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1.
Public Health ; 228: 73-81, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38325059

ABSTRACT

OBJECTIVES: Public health messaging during disasters help to provide knowledge and guidance for preventative behaviours and risk reduction. The aim of this review is to explore how public health messages are currently being provided during disasters and identify what influencing factors contribute to the effectiveness of these messages. STUDY DESIGN: Scoping review. METHODS: A scoping review was conducted using guidance from Joanna Briggs Methodology for Scoping Reviews. A narrative synthesis was utilised due to the heterogeneity of findings. The review included seventeen sources, addressing a variety of disasters around the globe over the past two decades. RESULTS: Three key influencing factors were identified and are illustrated in a concept model called the Audience, Information, Messenger and Mode (AIMM) Public Health Messaging Scale. This conceptual model depicts considerations such as the quantity, quality, and framing of information, the human and technological sources used for delivery and the audience needs and capabilities required for optimal message impact and effectiveness. CONCLUSIONS: Public health messages do influence prevention behaviours during disasters, but they must be carefully tailored and delivered to ensure adequate reach, comprehension, and compliance.


Subject(s)
Disasters , Public Health , Humans , Narration
2.
Bioconjug Chem ; 12(2): 195-202, 2001.
Article in English | MEDLINE | ID: mdl-11312680

ABSTRACT

A potent, long-lasting form of interferon alpha-2a mono-pegylated with a 40 kilodalton branched poly(ethylene glycol) was designed, synthesized, and characterized. Mono-pegylated interferon alpha-2a was comprised of four major positional isomers involving Lys31, Lys121, Lys131, and Lys134 of interferon. The in vitro anti-viral activity of pegylated interferon alpha-2a was found to be only 7% of the original activity. In contrast, the in vivo antitumor activity was severalfold enhanced compared to interferon alpha-2a. Pegylated interferon alpha-2a showed no immunogenicity in mice. After subcutaneous injection of pegylated interferon alpha-2a, a 70-fold increase in serum half-life and a 50-fold increase in mean plasma residence time concomitant with sustained serum concentrations were observed relative to interferon alpha-2a. These preclinical results suggest a significantly enhanced human pharmacological profile for pegylated interferon alpha-2a. Results of Phase II/III hepatitis C clinical trials in humans confirmed the superior efficacy of pegylated interferon alpha-2a compared to unmodified interferon alpha-2a.


Subject(s)
Antineoplastic Agents/chemical synthesis , Antiviral Agents/chemical synthesis , Interferon-alpha/chemical synthesis , Polyethylene Glycols/chemical synthesis , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/immunology , Antineoplastic Agents/pharmacology , Antiviral Agents/chemistry , Antiviral Agents/immunology , Antiviral Agents/pharmacology , Cell Line , Clinical Trials, Phase II as Topic , Clinical Trials, Phase III as Topic , Drug Design , Drug Screening Assays, Antitumor , Female , Hepatitis C/drug therapy , Humans , Immunoblotting , Interferon alpha-2 , Interferon-alpha/chemistry , Interferon-alpha/immunology , Interferon-alpha/pharmacology , Mice , Mice, Nude , Molecular Structure , Neoplasms/drug therapy , Polyethylene Glycols/chemistry , Polyethylene Glycols/pharmacology , Rats , Rats, Sprague-Dawley , Recombinant Proteins , Vesicular stomatitis Indiana virus/drug effects
3.
Biotechnol Prog ; 16(3): 506-12, 2000.
Article in English | MEDLINE | ID: mdl-10835256

ABSTRACT

In this work, a previously proposed methodology for the optimization of analytical scale protein separations using ion-exchange chromatography is subjected to two challenging case studies. The optimization methodology uses a Doehlert shell design for design of experiments and a novel criteria function to rank chromatograms in order of desirability. This chromatographic optimization function (COF) accounts for the separation between neighboring peaks, the total number of peaks eluted, and total analysis time. The COF is penalized when undesirable peak geometries (i.e., skewed and/or shouldered peaks) are present as determined by a vector quantizing neural network. Results of the COF analysis are fit to a quadratic response model, which is optimized with respect to the optimization variables using an advanced Nelder and Mead simplex algorithm. The optimization methodology is tested on two case study sample mixtures, the first of which is composed of equal parts of lysozyme, conalbumin, bovine serum albumin, and transferrin, and the second of which contains equal parts of conalbumin, bovine serum albumin, tranferrin, beta-lactoglobulin, insulin, and alpha -chymotrypsinogen A. Mobile-phase pH and gradient length are optimized to achieve baseline resolution of all solutes for both case studies in acceptably short analysis times, thus demonstrating the usefulness of the empirical optimization methodology.


Subject(s)
Chromatography, High Pressure Liquid/methods , Chromatography, Ion Exchange/methods , Neural Networks, Computer , Proteins/isolation & purification , Algorithms
4.
J Pharmacol Exp Ther ; 292(1): 440-8, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10604981

ABSTRACT

We have hypothesized previously that a salt-bridge constraint exists in the alpha(1b)-adrenergic receptor (AR). Docking of the agonist epinephrine can disrupt this constraint via competition of its protonated amine, leading to an agonist-induced activation of second messengers. The amino acids, K331 and D125, which comprise this salt-bridge, should be closely associated with each other in the unbound form of the alpha(1b)-AR. This ionic association should stabilize the negative charge of D125, leading to an increase in its acid strength or a decreased pK(a). If the charged state of D125 is important for agonist binding, then changing the type of amino acid at position 331 should decrease the acid strength of D125, leading to epinephrine affinity changes for the alpha(1b)-AR. To test this hypothesis, site-directed mutagenesis was performed at position 331 of the alpha(1b)-AR. The effect these substitutions had on D125 acid strength was quantitated via epinephrine affinity changes calculated from competition binding experiments performed at different pH values. For all mutations of the alpha(1b)-AR where the positive charge at position 331 was eliminated, there was a significant increase in the pK(a) ( congruent with 0.73) of an acidic amino acid(s). In addition, there was an increase in the binding affinity of epinephrine for these mutants that was associated with a gain in the basal production of inositol triphosphates. These results are consistent with an aspartic acid residue as the counterion for K331 of the salt-bridge constraint, which disrupted, is a part of the receptor activation process. Moreover, changes in the pK(a) of D125 were not dependent on the type of amino acid substituted at position 331. This suggests a mechanism in which K331 is no longer influencing D125 after salt-bridge disruption in the wild-type alpha(1b)-AR, but may move to another stabilized position, analogous to what has been suggested for bacteriorhodopsin. Differences from the wild-type receptor in D125 pK(a) for the K331 mutations were used to estimate the free-energy potential of the constraining salt-bridge. This free energy ( congruent with 1 kcal/mol) is significant, but weak enough to be consistent with an activational mechanism where docking of the receptor agonist has sufficient free energy to cause disruption of the salt-bridge.


Subject(s)
Aspartic Acid/metabolism , Lysine/metabolism , Receptors, Adrenergic, alpha-1/metabolism , Animals , Binding, Competitive , COS Cells , Cells, Cultured , Cricetinae , Dose-Response Relationship, Drug , Epinephrine/metabolism , Hydrogen-Ion Concentration , Inositol Phosphates/metabolism , Mutagenesis, Site-Directed , Radioligand Assay , Salts/metabolism , Transfection
5.
J Biol Chem ; 274(49): 34535-8, 1999 Dec 03.
Article in English | MEDLINE | ID: mdl-10574914

