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1.
Comput Graph Forum ; 42(3): 423-435, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38505301

RESUMEN

Generative text-to-image models (as exemplified by DALL-E, MidJourney, and Stable Diffusion) have recently made enormous technological leaps, demonstrating impressive results in many graphical domains-from logo design to digital painting to photographic composition. However, the quality of these results has led to existential crises in some fields of art, leading to questions about the role of human agency in the production of meaning in a graphical context. Such issues are central to visualization, and while these generative models have yet to be widely applied in visualization, it seems only a matter of time until their integration is manifest. Seeking to circumvent similar ponderous dilemmas, we attempt to understand the roles that generative models might play across visualization. We do so by constructing a framework that characterizes what these technologies offer at various stages of the visualization workflow, augmented and analyzed through semi-structured interviews with 21 experts from related domains. Through this work, we map the space of opportunities and risks that might arise in this intersection, identifying doomsday prophecies and delicious low-hanging fruits that are ripe for research.

2.
HIV Med ; 22(1): 28-36, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32964664

RESUMEN

OBJECTIVES: We aimed to compare the effectiveness of antiretroviral therapy (ART) classes for achieving HIV RNA suppression to < 50 HIV-1 RNA copies/mL within 6 months of initiation with high viral loads (VLs). Secondary objectives were to compare viral suppression (VS) at 12 weeks and 12 months, partial HIV RNA suppression to < 200 copies/mL, time to VS, time to rebound, and change in CD4 cell count. METHODS: This was a multicentre, retrospective, observational study. Adult patients were included if they initiated ART between January 2005 and December 2016 with a VL ≥ 100 000 copies/mL. RESULTS: There were 220 patients included in the study. The median VL was 252 919 [interquartile range (IQR) 149 472-500 000] copies/mL. Nonnucleoside reverse transcriptase inhibitor (NNRTI) recipients were more likely to achieve VS by 6 months compared to those initiating ART containing protease inhibitors (PIs) [75.4% vs. 44.1%, respectively; odds ratio (OR) 3.34; 95% confidence interval (CI) 1.62-6.90] or integrase strand transfer inhibitors (INSTIs) (75.4% vs. 55.8%, respectively; OR 2.40; 95% CI 1.03-5.58). VS at 12 weeks was more frequent with INSTI-containing regimens than with PIs (28.9% vs. 9.0%, respectively; OR 4.10; 95% CI 1.69-9.92). VS at 12 months did not significantly differ between treatment regimens. Median time to complete VS for INSTI, PI and NNRTI recipients was 22.3 (95% CI 13.4-33), 30.1 (95% CI 25-36) and 19.9 (95% CI 16-22.3) weeks, respectively. There were no significant differences in time to viral rebound or change in CD4 cell counts. CONCLUSIONS: Patients with high VLs initiated on NNRTIs were more likely to achieve VS by 6 months on ART compared to INSTI and PI recipients.


Asunto(s)
Infecciones por VIH/tratamiento farmacológico , Inhibidores de Integrasa VIH/uso terapéutico , Inhibidores de la Transcriptasa Inversa/uso terapéutico , Carga Viral/efectos de los fármacos , Adulto , Terapia Antirretroviral Altamente Activa , Femenino , Infecciones por VIH/virología , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Carga Viral/estadística & datos numéricos
3.
Sci Total Environ ; 572: 1636-1644, 2016 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-26996523

RESUMEN

To predict ecosystem responses to anthropogenic change it is important to understand how and where plant productivity is limited by macronutrient availability. Nitrogen (N) is required in large quantities for plant growth, and is readily lost through leaching or gas fluxes, but reactive nitrogen can be obtained through dinitrogen fixation, and phosphorus (P) is often considered a more fundamental long-term constraint to growth and carbon sequestration in terrestrial ecosystems. Phosphorus limitation may be becoming more prevalent due to widespread pollution by atmospheric N. Assessments of the effects of macronutrient availability on productivity in natural ecosystems are however scarce. We measured standing biomass of bracken Pteridium aquilinum as a proxy for productivity across sites with similar climate but varied geology. Total above-ground biomass varied from 404 to 1947gm-2, yet despite 12-fold to 281-fold variation in soil macronutrient stocks these were remarkably poor at explaining variation in productivity. Soil total nitrogen, organic phosphorus, calcium, magnesium and zinc had no relationship with productivity, whether expressed as concentrations, stocks or element/C ratios, and nor did foliar N/P. Soil potassium (K) and molybdenum stocks both showed weak relationships with productivity. The stock of K in bracken biomass was considerably greater as a proportion of soil stock than for other nutrient elements, suggesting that this nutrient element can be important in determining productivity. Moisture availability, as indicated by environmental trait scores for plant species present, explained considerably more of the variation in productivity than did K stock, with less production in wetter sites. Soil N/C ratio and organic P stock were relatively unimportant in determining productivity across these bracken sites. It is possible that more-direct measures of N and P availability would explain variation in productivity, but the study shows the importance of considering other essential elements and other environmental factors when predicting productivity.


