RESUMEN
We consider a class of continuous-time branching processes called Markovian binary trees (MBTs), in which the individuals lifetime and reproduction epochs are modelled using a transient Markovian arrival process (TMAP). We develop methods for estimating the parameters of the TMAP by using either age-specific averages of reproduction and mortality rates, or age-specific individual demographic data. Depending on the degree of detail of the available information, we follow a weighted non-linear regression or a maximum likelihood approach. We discuss several criteria to determine the optimal number of states in the underlying TMAP. Our results improve the fit of an existing MBT model for human demography, and provide insights for the future conservation management of the threatened Chatham Island black robin population.
Asunto(s)
Demografía , Funciones de Verosimilitud , Cadenas de Markov , Animales , Aves , Especies en Peligro de Extinción , Femenino , Masculino , Mortalidad , Dinámica Poblacional , ReproducciónRESUMEN
[This corrects the article DOI: 10.1021/acsmedchemlett.7b00157.].
RESUMEN
The lack of a formal link between neural network structure and its emergent function has hampered our understanding of how the brain processes information. We have now come closer to describing such a link by taking the direction of synaptic transmission into account, constructing graphs of a network that reflect the direction of information flow, and analyzing these directed graphs using algebraic topology. Applying this approach to a local network of neurons in the neocortex revealed a remarkably intricate and previously unseen topology of synaptic connectivity. The synaptic network contains an abundance of cliques of neurons bound into cavities that guide the emergence of correlated activity. In response to stimuli, correlated activity binds synaptically connected neurons into functional cliques and cavities that evolve in a stereotypical sequence toward peak complexity. We propose that the brain processes stimuli by forming increasingly complex functional cliques and cavities.
RESUMEN
Further optimization of an initial DP2 receptor antagonist clinical candidate NVP-QAV680 led to the discovery of a follow-up molecule 2-(2-methyl-1-(4-(methylsulfonyl)-2-(trifluoromethyl)benzyl)-1H-pyrrolo[2,3-b]pyridin-3-yl)acetic acid (compound 11, NVP-QAW039, fevipiprant), which exhibits improved potency on human eosinophils and Th2 cells, together with a longer receptor residence time, and is currently in clinical trials for severe asthma.
RESUMEN
Optimization of a 7-azaindole-3-acetic acid CRTh2 receptor antagonist chemotype derived from high throughput screening furnished a highly selective compound NVP-QAV680 with low nM functional potency for inhibition of CRTh2 driven human eosinophil and Th2 lymphocyte activation in vitro. The molecule exhibited good oral bioavailability in the rat, combined with efficacy in rodent CRTh2-dependent mechanistic and allergic disease models and was suitable for clinical development.
Asunto(s)
Indolizinas/química , Receptores Inmunológicos/antagonistas & inhibidores , Receptores de Prostaglandina/antagonistas & inhibidores , Administración Oral , Animales , Células CHO , Cricetinae , Cricetulus , Dermatitis por Contacto/tratamiento farmacológico , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos , Eosinófilos/efectos de los fármacos , Eosinófilos/metabolismo , Semivida , Humanos , Hipersensibilidad/tratamiento farmacológico , Indolizinas/farmacocinética , Indolizinas/uso terapéutico , Ratones , Ratones Endogámicos BALB C , Unión Proteica , Ratas , Ratas Sprague-Dawley , Receptores Inmunológicos/genética , Receptores Inmunológicos/metabolismo , Receptores de Prostaglandina/genética , Receptores de Prostaglandina/metabolismo , Relación Estructura-Actividad , Células Th2/inmunología , Células Th2/metabolismoRESUMEN
The synthesis of a series of indacaterol analogues in which each of the three structural regions of indacaterol are modified in a systematic manner is described. Evaluation of the affinity of these analogues for the ß(2)-adrenoceptor identified the 3,4-dihydroquinolinone and 5-n-butylindanyl analogues to demonstrate the most similar profiles to indacaterol. An α-methyl aminoindane analogue was discovered to be 25-fold more potent than indacaterol, and functional studies revealed an atypical ß(2)-adrenoceptor activation profile for this compound consistent with that of a slowly dissociating 'super agonist'.