ABSTRACT

Agonist-dependent activation of the alpha(1)-adrenergic receptor is postulated to be initiated by disruption of an interhelical salt-bridge constraint between an aspartic acid (Asp-125) and a lysine residue (Lys-331) in transmembrane domains three and seven, respectively. Single point mutations that disrupt the charges of either of these residues results in constitutive activity. To validate this hypothesis, we used site-directed mutagenesis to switch the position of these amino acids to observe, if possible, regeneration of the salt-bridge reverses that the constitutive activity of the single point mutations. The transiently expressed switch mutant receptor displayed an altered pharmacological profile. The affinity of selective alpha(1b)-adrenergic receptor antagonists for the switch mutant (D125K/K331D) was no different from the wild-type alpha(1b)-adrenergic receptor, suggesting that both receptors are maintaining similar tertiary structures in the cell membrane. However, there was a significant 4-6-fold decrease in the affinity of protonated amine receptor agonists and a 3-6-fold increase in the affinity of carboxylated catechol derivatives for the switch mutant compared with the wild-type alpha(1b)-adrenergic receptor. This pharmacology is consistent with a reversed charge at position 125 in transmembrane domain three. Interestingly, the ability of either a negatively or positively charged agonist to generate soluble inositol phosphates was similar for both types of receptors. Finally, the switch mutant (D125K/K331D) displayed similar basal signaling activity as the wild-type receptor, reversing the constitutive activity of the single point mutations (D125K and K331D). This suggests an ionic constraint has been reformed in the switch mutant analogous to the restraint previously described for the wild-type alpha(1b)-adrenergic receptor. These results strongly establish the disruption of an electrostatic interaction as an initial step in the agonist-dependent activation of alpha(1)-adrenergic receptors.


Subject(s)
Mutation , Receptors, Adrenergic, alpha-1/genetics , Receptors, Adrenergic, alpha-1/metabolism , Adrenergic alpha-1 Receptor Agonists , Adrenergic alpha-1 Receptor Antagonists , Amino Acids/metabolism , Animals , COS Cells , Catecholamines/pharmacokinetics , Inositol Phosphates/metabolism , Ions , Mutagenesis, Site-Directed , Phenylephrine/pharmacokinetics , Protein Binding
6.
Mol Pharmacol ; 53(4): 766-71, 1998 Apr.
Article in English | MEDLINE | ID: mdl-9547369

ABSTRACT

Alpha 1-adrenergic receptor (AR) activation is thought to be initiated by disruption of a constraining interhelical salt bridge (). Disruption of this salt bridge is achieved through a competition for the aspartic acid residue in transmembrane domain three by the protonated amine of the endogenous ligand norepinephrine and a lysine residue in transmembrane domain seven. To further test this hypothesis, we investigated the possibility that a simple amine could mimic an important functional group of the endogenous ligand and break this alpha 1-AR ionic constraint leading to agonism. Triethylamine (TEA) was able to generate concentration-dependent increases of soluble inositol phosphates in COS-1 cells transiently transfected with the hamster alpha 1b-AR and in Rat-1 fibroblasts stably transfected with the human alpha 1a-AR subtype. TEA was also able to synergistically potentiate the second messenger production by weak partial alpha 1-AR agonists and this effect was fully inhibited by the alpha 1-AR antagonist prazosin. However, this synergistic potentiation was not observed for full alpha 1-AR agonists. Instead, TEA caused a parallel rightward shift of the dose-response curve, consistent with the properties of competitive antagonism. TEA specifically bound to a single population of alpha 1-ARs with a Ki of 28.7 +/- 4.7 mM. In addition, the site of binding by TEA to the alpha 1-AR is at the conserved aspartic acid residue in transmembrane domain three, which is part of the constraining salt bridge. These results indicate a direct interaction of TEA in the receptor agonist binding pocket that leads to a disruption of the constraining salt bridge, thereby initiating alpha 1-AR activation.


