The Use of Neural Stem Cells-Derived Exosomes to Prevent Late Radiation-Induced Cognitive Impairments in Mice.

We studied the effect of intranasal administration of neural stem cell (NSC)-derived exosomes on behavior and cognitive functions of mice in the late period after head irradiation in a dose of 8 Gy. The used exosomes had specific markers (CD9+/CD63+, 99.5%; TSG101+, 98.4%) and mean size 105.7±8.8 nm according to dynamic light scattering data and 119.0±12.4 nm according to nanoparticle tracking analysis (NTA). Exosome suspension (2×1012 particles/ml according to NTA measurements) was administered intranasally for 4 weeks starting from 48 h after irradiation in a volume of 5 µl/nostril (2×1010 exosomes/mouse). It was shown that intranasal administration of mouse NSC-derived exosomes prevented delayed radiation-induced behavioral changes and recognition memory impairments in mice after head irradiation.

Improved Survival and Regeneration of Irradiated Mouse Neural Stem Cells after Co-Culturing with Non-Irradiated Mouse Neural Stem Cells or Mesenchymal Stem Cells from the Adipose Tissue.

We studied the effect of neural stem cells (NSC) and mesenchymal stem cells (MSC) from mouse adipose tissue on survival, clonogenic activity, and senescence of NSC after exposure to γ-radiation. It was found that survival and clonogenic activity of NSC irradiated in doses of 1 and 2 Gy was enhanced when irradiated cells were co-cultured with non-irradiated NSC and MSC in permeable Transwell inserts. The proportion of senescent NSC (cells with high ß-galactosidase activity) increased with increasing irradiation dose. Co-culturing with non-irradiated NSC in 3 days after irradiation in a dose of 1 Gy led to a decrease in the proportion of senescent cells among irradiated NSC. Factors secreted by NSC and MSC can become the basis for the development of means for prevention and treatment of damage to brain cells resulting from radiation therapy of head and neck cancer.

[The application of the method of radiofrequency myringotomy under the experimental conditions and in the clinical practice]. / Primenenie metoda radiovolnovoi miringotomii v usloviiakh éksperimenta i v klinicheskoi praktike.

Exudative otitis media is a widespread pathological condition in the human population. In the recent years, the treatment with the electric current having the frequency up to 3.8 MHz has found the increasingly frequent application, in addition to shunting and laser myringotomy, for the perforation of the tympanic membrane to facilitate removal of exudate. The objective of the present study was to evaluate the effectiveness of the application of the electric current with the frequency up to 4 MHz for myringotomy in the patients presenting with exudative otitis media under the experimental conditions and in the clinical practice. The experimental studies were carried out with the use of the isolated temporal bones (ex vivo) and laboratory animals (in vivo). The clinical studies included the surgical treatment of 41 patients presenting with exudative otitis media using the electric current with the frequency of 4 MHz and laser irradiation with the subsequent evaluation of the inflammatory manifestations in the tympanic membrane tissues during the early post-operative period. It was shown that the method of myringotomy with the application of the electric current having the frequency of 4 MHz is safe and causes no complications. Moreover, it is accompanied by the development of the minimally active inflammatory processes in the tympanic membrane tissues during the early post-operative period.