Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 60
Filtrar
1.
Br J Cancer ; 117(11): 1592-1599, 2017 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-28972963

RESUMO

BACKGROUND: ARQ 087 is an orally administered pan-FGFR inhibitor with multi-kinase activity. This Phase 1 study evaluated safety, pharmacokinetics, and pharmacodynamics of ARQ 087 and defined the recommended Phase 2 dose (RP2D). METHODS: Patients with advanced solid tumours received ARQ 087 administered initially at 25 mg every other day and dose-escalated from 25 to 425 mg daily (QD) continuous dosing. FGF19, 21, 23, and serum phosphate were assessed as potential biomarkers of target engagement. RESULTS: 80 patients were enrolled, 61 in dose-escalation/food-effect cohorts and 19 with pre-defined tumour types in the expansion cohort. The most common ARQ 087-related adverse events were fatigue (49%), nausea (46%), aspartate aminotransferase (AST) increase (30%), and diarrhoea (23%). Four patients (5%) experienced grade 1 treatment-related hyperphosphataemia. Dose-limiting toxicity was reversible grade 3 AST increase. The RP2D was 300 mg QD. Pharmacokinetics were linear and dose-proportional from 25 to 325 mg QD, and were unaffected by food. Statistically significant changes (P-value<0.05) suggest phosphate and FGF19 levels as markers of target engagement. In 18 evaluable patients with FGFR genetic alterations, 3 confirmed partial responses (two intrahepatic cholangiocarcinomas (iCCA) with FGFR2 fusions and one urothelial cancer with FGFR2 and FGF19 amplification) and two durable stable disease at ⩾16 weeks with tumour reduction (FGFR2 fusion-positive iCCA and adrenocortical carcinoma with FGFR1 amplification) were observed. CONCLUSIONS: ARQ 087 had manageable toxicity at the RP2D of 300 mg QD, showed pharmacodynamics effects, and achieved objective responses, notably in patients with FGFR2 genetic alterations.


Assuntos
Compostos de Anilina/uso terapêutico , Neoplasias/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Quinazolinas/uso terapêutico , Receptores de Fatores de Crescimento de Fibroblastos/antagonistas & inibidores , Administração Oral , Adulto , Idoso , Compostos de Anilina/efeitos adversos , Compostos de Anilina/farmacocinética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Quinazolinas/efeitos adversos , Quinazolinas/farmacocinética , Receptores de Fatores de Crescimento de Fibroblastos/genética
2.
Clin Pharmacol Ther ; 102(2): 313-320, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28074547

RESUMO

Clearance of trebananib (AMG 386), a 64-kD antiangiogenic peptibody, has been associated with estimated glomerular filtration rate (eGFR). We prospectively evaluated trebananib pharmacokinetics and safety/tolerability in advanced solid tumor patients with varying degrees of renal function. Patients were assigned to normal renal function, mild, moderate, or severe renal dysfunction cohorts based on eGFR, received trebananib 15 mg/kg i.v. weekly, and underwent week 1 and week 5 pharmacokinetic and weekly safety assessments. For 28 patients, trebananib clearance decreased from normal renal function (1.52 mL/hr/kg), to mild (1.20 mL/hr/kg), moderate (0.79 mL/hr/kg), and severe (0.53 mL/hr/kg) renal dysfunction (P ≤ 0.001). Treatment-related adverse events showed no association with clearance. Trebananib clearance was proportional to eGFR and unrelated to pretreatment protein excretion. These data confirm a role for renal clearance of a recombinant peptibody with molecular weight <69 kD and support a longer dosing interval for patients with severe renal dysfunction.


Assuntos
Nefropatias/metabolismo , Rim/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Proteínas Recombinantes de Fusão/efeitos adversos , Proteínas Recombinantes de Fusão/farmacocinética , Adulto , Idoso , Inibidores da Angiogênese/efeitos adversos , Inibidores da Angiogênese/farmacocinética , Feminino , Taxa de Filtração Glomerular/efeitos dos fármacos , Taxa de Filtração Glomerular/fisiologia , Humanos , Rim/fisiologia , Nefropatias/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
3.
Support Care Cancer ; 23(9): 2789-97, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25708126

