Reactive Oxygen Species and Antioxidants in Carcinogenesis and Tumor Therapy.

Strictly regulated balance between the formation and utilization of reactive oxygen species (ROS) is the basis of normal functioning of organisms. ROS play an important role in the regulation of many metabolic processes; however, excessive content of ROS leads to the development of various disorders, including oncological diseases, as a result of ROS-induced mutations in DNA. In tumors, high levels of oxygen radicals promote cell proliferation and metastasis. On the other hand, high content of ROS can trigger cell death, a phenomenon used in the antitumor therapy. Water- and lipid-soluble antioxidants, as well as antioxidant enzyme systems, can inhibit ROS generation; however, they should be used with caution. Antioxidants can suppress ROS-dependent cell proliferation and metastasis, but at the same time, they may inhibit the death of tumor cells if the antitumor therapeutic agents stimulate oxidative stress. The data on the role of antioxidants in the death of tumor cells and on the effects of antioxidants taken as dietary supplements during antitumor therapy, are contradictory. This review focuses on the mechanisms by which antioxidants can affect tumor and healthy cells.

[Methodological features of DNA isolation for nested PCR for the differential diagnosis of malaria].

Current PCR assays for the differential diagnosis of malaria need to be further developed and certified in the Russian Federation. PCR may serve as a control diagnostic method. These investigations have demonstrated that an erythrocytic clot may be used as an adjunct to microscopy and the described procedure can be employed to isolate DNA for PRC in an inpatient setting.