Subject(s)
Adrenergic alpha-1 Receptor Agonists , Ethylamines/pharmacology , Receptors, Adrenergic, alpha-1/metabolism , Sodium Chloride/chemistry , Animals , Binding Sites/genetics , COS Cells , Cell Line , Cricetinae , Drug Synergism , Ethylamines/metabolism , Humans , Inositol Phosphates/metabolism , Mutagenesis, Site-Directed , Protein Structure, Secondary , Rats , Receptors, Adrenergic, alpha-1/chemistry , Receptors, Adrenergic, alpha-1/genetics , Sodium Chloride/pharmacology , Solubility , Structure-Activity Relationship
8.
J Biol Chem ; 273(6): 3401-7, 1998 Feb 06.
Article in English | MEDLINE | ID: mdl-9452461

ABSTRACT

A cysteine-to-phenylalanine mutation of residue 116 in the third transmembrane domain of the beta2-adrenergic receptor caused selective constitutive activation of Na+/H+ exchange through a pathway not involving cAMP. This selectivity was identified by comparing binding and signaling characteristics of wild-type (WT) versus C116F mutant receptors transiently transfected into COS-1 cells. Indicating constitutive activity, ligand binding to the C116F mutant showed a 78-fold higher than WT affinity for isoproterenol and a 40-fold lower than WT affinity for ICI 118551. Although agonist-independent activation of cAMP production was not exhibited by the C116F mutant, a constitutive stimulation of the Na+/H+ exchanger (NHE1) was observed. This was identified by measuring either basal intracellular pH (pHi) or rate of pHi recovery from cellular acid load. Due to a higher rate of H+ efflux through NHE1, C116F transfectants exhibited a significantly higher pHi (7.42) than did WT transfectants (7.1). Furthermore, the rate of pHi recovery from acid load facilitated by NHE1 was 2.1-fold faster in mutant transfectants than in WT transfectants. The lower rate seen in the WT case was stimulated by epinephrine, and the higher rate seen in the mutant case was inhibited by ICI 118551. These findings, which show that a C116F mutation of the beta2-adrenergic receptor evokes selective constitutive coupling to NHE1 over cAMP, form the basis of our prediction that multiple and distinct activation states can exist in G protein-coupled receptors.


Subject(s)
Receptors, Adrenergic, beta-2/metabolism , Adrenergic beta-Agonists/pharmacology , Amino Acid Sequence , Animals , COS Cells , Conserved Sequence , Cyclic AMP/biosynthesis , GTP-Binding Proteins/metabolism , Hydrogen-Ion Concentration , Isoproterenol/pharmacology , Kinetics , Molecular Sequence Data , Mutagenesis, Site-Directed , Receptors, Adrenergic, beta-2/drug effects , Receptors, Adrenergic, beta-2/genetics , Sequence Homology, Amino Acid , Sodium-Hydrogen Exchangers/metabolism
9.
Anal Biochem ; 247(2): 434-40, 1997 May 01.
Article in English | MEDLINE | ID: mdl-9177709

ABSTRACT

The success of recombinant interferon alpha in the clinic in part is limited by two properties of the protein: short serum half-life and immunogenicity. To improve these properties, interferon alpha-2a was conjugated with polyethylene glycol (PEG-5000). A homogeneous preparation of monopegylated interferon alpha-2a was subjected to vigorous analytical and activity characterization. A newly developed ampholyte-free chromatofocussing-like cation-exchange HPLC method utilizing a sulfopropyl resin was used to separate the monopegylated protein into 11 species. Peptide mapping, sequencing, and mass spectrometric analyses indicated that these species are positional isomers where each isomer represents a single polymer molecule conjugated to one specific lysine residue. No species with a modification at the amino terminus was observed. All 11 isomers show antiviral and antiproliferative activities in the same range as the parent monopegylated interferon alpha-2a.


Subject(s)
Interferon-alpha/chemistry , Polyethylene Glycols/chemistry , Animals , Antiviral Agents/chemistry , Antiviral Agents/isolation & purification , Antiviral Agents/pharmacology , Cell Division/drug effects , Cell Line , Chromatography, High Pressure Liquid/methods , Chromatography, Ion Exchange/methods , Cytopathogenic Effect, Viral/drug effects , Dogs , Humans , Interferon alpha-2 , Interferon-alpha/isolation & purification , Interferon-alpha/pharmacology , Isomerism , Molecular Structure , Polyethylene Glycols/isolation & purification , Polyethylene Glycols/pharmacology , Recombinant Proteins
10.
Biochemistry ; 36(3): 633-9, 1997 Jan 21.
Article in English | MEDLINE | ID: mdl-9012678