RESUMO

PURPOSE: Little qualitative research exploring the impact of multiple myeloma (MM) and its treatment on the health-related quality of life (HRQL) of patients has been published. This study aimed to explore the burden of MM symptoms and treatment and the impact of these on HRQL. A model was developed to illustrate key concepts and their interrelationships. METHODS: Patients with MM were recruited to this cross-sectional, qualitative study through a patient panel and at two clinical sites in the USA. An interview discussion guide was developed using a review of published literature and interviews with experienced MM clinicians. In-depth, semistructured telephone interviews with MM patients were conducted to explore their experiences of the disease and its treatment. Data were analyzed using a thematic analysis approach. RESULTS: Twenty MM patients at various stages of treatment participated in open-ended, semistructured interviews. Patients reported both current and previous MM symptoms; most had experienced fatigue and pain. Other commonly reported symptoms were fractures, anemia, neuropathy, aches, and infections. MM treatment was found to have a negative impact on patients' HRQL; treatment-related adverse events included fatigue, neuropathy, insomnia, and gastrointestinal symptoms. MM treatment placed a substantial psychological and physical burden on patients, disrupting social activities, decreasing independence, and impacting on relationships. A model was developed to illustrate the relationship between these concepts. CONCLUSION: The conceptual model developed in this study illustrates the many aspects of MM and its treatment and how they can have a negative impact on patients' HRQL.


Assuntos
Modelos Psicológicos , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/psicologia , Idoso , Antineoplásicos/efeitos adversos , Antineoplásicos/uso terapêutico , Estudos Transversais , Fadiga/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor/psicologia , Pesquisa Qualitativa , Qualidade de Vida , Inquéritos e Questionários
4.
Am J Transplant ; 14(12): 2691-703, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25359003

RESUMO

Many critical issues remain concerning how best to deploy adoptive regulatory T cell (Treg) immunotherapy to the clinic. These include a determination of their pharmacokinetic characteristics, their optimal dose, their phenotypic stability and the best therapies with which to pair Tregs. By performing a CFSE-labeled autologous Treg pulse experiment, we determined that the accessible peripheral blood Treg pool in rhesus macaques is quite large (75 ± 11 × 10(6) Tregs/kg). Pharmacokinetic analysis revealed that Tregs have two phases of elimination: an α phase, with a T1/2 in the peripheral blood of 32.4 ± 11.3 h and a ß phase with a T1/2 of 120.4 ± 19.7 h. In addition to their short initial half-life, Tregs underwent rapid phenotypic shifts after infusion, with significant loss of both CD25 and FoxP3 by day +6. While tacrolimus stabilized CD25 expression, it did not improve T1/2 , nor mitigate the loss of FoxP3. In contrast, rapamycin significantly stabilized both CD25 and FoxP3, and supported an increased half-life, with an α phase of 67.7 ± 6.9 h and a ß phase of 252.1 ± 54.9 h. These results suggest that rapamycin may be a necessary addition to Treg immunotherapy, and that tacrolimus may be deleterious to Treg integrity posttransfer.


Assuntos
Transferência Adotiva , Linfócitos T CD4-Positivos/imunologia , Imunossupressores/farmacologia , Sirolimo/farmacologia , Linfócitos T Reguladores/imunologia , Tacrolimo/farmacologia , Animais , Proliferação de Células , Células Cultivadas , Citometria de Fluxo , Fluoresceínas , Corantes Fluorescentes , Fatores de Transcrição Forkhead/metabolismo , Meia-Vida , Imunossupressores/farmacocinética , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Macaca mulatta , Fenótipo , Sirolimo/farmacocinética , Succinimidas , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/transplante , Tacrolimo/farmacocinética , Distribuição Tecidual , Transplante Autólogo
6.
Clin Pharmacol Ther ; 96(2): 214-23, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24690569

RESUMO

Therapeutic antibodies that block the programmed cell death protein-1 (PD-1) immune checkpoint pathway prevent T-cell downregulation and promote immune responses against cancer. Several PD-1 pathway inhibitors have shown robust activity in initial trials. This article reviews the preclinical evidence, rationale, and clinical pharmacology of blockade of PD-1 or its ligands as therapy for lung cancer and provides an overview of agents in development, clinical evidence to date, and implications for clinical application.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Imunidade Celular/efeitos dos fármacos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/imunologia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/metabolismo , Animais , Humanos , Fatores Imunológicos/administração & dosagem , Imunoterapia/métodos , Receptor de Morte Celular Programada 1/imunologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Resultado do Tratamento
7.
Br J Cancer ; 108(4): 762-5, 2013 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-23322195