Asunto(s)
Carbono/metabolismo , Nitrógeno/metabolismo , Fósforo/metabolismo , Pteridium/crecimiento & desarrollo , Suelo/química , Biomasa , Secuestro de Carbono , Pteridium/metabolismo
4.
HIV Med ; 14(7): 401-9, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23433482

RESUMEN

OBJECTIVES: The pharmacokinetics (PK) of antiretrovirals (ARVs) in older HIV-infected patients are poorly described. Here, the steady-state PK of two common ARV regimens [tenofovir (TFV)/emtricitabine (FTC)/efavirenz (EFV) and TFV/FTC/atazanavir (ATV)/ritonavir (RTV)] in older nonfrail HIV-infected patients are presented. METHODS: HIV-infected subjects ≥ 55 years old not demonstrating the frailty phenotype were enrolled in an unblinded, intensive-sampling PK study. Blood plasma (for TFV, FTC, EFV, ATV and RTV concentrations) and peripheral blood mononuclear cells [PBMCs; for tenofovir diphosphate (TFV-DP) and emtricitabine triphosphate (FTC-TP) concentrations] were collected at 11 time-points over a 24-hour dosing interval. Drug concentrations were analysed using validated liquid chromatography-ultraviolet detection (LC-UV) or liquid chromatography tandem mass spectrometry (LC-MS/MS) methods. Noncompartmental pharmacokinetic analysis was used to estimate PK parameters [area under the concentration-time curve over 24 h (AUC0-24h ) and maximal concentration (Cmax )]. These parameters were compared with historical values from the general HIV-infected population. RESULTS: Six subjects on each regimen completed the study. Compared with the general population, these elderly subjects had 8-13% decreased TFV AUC0-24h and Cmax , and 19-78% increased FTC and RTV AUC0-24h and Cmax . Decreased ATV AUC0-24h (12%) and increased Cmax (9%) were noted, while EFV exposure was unchanged (5%) with a 16% decrease in Cmax . Intracellular nucleoside/tide metabolite concentrations and AUC are also reported for these subjects. CONCLUSIONS: This study demonstrates that the PK of these ARVs are altered by 5-78% in an older HIV-infected population. Implications of PK differences for clinical outcomes, particularly with the active nucleoside metabolites, remain to be explored. This study forms the basis for further study of ARV PK, efficacy, and toxicity in older HIV-infected patients.


Asunto(s)
Adenina/análogos & derivados , Fármacos Anti-VIH/farmacocinética , Benzoxazinas/farmacocinética , Desoxicitidina/análogos & derivados , Infecciones por VIH/tratamiento farmacológico , Oligopéptidos/farmacocinética , Organofosfonatos/farmacocinética , Piridinas/farmacocinética , Ritonavir/farmacocinética , Adenina/administración & dosificación , Adenina/farmacocinética , Adenina/uso terapéutico , Negro o Afroamericano/etnología , Anciano , Alquinos , Fármacos Anti-VIH/administración & dosificación , Fármacos Anti-VIH/uso terapéutico , Sulfato de Atazanavir , Benzoxazinas/administración & dosificación , Benzoxazinas/uso terapéutico , Ciclopropanos , Interpretación Estadística de Datos , Desoxicitidina/administración & dosificación , Desoxicitidina/farmacocinética , Desoxicitidina/uso terapéutico , Emtricitabina , Femenino , Anciano Frágil , VIH/efectos de los fármacos , VIH/patogenicidad , Infecciones por VIH/virología , Humanos , Masculino , Persona de Mediana Edad , Oligopéptidos/administración & dosificación , Oligopéptidos/uso terapéutico , Organofosfonatos/administración & dosificación , Organofosfonatos/uso terapéutico , Proyectos Piloto , Piridinas/administración & dosificación , Piridinas/uso terapéutico , Ritonavir/administración & dosificación , Ritonavir/uso terapéutico , Tenofovir , Población Blanca/etnología
5.
Osteoporos Int ; 24(4): 1195-206, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23100119