ABSTRACT

Recently a number of mutations have been found in vitro which maintain alpha 1-adrenergic receptors (ARs) in a partially activated form. We have previously identified two amino acid residue positions in the alpha 1b-adrenergic receptor (AR), Cys128 and Ala204, one in each of the third and fifth transmembrane segments, that constitutively activate the receptor when substituted for a phenylalanine or valine, respectively [Perez et al. (1996) Mol. Pharmacol. 49, 112-122; Hwa et al. (1996) J. Biol. Chem. 271, 7956-7964]. Another mutation analyzed previously, Ala293Glu, located in the third intracellular loop, also constitutively activates the receptor [Kjelsborg et al. (1992) J. Biol. Chem. 267, 1430-1433]. All three mutations displayed similar manifestations of constitutive activity such as higher binding affinity and potency for agonists as well as higher basal signal transduction as predicted by the revised ternary complex model of receptor activation. We hypothesized that the individual mutations because of their critical location alter the conformation of the transmembrane helices such that mimicry occur that partially conforms to the activated state, R*. To explore whether these potential conformations are independent, we combined these three mutations in all possible permutations. The combined triple mutation displays 700-fold higher binding affinity for (-)-epinephrine and 20-fold higher basal IP3 release than the wild-type receptor. We also observed that each mutation contributed independently and synergistically to both receptor agonist binding and activation with the combined mutations basal activity exceeding that of the fully-stimulated wild-type receptor. There was also a direct correlation between epinephrine's binding affinity and the degree of constitutive activity. Because the mutations affect different transmembrane domains, these results are consistent with a mechanism that helical movement acts in a concerted fashion in agonist-induced activation, a synergism predicted if multiple helix movement is involved in receptor activation.


Subject(s)
Receptors, Adrenergic, alpha-1/metabolism , Animals , COS Cells , Drug Synergism , Epinephrine/metabolism , Inositol 1,4,5-Trisphosphate/metabolism , Models, Molecular , Mutagenesis, Site-Directed
11.
J Biol Chem ; 271(45): 28318-23, 1996 Nov 08.
Article in English | MEDLINE | ID: mdl-8910453

ABSTRACT

Rhodopsin receptor activation involves the disruption of a salt bridge constraint between glutamic acid 113 on transmembrane 3 and a lysine 296 in transmembrane 7, which forms a Schiff's base with retinal. Light-induced isomerization of cis-retinal to the all trans form breaks this rhodopsin salt bridge leading to receptor activation. The analogous residues in alpha1b-adrenergic receptors, aspartic acid 125 and lysine 331, also have the potential of forming a constraining salt bridge holding the receptor to an inactive protein configuration. This alpha1b-adrenergic receptor salt bridge constraint is then released upon binding by the receptor agonist. To test this hypothesis, site-directed mutagenesis was used to eliminate the positive charge at position 331 by substitution of an alanine. The expressed alpha1b-adrenergic receptor mutant demonstrated a 6-fold increased epinephrine binding affinity with no alterations of affinity values for selective adrenergic receptor antagonists. Furthermore, an increased epinephrine potency for total soluble inositol phosphate production along with an elevated basal inositol triphosphate level was observed in COS-1 cells transfected with mutant versus wild-type alpha1b-adrenergic receptors. Similar results were obtained for a lysine to a glutamic acid alpha1b-adrenergic receptor mutation. In addition, increased basal inositol triphosphate levels were also observed for two aspartic acid 125 alpha1b-adrenergic receptor mutations, consistent with this residue's role as the counterion of the salt bridge. Taken together, these alpha1b-adrenergic receptor mutations suggest a molecular mechanism by which the positively charged lysine 331 stabilizes the negatively charged aspartic acid 125 via a salt bridge constraint until bound by the receptor agonist.


Subject(s)
Receptors, Adrenergic, alpha-1/metabolism , Animals , COS Cells , Cricetinae , Epinephrine/pharmacology , Glutamic Acid , Inositol Phosphates/metabolism , Lysine , Methoxamine/pharmacology , Mutagenesis, Site-Directed , Norepinephrine/pharmacology , Protein Conformation , Receptors, Adrenergic, alpha-1/genetics , Signal Transduction/drug effects , Structure-Activity Relationship
12.
Jt Comm J Qual Improv ; 21(8): 395-406, 1995 Aug.
Article in English | MEDLINE | ID: mdl-7496453

ABSTRACT

BACKGROUND: In 1992, 12 large children's hospitals established the Benchmarking Effort for Networking Children's Hospitals (BENCHmark). The goal was for the BENCHmark effort to supplement the hospitals' continuous quality improvement (CQI) programs and to speed adoption of best practices from peer institutions. For three years, the hospitals have been comparing data on cost, quality, and speed indicators. Also, "best practice" groups have met to share information on how processes can be improved. RESULTS: The BENCHmark hospitals have experienced significant process improvement in areas such as emergency department waiting time and admitting process time. EXAMPLE: The BENCHmark hospitals selected admitting as one of the first best practice groups to meet. Interdisciplinary staff from all BENCHmark hospitals met three times over the course of a year to define their indicator and share information on best practices. St Louis Children's Hospital, as a result, instituted a pre-arrival team and cross-trained staff, with the result being a reduction of admitting processing time from 58 minutes to 19 minutes. Same-day surgery patients now bypass the admitting department and go directly to the surgical floor. Patient and surgeon satisfaction has increased greatly. CONCLUSIONS: Hospitals that are planning to benchmark are encouraged to reach consensus on project goals and to focus on indicators that provide a clear business advantage. Physician involvement is key to improving performance and physicians will only be engaged if the hospitals against whom they are benchmarked are considered peers. Being willing to share initial data openly seems to be a key factor in determining successful integration of the BENCHmark process into hospital CQI efforts. The BENCHmark project has been so successful that a second group of 12 comparable pediatric institutions, known as the Network II, has been established.


Subject(s)
Hospitals, Pediatric/standards , Interinstitutional Relations , Total Quality Management/organization & administration , Efficiency, Organizational , Hospital-Patient Relations , Hospital-Physician Relations , Hospitals, Pediatric/organization & administration , Humans , Models, Organizational , Organizational Objectives , Outcome Assessment, Health Care , Program Development/methods , Reference Values , United States
13.
Altern Ther Health Med ; 1(3): 80, 1995 Jul.
Article in English | MEDLINE | ID: mdl-9419801
15.
Regul Pept ; 54(2-3): 489-93, 1994 Dec 15.
Article in English | MEDLINE | ID: mdl-7716281

ABSTRACT

Peptide methionine-tyrosine (PMY), a peptide of the neuropeptide Y (NPY) superfamily isolated from the brain and intestine of the sea lamprey, had the same maximum effect but was 11-fold less potent than pig NPY in inhibiting field-stimulated contraction of the rat vas deferens, an effect mediated through the Y2 receptor. In contrast, PMY produced a 9-fold greater maximum effect but was 3-fold less potent than pig NPY in contracting the guinea pig mesenteric artery, an effect mediated through the Y1 receptor. Molecular modelling has suggested that the conformation of PMY is appreciably different from NPY only in the beta-turn region of the molecule (residues 9-14). Our data suggest, therefore, that modifications in this region of NPY may useful in the design of receptor selective analogs.


Subject(s)
Peptides/pharmacology , Receptors, Neuropeptide Y/drug effects , Amino Acid Sequence , Animals , Brimonidine Tartrate , Guinea Pigs , In Vitro Techniques , Male , Mesenteric Arteries , Molecular Sequence Data , Muscle Contraction/drug effects , Muscle, Smooth/drug effects , Muscle, Smooth, Vascular/drug effects , Quinoxalines/pharmacology , Rats , Rats, Sprague-Dawley , Vas Deferens
17.
Br J Clin Psychol ; 33(1): 49-63, 1994 02.
Article in English | MEDLINE | ID: mdl-8173543

ABSTRACT

A number of studies have linked the development of substance abuse problems to a lack of purpose or meaning in life, and a few studies have demonstrated an increase in sense of life purpose through substance abuse treatment programmes. The present study extended past research by examining the relationship of purpose in life to treatment outcome assessed three months after completion of treatment. The subject sample comprised 131 people in in-patient treatment programmes or awaiting treatment for alcoholism (in some cases in addition to other drug addictions). Consistent with previous research, the mean Purpose in Life Test (PIL) score before treatment was significantly below the normal range and the mean PIL score at the end of in-patient treatment was within the normal range. Furthermore, the PIL score at the end of treatment was predictive of changes in intimate relationships and health at follow-up. It was also predictive of follow-up drinking/drug use status. However, the pattern of prediction differed in the two treatment groups. Post-treatment PIL score was a positive predictor of improvement in a skill-based treatment centre, and a negative predictor in a more authoritarian, confrontation-based programme. The distinction between internally and externally derived senses of meaning is presented as one possible explanation of these findings.


Subject(s)
Alcoholism/rehabilitation , Internal-External Control , Life Style , Motivation , Adaptation, Psychological , Adult , Alcoholics Anonymous , Alcoholism/psychology , Cocaine , Combined Modality Therapy , Comorbidity , Female , Follow-Up Studies , Heroin Dependence/psychology , Heroin Dependence/rehabilitation , Humans , Length of Stay , Male , Middle Aged , Patient Care Team , Religion and Psychology , Substance Abuse Treatment Centers , Substance-Related Disorders/psychology , Substance-Related Disorders/rehabilitation , Treatment Outcome
19.
BMJ ; 306(6871): 208-9, 1993 Jan 16.
Article in English | MEDLINE | ID: mdl-8443506
20.
J Pharmacol Exp Ther ; 263(3): 1062-7, 1992 Dec.
Article in English | MEDLINE | ID: mdl-1335054

ABSTRACT

Subtypes of alpha-1 adrenergic receptors on rat parotid gland acinar cell membranes were characterized using subtype selective alpha adrenergic receptor antagonists. The alpha-1 adrenergic receptor antagonist beta-iodo-[125I]-4-hydroxyphenyl-ethyl-aminomethyl-tetralone (125IBE) had an equilibrium dissociation constant for specific binding sites on these membranes of 0.241 +/- 0.03 nM and a total number of specific radioligand binding sites of 41 +/- 4 fmol bound/mg of protein. Displacement of 125IBE binding by subtype-selective alpha-1 adrenergic receptor antagonists 2-(2,6-dimethoxyphenoxyethyl)-aminomethyl-1,4-benzodioxane HCl (WB4101) and 5-methylurapidil fit best to biphasic competition curves. The high- and low-affinity inhibition equilibrium dissociation constant for WB4101 were 0.45 +/- 0.1 and 27 +/- 6 nM, respectively. Similarly, the high- and low-affinity inhibition equilibrium dissociation constants for 5-methylurapidil were 0.16 +/- 0.03 and 71 +/- 20 nM, respectively. These affinities for 125IBE binding sites suggest the presence of alpha-1A and alpha-1B adrenergic receptor subtypes on acinar cell membranes. The irreversible alpha-1 adrenergic receptor antagonist chloroethylclonidine was used to inactivate alpha-1B adrenergic receptors on acinar cell membranes. After treatment with chloroethylclonidine, saturation binding analysis demonstrated no change in the total number of 125IBE binding sites. In addition, competition curves for WB4101 and 5-methylurapidil again showed two sites of 125IBE displacement, with no change in antagonist affinities in membranes treated with chloroethylclonidine.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Parotid Gland/chemistry , Receptors, Adrenergic, alpha/analysis , Tetralones , Animals , Cerebral Cortex/chemistry , Dioxanes/metabolism , Male , Phenethylamines/metabolism , Piperazines/metabolism , Rats , Rats, Sprague-Dawley
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