RESUMO

BACKGROUND: This phase 1 trial utilising a Bayesian continual reassessment method evaluated bortezomib and sunitinib to determine the maximum tolerated dose (MTD), dose-limiting toxicities (DLT), and recommended doses of the combination. METHODS: Patients with advanced solid organ malignancies were enrolled and received bortezomib weekly with sunitinib daily for 4 weeks, every 6 weeks. Initial doses were sunitinib 25 mg and bortezomib 1 mg m(-2). Cohort size and dose level estimation was performed utilising the Escalation with Overdose Control (EWOC) adaptive method. Seven dose levels were evaluated; initially, sunitinib was increased to a goal dose of 50 mg with fixed bortezomib, then bortezomib was increased. Efficacy assessment occurred after each cycle using RECIST criteria. RESULTS: Thirty patients were evaluable. During sunitinib escalation, DLTs of grade 4 thrombocytopenia (14%) and neutropenia (6%) at sunitinib 50 mg and bortezomib 1.3 mg m(-2) were seen. Subsequent experience showed tolerability and activity for sunitinib 37.5 mg and bortezomib 1.9 mg m(-2). Common grade 3/4 toxicities were neutropenia, thrombocytopenia, hypertension, and diarrhoea. The recommended doses for further study are bortezomib 1.9 mg m(-2) and sunitinib 37.5 mg. Four partial responses were seen. Stable disease >6 months was noted in an additional six patients. CONCLUSION: Bortezomib and sunitinib are well tolerated and have anticancer activity, particularly in thyroid cancer. A phase 2 study of this combination in thyroid cancer patients is planned.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ácidos Borônicos/administração & dosagem , Indóis/administração & dosagem , Pirazinas/administração & dosagem , Pirróis/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Teorema de Bayes , Bortezomib , Esquema de Medicação , Feminino , Humanos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Neoplasias/tratamento farmacológico , Sunitinibe , Neoplasias da Glândula Tireoide/tratamento farmacológico
8.
Diabet Med ; 29(6): 776-83, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22023553

RESUMO

AIMS: To develop and evaluate an image grading external quality assurance system for the Scottish Diabetic Retinopathy Screening Programme. METHOD: A web-based image grading system was developed which closely matches the current Scottish national screening software. Two rounds of external quality assurance were run in autumn 2008 and spring 2010, each time using the same 100 images. Graders were compared with a consensus standard derived from the top-level graders' results. After the first round, the centre lead clinicians and top-level graders reviewed the results and drew up guidance notes for the second round. RESULTS: Grader sensitivities ranged from 60.0 to 100% (median 92.5%) in 2008, and from 62.5 to 100% (median 92.5%) in 2010. Specificities ranged from 34.0 to 98.0% (median 86%) in 2008, and 54.0 to 100% (median 88%) in 2010. There was no difference in sensitivity between grader levels, but first-level graders had a significantly lower specificity than level-two and level-three graders. In 2008, one centre had a lower sensitivity but higher specificity than the majority of centres. Following the feedback from the first round, overall agreement improved in 2010 and there were no longer any significant differences between centres. CONCLUSIONS: A useful educational tool has been developed for image grading external quality assurance.


Assuntos
Retinopatia Diabética/diagnóstico , Aumento da Imagem/normas , Internet , Programas de Rastreamento , Garantia da Qualidade dos Cuidados de Saúde/normas , Auditoria Clínica , Feminino , Humanos , Masculino , Variações Dependentes do Observador , Fotografação/métodos , Reprodutibilidade dos Testes , Escócia/epidemiologia , Sensibilidade e Especificidade , Software
9.
Chem Phys Lipids ; 164(5): 341-50, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21477585

RESUMO

Five non-ionic dialkylglycerol poly(oxyethylene) ether surfactants, designated 2C(m)E(n) (where m, the number of carbons in each alkyl chain=16 or 18, and n, the number of oxyethylene units=12, 16 or 17) have been examined for their ability to form vesicles when dispersed in water or in an aqueous solution of 154 mM NaCl, alone or in the presence of 50 mol% cholesterol. Freeze fracture electron microscopy and light scattering showed that regardless of the hydrating fluid, all the non-ionic surfactants, with the exception of 2C(16)E(17) and 2C(18)E(17), formed vesicles in the absence of cholesterol - 2C(16)E(17) and 2C(18)E(17) instead formed micellar aggregates. All surfactants, however, formed vesicles in the presence of 50 mol% cholesterol. Small angle neutron scattering studies of the surfactant vesicles enabled the bilayer thickness and repeat distance (d-spacing) to be determined. The bilayers formed by all the non-ionic surfactants in the absence of cholesterol were surprisingly thin (∼50 Å for the E(12) containing surfactants and ∼64 Å for 2C(18)E(16)) most likely due to the intrusion of oxyethylene groups into the hydrophobic core of the bilayers. In contrast, however, the non-ionic surfactants exhibited a relatively large d-spacing of around ∼130-150 Å. The addition of 50 mol% cholesterol had a dramatic effect on the thickness of the vesicle bilayer, increasing its size by 10-20 Å, most probably because of an extrusion of oxyethylene from the hydrophobic region of the bilayer and/or a reduction in the tilt on the surfactant alkyl chains. Additionally the presence of cholesterol in a vesicle tended to reduce slightly both the d-spacing and the thickness of the water layer separating the bilayers. The presence of NaCl, even at the low concentrations used in the study, did affect the properties of the bilayer such that it reduced the d-spacing and, in the case of cholesterol-containing systems, also reduced bilayer thickness.


