RESUMO
The functional role of herbivores in tropical rainforests remains poorly understood. We quantified the magnitude of, and underlying controls on, carbon, nitrogen and phosphorus cycled by invertebrate herbivory along a 2800 m elevational gradient in the tropical Andes spanning 12°C mean annual temperature. We find, firstly, that leaf area loss is greater at warmer sites with lower foliar phosphorus, and secondly, that the estimated herbivore-mediated flux of foliar nitrogen and phosphorus from plants to soil via leaf area loss is similar to, or greater than, other major sources of these nutrients in tropical forests. Finally, we estimate that herbivores consume a significant portion of plant carbon, potentially causing major shifts in the pattern of plant and soil carbon cycling. We conclude that future shifts in herbivore abundance and activity as a result of environmental change could have major impacts on soil fertility and ecosystem carbon sequestration in tropical forests.
Assuntos
Ciclo do Carbono/fisiologia , Ecossistema , Alimentos , Herbivoria/fisiologia , Modelos Biológicos , Folhas de Planta/química , Árvores , Animais , Peru , Análise Espectral , Clima TropicalRESUMO
The genomic characteristics of Peruvian patients with gastric adenocarcinoma from diverse socioeconomic backgrounds were examined in consideration of the possibility that patients from different socioeconomic backgrounds may be exposed to different risk factors. We conducted a prospective pilot study in two Peruvian cities (Lima and Ica). This study enrolled 15 patients from low socioeconomic status (LSES) and 15 patients from medium/high socioeconomic status (MHSES). The genomic profiling of gastric adenocarcinoma samples was done through the FoundationOne CDx platform. We compared the genomic characteristics and the need for targeted therapy and immunotherapy between LSES and MHSES. The genes with higher rates of alterations were TP53 (73.3% vs. 50.0%, P = 0.2635); CDH1 (26.7% vs. 28.6%, P = 1); CDKN2A (20.0% vs. 28.6%, P = 1); KRAS (33.3% vs. 7.1%, P = 0.1686); ARID1A (20.0% vs. 14.3%, P = 1); MLL2 (13.3% vs. 21.4%, P = 1) and SOX9 (33.3% vs. 0.0%, P = 0.0421) in LSES versus HMSES, respectively. There was no significant difference in tumor mutational burden (P = 0.377) or microsatellite status (P = 1). The LSES group had a higher need for targeted therapy or immunotherapy according to gene involvement and alterations. A significant genomic difference exists among patients with gastric adenocarcinoma of different socioeconomic status, which may result in a different need for targeted therapy and immunotherapy.
Assuntos
Neoplasias Gástricas , Humanos , Neoplasias Gástricas/genética , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Adenocarcinoma/genética , Estudos Prospectivos , Genômica/métodos , Peru/epidemiologia , Projetos Piloto , Adulto , Fatores Socioeconômicos , Mutação , Classe Social , Disparidades Socioeconômicas em SaúdeRESUMO
Gastric cancer is one of the most important malignancies in the world due to the high burden of disease and lethality. In this work, we compared the main characteristics of gastric cancer between different regions of the world. We reviewed public repositories to retrieve epidemiological, molecular, clinicopathological, and risk factor data. Eastern Asia presents the highest incidence of gastric cancer, followed by eastern and central Europe. Intestinal histology was more frequent in Caucasians, while gastric tumors located in the cardias were less frequent in Africa and Latin America. TP53, LRP1B, and ARID1A are consistently the most frequently altered genes in all population groups. Gastric cancer is most frequent in men. African patients tend to be younger and have a higher proportion of women patients. Different patterns can be observed in the presentation of gastric cancer between different regions of the world. More research is needed in Latin America and Africa since these populations are underrepresented.