Animal Models of Barrett's Esophagus and Esophageal Adenocarcinoma–Past,Present, and Future

Esophageal adenocarcinoma is the fastest rising cancer in the United States. It develops from long‐standing gastroesophageal reflux disease which affects >20% of the general population. It carries a very poor prognosis with 5‐year survival <20%. The disease is known to sequentially progress from reflux esophagitis to a metaplastic precursor, Barrett''s esophagus and then onto dysplasia and esophageal adenocarcinoma. However, only few patients with reflux develop Barrett''s esophagus and only a minority of these turn malignant. The reason for this heterogeneity in clinical progression is unknown. To improve patient management, molecular changes which facilitate disease progression must be identified. Animal models can provide a comprehensive functional and anatomic platform for such a study. Rats and mice have been the most widely studied but disease homology with humans has been questioned. No animal model naturally simulates the inflammation to adenocarcinoma progression as in humans, with all models requiring surgical bypass or destruction of existing antireflux mechanisms. Valuable properties of individual models could be utilized to holistically evaluate disease progression. In this review paper, we critically examined the current animal models of Barrett''s esophagus, their differences and homologies with human disease and how they have shaped our current understanding of Barrett''s carcinogenesis.     

Checkpoint-blocker-induced autoimmunity is associated with favourable outcome in metastatic melanoma and distinct T-cell expression profiles

Background Immune checkpoint blockers (ICBs) activate CD8⁺ T cells, eliciting both anti-cancer activity and immune-related adverse events (irAEs). The relationship of irAEs with baseline parameters and clinical outcome is unclear.Methods Retrospective evaluation of irAEs on survival was performed across primary (N = 144) and secondary (N = 211) independent cohorts of patients with metastatic melanoma receiving single agent (pembrolizumab/nivolumab—sICB) or combination (nivolumab and ipilimumab—cICB) checkpoint blockade. RNA from pre-treatment and post-treatment CD8⁺ T cells was sequenced and differential gene expression according to irAE development assessed.Results 58.3% of patients developed early irAEs and this was associated with longer progression-free (PFS) and overall survival (OS) across both cohorts (log-rank test, OS: P < 0.0001). Median survival for patients without irAEs was 16.6 months (95% CI: 10.9–33.4) versus not-reached (P = 2.8 × 10⁻⁶). Pre-treatment monocyte and neutrophil counts, but not BMI, were additional predictors of clinical outcome. Differential expression of numerous gene pathway members was observed in CD8⁺ T cells according to irAE development, and patients not developing irAEs demonstrating upregulated CXCR1 pre- and post-treatment.Conclusions Early irAE development post-ICB is associated with favourable survival in MM. Development of irAEs is coupled to expression of numerous gene pathways, suggesting irAE development in-part reflects baseline immune activation.Subject terms: Immunotherapy, Melanoma     

煅石膏的研究进展及含钙止血材料应用概况

矿物药是传统中医药的重要组成部分，具有悠久的应用历史。其中矿物止血药对多种出血病证的临床应用广泛、用药经验丰富且疗效显著。石膏作为临床常用的矿物药，生石膏的功效为清热泻火、除烦止渴，而煅石膏为生石膏经高温煅烧的炮制品，主要由无水硫酸钙（CaSO₄）组成，具有收湿、生肌、敛疮、止血的功效，常外用于治疗溃疡不敛、湿疹瘙痒、水火烫伤、外伤出血等。止血机制研究表明，Ca²⁺作为凝血因子Ⅳ参与凝血过程的内外凝血级联多个关键环节，并且参与调节血小板活化、聚集，促进生成不溶性纤维蛋白，最终形成血凝块防止出血。Ca²⁺是重要的止血物质基础，但是石膏、煅石膏均含有Ca²⁺，煅石膏具有显著的止血作用，而石膏没有止血作用，石膏经过炮制后性味、功效发生了明显改变，体现了炮制特色，但目前尚未完全阐明煅石膏的炮制机制。因此，该文对石膏煅制前后比较研究情况进行总结与分析，围绕煅制工艺、晶型比较、元素含量、药效比较等进行综述，并总结Ca²⁺参与止血的各个环节。此外，对其他含钙矿物药及新型含钙止血材料如海藻酸钙、介孔硅酸钙和纳米凝胶止血材料的止血性能进行探讨，以期为阐明煅石膏的炮制机制提供借鉴，为临床辨证使用煅石膏提供依据，并为后续新型含钙止血材料的开发提供借鉴。