Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Más filtros













Base de datos
Intervalo de año de publicación
1.
Proc Biol Sci ; 290(2005): 20230414, 2023 08 30.
Artículo en Inglés | MEDLINE | ID: mdl-37608720

RESUMEN

Climate change can severely impact species that depend on temporary resources by inducing phenological mismatches between consumer and resource seasonal timing. In the winter moth, warmer winters caused eggs to hatch before their food source, young oak leaves, became available. This phenological mismatch changed the selection on the temperature sensitivity of egg development rate. However, we know little about the fine-scale fitness consequences of phenological mismatch at the individual level and how this mismatch affects population dynamics in the winter moth. To determine the fitness consequences of mistimed egg hatching relative to timing of oak budburst, we quantified survival and pupation weight in a feeding experiment. We found that mismatch greatly increased mortality rates of freshly hatched caterpillars, as well as affecting caterpillar growth and development time. We then investigated whether these individual fitness consequences have population-level impacts by estimating the effect of phenological mismatch on population dynamics, using our long-term data (1994-2021) on relative winter moth population densities at four locations in The Netherlands. We found a significant effect of mismatch on population density with higher population growth rates in years with a smaller phenological mismatch. Our results indicate that climate change-induced phenological mismatch can incur severe individual fitness consequences that can impact population density in the wild.


Asunto(s)
Mariposas Nocturnas , Crecimiento Demográfico , Animales , Estaciones del Año , Dinámica Poblacional , Cambio Climático
2.
J Pharmacol Exp Ther ; 384(1): 173-186, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36310034

RESUMEN

Acalabrutinib is a covalent Bruton tyrosine kinase (BTK) inhibitor approved for relapsed/refractory mantle cell lymphoma and chronic lymphocytic leukemia/small lymphocytic lymphoma. A major metabolite of acalabrutinib (M27, ACP-5862) was observed in human plasma circulation. Subsequently, the metabolite was purified from an in vitro biosynthetic reaction and shown by nuclear magnetic resonance spectroscopy to be a pyrrolidine ring-opened ketone/amide. Synthesis confirmed its structure, and covalent inhibition of wild-type BTK was observed in a biochemical kinase assay. A twofold lower potency than acalabrutinib was observed but with similar high kinase selectivity. Like acalabrutinib, ACP-5862 was the most selective toward BTK relative to ibrutinib and zanubrutinib. Because of the potency, ACP-5862 covalent binding properties, and potential contribution to clinical efficacy of acalabrutinib, factors influencing acalabrutinib clearance and ACP-5862 formation and clearance were assessed. rCYP (recombinant cytochrome P450) reaction phenotyping indicated that CYP3A4 was responsible for ACP-5862 formation and metabolism. ACP-5862 formation Km (Michaelis constant) and Vmax were 2.78 µM and 4.13 pmol/pmol CYP3A/min, respectively. ACP-5862 intrinsic clearance was 23.6 µL/min per mg. Acalabrutinib weakly inhibited CYP2C8, CYP2C9, and CYP3A4, and ACP-5862 weakly inhibited CYP2C9 and CYP2C19; other cytochrome P450s, UGTs (uridine 5'-diphospho-glucuronosyltransferases), and aldehyde oxidase were not inhibited. Neither parent nor ACP-5862 strongly induced CYP1A2, CYP2B6, or CYP3A4 mRNA. Acalabrutinib and ACP-5862 were substrates of multidrug resistance protein 1 and breast cancer resistance protein but not OATP1B1 or OATP1B3. Our work indicates that ACP-5862 may contribute to clinical efficacy in acalabrutinib-treated patients and illustrates how proactive metabolite characterization allows timely assessment of drug-drug interactions and potential contributions of metabolites to pharmacological activity. SIGNIFICANCE STATEMENT: This work characterized the major metabolite of acalabrutinib, ACP-5862. Its contribution to the pharmacological activity of acalabrutinib was assessed based on covalent Bruton tyrosine kinase binding kinetics, kinase selectivity, and potency in cellular assays. The metabolic clearance and in vitro drug-drug interaction potential were also evaluated for both acalabrutinib and ACP-5862. The current data suggest that ACP-5862 may contribute to the clinical efficacy observed in acalabrutinib-treated patients and demonstrates the value of proactive metabolite identification and pharmacological characterization.


