinical pharmacokinetics and tolerability of Alpidem in healthy subjects given increasing single doses
European Journal of Clinical Pharmacology, 1991Co-Authors: J H G Jonkman, J P Thénot, G. Bianchetti, G Grasmeijer, B Oosterhuis, J F Thiercelin, Ph Guillet, P. L. MorselliAbstract:In a double-blind, placebo-controlled, crossover experiment in 21 healthy male volunteers, aged 19 to 27 y, the pharmacokinetics and tolerance of the new anxiolytic drug Alpidem (SL80.0342) and its three major metabolites were studied after single doses of 25, 50, 100 and 200 mg. Plasma concentrations of Alpidem (in 20 subjects) and metabolites (in 6 subjects) were measured by HPLC over a period of 54 h after dosing.
Philip F Vonvoigtlander - One of the best experts on this subject based on the ideXlab platform.
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potentiation of gamma aminobutyric acid induced chloride currents by various benzodiazepine site agonists with the alpha 1 gamma 2 beta 2 gamma 2 and alpha 1 beta 2 gamma 2 subtypes of cloned gamma aminobutyric acid type a receptors
Molecular Pharmacology, 1993Co-Authors: H K Im, Wha Bin Im, B J Hamilton, Donald B Carter, Philip F VonvoigtlanderAbstract:Previous studies with cloned gamma-aminobutyric acid type A receptors expressed in human embryonic kidney cells have indicated that the alpha 1 beta 2 gamma 2 and alpha 1 gamma 2 (but not alpha 1 beta 2) subtypes have benzodiazepine sites. We found in this study that even the beta 2 gamma 2 subtype displays gamma-aminobutyric acid-induced Cl- currents that are potentiated by triazolam (a triazolobenzodiazepine). The maximal efficacy of the drug among the subtypes was highest with the alpha 1 beta 2 gamma 2 subtype, followed by the alpha 1 gamma 2 and beta 2 gamma 2 subtypes. These observations led us to compare the ability of several benzodiazepine site agonists of diverse chemical structures to potentiate Cl- currents with these subtypes. With the alpha 1 gamma 2 subtype, diazepam, Alpidem, zolpidem, Cl-218872, zopiclone, U-79098 (an imidazoquinoxaline derivative), and U-90167 (a diimidazoquinazoline derivative) at 5 microM potentiated Cl- currents to essentially similar levels (slightly lower for a few ligands), compared with those with the alpha 1 beta 2 gamma 2 subtype. With the beta 2 gamma 2 subtype, the type 1 ligands zolpidem, Alpidem, and Cl-218872 showed no or very low levels of potentiation, whereas less selective ligands such as diazepam, zopiclone, U-78098, and U-90167 displayed levels of Cl- current potentiation comparable to those observed with the subtypes containing the alpha 1 and gamma 2 subunits. These data indicate that, in the presence of gamma 2, beta 2 may substitute for alpha 1 in forming the benzodiazepine site of limited sensitivity to the type 1 ligands. It appears that individual ligands for benzodiazepine sites have their own sets of interacting domains, which are distributed in alpha 1 and gamma 2, and the agonistic activity of type 1 ligands may be more dependent on the alpha 1-specific domains than is that of less selective ligands.
Hansrudolf Wenk - One of the best experts on this subject based on the ideXlab platform.