Assuntos
Colesterol/química , Eletrólitos/química , Lipossomos/química , Polietilenoglicóis/química , Tensoativos/química , Técnica de Fratura por Congelamento , Microscopia Eletrônica , Difração de Nêutrons , Fosfatidilcolinas/química , Espalhamento a Baixo Ângulo
11.
J Colloid Interface Sci ; 317(1): 314-25, 2008 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-17931647

RESUMO

The monolayer formed at an air/water interface by the synthetic non-ionic surfactant, 1,2-di-O-octadecyl-rac-glyceryl-3-(omega-methoxydodecakis (ethylene glycol)) (2C18E12) has been characterized using Langmuir trough measurements, Brewster angle microscopy (BAM), and neutron reflectometry. The BAM and reflectometry studies were performed at four different surface pressures (pi) in the range 15-40 mN/m. The BAM studies (which give information on the in-plane organisation of the surfactant layer) demonstrate that the 2C18E12 molecules are arranged on the water surface to form distinct, approximately circular, 5 microm diameter domains. As the surface pressure is increased these domains retain their size and shape but are made progressively more close-packed, such that the monolayer is made more or less complete at pi=40 mN/m. The neutron reflectometry measurements were made to determine the structure of the interfacial surfactant layer at pi=15, 28, 34 and 40 mN/m, providing information on the thickness of the 2C18E12 alkyl chains', head groups' and associated solvent distributions (measured along the surface normal), along with the separations between these distributions, and the effective interfacial area per molecule. Partial structure factor analyses of the reflectivity data show that the effective interfacial area occupied decreases from 217 A2 per 2C18E12 molecule at pi=15 mN/m down to 102 A2 at pi=40 mN/m. There are concomitant increases in the widths of the surfactant's alkyl chains' and head groups' distributions (modelled as Gaussians), with the former rising from 12 A (at pi=15 mN/m) up to 19 A (at pi=40 mN/m) and the latter rising from 13 A (at pi=15 mN/m) up to 24 A (at pi=40 mN/m). The compression of the monolayer is also shown to give rise to an increased surface roughness, some of which is due to the thermal roughness caused by capillary waves, but with a significant contribution also coming from the intrinsic/structural disorder in the monolayer. At all surface pressures studied, the alkyl chains and head groups of the 2C18E12 are found to exhibit a significant overlap, and this increases with increasing pi. Given the various trends noted on how the structure of the 2C18E12 monolayer changes as a function of pi, we extrapolate to consider the structure of the monolayer at pi>40 mN/m (making comparison with its single chain (CnEm) counterparts) and then relate these findings to the observations recorded on the structure and solute entrapment efficiency of 2C18E12 vesicles.


Assuntos
Membranas Artificiais , Polietilenoglicóis/química , Tensoativos/química , Triglicerídeos/química , Ar , Microscopia/métodos , Modelos Moleculares , Estrutura Molecular , Nêutrons , Tamanho da Partícula , Pressão , Espalhamento de Radiação , Propriedades de Superfície , Temperatura , Água/química
12.
J Colloid Interface Sci ; 316(2): 741-50, 2007 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-17825312