RESUMEN

UNLABELLED: We examined the association between osteoporosis treatment change and adherence, incident fractures, and healthcare costs among Medicare Advantage Prescription Drug (MAPD) plan members. Treatment change was associated with a small but significant increase in adherence, but was not associated with incident fracture or total healthcare costs. Overall adherence remained low. INTRODUCTION: We examined the association between osteoporosis treatment change and adherence, incident fractures, and healthcare costs among MAPD plan members in a large US health plan. METHODS: We conducted a retrospective cohort study of MAPD plan members aged≥50 years newly initiated on an osteoporosis medication between 1 January 2006 and 31 December 2008. Members were identified as having or not having an osteoporosis treatment change within 12 months after initiating osteoporosis medication. Logistic regression analyses and difference-in-difference (DID) generalized linear models were used to investigate the association between osteoporosis treatment change and (1) adherence to treatment, (2) incident fracture, and (3) healthcare costs at 12 and 24 months follow-up. RESULTS: Of the 33,823 members newly initiated on osteoporosis treatment, 3,573 (10.6%) changed osteoporosis treatment within 12 months. After controlling for covariates, osteoporosis treatment change was associated with significantly higher odds of being adherent (medication possession ratio [MPR]≥0.8) at 12 months (odds ratio [OR]=1.18) and 24 months (OR=1.13) follow-up. However, overall adherence remained low (MPR=0.59 and 0.51 for the change cohort and MPR=0.51 and 0.44 for the no-change cohort at 12 and 24 months, respectively). Osteoporosis treatment change was not significantly associated with incident fracture (OR=1.00 at 12 months and OR=0.98 at 24 months) or total direct healthcare costs (p>0.4) in the DID analysis, but was associated with higher pharmacy costs (p<0.004). CONCLUSIONS: Osteoporosis treatment change was associated with a small but significant increase in adherence, but was not associated with incident fracture or total healthcare costs in the MAPD plan population. Overall adherence to therapy remained low.


Asunto(s)
Conservadores de la Densidad Ósea/uso terapéutico , Costos de la Atención en Salud/estadística & datos numéricos , Cumplimiento de la Medicación/estadística & datos numéricos , Osteoporosis/tratamiento farmacológico , Fracturas Osteoporóticas/prevención & control , Anciano , Anciano de 80 o más Años , Conservadores de la Densidad Ósea/economía , Costos de los Medicamentos/estadística & datos numéricos , Sustitución de Medicamentos/economía , Sustitución de Medicamentos/estadística & datos numéricos , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Medicare Part C/economía , Persona de Mediana Edad , Osteoporosis/economía , Osteoporosis/epidemiología , Fracturas Osteoporóticas/economía , Fracturas Osteoporóticas/epidemiología , Estados Unidos/epidemiología
7.
Thorac Cardiovasc Surg ; 56(4): 190-4, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18481235

RESUMEN

BACKGROUND: The current activity guidelines for coronary artery bypass graft surgery (CABG) patients are overly restrictive, hindering recovery. As the sternotomy repair must withstand repeated coughs during convalescence, this provides a benchmark for the force tending to separate the incision that can be tolerated. METHODS: Nine volunteers performed 5 weightlifting activities (lifting 5 lbs [2.3 kg], lifting a 25-lb simulated grandchild [11.4 kg], lifting a 30-lb suitcase [13.6 kg], lifting two 20-lb weights [18.2 kg], and lifting a gallon of milk to a counter [3.7 kg]), plus coughing. Valsalva forces were detected using a mouthpiece configured with an Ashcroft Inc. expiratory pressure gauge (model N10-120CMW). Three measurements were taken for each activity to calculate the mean internal forces while external forces on the sternotomy were calculated using vector algebra. Total force exerted on the sternotomy by the cough was compared to the total force exerted by each of the 5 activities using paired T-tests. RESULTS: The cough exerted a significantly greater force across the median sternotomy (mean 27.5 kg-mass) than any of the five weightlifting activities ( P < 0.05). The greatest difference was observed was for lifting a 5-lb weight (22.5 kg-mass), and the smallest for lifting two 20-lb weights (4.4 kg-mass). CONCLUSION: Lifting even 40 lbs puts less force on the median sternotomy incision than a cough. The strength of the repair is significantly greater than is implied by the recommendation to "not lift more than 5 lbs".


Asunto(s)
Actividades Cotidianas , Puente de Arteria Coronaria/rehabilitación , Tos/fisiopatología , Elevación , Cuidados Posoperatorios/rehabilitación , Esternón/fisiopatología , Maniobra de Valsalva , Adulto , Anciano , Fenómenos Biofísicos , Biofisica , Contraindicaciones , Femenino , Humanos , Masculino , Persona de Mediana Edad , Presión , Análisis y Desempeño de Tareas
8.
Prostate ; 67(11): 1211-8, 2007 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-17525933

RESUMEN

BACKGROUND: In normal prostate epithelial cells low m-aconitase activity decreases citrate oxidation leading to citrate accumulation. In prostate cancer cells m-aconitase activity is increased and citrate content is lower. The effect of inhibition of m-aconitase on ATP production by prostate cancer cells (PC3) is not known nor is the contribution of glycolysis versus respiration. METHODS: ATP content of PC3 cells as affected by inhibition of m-aconitase (fluoroacetate (FA), zinc), inhibition of glycolysis (2DxG), or respiration (DNP, oligomycin) was determined. The ability to maintain ATP using glucose or glutamine as sole substrate was also determined. Intermediates including ATP, lactate, glucose, and glutamine were assayed in neutralized perchloric acid (PCA) cell extracts, virgin, and conditioned medium by enzymatic fluorometry. RESULTS: Data show that inhibition of m-aconitase, glycolysis, or respiration alone did not decrease ATP content. Inhibition of both glycolysis and respiration were required to decrease ATP content. PC3 cells were able to produce ATP with either glucose or glutamine as sole substrate. Though FA clearly inhibited m-aconitase there was no evidence that zinc had a similar effect. CONCLUSION: PC3 cells can support ATP production when m-aconitase is inhibited by using glycolysis or oxidation of substrate (e.g., glutamine) entering the TCA cycle distal to citrate.


Asunto(s)
Adenosina Trifosfato/análisis , Antimetabolitos/farmacología , Ácido Cítrico/análisis , Neoplasias de la Próstata/química , Aconitato Hidratasa/antagonistas & inhibidores , Línea Celular Tumoral , Desoxiglucosa/farmacología , Dinitrofenoles/farmacología , Inhibidores Enzimáticos/farmacología , Fluoroacetatos/farmacología , Glucólisis/efectos de los fármacos , Humanos , Masculino , Oligomicinas/farmacología , Consumo de Oxígeno/efectos de los fármacos , Zinc/farmacología
9.
Microb Ecol ; 42(2): 150-8, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11680502

RESUMEN

Successional theory predicts that opportunistic species with high investment of energy in reproduction and wide niche width will be replaced by equilibrium species with relatively higher investment of energy in maintenance and narrower niche width as communities develop. Since the ability to rapidly grow into a detectable colony on nonselective agar medium could be considered as characteristic of opportunistic types of bacteria, the percentage of culturable cells may be an indicator of successional state in microbial communities. The ratios of culturable cells (colony forming units on R2A agar) to total cells (acridine orange direct microscopic counts) and culturable cells to active cells (reduction of 5-cyano-2,3-ditolyl tetrazolium chloride) were measured over time in two types of laboratory microcosms (the rhizosphere of hydroponically grown wheat and aerobic, continuously stirred tank reactors containing plant biomass) to determine the effectiveness of culturabilty as an index of successional state. The culturable cell:total cell ratio in the rhizosphere decreased from approximately 0.25 to less than 0.05 during the first 30-50 days of plant growth, and from 0.65 to 0.14 during the first 7 days of operation of the bioreactor. The culturable cell:active cell ratio followed similar trends, but the values were consistently greater than the culturable cell:total cell ratio, and even exceeded I in early samples. Follow-up studies used a cultivation-independent method, terminal restriction fragment length polymorphisms (TRFLP) from whole community DNA, to assess community structure. The number of TRFLP peaks increased with time, while the number of culturable types did not, indicating that the general decrease in culturability is associated with a shift in community structure. The ratio of respired to assimilated C-14-labeled amino acids increased with the age of rhizosphere communities, supporting the hypothesis that a shift in resource allocation from growth to maintenance occurs with time. Results from this work indicate that the percentage of culturable cells may be a useful method for assessing the successional state of microbial communities.


Asunto(s)
Ecosistema , Ambiente Controlado , Raíces de Plantas/microbiología , Triticum/microbiología , Microbiología del Agua , Aminoácidos/farmacocinética , Bacterias/crecimiento & desarrollo , Bacterias/metabolismo , Biomasa , Reactores Biológicos , Recuento de Colonia Microbiana , Ecología , Hidroponía , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Factores de Tiempo , Triticum/crecimiento & desarrollo , Triticum/metabolismo
10.
Bioorg Med Chem Lett ; 11(21): 2867-70, 2001 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-11597418

RESUMEN

Optimization of a series of N-1-cycloalkyl-4-aryl-5-(pyrimidin-4-yl)imidazole inhibitors of p38 kinase is reported. Oral administration of inhibitors possessing a cyclohexan-4-ol or piperidin-4-yl group at N-1 in combination with alkoxy, amino(alkyl), phenoxy and anilino substitution at the 2-position of the pyrimidine was found to potently inhibit LPS-induced TNF in mice and rats. The selectivity of these new inhibitors for p38 kinase versus eight other protein kinases is high and in all cases exceeds that of SB 203580.


Asunto(s)
Inhibidores Enzimáticos/farmacología , Imidazoles/farmacología , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Pirimidinas/química , Administración Oral , Animales , Inhibidores Enzimáticos del Citocromo P-450 , Inhibidores Enzimáticos/química , Imidazoles/química , Lipooxigenasa/efectos de los fármacos , Hígado/enzimología , Ratones , Prostaglandina-Endoperóxido Sintasas/efectos de los fármacos , Ratas , Proteínas Quinasas p38 Activadas por Mitógenos
11.
Circulation ; 104(11): 1292-8, 2001 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-11551882

RESUMEN

BACKGROUND: Numerous pathological mediators of cardiac hypertrophy (eg, neurohormones, cytokines, and stretch) have been shown to activate p38 MAPK. The purpose of the present study was to examine p38 MAPK activation and the effects of its long-term inhibition in a model of hypertensive cardiac hypertrophy/dysfunction and end-organ damage. METHODS AND RESULTS: In spontaneously hypertensive stroke-prone (SP) rats receiving a high-salt/high-fat diet (SFD), myocardial p38 MAPK was activated persistently during the development of cardiac hypertrophy and inactivated during decompensation. Long-term oral treatment of SFD-SP rats with a selective p38 MAPK inhibitor (SB239063) significantly enhanced survival over an 18-week period compared with the untreated group (100% versus 50%). Periodic echocardiographic analysis revealed a significant reduction in LV hypertrophy and dysfunction in the SB239063-treatment groups. Little or no difference in blood pressure was noted in the treatment or vehicle groups. Basal and stimulated (lipopolysaccharide) plasma tumor necrosis factor-alpha concentrations were reduced in the SB239063-treatment groups. In vitro vasoreactivity studies demonstrated a significant preservation of endothelium-dependent relaxation in animals treated with the p38 MAPK inhibitor without effects on contraction or NO-mediated vasorelaxation. Proteinuria and the incidence of stroke (53% versus 7%) were also reduced significantly in the SB239063-treated groups. CONCLUSIONS: These results demonstrate a crucial role for p38 MAPK in hypertensive cardiac hypertrophy and end-organ damage. Interrupting its function with a specific p38 MAPK inhibitor halts clinical deterioration.


Asunto(s)
Cardiomegalia/fisiopatología , Hipertensión/fisiopatología , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Animales , Cardiomegalia/enzimología , Cardiomegalia/mortalidad , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Ecocardiografía , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/fisiopatología , Activación Enzimática , Corazón/efectos de los fármacos , Corazón/fisiopatología , Hemodinámica/efectos de los fármacos , Imidazoles/farmacología , Riñón/efectos de los fármacos , Riñón/fisiopatología , Lipopolisacáridos/farmacología , Masculino , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Miocardio/metabolismo , Miocardio/patología , Fosforilación , Proteinuria/prevención & control , Proteinuria/orina , Pirimidinas/farmacología , Ratas , Ratas Endogámicas SHR , Ratas Endogámicas WKY , Accidente Cerebrovascular/patología , Accidente Cerebrovascular/prevención & control , Tasa de Supervivencia , Factores de Tiempo , Factor de Necrosis Tumoral alfa/efectos de los fármacos , Factor de Necrosis Tumoral alfa/metabolismo , Vasodilatación/efectos de los fármacos , Proteínas Quinasas p38 Activadas por Mitógenos
12.
J Med Chem ; 44(12): 2015-26, 2001 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-11384246

RESUMEN

5-Dialkylaminosulfonylisatins have been identified as potent, nonpeptide inhibitors of caspases 3 and 7. The most active compound within this series (34) inhibited caspases 3 and 7 in the 2-6 nM range and exhibited approximately 1000-fold selectivity for caspases 3 and 7 versus a panel of five other caspases (1, 2, 4, 6, and 8) and was at least 20-fold more selective versus caspase 9. Sequence alignments of the active site residues of the caspases strongly suggest that the basis of this selectivity is due to binding in the S2 subsite comprised of residues Tyr204, Trp206, and Phe256 which are unique to caspases 3 and 7. These compounds inhibit apoptosis in three cell-based models: human Jurkat T cells, human chondrocytes, and mouse bone marrow neutrophils.


Asunto(s)
Inhibidores de Caspasas , Inhibidores de Cisteína Proteinasa/síntesis química , Isatina/análogos & derivados , Isatina/síntesis química , Sulfonamidas/síntesis química , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Antineoplásicos/toxicidad , Apoptosis/efectos de los fármacos , Caspasa 3 , Caspasa 7 , Línea Celular , Supervivencia Celular/efectos de los fármacos , Condrocitos/citología , Condrocitos/efectos de los fármacos , Inhibidores de Cisteína Proteinasa/química , Inhibidores de Cisteína Proteinasa/farmacología , Diseño de Fármacos , Humanos , Isatina/química , Isatina/farmacología , Células Jurkat , Cinética , Ratones , Modelos Moleculares , Conformación Molecular , Neutrófilos/citología , Neutrófilos/efectos de los fármacos , Neutrófilos/fisiología , Proteínas Recombinantes/antagonistas & inhibidores , Relación Estructura-Actividad , Sulfonamidas/química , Sulfonamidas/farmacología
13.
J Immunol ; 166(10): 6341-8, 2001 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-11342658

RESUMEN

The anaphylatoxin C3a is a potent chemotactic peptide and inflammatory mediator released during complement activation which binds to and activates a G-protein-coupled receptor. Molecular cloning of the C3aR has facilitated studies to identify nonpeptide antagonists of the C3aR. A chemical lead that selectively inhibited the C3aR in a high throughput screen was identified and chemically optimized. The resulting antagonist, N(2)-[(2,2-diphenylethoxy)acetyl]-L-arginine (SB 290157), functioned as a competitive antagonist of (125)I-C3a radioligand binding to rat basophilic leukemia (RBL)-2H3 cells expressing the human C3aR (RBL-C3aR), with an IC(50) of 200 nM. SB 290157 was a functional antagonist, blocking C3a-induced C3aR internalization in a concentration-dependent manner and C3a-induced Ca(2+) mobilization in RBL-C3aR cells and human neutrophils with IC(50)s of 27.7 and 28 nM, respectively. SB 290157 was selective for the C3aR in that it did not antagonize the C5aR or six other chemotactic G protein-coupled receptors. Functional antagonism was not solely limited to the human C3aR; SB 290157 also inhibited C3a-induced Ca(2+) mobilization of RBL-2H3 cells expressing the mouse and guinea pig C3aRS: It potently inhibited C3a-mediated ATP release from guinea pig platelets and inhibited C3a-induced potentiation of the contractile response to field stimulation of perfused rat caudal artery. Furthermore, in animal models, SB 290157, inhibited neutrophil recruitment in a guinea pig LPS-induced airway neutrophilia model and decreased paw edema in a rat adjuvant-induced arthritis model. This selective antagonist may be useful to define the physiological and pathophysiological roles of the C3aR.


Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Arginina/farmacología , Compuestos de Bencidrilo/farmacología , Complemento C3a/metabolismo , Proteínas Inactivadoras de Complemento/farmacología , Proteínas de la Membrana , Receptores de Complemento/antagonistas & inhibidores , Animales , Antiinflamatorios no Esteroideos/metabolismo , Antiinflamatorios no Esteroideos/farmacocinética , Arginina/análogos & derivados , Arginina/metabolismo , Arginina/farmacocinética , Artritis Experimental/inmunología , Artritis Experimental/patología , Compuestos de Bencidrilo/metabolismo , Compuestos de Bencidrilo/farmacocinética , Unión Competitiva , Línea Celular , Proteínas Inactivadoras de Complemento/metabolismo , Proteínas Inactivadoras de Complemento/farmacocinética , Modelos Animales de Enfermedad , Edema/patología , Edema/prevención & control , Cobayas , Miembro Posterior , Humanos , Inyecciones Intraperitoneales , Leucocitosis/inmunología , Leucocitosis/patología , Masculino , Ratones , Contracción Muscular/efectos de los fármacos , Infiltración Neutrófila/efectos de los fármacos , Ratas , Ratas Endogámicas Lew , Ratas Sprague-Dawley , Receptores de Complemento/metabolismo , Células Tumorales Cultivadas
14.
Bioorg Med Chem Lett ; 11(9): 1123-6, 2001 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-11354358

RESUMEN

As a continuation of our work with 1,4,5 substituted imidazole inhibitors of p38alpha, we report a series of 1-(4-piperidinyl)-4-(4-fluorophenyl)-5-(2-phenoxy-4-pyrimidinyl) imidazoles related to 7. The compounds have IC50's for inhibition of p38alpha ranging from 6.0 to 650nM. Statistical analysis of the p38beta inhibitor potencies shows a correlation of IC50's with the electron donating strength of low molecular weight substituents.


Asunto(s)
Inhibidores Enzimáticos/síntesis química , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Fenoles/síntesis química , Fenoles/farmacología , Pirimidinas/síntesis química , Pirimidinas/farmacología , Inhibidores Enzimáticos/farmacología , Modelos Moleculares , Proteínas Quinasas p38 Activadas por Mitógenos
15.
Med Res Rev ; 21(2): 129-45, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11223862

RESUMEN

Mitogen-activated protein kinases (MAPKs) are involved in many cellular processes. The stress-activated MAPK, p38, has been linked to inflammatory cytokine production and cell death following cellular stress. Here, we demonstrate focal ischemic stroke-induced p38 enzyme activation (i.e., phosphorylation) in the brain. The second generation p38 MAPK inhibitor SB 239063 was identified to exhibit increased kinase selectivity and improved cellular and in vivo activity profiles, and thus was selected for evaluation in two rat models of permanent focal ischemic stroke. SB 239063 was administered orally pre- and post-stroke and intravenously post-stroke. Plasma concentration levels were achieved in excess of those that effectively inhibit p38 activity. In both moderate and severe stroke, SB 239063 reduced infarct size by 28-41%, and neurological deficits by 25-35%. In addition, neuroprotective plasma concentrations of SB 239063 that reduced p38 activity following stroke also reduced the stroke-induced expression of IL-1beta and TNFalpha (i.e., cytokines known to contribute to stroke-induced brain injury). SB 239063 also provided direct protection of cultured brain tissue to in vitro ischemia. This robust SB 239063-induced neuroprotection emphasizes a significant opportunity for targeting MAPK pathways in ischemic stroke injury, and also suggests that p38 inhibition be evaluated for protective effects in other experimental models of nervous system injury and neurodegeneration.


Asunto(s)
Isquemia Encefálica/tratamiento farmacológico , Imidazoles/uso terapéutico , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Fármacos Neuroprotectores/uso terapéutico , Pirimidinas/uso terapéutico , Animales , Isquemia Encefálica/metabolismo , Células Cultivadas , Corteza Cerebral/enzimología , Corteza Cerebral/metabolismo , Corteza Cerebral/patología , Humanos , Imidazoles/administración & dosificación , Imidazoles/farmacocinética , Interleucina-1/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Fármacos Neuroprotectores/administración & dosificación , Fármacos Neuroprotectores/farmacocinética , Pirimidinas/administración & dosificación , Pirimidinas/farmacocinética , Ratas , Factor de Necrosis Tumoral alfa/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos
16.
J Pharmacol Exp Ther ; 296(2): 312-21, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11160612

RESUMEN

The stress-activated mitogen-activated protein kinase (MAPK) p38 has been linked to the production of inflammatory cytokines/mediators/inflammation and death/apoptosis following cell stress. In these studies, a second-generation p38 MAPK inhibitor, SB 239063 (IC(50) = 44 nM), was found to exhibit improved kinase selectivity and increased cellular (3-fold) and in vivo (3- to 10-fold) activity over first-generation inhibitors. Oral SB 239063 inhibited lipopolysaccharide-induced plasma tumor necrosis factor production (IC(50) = 2.6 mg/kg) and reduced adjuvant-induced arthritis (51% at 10 mg/kg) in rats. SB 239063 reduced infarct volume (48%) and neurological deficits (42%) when administered orally (15 mg/kg, b.i.d.) before moderate stroke. Intravenous SB 239063 exhibited a clearance of 34 ml/min/kg, a volume of distribution of 3 l/kg, and a plasma half-life of 75 min. An i.v. dosing regimen that provided effective plasma concentrations of 0.38, 0.75, or 1.5 microg/ml (i.e., begun 15 min poststroke and continuing over the initial 6-h p38 activation period) was used. Significant and dose-proportional brain penetration of SB 239063 was demonstrated during these infusion periods. In both moderate and severe stroke, intravenous SB 239063 produced a maximum reduction of infarct size by 41 and 27% and neurological deficits by 35 and 33%, respectively. No effects of the drug were observed on cerebral perfusion, hemodynamics, or body temperature. Direct neuroprotective effects from oxygen and glucose deprivation were also demonstrated in organotypic cultures of rat brain tissue. This robust in vitro and in vivo SB 239063-induced neuroprotection emphasizes the potential role of MAPK pathways in ischemic stroke and also suggests that p38 inhibition warrants further study, including protection in other models of nervous system injury and neurodegeneration.


Asunto(s)
Encéfalo/patología , Inhibidores Enzimáticos/uso terapéutico , Imidazoles/uso terapéutico , Ataque Isquémico Transitorio/tratamiento farmacológico , Ataque Isquémico Transitorio/patología , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Fármacos Neuroprotectores/uso terapéutico , Pirimidinas/uso terapéutico , Animales , Antiinflamatorios no Esteroideos/uso terapéutico , Temperatura Corporal/efectos de los fármacos , Circulación Cerebrovascular/efectos de los fármacos , Hemodinámica/efectos de los fármacos , Hipocampo/patología , Inflamación/patología , Inflamación/prevención & control , Técnicas de Cultivo de Órganos , Piridinas/uso terapéutico , Ratas , Ratas Endogámicas Lew , Ratas Endogámicas SHR , Proteínas Quinasas p38 Activadas por Mitógenos
17.
J Clin Oncol ; 19(1): 105-10, 2001 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-11134202

RESUMEN

PURPOSE: To summarize evidence on the costs of treating patients in clinical trials and to describe the Cost of Cancer Treatment Study, an ongoing effort to produce generalizable estimates of the incremental costs of government-sponsored cancer trials. METHODS: A retrospective study of costs will be conducted with 1,500 cancer patients recruited from a randomly selected sample of institutions in the United States. Patients accrued to either phase II or phase III National Cancer Institute-sponsored clinical trials during a 15-month period will be asked to participate in a study of their health care utilization (n = 750). Costs will be measured approximately 1 year after their trial enrollment from a combination of billing records, medical records, and an in-person survey questionnaire. Similar data will be collected for a comparable group of cancer patients not in trials (n = 750) to provide an estimate of the incremental cost. RESULTS: Evidence suggests insurers limit access to trials because of cost concerns. Public and private efforts are underway to change these policies, but their permanent status is unclear. Previous studies found that treatment costs in clinical trials are similar to costs of standard therapy. However, it is difficult to generalize from these studies because of the unique practice settings, insufficient sample sizes, and the exclusion of potentially important costs. CONCLUSION: Denials of coverage for treatment in a clinical trial limit patient access to trials and could impede clinical research. Preliminary estimates suggest changes to these policies would not be expensive, but these results are not generalizable. The Cost of Cancer Treatment Study is an ongoing effort to provide generalizable estimates of the incremental treatment cost of phase II and phase III cancer trials. The results should be of great interest to insurers and the research community as they consider permanent ways to finance cancer trials.


Asunto(s)
Ensayos Clínicos como Asunto/economía , Costos de la Atención en Salud , Planificación en Salud , Cobertura del Seguro , Seguro de Salud , Neoplasias/economía , Ensayos Clínicos Fase II como Asunto/economía , Ensayos Clínicos Fase III como Asunto/economía , Accesibilidad a los Servicios de Salud , Humanos , Proyectos de Investigación , Estudios Retrospectivos , Estados Unidos
18.
Prog Med Chem ; 38: 1-60, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11774793
19.
Proc (Bayl Univ Med Cent) ; 14(2): 179-82; discussion 182, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16369612

RESUMEN

OBJECTIVE: To evaluate the Leap for Life cardiovascular risk factor education program based on outcome measurements of self-reported hospital readmission, goal achievement, satisfaction, and educational model preference. SETTING: Four hospitals and one senior center of Baylor Health Care System in the Dallas, Texas, area. DESIGN: Administration of a satisfaction questionnaire and resurvey of participants by telephone at 3, 6, and 12 months. PATIENTS: 161 patients with cardiovascular disease enrolled in the Leap for Life program during calendar year 1997. Patients were primarily male (59%), with an average age of 66 years; they had an average of 4 cardiovascular disease risk factors. RESULTS: Of the 152 participants who took part in the telephone follow-up, 19% reported a hospital admission with a cardiovascular diagnosis during the 12-month follow-up period. Twenty-one percent reported meeting all of their goals; 56%, some of their goals; and 23%, none of their goals. All stated that the educational sessions met their informational needs, and 75% preferred the Leap for Life setting over other educational settings. CONCLUSION AND NEXT STEPS: These data provide initial validation of the program and are being used as a starting point for another assessment that involves individualized health enhancement measures and 6- and 12-month follow-up of participants using a survey designed to assess readiness, lifestyle changes, and quality of life.

20.
J Immunol ; 165(9): 5211-20, 2000 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-11046054

RESUMEN

The stress-activated protein kinase p38 plays a central role in the regulation of cytokine biosynthesis by various cell types in response to a wide range of stimuli. Because the local inflammatory response and the infiltration of neutrophils is thought to contribute to the symptoms and sequelae of rhinovirus infection, we investigated the role of p38 kinase in cytokine and chemokine elaboration in airway epithelial cells infected with human rhinovirus. Rhinovirus-39 infection of BEAS-2B cells resulted in synthesis of cytokines (IL-1, IL-6, G-CSF, and GM-CSF) and CXC chemokines (IL-8, epithelial neutrophil-activating protein-78, and growth-related oncogene-alpha), evident 24-72 h postinfection. Rhinovirus infection induced a time- and dose-dependent increase in tyrosine phosphorylation of p38 kinase, which peaked 30 min postinfection and remained elevated for 1 h. Treatment of infected cells with SB 239063, a potent pyridinyl imidazole inhibitor of p38 kinase, resulted in up to 100% inhibition of mediator production and partially reduced levels of IL-8 mRNA as determined by quantitative RT-PCR. Treatment with SB 239063 had no effect on virus replication and was not cytotoxic at concentrations

Asunto(s)
Bronquios/enzimología , Bronquios/inmunología , Citocinas/biosíntesis , Células Epiteliales/enzimología , Células Epiteliales/inmunología , Proteínas Quinasas Activadas por Mitógenos/fisiología , Rhinovirus/inmunología , Bronquios/metabolismo , Bronquios/virología , Línea Celular , Citocinas/antagonistas & inhibidores , Citocinas/genética , Citocinas/metabolismo , Inhibidores Enzimáticos/farmacología , Células Epiteliales/metabolismo , Células Epiteliales/virología , Células HeLa , Humanos , Imidazoles/farmacología , Interleucina-1/fisiología , Interleucina-8/antagonistas & inhibidores , Interleucina-8/biosíntesis , Interleucina-8/genética , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Fosforilación , Infecciones por Picornaviridae/inmunología , Infecciones por Picornaviridae/virología , Piridinas/farmacología , ARN Mensajero/antagonistas & inhibidores , ARN Mensajero/biosíntesis , ARN Mensajero/metabolismo , Rhinovirus/efectos de la radiación , Tirosina/metabolismo , Rayos Ultravioleta , Activación Viral/efectos de la radiación , Proteínas Quinasas p38 Activadas por Mitógenos
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