No abstract

A rapid flow injection catalytic cold vapor atomic absorption spectrometric (FI-CCV-AAS) method is described for determination of total mercury in urine samples.

Immunotoxins, as a class of antitumor agents, consist of tumor-selective ligands linked to highly toxic protein molecules. This type of modified antibody has been designed for the therapy of cancers and a few viral infections. In this study, we designed immunotoxin consisting of mouse programmed cell death protein-1 (PD1), which genetically fused to diphtheria toxin (DT) subunit A (DT386). DNA construct was cloned, expressed in a bacterial system, purified, and confirmed by western blotting. The immunotoxin potency in the treatment of tumorous C57BL/6 mice was evaluated. Immunotoxin was injected intratumoral to mice, and through eight injections, 67% of the tumor volume of the test group started shrinking dramatically. On the contrary, the tumor size of the control group, treated with phosphate-buffered saline, continued its growth. The successful targeting of solid tumor cells by PD1-DT immunotoxin demonstrates the potential therapeutic utility of these conjugates.

Background: Overexpression of programmed cell death ligand 1 (PD-L1) in tumor cells and subsequent interaction with the programmed cell death protein 1 (PD-1) in tumor-infiltrating T cells cause an immune evasion of the tumor from cytotoxic T-cells. Therefore, inhibiting such interaction by a recombinant PD-1 can hinder tumor growth and extend the survival rate. Methods: The mouse extracellular domain of PD-1 (mPD-1) was expressed in E. coli BL21 (DE3) strain and purified using nickel affinity chromatography. The binding ability of the purified protein to human PD-L1 was studied using ELISA. Finally, the tumor-bearing mice were used to evaluate the potential antitumor effect. Results: The recombinant mPD-1 showed a significant binding capacity to human PD-L1 at the molecular level. The tumor size significantly decreased in the tumor-bearing mice after the intra-tumoral injections of mPD-1. Moreover, the survival rate increased significantly after eight weeks of monitoring. The histopathology revealed the necrosis in the tumor tissue of the control group compared to the mPD-1 received mice. Conclusions: Our outcomes propose that interaction blockade between PD-1 and PD-L1 is a promising approach for targeted tumor therapy.