RESUMO

The behaviour of monolayers and bilayers formed by the dialkyl chain non-ionic surfactant, 1,2-di-O-octadecyl-rac-glycerol-3-omega-methoxydodecaethylene glycol (2C(18)E(12)) in water at 297 K has been investigated. Using a surface film balance (or Langmuir trough) the compression-expansion cycle of the 2C(18)E(12) monolayer was found to be reversible when compressed to surface pressures (pi) less than 42 mN m(-1). Compression of 2C(18)E(12) monolayer to pi greater than 42 mN m(-1) above this resulted in a considerable hysteresis upon expansion with the pi remaining high relative to that obtained upon compression, suggesting a time/pressure dependent re-arrangement of 2C(18)E(12) molecules in the film. Morphology of the 2C(18)E(12) monolayer, investigated using Brewster angle microscopy, was also found to depend upon monolayer history. Bright, randomly dispersed domains of 2C(18)E(12) of approximately 5 mum in size were observed during compression of the monolayer to pi less than 42 mN m(-1). At pi of 42 mN m(-1) and above, the surfactant film appeared to be almost completely 'solid-like.' Regardless of the extent of compression of the monolayer film, expansion of the film caused formation of chains or 'necklaces' of individual surfactant domains, with the extent of chain formation dependent upon pressure of compression of the monolayer and the length of time held at that pressure. Irreversible effects on 2C(18)E(12) vesicle size were also seen upon temperature cycling the vesicles through their liquid-crystalline phase transition temperature with vesicles shrinking in size and not returning to their original size upon standing at 298 K for periods of more than 24 h. No comparable hysteresis, time, pressure or temperature effects were observed with the monolayer or vesicles formed by the corresponding phospholipid, disteaorylphosphatidylcholine, under identical conditions. The effects observed with 2C(18)E(12) are attributed to the ability of the polyoxyethylene head group to dehydrate and intrude into the hydrophobic chain region of the mono- and bilayers. These studies have important implications for the use of the vesicles formed by 2C(18)E(12) as drug delivery vehicles.


Assuntos
Sistemas de Liberação de Medicamentos , Membranas Artificiais , Polietilenoglicóis/química , Tensoativos/química , Triglicerídeos/química , Microscopia/métodos , Tamanho da Partícula , Veículos Farmacêuticos/química , Propriedades de Superfície , Temperatura
13.
J Physiol ; 537(Pt 3): 779-92, 2001 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-11744754

RESUMO

1. The purpose of this study was to investigate the hypothesis that tyrosine kinase activity contributes to alpha(1)-adrenergic inhibition of beta-adrenergic responses in cardiac myocytes. We addressed this question by studying the pharmacological regulation of the L-type Ca(2+) current in acutely isolated adult guinea-pig ventricular myocytes using the whole-cell patch-clamp technique. 2. The selective alpha(1)-adrenergic receptor agonist methoxamine had no effect on the basal L-type Ca(2+) current. Methoxamine also had no effect on cAMP-dependent stimulation of the Ca(2+) current mediated by H(2) histamine receptor activation. However, methoxamine did inhibit cAMP-dependent stimulation of the Ca(2+) current mediated by beta-adrenergic receptor activation. The ability of methoxamine to inhibit beta-adrenergic regulation of the Ca(2+) current was significantly antagonized by the tyrosine kinase inhibitors genistein and lavendustin A. 3. The inhibitory effect of methoxamine was also mimicked by the phosphotyrosine phosphatase inhibitor pervanadate (PVN). PVN had no effect on basal Ca(2+) current or Ca(2+) current stimulated by histamine, but it did inhibit Ca(2+) current stimulated by beta-adrenergic receptor activation. Furthermore, the ability of PVN to inhibit beta-adrenergic stimulation of the Ca(2+) current was antagonized by lavendustin A. 4. These results are consistent with the conclusion that in guinea-pig ventricular myocytes alpha-adrenergic inhibition of beta-adrenergic responses involves a tyrosine kinase-dependent signalling pathway. The fact that methoxamine and PVN antagonized cAMP-dependent responses mediated by beta-adrenergic, but not H(2) histamine, receptor activation suggests that the inhibitory effect of alpha-adrenergic stimulation and tyrosine kinase activity is at the level of the beta-adrenergic receptor.


Assuntos
Canais de Cálcio Tipo L/fisiologia , Miocárdio/metabolismo , Proteínas Tirosina Quinases/metabolismo , Receptores Adrenérgicos alfa/fisiologia , Receptores Adrenérgicos beta/fisiologia , Agonistas alfa-Adrenérgicos/farmacologia , Animais , Condutividade Elétrica , Inibidores Enzimáticos/farmacologia , Cobaias , Histamina/farmacologia , Antagonistas dos Receptores Histamínicos/farmacologia , Miocárdio/citologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Receptores Adrenérgicos beta/efeitos dos fármacos , Vanadatos/farmacologia
14.
J Physiol ; 536(Pt 3): 677-92, 2001 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-11691864