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Phillipsite and Al-tobermorite mineral cements produced through low-temperature water-rock reactions in Roman marine concrete
American Mineralogist, 2017Co-Authors: Marie D Jackson, Sean R Mulcahy, Heng Chen, Piergiulio Cappelletti, Hansrudolf WenkAbstract:Author(s): Jackson, MD; Mulcahy, SR; Chen, H; Li, Y; Li, Q; Cappelletti, P; Wenk, HR | Abstract: © 2017 by Walter de Gruyter Berlin/Boston. Pozzolanic reaction of volcanic ash with hydrated lime is thought to dominate the cementing fabric and durability of 2000-year-old Roman harbor concrete. Pliny the Elder, however, in first century CE emphasized rock-like cementitious processes involving volcanic ash (pulvis) "that as soon as it comes into contact with the waves of the sea and is submerged becomes a single stone mass (fierem unum lapidem), impregnable to the waves and every day stronger" (Naturalis Historia 35.166). Pozzolanic crystallization of Al-tobermorite, a rare, hydrothermal, calcium-silicate-hydrate mineral with cation exchange capabilities, has been previously recognized in relict lime clasts of the concrete. Synchrotron-based X-ray microdiffraction maps of cementitious microstructures in Baianus Sinus and Portus Neronis submarine breakwaters and a Portus Cosanus subaerial pier now reveal that Al-tobermorite also occurs in the leached perimeters of feldspar fragments, zeolitized pumice vesicles, and in situ phillipsite fabrics in relict pores. Production of alkaline pore fluids through dissolution-precipitation, cation-exchange and/or carbonation reactions with Campi Flegrei ash components, similar to processes in altered trachytic and basaltic tuffs, created multiple pathways to post-pozzolanic phillipsite and Al-tobermorite crystallization at ambient seawater and surface temperatures. Long-term chemical resilience of the concrete evidently relied on water-rock interactions, as Pliny the Elder inferred. Raman spectroscopic analyses of Baianus Sinus Al-tobermorite in diverse microstructural environments indicate a cross-linked structure with Al3+ substitution for Si4+ in Q3 tetrahedral sites, and suggest coupled [Al3++Na+] substitution and potential for cation exchange. The mineral fabrics provide a geoarchaeological prototype for developing cementitious processes through low-temperature rock-fluid interactions, subsequent to an initial phase of reaction with lime that defines the activity of natural pozzolans. These processes have relevance to carbonation reactions in storage reservoirs for CO2 in pyroclastic rocks, production of alkali-activated mineral cements in maritime concretes, and regenerative cementitious resilience in waste encapsulations using natural volcanic pozzolans.
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phillipsite and al tobermorite mineral cements produced through low temperature water rock reactions in roman marine concrete
American Mineralogist, 2017Co-Authors: Marie D Jackson, Sean R Mulcahy, Heng Chen, Yao Li, Qinfei Li, Piergiulio Cappelletti, Hansrudolf WenkAbstract:Author(s): Jackson, MD; Mulcahy, SR; Chen, H; Li, Y; Li, Q; Cappelletti, P; Wenk, HR | Abstract: © 2017 by Walter de Gruyter Berlin/Boston. Pozzolanic reaction of volcanic ash with hydrated lime is thought to dominate the cementing fabric and durability of 2000-year-old Roman harbor concrete. Pliny the Elder, however, in first century CE emphasized rock-like cementitious processes involving volcanic ash (pulvis) "that as soon as it comes into contact with the waves of the sea and is submerged becomes a single stone mass (fierem unum lapidem), impregnable to the waves and every day stronger" (Naturalis Historia 35.166). Pozzolanic crystallization of Al-tobermorite, a rare, hydrothermal, calcium-silicate-hydrate mineral with cation exchange capabilities, has been previously recognized in relict lime clasts of the concrete. Synchrotron-based X-ray microdiffraction maps of cementitious microstructures in Baianus Sinus and Portus Neronis submarine breakwaters and a Portus Cosanus subaerial pier now reveal that Al-tobermorite also occurs in the leached perimeters of feldspar fragments, zeolitized pumice vesicles, and in situ phillipsite fabrics in relict pores. Production of alkaline pore fluids through dissolution-precipitation, cation-exchange and/or carbonation reactions with Campi Flegrei ash components, similar to processes in altered trachytic and basaltic tuffs, created multiple pathways to post-pozzolanic phillipsite and Al-tobermorite crystallization at ambient seawater and surface temperatures. Long-term chemical resilience of the concrete evidently relied on water-rock interactions, as Pliny the Elder inferred. Raman spectroscopic analyses of Baianus Sinus Al-tobermorite in diverse microstructural environments indicate a cross-linked structure with Al3+ substitution for Si4+ in Q3 tetrahedral sites, and suggest coupled [Al3++Na+] substitution and potential for cation exchange. The mineral fabrics provide a geoarchaeological prototype for developing cementitious processes through low-temperature rock-fluid interactions, subsequent to an initial phase of reaction with lime that defines the activity of natural pozzolans. These processes have relevance to carbonation reactions in storage reservoirs for CO2 in pyroclastic rocks, production of alkali-activated mineral cements in maritime concretes, and regenerative cementitious resilience in waste encapsulations using natural volcanic pozzolans.
