RESUMO
Gastric cancer(GC)is one of the most common gastrointestinal malignant tumors in the world, requiring the development of novel therapeutic agents with reduced toxicity. Rehmannia polysaccharide (RPS) possesses immunomodulatory and anti-tumor properties, yet its efficacy is suboptimal. To enhance its biological activity, we subjected RPS to molecular modifications, resulting in phosphorylated Rehmannia polysaccharides (P-RPS). Using the mixed phosphate method, we synthesized P-RPS and optimized the synthesis conditions through a combination of single-factor and response surface methodologies. In vitro studies on P-RPS's anti-tumor activity showed no direct influence on the viability of GC cells. However, P-RPS induced the transformation of PMA-activated THP-1 cells into the M1 phenotype. We collected conditioned medium (CM) of THP-1 cells to stimulate gastric cancer cells and CM-P-RPS significantly promoted apoptosis of gastric cancer cells and inhibited cell proliferation, and reduced cell migration. Mechanistically, CM-P-RPS inhibits the Wnt/ß-catenin signaling pathway through LGR6, leading to the suppression of tumor growth. Furthermore, P-RPS demonstrated a significant inhibitory effect on tumor growth in vivo, suggesting its potential as a promising therapeutic agent for GC treatment.
Assuntos
Proliferação de Células , Polissacarídeos , Rehmannia , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/patologia , Neoplasias Gástricas/metabolismo , Rehmannia/química , Polissacarídeos/farmacologia , Polissacarídeos/química , Proliferação de Células/efeitos dos fármacos , Linhagem Celular Tumoral , Animais , Apoptose/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Movimento Celular/efeitos dos fármacos , Via de Sinalização Wnt/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Massive Open Online Courses (MOOCs) are used to support professional learning at scale in many countries. The present study examined a MOOC named Flipped Classrooms that was specially designed for in-service teachers in China. This MOOC was offered for seven consecutive iterations across three years and allowed teachers to re-take this course in connection with their teaching practice. Overall, 16% of all 105,370 learners enrolled in at least two iterations of the MOOC. To understand their learning motivations, their learning engagement within the MOOC, and the connections they forged between the MOOC and their teaching, we conducted a mixed-methods study using multiple data sources including course registration records, course entry surveys, learning performance data, click logs, and semi-structured interviews. Results indicated that teacher-learners re-took the MOOC for various reasons such as refreshing domain understanding, improving grades, and addressing practical problems. Click log analysis found MOOC re-takers with different performance trajectories demonstrated distinct learning patterns across iterations. Qualitative analysis of the interview data revealed additional insights into learning within the MOOC and connections forged by the re-takers between the MOOC and their teaching practice. This study contributes fresh insights into the MOOC literature by investigating MOOC re-takers and sheds light on the promise of using MOOC to support networked professional learning. Implications for future MOOCs and teacher learning opportunities are discussed.
Assuntos
Educação a Distância , Educação Profissionalizante , Pessoal de Educação/educação , Adulto , China , Educação a Distância/métodos , Educação Profissionalizante/métodos , Avaliação Educacional , Feminino , Humanos , Aprendizagem , Masculino , Pessoa de Meia-Idade , Motivação , Rede Social , Adulto JovemRESUMO
This research investigated effects of dietary phytosterols supplementation on growth performance and cecal gut microflora in yellow-feather broilers. A total of 360 yellow-feather broilers (1-day-old) were randomly assigned to 3 treatment groups: control group (basal diet), antibiotic group (basal diet supplemented with 200 mg/kg oxytetracycline calcium and 250 mg/kg nosiheptide), and phytosterols groups (basal diet supplemented with 25 mg/kg phytosterols). Each treatment group had 6 replicates, and there were 20 broilers within each replicate. No treatment effects on average daily feed intake, average daily gain, and food conversion rate were observed. The antibiotic group had a lower liver index compared with control group and phytosterols group. Other visceral indexes including bursa of Fabricius, spleen, and heart were not different among the 3 treatment groups. In terms of alpha diversity, no treatment effects on Shannon and Simpson indexes were observed. Supplementation of phytosterols significantly decreased the Chao1 and Ace indexes, indicating lower community richness of the gut microflora. At phylum level, the phytosterols group had a higher abundance of Bacteroidetes compared with the control group. At genus level, no treatment effect was observed on the top 10 genera. Overall, supplementation of phytosterols at 25 mg/kg level did not affect the growth performance of yellow-feather broilers, and its effect on gut microflora was limited.