RESUMO

1. The effects that muscarinic receptor stimulation have on the cAMP-dependent regulation of L-type Ca(2+) currents were studied in isolated guinea-pig ventricular myocytes using the whole-cell configuration of the patch-clamp technique. 2. The muscarinic agonist ACh inhibited the Ca(2+) current stimulated by the beta-adrenergic agonist isoprenaline (Iso), and washout of ACh revealed a stimulatory response that appeared as a transient rebound increase in the amplitude of the Ca(2+) current. The ACh-induced stimulatory effect was not observed in the absence of Iso. 3. ACh-induced rebound stimulation was also observed in the presence of H(2) histamine receptor activation and cholera toxin treatment, which like beta-adrenergic receptor activation enhance adenylyl cyclase (AC) activity in a stimulatory G protein (G(s))-dependent manner. ACh-induced rebound stimulation was not observed in the presence of forskolin, which enhances AC activity in a G(s)-independent manner. 4. Pertussis toxin (PTX) treatment blocked both the stimulatory and inhibitory effects of ACh. Intracellular dialysis with QEHA, a peptide that binds free G protein betagamma subunits, selectively antagonized the stimulatory effect, leaving an enhanced inhibitory effect. 5. Evidence for the expression of AC4, an isoform of AC that can be stimulated by Gbetagamma but only in the presence of Galpha(s), was obtained by Western blot analysis of guinea-pig ventricular myocyte membrane preparations. 6. These results suggest that muscarinic receptor stimulation facilitates as well as inhibits cAMP-dependent regulation of the Ca(2+) current and that the net response is a balance between these two actions. We suggest that the stimulatory effect is due to a direct activation of AC4 by the betagamma subunits of a PTX-sensitive G protein.


Assuntos
Acetilcolina/farmacologia , Adenilil Ciclases/metabolismo , Agonistas dos Canais de Cálcio/farmacologia , Canais de Cálcio Tipo L/efeitos dos fármacos , Subunidades alfa Gs de Proteínas de Ligação ao GTP/fisiologia , Miocárdio/metabolismo , 3',5'-AMP Cíclico Fosfodiesterases/metabolismo , Toxina Adenilato Ciclase , Animais , Nucleotídeo Cíclico Fosfodiesterase do Tipo 3 , Estimulação Elétrica , Ativação Enzimática/efeitos dos fármacos , Cobaias , Ventrículos do Coração/citologia , Ventrículos do Coração/metabolismo , Immunoblotting , Técnicas In Vitro , Potenciais da Membrana/fisiologia , Agonistas Muscarínicos/farmacologia , Miocárdio/citologia , Óxido Nítrico Sintase/metabolismo , Técnicas de Patch-Clamp , Toxina Pertussis , Receptores Adrenérgicos beta/efeitos dos fármacos , Fatores de Virulência de Bordetella/farmacologia
15.
J Soc Psychol ; 141(2): 174-89, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11372564

RESUMO

In an attempt to define stigmatization from the perspective of stigmatized group members, the author focused on the development and validation of a stigmatization scale. The scale's content validity was established with the assistance of experts in the field. European American, African American, and Native American students from 5 different U.S. universities completed the Stigmatization Scale. The construct validity of the scale was suggested by its convergence with similar measures of social alienation and its divergence from measures of personal subjective well-being. The finding that both the African American and Native American students reported significantly higher stigmatization scores than did the European Americans indicated the scale's known-groups validity. African American students at a predominantly Black university reported lower stigmatization than did African American students at a predominantly White university, suggesting the scale's malleability to context.


Assuntos
Etnicidade/estatística & dados numéricos , Estereotipagem , Inquéritos e Questionários , Adulto , Comparação Transcultural , Humanos , Preconceito , Reprodutibilidade dos Testes , Autoimagem , Percepção Social
16.
Curr Treat Options Oncol ; 2(6): 537-47, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12057099

RESUMO

Metastatic tumors to the brain are an increasing cause of morbidity and mortality in patients with systemic cancers. Many new therapies used to treat systemic cancers do not penetrate the central nervous system (CNS) and do not protect patients from the development of brain metastases. Surgery, radiosurgery, and radiation therapy are all used to treat brain metastases. It is in our opinion a mistake to use only one or two of these modalities to the exclusion of other(s). The role of systemic chemotherapy is still limited, due to both the issues of drug delivery caused by the blood brain barrier and to the relative resistance of many of these tumors to chemotherapy. Traditionally, brain metastases have been grouped together regardless of the origin of the tumor and have been treated with a single algorithm. As we encounter more patients for whom treatment of the brain metastases is an important determinant of survival, we must tailor our treatment strategies to individual tumor types. Also, we must recognize differences in each tumor's sensitivity to chemotherapy and radiotherapy and differences in their biology.


