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1.
Ann Oncol ; 30(11): 1697-1727, 2019 11 01.
Article in English | MEDLINE | ID: mdl-31740927

ABSTRACT

BACKGROUND: Although guidelines exist for advanced and variant bladder cancer management, evidence is limited/conflicting in some areas and the optimal approach remains controversial. OBJECTIVE: To bring together a large multidisciplinary group of experts to develop consensus statements on controversial topics in bladder cancer management. DESIGN: A steering committee compiled proposed statements regarding advanced and variant bladder cancer management which were assessed by 113 experts in a Delphi survey. Statements not reaching consensus were reviewed; those prioritised were revised by a panel of 45 experts before voting during a consensus conference. SETTING: Online Delphi survey and consensus conference. PARTICIPANTS: The European Association of Urology (EAU), the European Society for Medical Oncology (ESMO), experts in bladder cancer management. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Statements were ranked by experts according to their level of agreement: 1-3 (disagree), 4-6 (equivocal), 7-9 (agree). A priori (level 1) consensus was defined as ≥70% agreement and ≤15% disagreement, or vice versa. In the Delphi survey, a second analysis was restricted to stakeholder group(s) considered to have adequate expertise relating to each statement (to achieve level 2 consensus). RESULTS AND LIMITATIONS: Overall, 116 statements were included in the Delphi survey. Of these, 33 (28%) statements achieved level 1 consensus and 49 (42%) statements achieved level 1 or 2 consensus. At the consensus conference, 22 of 27 (81%) statements achieved consensus. These consensus statements provide further guidance across a broad range of topics, including the management of variant histologies, the role/limitations of prognostic biomarkers in clinical decision making, bladder preservation strategies, modern radiotherapy techniques, the management of oligometastatic disease and the evolving role of checkpoint inhibitor therapy in metastatic disease. CONCLUSIONS: These consensus statements provide further guidance on controversial topics in advanced and variant bladder cancer management until a time where further evidence is available to guide our approach.


Subject(s)
Consensus , Medical Oncology/standards , Practice Guidelines as Topic , Urinary Bladder Neoplasms/therapy , Urology/standards , Delphi Technique , Europe , Humans , International Cooperation , Medical Oncology/methods , Neoplasm Staging , Societies, Medical/standards , Stakeholder Participation , Surveys and Questionnaires , Urinary Bladder/pathology , Urinary Bladder Neoplasms/pathology , Urology/methods
2.
Article in English | MEDLINE | ID: mdl-28840620

ABSTRACT

There is a growing body of evidence on the importance of work following a diagnosis of cancer and the need to provide better information, advice and related support to patients on work engagement. The aim of this study was to better understand the nature of those needs and to identify better ways to meet these for those with a urological cancer. The focus was on the issues that were common to three key stakeholder groups. Semi-structured interviews were conducted with stakeholders in North East Scotland: 12 individuals with kidney, bladder or prostate cancer, 10 healthcare providers and 10 managers from large organisations. Five key themes emerged from the Framework Analysis: perceived importance of work engagement; decision-making: treatment, work and cancer; roles and responsibilities; education and training; information, advice and support resources. The data confirmed that work engagement is important to those with urological cancer. It also made clear that the current provision of information and advice could be improved. Any such interventions should involve all three key stakeholder groups with greater clarity on their respective roles and responsibilities. Finally, any new system would be best integrated with existing care provision and supported by adequate education and training of those involved.


Subject(s)
Patient Education as Topic , Social Support , Urologic Neoplasms/rehabilitation , Work Engagement , Adult , Counseling , Female , Humans , Male , Middle Aged , Qualitative Research , Scotland
3.
Vox Sang ; 110(4): 329-35, 2016 May.
Article in English | MEDLINE | ID: mdl-26766162

ABSTRACT

BACKGROUND: Ebola virus disease is a public health emergency of international concern, and enormous efforts are being made in the development of vaccines and therapies. Ebola virus convalescent plasma is a promising anti-infective treatment of Ebola virus disease. Therefore, we developed and implemented a pathogen-reduced Ebola virus convalescent plasma concept in accordance with national, European and global regulatory framework. MATERIALS AND METHODS: Ebola virus convalescent plasma manufacture and distribution was managed by a collection centre, two medical centres and an expert group from the European Blood Alliance. Ebola virus convalescent plasma was collected twice with an interval of 61 days from a donor recovering from Ebola virus disease in Germany. After pathogen reduction, the plasma was analysed for Ebola virus-specific immunoglobulin G (IgG) antibodies and its Ebola virus neutralizing activity. RESULTS: Convalescent plasma could be collected without adverse events. Anti-Ebola virus IgG titres and Ebola-specific neutralizing antibodies in convalescent plasma were only slightly reduced after pathogen reduction treatment with S59 amotosalen/UVA. A patient in Italy with Ebola virus disease was treated with convalescent plasma without apparent adverse effects. DISCUSSION: As proof of principle, we describe a concept and practical implementation of pathogen-reduced Ebola virus convalescent plasma manufacture, quality control and its clinical application to an Ebola virus disease patient.


Subject(s)
Antibodies, Neutralizing/isolation & purification , Ebolavirus/immunology , Hemorrhagic Fever, Ebola/prevention & control , Immunoglobulin G/isolation & purification , Adult , Antibodies, Neutralizing/immunology , Antibodies, Neutralizing/therapeutic use , Blood Donors , Convalescence , Furocoumarins/pharmacology , Germany , Humans , Immunoglobulin G/immunology , Immunoglobulin G/therapeutic use , Male , Middle Aged , Photosensitizing Agents/pharmacology , Quality Control , Ultraviolet Rays , Virus Inactivation/drug effects , Virus Inactivation/radiation effects
5.
Lupus ; 24(2): 174-9, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25239925

ABSTRACT

OBJECTIVE: Antiphospholipid (Hughes) syndrome (APS) affects mainly women 15 to 50 years of age and is responsible for approximately 20% of strokes in people <40 years. Little is known about the psychological burden of this long-term condition. We investigated HRQoL in APS. METHODS: We conducted a cross-sectional survey involving 270 members of the Hughes Syndrome Foundation worldwide. Data included HRQoL (SF-36), demographics, and APS-related self-reported major issues. Response rate was 60%. RESULTS: T-tests indicated significantly worse mean scores for seven of the eight domains of the SF-36 in secondary antiphospholipid syndrome (SAPS) compared to primary antiphospholipid syndrome (PAPS), e.g. bodily pain t(263) = 6.10 p < 0.001 except for mental health t(267) = 1.95 p = 0.053. PAPS appeared to be associated with poorer HRQoL in most mental health domains but overall better physical domains compared to systemic lupus erythematosus (SLE) alone. SAPS appeared to have a more adverse impact on HRQoL compared to PAPS and SLE. Major issues identified: pain and fatigue, lack of health care professional/public awareness, and medication unpredictability. CONCLUSION: HRQoL in PAPS appears to be generally better than SLE and SAPS in physical domains, but poorer in mental domains. APS patients might need more social support in terms of information and awareness of the condition to improve their coping strategies.


Subject(s)
Antiphospholipid Syndrome/physiopathology , Fatigue/etiology , Pain/etiology , Quality of Life , Adaptation, Psychological , Adolescent , Adult , Aged , Aged, 80 and over , Child , Cross-Sectional Studies , Data Collection , Female , Humans , Lupus Erythematosus, Systemic/physiopathology , Male , Middle Aged , Social Support , Young Adult
6.
Transfus Med ; 24(2): 89-98, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24410716

ABSTRACT

BACKGROUND/OBJECTIVES: U.K. blood component labels have evolved to accommodate a plethora of information. Concern has, however, been expressed that current U.K. labelling is too 'cluttered', detracting from the clarity of critical information. This prompted a holistic review of labelling and available information technology (IT) with the aim of improving the situation. METHODS/MATERIALS: A survey was circulated requiring U.K. hospital participants to rank each item of information on the label according to its 'criticality' and assess three novel 'future' and one 'transition' prototype labels. Prototypes were based on applicable regulatory standards, best practice guidance, international benchmark data and U.K. expert input. The prototypes support steps towards 'full face' label printing and utilise 2D and quick response (QR) barcodes. RESULTS: Two-hundred eleven completed surveys were received identifying 110 contributing hospitals with 41% from clinical staff, 37% from transfusion laboratory staff and 22% from transfusion practitioners. There was excellent agreement between the three groups on the critical information, i.e., blood group, expiry date, blood component name, unique donation identification number (DIN) and blood component volume but far less on the other information, especially the various warning messages. Of the 'future' labels, option 3 (closest to the current 'quadrant model') was most popular. Option 1, with its additional inverted section replicating critical information was least popular and prompted significant safety concerns. CONCLUSION: The prototype labels correctly identified the critical items of information and extensive comments confirmed that this was more prominently and clearly displayed. Laboratory staff commented that the transition label was essential to enable IT systems to be adapted.


Subject(s)
Blood Component Transfusion , Data Collection , Hospitals , Product Labeling , Female , Humans , Male , United Kingdom
7.
Ecol Lett ; 16(5): 635-41, 2013 May.
Article in English | MEDLINE | ID: mdl-23461543

ABSTRACT

Conservationists often advocate for landscape approaches to wildlife management while others argue for physical separation between protected species and human communities, but direct empirical comparisons of these alternatives are scarce. We relate African lion population densities and population trends to contrasting management practices across 42 sites in 11 countries. Lion populations in fenced reserves are significantly closer to their estimated carrying capacities than unfenced populations. Whereas fenced reserves can maintain lions at 80% of their potential densities on annual management budgets of $500 km(-2) , unfenced populations require budgets in excess of $2000 km(-2) to attain half their potential densities. Lions in fenced reserves are primarily limited by density dependence, but lions in unfenced reserves are highly sensitive to human population densities in surrounding communities, and unfenced populations are frequently subjected to density-independent factors. Nearly half the unfenced lion populations may decline to near extinction over the next 20-40 years.


Subject(s)
Carnivora , Conservation of Natural Resources/methods , Lions , Population Density , Animals , Conservation of Natural Resources/economics , Ghana , Humans , Namibia , Population Dynamics , Private Sector , South Africa
8.
Vox Sang ; 103(2): 107-12, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22404076

ABSTRACT

BACKGROUND AND OBJECTIVES: During the 1918, pandemic blood components were successfully used to treat severe influenza pneumonia. A Proof of Principle trial investigating the clinical benefit of convalescent plasma was proposed in the 2009 H1N1v epidemic with the aim of screening donors for high titre antibody in order to stockpile plasma packs to be used for treatment for severe pneumonia. MATERIALS AND METHODS: Serum samples were collected from donors. IgG antibody capture format enzyme-linked immunoassays using recombinant proteins (GACELISAs) were compared with microneutralization (MN) and haemagglutination inhibition (HAI). The influence of age and history of influenza-like illness (ILI) on the detection of high titre antibody was examined. RESULTS: 1598 unselected donor sera collected in October and December 2009 were tested by HAI. The HAI and demographic data defined a possible strategy for selective donor screening. One of the GACELISAs was highly specific for recent infection but showed lower sensitivity than HAI. CONCLUSIONS: During the 2009 pandemic screening 17- to 30-year-old donors by HAI delivered around 10% with high antibody levels. The ELISA using a short recombinant H1N1v HA detected fewer reactives but was more specific for high titre antibody (≥1:256). Screening strategies are proposed based on using HAI on serum or GACELISA on plasma.


Subject(s)
Antibodies, Viral/blood , Blood Donors , Convalescence , Donor Selection/methods , Influenza A Virus, H1N1 Subtype , Influenza, Human/blood , Influenza, Human/epidemiology , Pandemics , Adolescent , Adult , England/epidemiology , Female , Humans , Plasma
9.
Ophthalmologe ; 105(7): 639-43, 2008 Jul.
Article in German | MEDLINE | ID: mdl-18592251

ABSTRACT

The majority of patients with dry eye syndromes respond to conventional treatment aimed at optimising the ocular surface environment. There are some, however, who do not respond adequately to conventional lubricants. The first description of the use of autologous serum as a nutrient tears substitute was published more than 20 years ago. In 1997, NHS Blood and Transplant (NHSBT) developed a reliable and reproducible method for the production of eyedrops derived from autologous serum according to GMP Guidelines. The current cost of a batch of eyedrops (i. e. the product from one donation episode) is approximately 1300 GBP - this covers costs of collection, processing, testing and distribution. One "batch" of eyedrops will last for approximately 5 months if a bottle a day is used. A 6 month shelf life is put on the product and patients keep them in their domestic freezer.


Subject(s)
Biological Products/standards , Biological Products/therapeutic use , Blood Banks/organization & administration , Corneal Diseases/drug therapy , Ophthalmic Solutions/standards , Ophthalmic Solutions/therapeutic use , Serum , England , Humans , Blood Banking/methods
10.
Transfus Clin Biol ; 24(1): 34-35, 2017 Feb.
Article in English | MEDLINE | ID: mdl-28139398

ABSTRACT

Allergy accounts to near 0.5% of all reported transfusion adverse events. The responsibility of blood components themselves and - therefore - of blood donors is still questioned. The European Community undertook a large international survey to address the consistency and homogeneity of medical selection of blood donors with regard to the risk of allergy, and especially of transferring allergy to recipients. This short report presents the salient points of the survey, stressing that there is inconsistency in addressing the allergy question within countries or systems, with paths of improvement.


Subject(s)
Blood Donors , Donor Selection/standards , Hypersensitivity/epidemiology , Transfusion Reaction/prevention & control , Anti-Allergic Agents/blood , Drug Hypersensitivity/blood , Drug Hypersensitivity/epidemiology , Europe/epidemiology , Health Care Surveys , Health Policy , Humans , Hypersensitivity/blood , Hypersensitivity/prevention & control , Surveys and Questionnaires
13.
J Med Chem ; 40(15): 2347-62, 1997 Jul 18.
Article in English | MEDLINE | ID: mdl-9240350

ABSTRACT

The design, synthesis, and activity of a novel series of 2,5-substituted tryptamine derivatives at vascular 5HT1B-like receptors is described. Several important auxiliary binding sites of the 5HT1B-like receptor have been proposed following various modifications to the 2-substituent and especially to the methylene- or ethylene-linked 5-side chain. Careful design of new molecules based on a proposed pharmacophoric model of the 5HT1B-like receptor has resulted in the discovery of ethyl 3-[2-(dimethylamino)ethyl]-5-[2-(2, 5-dioxo-1-imidazolidinyl)ethyl]-1H-indole-2-carboxylate (40), a highly potent, silent, competitive, and selective antagonist which shows affinity at the vascular 5HT1B-like receptors only. Changes to the size of the 2-ester substituent have a significant effect on affinity at the 5HT1B-like receptor and other receptors. Prudent placement of the carbonyl substituent in the heterocycle of the 5-side chain is crucial for good affinity and selectivity over the 5HT2A and other receptors. Several key structural and electronic features were identified which are crucial for producing antagonism within a tryptamine-based series. An electron deficient indole ring system appears essential in order to achieve antagonism, and this is achieved by the inclusion of electron-withdrawing groups at the 2-position of the indole ring. The molecule displacement within the receptor resulting from the inclusion of the bulky 2-substituents also enhances antagonism as this results in the removal of the pi electron density of the indole ring from the region of the receptor normally occupied by the indole ring of 5HT. There also appears to be a structural requirement on the side chain incorporating the protonatable nitrogen, and this is achieved by the inclusion of the bulky 2-ester group which neighbors the 3-ethylamine side chain.


