Low Levels of Urinary PSA Better Identify Prostate Cancer Patients

Serum prostatic specific antigen (PSA) has proven to have limited accuracy in early diagnosis and in making clinical decisions about different therapies for prostate cancer (PCa). This is partially due to the fact that an increase in PSA in the blood is due to the compromised architecture of the prostate, which is only observed in advanced cancer. On the contrary, PSA observed in the urine (uPSA) reflects the quantity produced by the prostate, and therefore can give more information about the presence of disease. We enrolled 574 men scheduled for prostate biopsy at the urology clinic, and levels of uPSA were evaluated. uPSA levels resulted lower among subjects with PCa when compared to patients with negative biopsies. An indirect correlation was observed between uPSA amount and the stage of disease. Loss of expression of PSA appears as a characteristic of prostate cancer development and its evaluation in urine represents an interesting approach for the early detection of the disease and the stratification of patients.

Influence of polyelectrolytes on increasing sensitivity of an immunofluorescent analysis based on plasmon silver nanoparticles

It was studied the dependence of the interaction of the components of the immunofluorescence test system for the quantitative determination of prostate specific antigen based on plasmon silver nanoparticles on the physicochemical nature of various polyelectrolytes used to coat films of silver nanoparticles. It has been shown that the use of a weakly charged polycationic polyelectrolyte poly-L-lysine can increase the antigenic binding of the test system by 2.34 times, and the use of a highly charged polycationic polyelectrolyte polydiallyldimethylammonium chloride increases the binding affinity of prostatic specific antigen by 5 times. When developing various immunochemical test systems using films of silver nanoparticles, an important parameter is the choice of a polyelectrolyte for coating a silver nanolayer, since the physicochemical and electrostatic properties of the polyelectrolyte can significantly affect both the sorption capacity of the solid phase and the conformational state functional activity of immobilized protein molecules. Both specificity and sensitivity of the immunochemical test system, as well as the minimum possible detectable concentration of bioanalyte, largely depend on these parameters.