Assuntos
Neoplasias Encefálicas/secundário , Carcinoma/secundário , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/terapia , Neoplasias da Mama/patologia , Carcinoma/diagnóstico , Carcinoma/mortalidade , Carcinoma/terapia , Quimioterapia Adjuvante , Terapia Combinada , Irradiação Craniana , Craniotomia , Diagnóstico por Imagem , Progressão da Doença , Métodos Epidemiológicos , Feminino , Humanos , Neoplasias Pulmonares/patologia , Masculino , Melanoma/diagnóstico , Melanoma/mortalidade , Melanoma/secundário , Melanoma/terapia , Prognóstico , Radiocirurgia , Radioterapia Adjuvante , Análise de Sobrevida , Resultado do Tratamento
17.
Mol Pharmacol ; 58(6): 1213-21, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11093756

RESUMO

beta-Adrenergic receptor stimulation regulates the activity of several different cardiac ion channels through an adenylate cyclase/cAMP/protein kinase A-dependent mechanism. Previous work has suggested that basal tyrosine kinase activity attenuates the beta-adrenergic responsiveness of these cardiac ion channels, supporting the idea that tyrosine phosphorylation exerts an inhibitory effect at some point in the common signaling pathway. To determine which element in the beta-adrenergic pathway is regulated by tyrosine kinase activity, we studied the effects of various protein tyrosine phosphatase (PTP) inhibitors on the cAMP-dependent regulation of the L-type Ca(2+) current in guinea pig ventricular myocytes. Three such compounds, sodium orthovanadate, peroxovanadate, and bpV(phen), had no effect on the basal Ca(2+) current, yet each caused a pronounced inhibition of the Ca(2+) current stimulated by the beta-adrenergic receptor agonist isoproterenol. These observations are consistent with the idea that basal tyrosine kinase activity is capable of inhibiting beta-adrenergic responses. However, these PTP inhibitors had no effect on cAMP-dependent stimulation of the Ca(2+) current via activation of adenylate cyclase with forskolin or activation of H(2)-histaminergic receptors with histamine. These results are consistent with the idea that inhibition of PTP activity produces an inhibitory effect involving a tyrosine kinase-dependent mechanism acting selectively at the level of the beta-adrenergic receptor. This signaling mechanism does not seem to be linked to tyrosine kinase activity associated with insulin and insulin-like growth factor receptors, because acute exposure to agonists of these receptors did not inhibit isoproterenol regulation of the Ca(2+) current.


Assuntos
Canais de Cálcio Tipo L/fisiologia , Inibidores Enzimáticos/farmacologia , Proteínas Tirosina Fosfatases/antagonistas & inibidores , Proteínas Tirosina Quinases/fisiologia , Receptores Adrenérgicos beta/fisiologia , Animais , Canais de Cálcio Tipo L/efeitos dos fármacos , Células Cultivadas , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Eletrofisiologia , Cobaias , Coração/efeitos dos fármacos , Coração/fisiologia , Miocárdio/metabolismo , Compostos Organometálicos/farmacologia , Fenantrolinas/farmacologia , Proteínas Tirosina Fosfatases/fisiologia , Vanadatos/farmacologia
18.
J Physiol ; 528 Pt 2: 279-89, 2000 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-11034618

RESUMO

Using conventional and perforated patch-clamp techniques, the inhibitory and stimulatory effects of acetylcholine (ACh) on beta-adrenergic regulation of the L-type Ca2+ current (ICa) were studied in ventricular myocytes from wild-type mice (WT) and from mice lacking endothelial nitric oxide synthase (eNOS or NOS3; NOS3-KO mice). To validate the direct comparison of ACh effects on beta-adrenergic responses, the sensitivity of ICa to the beta-adrenergic agonist isoprenaline (Iso) was studied in both WT and NOS3-KO mouse myocytes. ICa sensitivity to Iso was not found to be significantly different in WT and NOS3-KO myocytes: Iso increased ICa with an EC50 of 4.9 and 3.7 nM in WT and NOS3-KO myocytes, respectively. ACh-induced inhibition of ICa did not significantly differ in ventricular myocytes from WT and NOS3-KO mice. ACh (10 microM) inhibited the stimulatory effect of 3 nM Iso by 39 and 35% in WT and NOS3-KO myocytes, respectively. Exposure to and subsequent washout of ACh in the continuous presence of submaximally stimulating concentrations of Iso (1-3 nM) resulted in a transient rebound stimulation of ICa in both WT and NOS3-KO mouse myocytes. The magnitude of the stimulatory effect of ACh did not significantly differ in WT and NOS3-KO mice. These results indicate that nitric oxide (NO) generated by NOS3 does not significantly affect the beta-adrenergic responsiveness of ICa. The results also confirm previous work indicating that NO generated by NOS3 is not obligatory for muscarinic inhibition of the beta-adrenergically regulated ICa in ventricular myocytes. Finally these results demonstrate for the first time that NO generated by NOS3 is not involved in muscarinic rebound stimulation of ICa in ventricular myocytes.


