Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Blood ; 2024 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-38768337

RESUMO

Estimating progression-free survival (PFS) and overall survival (OS) superiority during clinical trials of multiple myeloma (MM) has become increasingly challenging as novel therapeutics have improved patient outcomes. Thus, it is imperative to identify earlier endpoint surrogates that are predictive of long-term clinical benefit to expedite development of more effective therapies. Minimal residual disease (MRD)-negativity is a common intermediate endpoint that has shown prognostic value for clinical benefit in trials of patients with multiple myeloma (MM). This meta-analysis was based on the FDA guidance for considerations for a meta-analysis of MRD as a clinical endpoint and evaluates MRD-negativity as an early endpoint reasonably likely to predict long-term clinical benefit. Eligible studies were phase 2 or 3 randomized controlled clinical trials measuring MRD negativity as an endpoint in patients with MM, with follow-up of ≥6 months following an a priori defined time point of 12±3 months post-randomization. Eight newly diagnosed MM-(NDMM)-studies evaluating 4,907 patients were included. Trial-level associations between MRD-negativity and PFS were R2WLSiv (95% CI) 0.67 (0.43-0.91) and R2copula 0.84 (0.64->0.99) at the 12-month timepoint. The individual-level association between 12-month MRD negativity and PFS resulted in a global odds ratio of 4.02 (95% CI: 2.57-5.46). For relapse/refractory MM-(RRMM), there were four studies included, and the individual-level association between 12-month MRD negativity and PFS resulted in a global odds ratio of 7.67 (4.24-11.10). A clinical trial demonstrating a treatment effect on MRD is reasonably likely to eventually demonstrate a treatment effect on PFS, suggesting that MRD may be an early clinical endpoint reasonably likely to predict clinical benefit in MM, that may be used to support accelerated approval and thereby expedite the availability of new drugs to patients with MM.

2.
Nat Ecol Evol ; 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38684740
3.
Leuk Lymphoma ; : 1-10, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38497533

RESUMO

Once-weekly carfilzomib at 56 mg/m2 plus immunomodulatory drugs and dexamethasone has shown efficacy and tolerability treating early relapsed/refractory multiple myeloma (RRMM). The phase 2 SELECT study (NCT04191616) evaluated efficacy/safety of weekly carfilzomib, pomalidomide, and dexamethasone (KPd) in early RRMM patients refractory to lenalidomide. All 52 treated patients were refractory to prior treatment, and 19 (37%) were triple-class refractory. Overall response rate (ORR; primary endpoint) was 58% (35% ≥ very good partial response, 6% ≥ complete response); median response duration was 20.3 months. Minimal residual disease negativity (10-5) was achieved in 10% of patients. Median progression-free survival was 11.1 months; median overall survival was 18.8 months. Adverse events (AEs) were consistent with the known safety profile including grade ≥3 treatment-emergent AEs reported in 67% of patients. Although the primary endpoint of ORR was not met, KPd showed meaningful clinical benefits in lenalidomide-refractory RRMM patients, including those who were daratumumab-refractory and/or triple-class refractory.

4.
Nat Commun ; 15(1): 1921, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38429327

RESUMO

Rising temperatures are leading to increased prevalence of warm-affinity species in ecosystems, known as thermophilisation. However, factors influencing variation in thermophilisation rates among taxa and ecosystems, particularly freshwater communities with high diversity and high population decline, remain unclear. We analysed compositional change over time in 7123 freshwater and 6201 terrestrial, mostly temperate communities from multiple taxonomic groups. Overall, temperature change was positively linked to thermophilisation in both realms. Extirpated species had lower thermal affinities in terrestrial communities but higher affinities in freshwater communities compared to those persisting over time. Temperature change's impact on thermophilisation varied with community body size, thermal niche breadth, species richness and baseline temperature; these interactive effects were idiosyncratic in the direction and magnitude of their impacts on thermophilisation, both across realms and taxonomic groups. While our findings emphasise the challenges in predicting the consequences of temperature change across communities, conservation strategies should consider these variable responses when attempting to mitigate climate-induced biodiversity loss.


Assuntos
Biodiversidade , Ecossistema , Animais , Tamanho Corporal , Clima , Água Doce
5.
Leuk Lymphoma ; 65(4): 481-492, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38345269

RESUMO

Nearly all patients with multiple myeloma eventually relapse or become refractory to treatment. Lenalidomide is increasingly administered in the frontline until disease progression or intolerance to therapy, resulting in the need for highly effective, lenalidomide-sparing options. In this study, carfilzomib plus daratumumab and dexamethasone were evaluated against lenalidomide-sparing, pomalidomide-containing triplets using matching-adjusted indirect comparison in the absence of head-to-head data. The analyses utilized long-term follow-up data from the CANDOR study (NCT03158688). Treatment with carfilzomib, daratumumab, and dexamethasone resulted in significantly longer progression-free survival (hazard ratio 0.60 [95% confidence interval: 0.37, 0.88])vs. pomalidomide plus bortezomib and dexamethasone, and numerically longer progression-free survival (hazard ratio 0.77 [95% confidence interval: 0.50, 1.08]) vs. daratumumab plus pomalidomide and dexamethasone in patients with relapsed/refractory multiple myeloma and previous lenalidomide exposure, the majority of whom were lenalidomide refractory. Carfilzomib plus daratumumab and dexamethasone offers a highly effective, lenalidomide-sparing treatment option for this population.


Assuntos
Anticorpos Monoclonais , Mieloma Múltiplo , Oligopeptídeos , Talidomida , Humanos , Anticorpos Monoclonais/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Dexametasona , Lenalidomida/uso terapêutico , Mieloma Múltiplo/diagnóstico , Mieloma Múltiplo/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Talidomida/análogos & derivados
6.
Nature ; 622(7983): 537-544, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37758942

RESUMO

Climate's effect on global biodiversity is typically viewed through the lens of temperature, humidity and resulting ecosystem productivity1-6. However, it is not known whether biodiversity depends solely on these climate conditions, or whether the size and fragmentation of these climates are also crucial. Here we shift the common perspective in global biodiversity studies, transitioning from geographic space to a climate-defined multidimensional space. Our findings suggest that larger and more isolated climate conditions tend to harbour higher diversity and species turnover among terrestrial tetrapods, encompassing more than 30,000 species. By considering both the characteristics of climate itself and its geographic attributes, we can explain almost 90% of the variation in global species richness. Half of the explanatory power (45%) may be attributed either to climate itself or to the geography of climate, suggesting a nuanced interplay between them. Our work evolves the conventional idea that larger climate regions, such as the tropics, host more species primarily because of their size7,8. Instead, we underscore the integral roles of both the geographic extent and degree of isolation of climates. This refined understanding presents a more intricate picture of biodiversity distribution, which can guide our approach to biodiversity conservation in an ever-changing world.


Assuntos
Biodiversidade , Clima , Geografia , Animais , Conservação dos Recursos Naturais/métodos , Mapeamento Geográfico , Umidade , Temperatura , Clima Tropical
7.
Oecologia ; 201(3): 761-770, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36754882

RESUMO

On-going land-use change has profound impacts on biodiversity by filtering species that cannot survive in disturbed landscapes and potentially altering biotic interactions. In particular, how land-use change reshapes biotic interactions remains an open question. Here, we used selectivity experiments with nectar feeders in natural and converted forests to test the direct and indirect effects of land-use change on resource competition in Andean hummingbirds along an elevational gradient. Selectivity was defined as the time hummingbirds spent at high resource feeders when feeders with both low and high resource values were offered in the presence of other hummingbird species. Selectivity approximates the outcome of interspecific competition (i.e., the resource intake across competing species); in the absence of competition, birds should exhibit higher selectivity. We evaluated the indirect effect of forest conversion on selectivity, as mediated by morphological dissimilarity and flower resource abundance, using structural equation models. We found that forest conversion influenced selectivity at low and mid-elevations, but the influence of morphological dissimilarity and resource availability on selectivity varied between these elevations. At mid-elevation, selectivity was more influenced by the presence of morphologically similar competitors than by resource abundance while at low-elevation resource abundance was a more important predictor of selectivity. Our results suggest that selectivity is influenced by forest conversion, but that the drivers of these changes vary across elevation, highlighting the importance of considering context-dependent variation in the composition of resources and competitors when studying competition.


Assuntos
Aves , Néctar de Plantas , Animais , Aves/fisiologia , Flores , Florestas , Biodiversidade , Ecologia
8.
Ecol Lett ; 26(2): 203-218, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36560926

RESUMO

Human impacts such as habitat loss, climate change and biological invasions are radically altering biodiversity, with greater effects projected into the future. Evidence suggests human impacts may differ substantially between terrestrial and freshwater ecosystems, but the reasons for these differences are poorly understood. We propose an integrative approach to explain these differences by linking impacts to four fundamental processes that structure communities: dispersal, speciation, species-level selection and ecological drift. Our goal is to provide process-based insights into why human impacts, and responses to impacts, may differ across ecosystem types using a mechanistic, eco-evolutionary comparative framework. To enable these insights, we review and synthesise (i) how the four processes influence diversity and dynamics in terrestrial versus freshwater communities, specifically whether the relative importance of each process differs among ecosystems, and (ii) the pathways by which human impacts can produce divergent responses across ecosystems, due to differences in the strength of processes among ecosystems we identify. Finally, we highlight research gaps and next steps, and discuss how this approach can provide new insights for conservation. By focusing on the processes that shape diversity in communities, we aim to mechanistically link human impacts to ongoing and future changes in ecosystems.


Assuntos
Efeitos Antropogênicos , Ecossistema , Humanos , Biodiversidade , Água Doce , Evolução Biológica , Mudança Climática
9.
Proc Biol Sci ; 289(1980): 20221020, 2022 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-35946161

RESUMO

Quaternary climate fluctuations can affect speciation in regional biodiversity assembly in two non-mutually exclusive ways: a glacial species pump, where isolation in glacial refugia accelerates allopatric speciation, and adaptive radiation in underused adaptive zones during ice-free periods. We detected biogeographic and genetic signatures associated with both mechanisms in the assembly of the biota of the European Alps. Age distributions of endemic and widespread species within aquatic and terrestrial taxa (amphipods, fishes, amphibians, butterflies and flowering plants) revealed that endemic fish evolved only in lakes, are highly sympatric, and mainly of Holocene age, consistent with adaptive radiation. Endemic amphipods are ancient, suggesting preglacial radiation with limited range expansion and local Pleistocene survival, perhaps facilitated by a groundwater-dwelling lifestyle. Terrestrial endemics are mostly of Pleistocene age and are thus more consistent with the glacial species pump. The lack of evidence for Holocene adaptive radiation in the terrestrial biome is consistent with faster recolonization through range expansion of these taxa after glacial retreats. More stable and less seasonal ecological conditions in lakes during the Holocene may also have contributed to Holocene speciation in lakes. The high proportion of young, endemic species makes the Alpine biota vulnerable to climate change, but the mechanisms and consequences of species loss will likely differ between biomes because of their distinct evolutionary histories.


Assuntos
Borboletas , Emigração e Imigração , Animais , Biodiversidade , Ecossistema , Peixes , Especiação Genética , Filogenia , Refúgio de Vida Selvagem
10.
Leuk Lymphoma ; 63(10): 2413-2421, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35549810

RESUMO

Pooled analyses of four single-arm phase 1 and 2 studies (NCT01816971, NCT02405364, NCT01029054, NCT01402284) investigated the clinical effectiveness of carfilzomib-lenalidomide-dexamethasone (KRd) in newly diagnosed multiple myeloma (NDMM). Patients who did (Cohort 1; n = 122) and did not (Cohort 2; n = 99) undergo autologous stem cell transplant (high-dose melphalan [HDM]-ASCT) were included. Patients received a 28-day cycle of induction KRd. The rate of very good partial response or better, the primary endpoint, was 93% in Cohort 1 and 90% in Cohort 2. Two-year progression-free survival and overall survival rates were 88% and 96% for Cohort 1, and 85% and 97% for Cohort 2. At least 90% of patients in each cohort reported ≥1 grade 3 or 4 treatment-emergent adverse events. Subgroup analyses by age, International Staging System stage, and cytogenetic risk were consistent with the overall population. KRd is an effective and tolerable treatment option for patients with NDMM regardless of HDM-ASCT eligibility.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Mieloma Múltiplo , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , Dexametasona/uso terapêutico , Humanos , Lenalidomida/uso terapêutico , Melfalan/uso terapêutico , Mieloma Múltiplo/tratamento farmacológico , Oligopeptídeos/uso terapêutico
11.
Ecol Lett ; 25(3): 686-696, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35199916

RESUMO

Species interactions are influenced by the trait structure of local multi-trophic communities. However, it remains unclear whether mutualistic interactions in particular can drive trait patterns at the global scale, where climatic constraints and biogeographic processes gain importance. Here we evaluate global relationships between traits of frugivorous birds and palms (Arecaceae), and how these relationships are affected, directly or indirectly, by assemblage richness, climate and biogeographic history. We leverage a new and expanded gape size dataset for nearly all avian frugivores, and find a positive relationship between gape size and fruit size, that is, trait matching, which is influenced indirectly by palm richness and climate. We also uncover a latitudinal gradient in trait matching strength, which increases towards the tropics and varies among zoogeographic realms. Taken together, our results suggest trophic interactions have consistent influences on trait structure, but that abiotic, biogeographic and richness effects also play important, though sometimes indirect, roles in shaping the functional biogeography of mutualisms.


Assuntos
Arecaceae , Dispersão de Sementes , Animais , Aves , Frutas , Simbiose
12.
Ecol Lett ; 22(7): 1126-1135, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31066203

RESUMO

Latitudinal and elevational richness gradients have received much attention from ecologists but there is little consensus on underlying causes. One possible proximate cause is increased levels of species turnover, or ß diversity, in the tropics compared to temperate regions. Here, we leverage a large botanical dataset to map taxonomic and phylogenetic ß diversity, as mean turnover between neighboring 100 × 100 km cells, across the Americas and determine key climatic drivers. We find taxonomic and tip-weighted phylogenetic ß diversity is higher in the tropics, but that basal-weighted phylogenetic ß diversity is highest in temperate regions. Supporting Janzen's 'mountain passes' hypothesis, tropical mountainous regions had higher ß diversity than temperate regions for taxonomic and tip-weighted metrics. The strongest climatic predictors of turnover were average temperature and temperature seasonality. Taken together, these results suggest ß diversity is coupled to latitudinal richness gradients and that temperature is a major driver of plant community composition and change.


Assuntos
Biodiversidade , Plantas , Temperatura , Filogenia
13.
Ecology ; 100(3): e02591, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30582633

RESUMO

Environmental filtering and dispersal limitation can both maintain diversity in plant communities by aggregating conspecifics, but parsing the contribution of each process has proven difficult empirically. Here, we assess the contribution of filtering and dispersal limitation to the spatial aggregation patterns of 456 tree species in a hyperdiverse Amazonian forest and find distinct functional trait correlates of interspecific variation in these processes. Spatial point process model analysis revealed that both mechanisms are important drivers of intraspecific aggregation for the majority of species. Leaf drought tolerance was correlated with species topographic distributions in this aseasonal rainforest, showing that future increases in drought severity could significantly impact community structure. In addition, seed mass was associated with the spatial scale and density of dispersal-related aggregation. Taken together, these results suggest environmental filtering and dispersal limitation act in concert to influence the spatial and functional structure of diverse forest communities.


Assuntos
Florestas , Árvores , Fenótipo , Folhas de Planta , Floresta Úmida , Clima Tropical
14.
Nanoscale ; 7(2): 500-10, 2015 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-25408159

RESUMO

Tumor associated macrophages (TAMs) can modify the tumor microenvironment to create a pro-tumor niche. Manipulation of the TAM phenotype is a novel, potential therapeutic approach to engage anti-cancer immunity. siRNA is a molecular tool for knockdown of specific mRNAs that is tunable in both strength and duration. The use of siRNA to reprogram TAMs to adopt an immunogenic, anti-tumor phenotype is an attractive alternative to ablation of this cell population. One current difficulty with this approach is that TAMs are difficult to specifically target and transfect. We report here successful utilization of novel mannosylated polymer nanoparticles (MnNP) that are capable of escaping the endosomal compartment to deliver siRNA to TAMs in vitro and in vivo. Transfection with MnNP-siRNA complexes did not significantly decrease TAM cell membrane integrity in culture, nor did it create adverse kidney or liver function in mice, even at repeated doses of 5 mg kg(-1). Furthermore, MnNP effectively delivers labeled nucleotides to TAMs in mice with primary mammary tumors. We also confirmed TAM targeting in the solid tumors disseminated throughout the peritoneum of ovarian tumor bearing mice following injection of fluorescently labeled MnNP-nucleotide complexes into the peritoneum. Finally, we show enhanced uptake of MnNP in lung metastasis associated macrophages compared to untargeted particles when using an intubation delivery method. In summary, we have shown that MnNP specifically and effectively deliver siRNA to TAMs in vivo.


Assuntos
Materiais Biocompatíveis/química , Portadores de Fármacos/química , Endossomos/metabolismo , Manose/química , Nanopartículas/química , RNA Interferente Pequeno/metabolismo , Animais , Materiais Biocompatíveis/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular , Técnicas de Cocultura , Feminino , Corantes Fluorescentes/química , Pulmão/metabolismo , Pulmão/patologia , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/terapia , Macrófagos/citologia , Macrófagos/metabolismo , Macrófagos/transplante , Neoplasias Mamárias Animais/patologia , Neoplasias Mamárias Animais/secundário , Neoplasias Mamárias Animais/terapia , Manose/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Microscopia de Fluorescência , Nanopartículas/metabolismo , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Polímeros/química , RNA Interferente Pequeno/química , RNA Interferente Pequeno/uso terapêutico , Transplante Homólogo , Microambiente Tumoral
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...