H K Im - One of the best experts on this subject based on the ideXlab platform.
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potentiation of gamma aminobutyric acid induced chloride currents by various benzodiazepine site agonists with the alpha 1 gamma 2 beta 2 gamma 2 and alpha 1 beta 2 gamma 2 subtypes of cloned gamma aminobutyric acid type a receptors
Molecular Pharmacology, 1993Co-Authors: H K Im, Wha Bin Im, B J Hamilton, Donald B Carter, Philip F VonvoigtlanderAbstract:Previous studies with cloned gamma-aminobutyric acid type A receptors expressed in human embryonic kidney cells have indicated that the alpha 1 beta 2 gamma 2 and alpha 1 gamma 2 (but not alpha 1 beta 2) subtypes have benzodiazepine sites. We found in this study that even the beta 2 gamma 2 subtype displays gamma-aminobutyric acid-induced Cl- currents that are potentiated by triazolam (a triazolobenzodiazepine). The maximal efficacy of the drug among the subtypes was highest with the alpha 1 beta 2 gamma 2 subtype, followed by the alpha 1 gamma 2 and beta 2 gamma 2 subtypes. These observations led us to compare the ability of several benzodiazepine site agonists of diverse chemical structures to potentiate Cl- currents with these subtypes. With the alpha 1 gamma 2 subtype, diazepam, Alpidem, zolpidem, Cl-218872, zopiclone, U-79098 (an imidazoquinoxaline derivative), and U-90167 (a diimidazoquinazoline derivative) at 5 microM potentiated Cl- currents to essentially similar levels (slightly lower for a few ligands), compared with those with the alpha 1 beta 2 gamma 2 subtype. With the beta 2 gamma 2 subtype, the type 1 ligands zolpidem, Alpidem, and Cl-218872 showed no or very low levels of potentiation, whereas less selective ligands such as diazepam, zopiclone, U-78098, and U-90167 displayed levels of Cl- current potentiation comparable to those observed with the subtypes containing the alpha 1 and gamma 2 subunits. These data indicate that, in the presence of gamma 2, beta 2 may substitute for alpha 1 in forming the benzodiazepine site of limited sensitivity to the type 1 ligands. It appears that individual ligands for benzodiazepine sites have their own sets of interacting domains, which are distributed in alpha 1 and gamma 2, and the agonistic activity of type 1 ligands may be more dependent on the alpha 1-specific domains than is that of less selective ligands.
Marie D Jackson - One of the best experts on this subject based on the ideXlab platform.
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Phillipsite and Al-tobermorite mineral cements produced through low-temperature water-rock reactions in Roman marine concrete
American Mineralogist, 2017Co-Authors: Marie D Jackson, Sean R Mulcahy, Heng Chen, Piergiulio Cappelletti, Hansrudolf WenkAbstract:Author(s): Jackson, MD; Mulcahy, SR; Chen, H; Li, Y; Li, Q; Cappelletti, P; Wenk, HR | Abstract: © 2017 by Walter de Gruyter Berlin/Boston. Pozzolanic reaction of volcanic ash with hydrated lime is thought to dominate the cementing fabric and durability of 2000-year-old Roman harbor concrete. Pliny the Elder, however, in first century CE emphasized rock-like cementitious processes involving volcanic ash (pulvis) "that as soon as it comes into contact with the waves of the sea and is submerged becomes a single stone mass (fierem unum lapidem), impregnable to the waves and every day stronger" (Naturalis Historia 35.166). Pozzolanic crystallization of Al-tobermorite, a rare, hydrothermal, calcium-silicate-hydrate mineral with cation exchange capabilities, has been previously recognized in relict lime clasts of the concrete. Synchrotron-based X-ray microdiffraction maps of cementitious microstructures in Baianus Sinus and Portus Neronis submarine breakwaters and a Portus Cosanus subaerial pier now reveal that Al-tobermorite also occurs in the leached perimeters of feldspar fragments, zeolitized pumice vesicles, and in situ phillipsite fabrics in relict pores. Production of alkaline pore fluids through dissolution-precipitation, cation-exchange and/or carbonation reactions with Campi Flegrei ash components, similar to processes in altered trachytic and basaltic tuffs, created multiple pathways to post-pozzolanic phillipsite and Al-tobermorite crystallization at ambient seawater and surface temperatures. Long-term chemical resilience of the concrete evidently relied on water-rock interactions, as Pliny the Elder inferred. Raman spectroscopic analyses of Baianus Sinus Al-tobermorite in diverse microstructural environments indicate a cross-linked structure with Al3+ substitution for Si4+ in Q3 tetrahedral sites, and suggest coupled [Al3++Na+] substitution and potential for cation exchange. The mineral fabrics provide a geoarchaeological prototype for developing cementitious processes through low-temperature rock-fluid interactions, subsequent to an initial phase of reaction with lime that defines the activity of natural pozzolans. These processes have relevance to carbonation reactions in storage reservoirs for CO2 in pyroclastic rocks, production of alkali-activated mineral cements in maritime concretes, and regenerative cementitious resilience in waste encapsulations using natural volcanic pozzolans.
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phillipsite and al tobermorite mineral cements produced through low temperature water rock reactions in roman marine concrete
American Mineralogist, 2017Co-Authors: Marie D Jackson, Sean R Mulcahy, Heng Chen, Yao Li, Qinfei Li, Piergiulio Cappelletti, Hansrudolf WenkAbstract:Author(s): Jackson, MD; Mulcahy, SR; Chen, H; Li, Y; Li, Q; Cappelletti, P; Wenk, HR | Abstract: © 2017 by Walter de Gruyter Berlin/Boston. Pozzolanic reaction of volcanic ash with hydrated lime is thought to dominate the cementing fabric and durability of 2000-year-old Roman harbor concrete. Pliny the Elder, however, in first century CE emphasized rock-like cementitious processes involving volcanic ash (pulvis) "that as soon as it comes into contact with the waves of the sea and is submerged becomes a single stone mass (fierem unum lapidem), impregnable to the waves and every day stronger" (Naturalis Historia 35.166). Pozzolanic crystallization of Al-tobermorite, a rare, hydrothermal, calcium-silicate-hydrate mineral with cation exchange capabilities, has been previously recognized in relict lime clasts of the concrete. Synchrotron-based X-ray microdiffraction maps of cementitious microstructures in Baianus Sinus and Portus Neronis submarine breakwaters and a Portus Cosanus subaerial pier now reveal that Al-tobermorite also occurs in the leached perimeters of feldspar fragments, zeolitized pumice vesicles, and in situ phillipsite fabrics in relict pores. Production of alkaline pore fluids through dissolution-precipitation, cation-exchange and/or carbonation reactions with Campi Flegrei ash components, similar to processes in altered trachytic and basaltic tuffs, created multiple pathways to post-pozzolanic phillipsite and Al-tobermorite crystallization at ambient seawater and surface temperatures. Long-term chemical resilience of the concrete evidently relied on water-rock interactions, as Pliny the Elder inferred. Raman spectroscopic analyses of Baianus Sinus Al-tobermorite in diverse microstructural environments indicate a cross-linked structure with Al3+ substitution for Si4+ in Q3 tetrahedral sites, and suggest coupled [Al3++Na+] substitution and potential for cation exchange. The mineral fabrics provide a geoarchaeological prototype for developing cementitious processes through low-temperature rock-fluid interactions, subsequent to an initial phase of reaction with lime that defines the activity of natural pozzolans. These processes have relevance to carbonation reactions in storage reservoirs for CO2 in pyroclastic rocks, production of alkali-activated mineral cements in maritime concretes, and regenerative cementitious resilience in waste encapsulations using natural volcanic pozzolans.