Asunto(s)
Citocromo P-450 CYP3A , Humanos , Adulto , Agammaglobulinemia Tirosina Quinasa , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2 , Citocromo P-450 CYP2C9 , Proteínas de Neoplasias , Inhibidores de Proteínas Quinasas/uso terapéutico
3.
Bioorg Med Chem Lett ; 30(14): 127261, 2020 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-32527559

RESUMEN

Bruton tyrosine kinase (BTK) is an important target in oncology and (auto)immunity. Various BTK inhibitors have been approved or are currently in clinical development. A novel BTK inhibitor series was developed starting with a quinazoline core. Moving from a quinazoline to a quinoline core provided a handle for selectivity for BTK over EGFR and resulted in the identification of potent and selective BTK inhibitors with good potency in human whole blood assay. Furthermore, proof of concept of this series for BTK inhibition was shown in an in vivo mouse model using one of the compounds identified.


Asunto(s)
Agammaglobulinemia Tirosina Quinasa/antagonistas & inhibidores , Descubrimiento de Drogas , Inhibidores de Proteínas Quinasas/farmacología , Quinolinas/farmacología , Agammaglobulinemia Tirosina Quinasa/metabolismo , Relación Dosis-Respuesta a Droga , Humanos , Modelos Moleculares , Estructura Molecular , Inhibidores de Proteínas Quinasas/química , Quinolinas/química , Relación Estructura-Actividad
4.
J Exp Biol ; 222(Pt 17)2019 09 03.
Artículo en Inglés | MEDLINE | ID: mdl-31371403

RESUMEN

The timing of breeding is under selection in wild populations as a result of climate change, and understanding the underlying physiological processes mediating this timing provides insight into the potential rate of adaptation. Current knowledge on this variation in physiology is, however, mostly limited to males. We assessed whether individual differences in the timing of breeding in females are reflected in differences in candidate gene expression and, if so, whether these differences occur in the upstream (hypothalamus) or downstream (ovary and liver) parts of the neuroendocrine system. We used 72 female great tits from two generations of lines artificially selected for early and late egg laying, which were housed in climate-controlled aviaries and went through two breeding cycles within 1 year. In the first breeding season we obtained individual egg-laying dates, while in the second breeding season, using the same individuals, we sampled several tissues at three time points based on the timing of the first breeding attempt. For each tissue, mRNA expression levels were measured using qPCR for a set of candidate genes associated with the timing of reproduction and subsequently analysed for differences between generations, time points and individual timing of breeding. We found differences in gene expression between generations in all tissues, with the most pronounced differences in the hypothalamus. Differences between time points, and early- and late-laying females, were found exclusively in the ovary and liver. Altogether, we show that fine-tuning of the seasonal timing of breeding, and thereby the opportunity for adaptation in the neuroendocrine system, is regulated mostly downstream in the neuro-endocrine system.


Asunto(s)
Expresión Génica , Comportamiento de Nidificación , Reproducción , Pájaros Cantores/fisiología , Animales , Variación Biológica Individual , Femenino , Hipotálamo/fisiología , Hígado/fisiología , Ovario/fisiología , Estaciones del Año , Pájaros Cantores/genética
5.
J Exp Biol ; 222(Pt 17)2019 09 09.
Artículo en Inglés | MEDLINE | ID: mdl-31413104

RESUMEN

Organisms need to time their annual-cycle stages, like breeding and migration, to occur at the right time of the year. Climate change has shifted the timing of annual-cycle stages at different rates, thereby tightening or lifting time constraints of these annual-cycle stages, a rarely studied consequence of climate change. The degree to which these constraints are affected by climate change depends on whether consecutive stages are causally linked (scenario I) or whether the timing of each stage is independent of other stages (scenario II). Under scenario I, a change in timing in one stage has knock-on timing effects on subsequent stages, whereas under scenario II, a shift in the timing of one stage affects the degree of overlap with previous and subsequent stages. To test this, we combined field manipulations, captivity measurements and geolocation data. We advanced and delayed hatching dates in pied flycatchers (Ficedula hypoleuca) and measured how the timing of subsequent stages (male moult and migration) were affected. There was no causal effect of manipulated hatching dates on the onset of moult and departure to Africa. Thus, advancing hatching dates reduced the male moult-breeding overlap with no effect on the moult-migration interval. Interestingly, the wintering location of delayed males was more westwards, suggesting that delaying the termination of breeding carries over to winter location. Because we found no causal linkage of the timing of annual-cycle stages, climate change could shift these stages at different rates, with the risk that the time available for some becomes so short that this will have major fitness consequences.


Asunto(s)
Migración Animal , Rasgos de la Historia de Vida , Pájaros Cantores/fisiología , Animales , Femenino , Masculino , Muda , Estaciones del Año , Factores de Tiempo
6.
J Pharmacol Exp Ther ; 363(2): 240-252, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28882879

RESUMEN

Several small-molecule Bruton tyrosine kinase (BTK) inhibitors are in development for B cell malignancies and autoimmune disorders, each characterized by distinct potency and selectivity patterns. Herein we describe the pharmacologic characterization of BTK inhibitor acalabrutinib [compound 1, ACP-196 (4-[8-amino-3-[(2S)-1-but-2-ynoylpyrrolidin-2-yl]imidazo[1,5-a]pyrazin-1-yl]-N-(2-pyridyl)benzamide)]. Acalabrutinib possesses a reactive butynamide group that binds covalently to Cys481 in BTK. Relative to the other BTK inhibitors described here, the reduced intrinsic reactivity of acalabrutinib helps to limit inhibition of off-target kinases having cysteine-mediated covalent binding potential. Acalabrutinib demonstrated higher biochemical and cellular selectivity than ibrutinib and spebrutinib (compounds 2 and 3, respectively). Importantly, off-target kinases, such as epidermal growth factor receptor (EGFR) and interleukin 2-inducible T cell kinase (ITK), were not inhibited. Determination of the inhibitory potential of anti-immunoglobulin M-induced CD69 expression in human peripheral blood mononuclear cells and whole blood demonstrated that acalabrutinib is a potent functional BTK inhibitor. In vivo evaluation in mice revealed that acalabrutinib is more potent than ibrutinib and spebrutinib. Preclinical and clinical studies showed that the level and duration of BTK occupancy correlates with in vivo efficacy. Evaluation of the pharmacokinetic properties of acalabrutinib in healthy adult volunteers demonstrated rapid absorption and fast elimination. In these healthy individuals, a single oral dose of 100 mg showed approximately 99% median target coverage at 3 and 12 hours and around 90% at 24 hours in peripheral B cells. In conclusion, acalabrutinib is a BTK inhibitor with key pharmacologic differentiators versus ibrutinib and spebrutinib and is currently being evaluated in clinical trials.


Asunto(s)
Benzamidas/farmacología , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Pirazinas/farmacología , Agammaglobulinemia Tirosina Quinasa , Animales , Benzamidas/química , Relación Dosis-Respuesta a Droga , Humanos , Células Jurkat , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/enzimología , Ratones , Ratones Endogámicos BALB C , Inhibidores de Proteínas Quinasas/química , Proteínas Tirosina Quinasas/sangre , Proteínas Tirosina Quinasas/metabolismo , Pirazinas/química
7.
PLoS One ; 11(7): e0159607, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27434128

RESUMEN

Acalabrutinib (ACP-196) is a second-generation inhibitor of Bruton agammaglobulinemia tyrosine kinase (BTK) with increased target selectivity and potency compared to ibrutinib. In this study, we evaluated acalabrutinib in spontaneously occurring canine lymphoma, a model of B-cell malignancy similar to human diffuse large B-cell lymphoma (DLBCL). First, we demonstrated that acalabrutinib potently inhibited BTK activity and downstream effectors in CLBL1, a canine B-cell lymphoma cell line, and primary canine lymphoma cells. Acalabrutinib also inhibited proliferation in CLBL1 cells. Twenty dogs were enrolled in the clinical trial and treated with acalabrutinib at dosages of 2.5 to 20mg/kg every 12 or 24 hours. Acalabrutinib was generally well tolerated, with adverse events consisting primarily of grade 1 or 2 anorexia, weight loss, vomiting, diarrhea and lethargy. Overall response rate (ORR) was 25% (5/20) with a median progression free survival (PFS) of 22.5 days. Clinical benefit was observed in 30% (6/20) of dogs. These findings suggest that acalabrutinib is safe and exhibits activity in canine B-cell lymphoma patients and support the use of canine lymphoma as a relevant model for human non-Hodgkin lymphoma (NHL).


Asunto(s)
Antineoplásicos/administración & dosificación , Benzamidas/administración & dosificación , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/veterinaria , Inhibidores de Proteínas Quinasas/administración & dosificación , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Pirazinas/administración & dosificación , Agammaglobulinemia Tirosina Quinasa , Animales , Anorexia/inducido químicamente , Anorexia/fisiopatología , Antineoplásicos/efectos adversos , Linfocitos B/efectos de los fármacos , Linfocitos B/inmunología , Linfocitos B/patología , Benzamidas/efectos adversos , Línea Celular Tumoral , Diarrea/inducido químicamente , Diarrea/fisiopatología , Modelos Animales de Enfermedad , Supervivencia sin Enfermedad , Perros , Esquema de Medicación , Evaluación Preclínica de Medicamentos , Femenino , Humanos , Letargia/inducido químicamente , Letargia/fisiopatología , Linfoma de Células B Grandes Difuso/enzimología , Linfoma de Células B Grandes Difuso/mortalidad , Masculino , Inhibidores de Proteínas Quinasas/efectos adversos , Proteínas Tirosina Quinasas/genética , Proteínas Tirosina Quinasas/metabolismo , Pirazinas/efectos adversos , Vómitos/inducido químicamente , Vómitos/fisiopatología , Pérdida de Peso/efectos de los fármacos
8.
PLoS One ; 7(3): e32292, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22403642

RESUMEN

Many plant seeds and invertebrates can survive passage through the digestive system of birds, which may lead to long distance dispersal (endozoochory) in case of prolonged retention by moving vectors. Endozoochorous dispersal by waterbirds has nowadays been documented for many aquatic plant seeds, algae and dormant life stages of aquatic invertebrates. Anecdotal information indicates that endozoochory is also possible for fully functional, active aquatic organisms, a phenomenon that we here address experimentally using aquatic snails. We fed four species of aquatic snails to mallards (Anas platyrhynchos), and monitored snail retrieval and survival over time. One of the snail species tested was found to survive passage through the digestive tract of mallards as fully functional adults. Hydrobia (Peringia) ulvae survived up to five hours in the digestive tract. This suggests a maximum potential transport distance of up to 300 km may be possible if these snails are taken by flying birds, although the actual dispersal distance greatly depends on additional factors such as the behavior of the vectors. We put forward that more organisms that acquired traits for survival in stochastic environments such as wetlands, but not specifically adapted for endozoochory, may be sufficiently equipped to successfully pass a bird's digestive system. This may be explained by a digestive trade-off in birds, which maximize their net energy intake rate rather than digestive efficiency, since higher efficiency comes with the cost of prolonged retention times and hence reduces food intake. The resulting lower digestive efficiency allows species like aquatic snails, and potentially other fully functional organisms without obvious dispersal adaptations, to be transported internally. Adopting this view, endozoochorous dispersal may be more common than up to now thought.


Asunto(s)
Migración Animal , Anseriformes/parasitología , Organismos Acuáticos/fisiología , Tracto Gastrointestinal/parasitología , Caracoles/fisiología , Exoesqueleto/anatomía & histología , Animales , Anseriformes/fisiología , Ingestión de Alimentos , Femenino , Masculino , Caracoles/anatomía & histología , Factores de Tiempo
9.
J Lipid Res ; 50(1): 148-53, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18695266

RESUMEN

The endothelial glycocalyx has been shown to serve as a protective barrier between the flowing blood and the vessel wall in experimental models. The aim of this study was to evaluate whether hypercholesterolemia is associated with glycocalyx perturbation in humans, and if so, whether statin treatment can restore this. We measured systemic glycocalyx volume (V(G)) in 13 patients with heterozygous familial hypercholesterolemia (FH) after cessation of lipid-lowering therapy for a minimum of 4 weeks and 8 weeks after initiating rosuvastatin therapy. Normocholesterolemic subjects were used as controls. V(G) was estimated by subtracting the intravascular distribution volume of a glycocalyx permeable tracer (dextran 40) from that of a glycocalyx impermeable tracer (labeled erythrocytes). V(G) in untreated FH patients [LDL 225 +/- 57 mg/dl (mean +/- SD)] was significantly reduced compared with controls (LDL 93 +/- 24 mg/dl) (V(G) 0.8 +/- 0.3 vs. 1.7 +/- 0.6, respectively, P < 0.001). After normalization of LDL levels (95 +/- 33 mg/dl) upon 8 weeks of statin treatment, V(G) recovered only partially (V(G) 1.1 +/- 0.4 L, P = 0.04). The endothelial glycocalyx is profoundly reduced in FH patients, which may contribute to increased atherogenic vulnerability. This perturbation is partially restored upon short-term statin therapy.


Asunto(s)
Fluorobencenos/uso terapéutico , Glicocálix/efectos de los fármacos , Glicocálix/metabolismo , Heterocigoto , Hipercolesterolemia/genética , Pirimidinas/uso terapéutico , Sulfonamidas/uso terapéutico , Adulto , Anticolesterolemiantes/farmacología , Aterosclerosis/genética , Aterosclerosis/metabolismo , Enfermedades Cardiovasculares/genética , LDL-Colesterol/metabolismo , Dextranos/metabolismo , Endotelio/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Permeabilidad , Rosuvastatina Cálcica
10.
Ecology ; 88(11): 2926-35, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18051661

RESUMEN

Mechanistic studies on herbivore functional responses have largely taken place in mammals; very little has been done in herbivorous birds so far. Here we aim to fill that gap by experimentally quantifying the (short-term) functional response of a large avian herbivore, the Bewick's Swan (Cygnus columbianus bewickii). We explicitly distinguish between encounter-limited and handling-limited foraging by analyzing the results in the framework of the models of D. E. Spalinger and N. T. Hobbs, originally developed for mammalian herbivory. Bite size in captive swans was experimentally manipulated by varying sward height. The time interval between two bites increased with bite size, which supports the handling-limited model (process 3) and rejects the encounter-limited models (processes 1 and 2). Subsequently, we took the obtained functional response parameters into the field in order to predict, from measurements of sward height, (1) bite sizes, (2) handling times, and (3) short-term intake rates in free-ranging swans. Indeed, for all three variables, the observed values closely matched the experimentally based predictions. Finally, we review functional response parameters available in the literature on avian herbivores and scale them allometrically in relation to mammals. This analysis revealed that maximum bite sizes, and therefore maximum intake rates, in herbivorous birds are smaller than in herbivorous mammals. We hypothesize and provide evidence that birds compensate by longer daily foraging times.


Asunto(s)
Anseriformes/fisiología , Ingestión de Alimentos/fisiología , Ingestión de Energía/fisiología , Conducta Alimentaria/fisiología , Modelos Biológicos , Animales , Mamíferos/fisiología , Factores de Tiempo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA