Nowe możliwości leczenia wirusowego zapalenia wątroby typu C

Chronic hepatitis C (CHC) is the leading causes of chronic liver disease and its irreversible conse­quences: liver cirrhosis and hepatocellular carcino­ma. According to the estimates of the World Health Organization, about 1.5% (~71 million) of the global population exhibits the active infection of hepatitis C virus (HCV), and the number of deaths associated with its complications reaches 500,000 per year. Clinically, the disease may be insidious for many years, with mild and non characteristic symptoms. Diagnosis can be established only at the stage of advanced liver disease. Not rarely, serious extra­hepatic pathology develops following chronic HCV infection. Until 2014 the most commonly used anti­viral therapy consisted of combination of pegylated interferon and ribavirin. Its efficacy did not exceed 50%, and serious side effects were a significant ob­stacle to its use. Since 2015 new oral directly act­ing antiviral drugs (DAA) have been available in the treatment of CHC. They are characterized by a very favorable safety profile and high efficacy, mak­ing it possible to cure HCV infection in 90–95% of cases

Brownian Motion Influence on AFM Exosomes’ Size Measurements

Extracellular vesicles are evaluated by nanoparticle tracking analysis (NTA), providing information on their hydrodynamic diameters, and by atomic force microscopy (AFM) to calculate their geometric diameters. The aim of this study is to explore the influence of Brownian movements in a sample drop and preparation time on imaging-based measurements and to determine the relationship between the geometric and hydrodynamic sizes of the extracellular vesicles measured by the AFM and the NTA, respectively. Exosomes derived from the human prostate cancer cell line PC3 were evaluated by NTA and AFM, and those results were compared with Monte Carlo simulations. The mean size, evaluated by AFM shortly after application on the mica substrate, is less than its real value. It obtains the correct value faster for a thinner sample drop. Fitting the log-normal distribution to the geometric and hydrodynamic diameters leads to the conclusion that the latter could arise from the former by linear scaling by a factor that could be used to characterize the analyzed extracellular vesicles. The size of the vesicles attached to the mica substrate depends on time. The effect of Brownian motion and stretch of the lipid bilayer should be considered in the context of exosome AFM studies