Asunto(s)
Agonistas de Receptores Adrenérgicos beta 2/farmacología , Indanos/farmacología , Quinolonas/farmacología , Receptores Adrenérgicos beta 2/metabolismo , Agonistas de Receptores Adrenérgicos beta 2/síntesis química , Agonistas de Receptores Adrenérgicos beta 2/química , Relación Dosis-Respuesta a Droga , Humanos , Indanos/síntesis química , Indanos/química , Estructura Molecular , Quinolonas/síntesis química , Quinolonas/química , Relación Estructura-ActividadRESUMEN
High throughput screening identified a 7-azaindole-3-acetic acid scaffold as a novel CRTh2 receptor antagonist chemotype, which could be optimised to furnish a highly selective compound with good functional potency for inhibition of human eosinophil shape change in whole blood and oral bioavailability in the rat.
Asunto(s)
Acetatos/química , Antiinflamatorios/química , Piridinas/química , Receptores Inmunológicos/antagonistas & inhibidores , Receptores de Prostaglandina/antagonistas & inhibidores , Acetatos/síntesis química , Acetatos/farmacocinética , Administración Oral , Animales , Antiinflamatorios/síntesis química , Antiinflamatorios/farmacocinética , Eosinófilos/efectos de los fármacos , Eosinófilos/inmunología , Humanos , Microsomas Hepáticos/metabolismo , Permeabilidad , Piridinas/síntesis química , Piridinas/farmacocinética , Ratas , Receptores Inmunológicos/metabolismo , Receptores de Prostaglandina/metabolismo , Relación Estructura-ActividadRESUMEN
High throughput screening identified a phenoxyacetic acid scaffold as a novel CRTh2 receptor antagonist chemotype, which could be optimised to furnish a compound with functional potency for inhibition of human eosinophil shape change and oral bioavailability in the rat.
Asunto(s)
Acetatos/farmacología , Receptores Inmunológicos/antagonistas & inhibidores , Receptores de Prostaglandina/antagonistas & inhibidores , Acetatos/química , Animales , Disponibilidad Biológica , Eosinófilos/efectos de los fármacos , Humanos , Ratas , Relación Estructura-ActividadRESUMEN
Inhibitors of PDE5 are useful therapeutic agents for treatment of erectile dysfunction. A series of novel xanthine derivatives has been identified as potent inhibitors of PDE5, with good levels of selectivity against other PDE isoforms, including PDE6. Studies in the dog indicate excellent oral bioavailability for compound 21.
Asunto(s)
3',5'-GMP Cíclico Fosfodiesterasas/antagonistas & inhibidores , Xantinas/farmacología , Animales , Disponibilidad Biológica , Bovinos , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 5 , Perros , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/uso terapéutico , Disfunción Eréctil/tratamiento farmacológico , Humanos , Concentración 50 Inhibidora , Masculino , Farmacocinética , Isoformas de Proteínas/efectos de los fármacos , Relación Estructura-Actividad , Xantinas/químicaRESUMEN
A series of novel corticosteroid derivatives featuring C-17 furoate ester functionality have been synthesised. Profiling in vitro and in vivo has resulted in the identification of a compound with a longer duration of action and a lower oral side effect profile in rodents compared to budesonide.
Asunto(s)
Androstenos/síntesis química , Ésteres/síntesis química , Glucocorticoides/síntesis química , Receptores de Glucocorticoides/agonistas , Androstenos/farmacocinética , Androstenos/farmacología , Animales , Disponibilidad Biológica , Línea Celular , Eosinofilia/tratamiento farmacológico , Ésteres/farmacocinética , Ésteres/farmacología , Glucocorticoides/farmacocinética , Glucocorticoides/farmacología , Humanos , Macrófagos/citología , Tamaño de los Órganos/efectos de los fármacos , Unión Proteica , Ratas , Relación Estructura-Actividad , Timo/efectos de los fármacos , Factor de Necrosis Tumoral alfa/análisis , Factor de Necrosis Tumoral alfa/antagonistas & inhibidoresRESUMEN
In clinical studies, several inhibitors of phosphodiesterase 5 (PDE5) have demonstrated utility in the treatment of erectile dysfunction. We describe herein a series of 8-aryl xanthine derivatives which function as potent PDE5 inhibitors with, in many cases, high levels of selectivity versus other PDE isoforms.