Assuntos
Canais de Cálcio Tipo L/metabolismo , Miocárdio/metabolismo , Óxido Nítrico Sintase/deficiência , Acetilcolina/farmacologia , Agonistas Adrenérgicos beta/farmacologia , Animais , Canais de Cálcio Tipo L/efeitos dos fármacos , Ventrículos do Coração/citologia , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/metabolismo , Técnicas In Vitro , Isoproterenol/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Miocárdio/citologia , Óxido Nítrico Sintase/genética , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico Sintase Tipo II , Óxido Nítrico Sintase Tipo III , Técnicas de Patch-Clamp , Receptores Muscarínicos/efeitos dos fármacos , Receptores Muscarínicos/metabolismo
19.
Ann Pharmacother ; 34(7-8): 851-7, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10928394

RESUMO

OBJECTIVE: To conduct a retrospective drug utilization evaluation comparing the use of granulocyte colony-stimulating factor (G-CSF) at a university medical center with the American Society of Clinical Oncology (ASCO) CSFs Practice Guidelines. METHODS: Patients who received G-CSF from June 1, 1996, to December 31, 1996, were identified through the pharmacy computer system and the medical records were reviewed for a randomly selected sample of 26% of the 289 patients identified. Outpatient, inpatient, and electronic medical records were reviewed for the indication, dosage, day of initiation, day of discontinuation, and absolute neutrophil count (ANC) monitoring plan for each course of G-CSF; these records were subsequently compared with the ASCO guidelines. RESULTS: The use of G-CSF after chemotherapy was evaluated in 51 patients who received a total of 182 courses of G-CSF. The goal of chemotherapy was curative in 61% of courses. Sixty-five percent of G-CSF courses were prescribed for primary prophylaxis. Of these, 74% followed chemotherapy in patients with an expected incidence of febrile neutropenia > or =40% or followed chemotherapy in patients with compromised marrow reserve secondary to extensive prior therapy or in patients older than 60 years. Most of the G-CSF courses (75%) were rounded to the nearest vial size. The areas of greatest departure from the ASCO guidelines included aspects of initiation and discontinuation of G-CSF courses and inadequate documentation of ANC recovery. CONCLUSIONS: These results demonstrate a number of specific opportunities for oncology pharmacists to improve the use of G-CSF in patients receiving chemotherapy. Recommendations were made to the pharmacy and therapeutics committee and medical oncologists to improve compliance with the ASCO guidelines.


Assuntos
Revisão de Uso de Medicamentos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/uso terapêutico , Neoplasias/tratamento farmacológico , Idoso , Antineoplásicos/uso terapêutico , Análise Custo-Benefício , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/administração & dosagem , Fidelidade a Diretrizes , Humanos , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica , Neoplasias/imunologia , Neutrófilos , Farmacêuticos , Distribuição Aleatória , Estudos Retrospectivos
20.
Br J Anaesth ; 80(6): 850-2, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9771323

RESUMO

The clinical course and diagnosis of a patient with Cushing's disease complicated by pregnancy is described, and the anaesthetic management of trans-sphenoidal selective adenomectomy performed during the second trimester outlined. Problems included obesity, diabetes, hypertension and a suboptimal airway. Fibreoptic awake intubation and intravenous anaesthesia were used. Insulin requirements decreased substantially after surgery. Early administration of hydrocortisone after surgery avoided the risk of an addisonian crisis but delayed biochemical confirmation of a metabolic cure.


Assuntos
Anestesia Geral/métodos , Síndrome de Cushing/cirurgia , Complicações na Gravidez/cirurgia , Adenoma/cirurgia , Adulto , Feminino , Humanos , Hipofisectomia/métodos , Neoplasias Hipofisárias/cirurgia , Gravidez
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA