Unravelling hidden threats of water disinfection: Toxicity evaluation and toxic products identification during diclofenac degradation.

Diclofenac (DCF) is a widely-used nonsteroidal anti-inflammatory drug that is routinely found in surface water bodies. While ozonation and ultraviolet (UV) radiation are commonly employed as disinfection methods in water treatment processes, the degradation of DCF in these processes occurs due to the strong oxidizing activity of the reactive oxygen species produced during both ozonation and UV radiation. Despite extensive studies reporting the removal and transformation of DCF through ozone and UV treatments, the potential hidden hazards of toxicity arising from these processes as well as the identification of the toxic transformation products have often been overlooked. In this study, various toxicities including microtoxicity, genotoxicity and antiestrogenicity were evaluated using multiple in-vitro bioassays. The transformation products were identified via ultra-performance liquid chromatography equipped with mass spectrometry (UPLC-MS). Correlation analysis was employed to gain deeper insight into the contributions of degradation products to overall toxicity. The results revealed that DCF possessed significant genotoxic and antiestrogenic effects, but displayed minimal microtoxicity. Microtoxic products such as those containing carbazole were generated during DCF degradation with ozone, UVA and UVC. Antiestrogenic products with dichloroaniline structures were observed in DCF ozonation but not in photodegradation by UVA and UVC. These findings highlighted the hidden risks associated with the disinfection of water containing micropollutants such as DCF.

Effects of collagenase type I on the structural features of collagen fibres from sea cucumber (Stichopus japonicus) body wall.

The autolysis of sea cucumber is caused by depolymerisation of collagen fibres and unfolding of fibrils. In order to highlight the role of collagenase in sea cucumber autolysis, collagen fibres from sea cucumber were hydrolysed with collagenase type I. Electron microscopy (EM) results indicated the collagenase caused partial depolymerisation of collagen fibres into fibrils due to the fracture of proteoglycan interfibrillar bridges, as well as uncoiling of collagen fibrils. Chemical analysis and SDS-PAGE both indicated collagenase induced a time-dependent release of glycosaminoglycans (GAGs) and soluble proteins, which further demonstrated the degradation of proteoglycan interfibrillar bridges. Collagenase also degraded collagens by releasing soluble hydroxyproline (Hpy), with the dissolution rate of Hyp reaching 11.11% after 72 h. Fourier transform infrared analysis showed that collagenase caused the reduction of intermolecular interactions and structural order of collagen. Hence, collagenase participated in the autolysis of sea cucumber by deteriorating both macromolecular and monomeric collagens.

[Therapeutic effect of agonistic CD40 monoclonal antibody combined with CTL on hu-SCID mouse B lymphoma model].

OBJECTIVE: To study the therapeutic effect of agonistic CD40 monoclonal antibody combined with tumor specific cytotoxic T lymphocyte (CTL) on B lymphoma. METHODS: Human B lymphoma cell line, Daudi cells, were cultured with CD40 mAb (5C11) for 24 and 48 hours, respectively. Annexin V/PI-binding assay was employed to analyze apoptosis, and FCM to analyze Fas (CD95) expression. Human peripheral monocyte-derived DC were loaded with apoptotic Daudi cells and stimulated by SC11 for further maturation. Tumor specific CTL were generated in vitro by co-culture of mature DC with autologous T lymphocytes. DNA fragmentations of Daudi cells treated with 5C11, CTL or 5C11 combined with CTL were determined by JAM assay. To establish the B lymphoma model, Daudi cells were subcutaneously injected into humanized SCID mice (hu-SCID). 1 or 3 weeks after tumor transfer. tumor-bearing mice were respectively treated with SC11, CTL, 5C11 combined with CTL by intraperitoneal injection. Tumor volume in differently treated mice was measured every week after therapy, and the survival of tumor-bearing mice was recorded. RESULTS: 5C11 significantly up-regulated FAS expression in Daudi cells, but had no significant effect on apoptosis rate of Daudi cells. Tumor-specific CTL could effectively kill Daudi cells. Fragmentation of Daudi cells co-cultured with CTL was remarkably enhanced by combination with SC11. Tumor growth in hu-SCID mice was apparently delayed by treatment with SC11, CTL, or SC11 combined with CTL. Moreover, minimal tumor burden mice got 30.0% or 70.0% complete remission (CR), respectively, when received CTL treatment or combination treatment of SC11 with CTL, and the lifespan of tumor bearing mice was also prolonged significantly. CONCLUSION: SC11 may enhance the sensitivity of Daudi cells to apoptosis by up-regulation of Fas expression and promote cytotoxicity of CTL in vitro and therapeutic effect in vivo.