Subject(s)
Receptors, Serotonin/drug effects , Serotonin Antagonists/pharmacology , Tryptamines/pharmacology , Animals , Arteries/drug effects , Arteries/physiology , In Vitro Techniques , Magnetic Resonance Spectroscopy , Male , Mass Spectrometry , Rabbits , Radioligand Assay , Receptor, Serotonin, 5-HT1B , Receptor, Serotonin, 5-HT1D , Serotonin Antagonists/chemistry , Structure-Activity Relationship , Tryptamines/chemistry , Vasoconstriction/drug effects , Veins/drug effects , Veins/physiology
14.
Br J Pharmacol ; 107(2): 418-21, 1992 Oct.
Article in English | MEDLINE | ID: mdl-1422590

ABSTRACT

1. The influence of the thromboxane A2-mimetic U46619 (11 alpha, 9 alpha-epoxymethano PGH2) on 5-hydroxy-tryptamine (5-HT)-induced contractions of the rabbit isolated femoral artery has been examined. 2. In the absence of U46619, 5-HT responses were mediated predominantly by 5-HT2-receptors as judged by potent, surmountable antagonism by the selective 5-HT2 receptor antagonists, spiperone and ketanserin. Both antagonists unmasked a population of 5-HT1-like receptors which accounted for approximately 10-15% of the 5-HT maximum response. 3. In the presence of U46619 (3-10 nM), 5-HT-induced contractions were largely resistant to blockade by 5-HT2 receptor antagonists since 5-HT1-like receptor-mediated contraction now accounted for approximately 60% of the 5-HT maximum response. 4. These results show that activation of thromboxane A2 receptors in a tissue possessing both 5-HT2 and 5-HT1-like receptors can convert 5-HT-induced contraction from one mediated predominantly by 5-HT2 receptors to one which is mediated predominantly by 5-HT1-like receptors.


Subject(s)
Femoral Artery/drug effects , Prostaglandin Endoperoxides, Synthetic/pharmacology , Receptors, Serotonin/physiology , Serotonin/pharmacology , Vasoconstriction/drug effects , Animals , Biphenyl Compounds/pharmacology , Heptanoic Acids/pharmacology , In Vitro Techniques , Ketanserin/pharmacology , Male , Muscle Contraction/drug effects , Muscle, Smooth, Vascular/drug effects , Rabbits , Receptors, Serotonin/drug effects , Spiperone/pharmacology , Thromboxane A2/antagonists & inhibitors
15.
Br J Pharmacol ; 97(3): 921-33, 1989 Jul.
Article in English | MEDLINE | ID: mdl-2503229

ABSTRACT

1. The interactions between 5-hydroxytryptamine (5-HT) and the antagonists ketanserin, methysergide and phentolamine were studied in isolated preparations of human umbilical artery (HUA) at physiological oxygen tension (Po2 approximately 15 mmHg) and at high PO2 (approximately 120 mmHg). 2. At physiological Po2 ketanserin, methysergide and phentolamine behaved as silent competitive antagonists of the 5-HT-induced contraction of HUA. pA2 values calculated by Schild analysis were 8.92, 8.52 and 6.37, respectively. 3. At high Po2, 5-HT-induced contractions were antagonised in a biphasic manner by ketanserin (0.1 microM); the response to low but not to high concentrations of 5-HT was resistant to blockade by ketanserin. The ketanserin-resistant component was abolished following cyclo-oxygenase inhibition by indomethacin (1 microM). 4. At high Po2, methysergide behaved as a partial agonist. Methysergide-induced contractions were inhibited but not abolished by indomethacin, and resistant to 5-HT2 receptor and alpha 1-adrenoceptor blockade. 5. At high Po2 the component of the response to 5-HT mediated by the ketanserin-resistant receptor was mimicked by the selective 5-HT1-like receptor agonist 5-carboxamidotryptamine (5-CT): 5-CT was 7 fold more potent than 5-HT. 6. At high Po2 the component of the response to 5-HT mediated by the ketanserin-resistant receptor was antagonised by phentolamine and the selective alpha 2-adrenoceptor antagonist Wy 26703. 7. These results suggest that (i) at physiological Po2 5-HT2 receptors almost exclusively mediate contractions induced by 5-HT, and (ii) at high Po2 the agonist potency order of 5-CT greater than 5-HT greater than methysergide suggests that ketanserin-resistant responses are mediated by 5-HT1-like receptors which require functional cyclo-oxygenase.


Subject(s)
Muscle, Smooth, Vascular/physiology , Prostaglandin-Endoperoxide Synthases/physiology , Receptors, Serotonin/physiology , Atmospheric Pressure , Female , Humans , In Vitro Techniques , Muscle Contraction/drug effects , Muscle, Smooth, Vascular/enzymology , Muscle, Smooth, Vascular/metabolism , Oxygen/pharmacology , Oxygen/physiology , Pregnancy , Prostaglandin-Endoperoxide Synthases/metabolism , Receptors, Serotonin/enzymology , Serotonin/analogs & derivatives , Serotonin/pharmacology , Serotonin Antagonists/pharmacology , Umbilical Arteries/drug effects
16.
Br J Pharmacol ; 84(1): 199-202, 1985 Jan.
Article in English | MEDLINE | ID: mdl-3978312

ABSTRACT

The 5-hydroxytryptamine (5-HT) receptor in human umbilical artery was found to be similar to that in rabbit aorta. The pD2 was 7.45, pA2 for methysergide 8.63 and pA2 for phentolamine 6.21. Noradrenaline gave only very weak contractions at non-physiological concentrations. Amidephrine and xylazine did not contract human umbilical artery. It is concluded that there is no significant population of functional alpha-adrenoceptors in this vessel. The implications of these findings are discussed in relation to the control of the umbilical circulation.


Subject(s)
Methysergide/pharmacology , Phentolamine/pharmacology , Receptors, Serotonin/drug effects , Serotonin/pharmacology , Umbilical Arteries/drug effects , Animals , Aorta/drug effects , Humans , In Vitro Techniques , Muscle Contraction/drug effects , Muscle, Smooth, Vascular/drug effects , Rabbits
17.
Br J Pharmacol ; 124(4): 619-22, 1998 Jun.
Article in English | MEDLINE | ID: mdl-9690851

ABSTRACT

The cannabinoid receptor antagonist SR141716A has been suggested to be an inverse agonist at CB1 receptors in some isolated intact tissues. We found that the basal incorporation of [35S]-GTPgammaS in Chinese hamster ovary cells expressing human recombinant CB1 and CB2 receptors was inhibited by SR141716A (mean pEC50s 8.26 and 6.00, respectively), whereas cannabinol (10 microM) had no significant effect at hCB1 receptors but inhibited the binding at hCB2 receptors. As cannabinol had no effect on basal [35S]-GTPmicroS binding at hCB1 at a concentration 100 fold higher than its binding affinity (K = 0.1 microM), we conclude that endogenous cannabinoid receptor agonists are not a confounding factor and suggest the actions of SR141716A at the hCB1 receptor, and the actions of SR141716A and cannabinol at the hCB2 receptor, are due to inverse agonism.


Subject(s)
Cannabinoids/metabolism , Piperidines/pharmacology , Pyrazoles/pharmacology , Receptors, Drug/agonists , Animals , CHO Cells , Cricetinae , Guanosine 5'-O-(3-Thiotriphosphate)/metabolism , Humans , Receptors, Cannabinoid , Receptors, Drug/metabolism , Recombinant Proteins/agonists , Recombinant Proteins/metabolism , Rimonabant
18.
Br J Pharmacol ; 129(7): 1333-8, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10742288

ABSTRACT

1. Human alpha(2A)-adrenoceptors heterologously expressed in Chinese hamster lung (CHL) fibroblasts have been characterized pharmacologically using a cytosensor microphysiometer to measure ligand-induced extracellular acidification rate changes. 2. In untransfected CHL cells, noradrenaline had no effect at concentrations up to 100 microM. In alpha(2A)-adrenoceptor transfected cells the rank order of agonist potency was A-54741 (mean pEC(50)=8.96)>dexmedetomidine (8.88)>UK-14304 (8.42)>B-HT 920 (7.05)>noradrenaline (6.92). A-54741, UK-14304 and noradrenaline had the same maximum response while dexmedetomidine and B-HT 920 behaved as partial agonists. 3. The selective alpha(2)-adrenoceptor ligand rauwolscine antagonized acidification rate changes with an affinity independent of the agonist used; the affinity (mean pK(B)) against noradrenaline was 8.43. 4. The selective alpha(1)-adrenoceptor ligands prazosin and doxazosin (each 3 microM) had no effect on noradrenaline responses. 5. Acidification rate changes induced by each agonist were abolished by pre-treatment of cells with pertussis toxin. 6. These data suggest that agonist-induced acidification rate responses in CHL cells transfected with the human alpha(2A)-adrenoceptor are mediated exclusively by the recombinant protein, via pertussis toxin sensitive G(i/o) proteins.


Subject(s)
Receptors, Adrenergic, alpha-2/metabolism , Adrenergic alpha-Agonists/pharmacology , Adrenergic alpha-Antagonists/pharmacology , Animals , Azepines/pharmacology , Brimonidine Tartrate , Cell Line , Cricetinae , Dexmedetomidine/pharmacology , Dose-Response Relationship, Drug , Doxazosin/pharmacology , Gene Expression , Humans , Hydrogen-Ion Concentration , Imidazoles/pharmacology , Norepinephrine/pharmacology , Prazosin/pharmacology , Quinoxalines/pharmacology , Receptors, Adrenergic, alpha-2/drug effects , Receptors, Adrenergic, alpha-2/genetics , Recombinant Fusion Proteins/drug effects , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Tetrahydronaphthalenes/pharmacology , Yohimbine/pharmacology
19.
Br J Pharmacol ; 129(7): 1339-46, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10742289

ABSTRACT

1. Human alpha(2A)-adrenoceptors expressed in Chinese hamster lung (CHL) fibroblasts have been pharmacologically characterized by measuring intracellular calcium (Ca(2+)(i)) changes using the Ca(2+)-sensitive dye Fluo3-AM, in conjunction with a fluorometric imaging plate reader (FLIPR). 2. Several alpha-adrenoceptor agonists were examined including the alpha(2)-adrenoceptor agonists UK-14304, B-HT 920, dexmedetomidine and A-54741, the selective alpha(1)-adrenoceptor agonist phenylephrine and the non-selective adrenergic agonist noradrenaline. Of these only noradrenaline (mean pEC(50)=6.49) and A-54741 (6.90) evoked changes in Ca(2+)(i); A-54741 was a partial agonist relative to noradrenaline, achieving only 33% of the noradrenaline maximum. 3. Ca(2+)(i) changes induced by noradrenaline and A-54741 were antagonized by the alpha(2)-selective antagonist rauwolscine (10 nM) and by the alpha(1)-selective antagonists prazosin (0.1 nM) and doxazosin (1.0 nM). 4. Phenylephrine (100 microM) and UK-14304 (10 microM) alone were ineffective in causing Ca(2+)(i) increase. In the presence of a fixed concentration of UK-14304 (3.0 microM), phenylephrine induced concentration-dependent increases in Ca(2+)(i) (mean pEC(50)=5.33). In the presence of phenylephrine (30.0 microM) UK-14304 induced Ca(2+)(i) release (pEC(50)=6.92). The effects of phenylephrine were abolished by prazosin (1.0 nM) or rauwolscine (100 nM). 5. In saturation radioligand binding experiments using membranes of parental (non-transfected) CHL cells there was a small, specific binding of [(3)H]-prazosin (B(max)=24 fmol mg protein(-1); pK(D)=10. 24). 6. Collectively, these data suggest that alpha-adrenoceptor agonist-induced Ca(2+)(i) release in CHL fibroblasts transfected with the human alpha(2A)-adrenoceptor is dependent upon co-activation of the recombinant receptor and a native alpha(1)-adrenoceptor.


Subject(s)
Calcium/metabolism , Receptors, Adrenergic, alpha-2/metabolism , Adrenergic alpha-Agonists/pharmacology , Adrenergic alpha-Antagonists/pharmacology , Aniline Compounds , Animals , Azepines/pharmacology , Binding, Competitive , Brimonidine Tartrate , Cell Line , Cricetinae , Dexmedetomidine/pharmacology , Dose-Response Relationship, Drug , Doxazosin/pharmacology , Estrenes/pharmacology , Fluorescence , Gene Expression , Humans , Imidazoles/pharmacology , Norepinephrine/pharmacology , Prazosin/metabolism , Prazosin/pharmacology , Pyrrolidinones/pharmacology , Quinoxalines/pharmacology , Radioligand Assay , Receptor Cross-Talk , Receptors, Adrenergic, alpha-1/metabolism , Receptors, Adrenergic, alpha-2/drug effects , Receptors, Adrenergic, alpha-2/genetics , Recombinant Fusion Proteins/drug effects , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Signal Transduction/drug effects , Tetrahydronaphthalenes/pharmacology , Thapsigargin/pharmacology , Xanthenes , Yohimbine/pharmacology
20.
Br J Pharmacol ; 121(8): 1721-9, 1997 Aug.
Article in English | MEDLINE | ID: mdl-9283709

ABSTRACT

1. In the dog saphenous vein alpha 1- and alpha 2-adrenoceptors mediate noradrenaline-induced contractions in vitro. In order to study the alpha 2-adrenoceptor in isolation, alpha 1-adrenoceptors were inactivated by treatment of tissues with the alkylating agent phenoxybenzamine (3.0 microM for 30 min) in the presence of rauwolscine (1 microM) to protect alpha 2-adrenoceptors. 2. Noradrenaline-induced contractions of tissues treated with phenoxybenzamine were antagonized competitively by the selective alpha 2-adrenoceptor antagonist rauwolscine, pKB = 8.63 +/- 0.07 (means +/- s.e. mean; n = 3), consistent with an interaction at alpha 2-adrenoceptors. 3. Noradrenaline was a full agonist at alpha 2-adrenoceptors in dog saphenous vein. By use of the method of partial receptor alkylation and analysis of concentration-effect curve data by direct, operational model fitting methods, the affinity (pKA) and efficacy (tau) were 5.74 +/- 0.07 and 7.50 +/- 1.05, respectively (n = 6). Nine other agonists which were examined each had affinities higher than noradrenaline, but with the exception of the imidazoline, A-54741 (5,6-dihydroxy-1,2,3,4-tetrahydro-1-naphthyl-imidazoline) had relatively lower efficacies. 4. To compare the alpha 2-adrenoceptor in dog saphenous vein to the human recombinant subtypes, the affinities of twenty-one compounds were estimated in functional studies in the dog saphenous vein and in radioligand binding studies for the human alpha 2A, alpha 2B and alpha 2C receptor subtypes expressed in Chinese hamster lung (CHL) cells. 5. Of twenty-one compounds examined in ligand binding studies, only nine had greater than ten fold selectivity for one human receptor subtype over either of the other two. These compounds were A-54741, oxymetazoline, guanfacine, guanabenz, prazosin, spiroxatrine, tolazoline, WB 4101 and idazoxan. In dog saphenous vein, their affinities (pKA and pKB for agonists and antagonists respectively) were: A-54741 (pKA = 8.03 +/- 0.05), oxymetazoline (pKA = 7.67 +/- 0.09), guanfacine (pKA = 6.79 +/- 0.03); guanabenz (pKA = 7.02 +/- 0.13); prazosin (pKB = 5.19 +/- 0.08), spiroxatrine (pKB = 6.59 +/- 0.04), tolazoline (pKB = 6.21 +/- 0.07), WB 4101 (pKB = 7.42 +/- 0.09) and idazoxan (pKB = 7.11 +/- 0.08). 6. Comparisons of affinity estimates for these nine compounds at the receptor in dog saphenous vein and at the human recombinant subtypes suggest that the vascular receptor is most similar to the h alpha 2A subtype; correlation coefficients (r) were 0.82 (h alpha 2A), 0.24 (h alpha 2B) and 0.04 (h alpha 2C).


Subject(s)
Receptors, Adrenergic, alpha-2/physiology , Saphenous Vein/physiology , Vasoconstriction/drug effects , Animals , Cricetinae , Dogs , Female , Humans , In Vitro Techniques , Male , Norepinephrine/pharmacology , Phenoxybenzamine/pharmacology , Quinolizines/metabolism , Receptors, Adrenergic, alpha-2/classification , Yohimbine/pharmacology
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