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Authors aimed to assess the correlation between the apparent diffusion coefficient (ADC of the tumor, ADC ratio) and final grade group (GG) after radical prostatectomy (RP), and to determine the threshold values of ADC for detecting clinically significant prostate cancer (PC) with subsequent evaluation in a prospective group. 118 patients with PC were included in the retrospective group. These patients underwent RP from 2012 to 2017 with preoperative 3 Tesla multiparametric MRI (mpMRT) with contrast enhancement in a single center. After analyzing all the MRI studies, the average values of tumor ADC and benign tissue ADC were calculated using the maps of ADC. The prospective part of the study included 60 patients with completed pre-biopsy mpMRI and subsequent RP from January 2018 to March 2019. The prospective part of the study demonstrated the effectiveness of applying the obtained diffusion coefficient thresholds. When used as a criterion for determining clinically significant prostate cancer (GG > 6), threshold value of ADC ratio had sensitivity, specificity, accuracy, positive predictive value and negative predictive value were 84%, 91%, 87%, 94% and 78% respectively.

X-ray contrast properties of the new perfluoroorganic emulsion lipobrom were studied in comparison to those of a traditional clinical Roentgen diagnostic agents omnnipaque and ultravist and the well-known blood substitute perftoran. The x-ray patterns were evaluated by a computer morphodensitometry technique.

A mathematical model is proposed to describe the antigen-antibody complex formation under the immunoassay conditions, which allows the antibody-antigen affinity to be evaluated. In particular, it is established that the dissociation constant of the antigen-antibody complex (for antibodies to a tuberculous Mycobacterium) confidently increases (p > 0.95) in the following sequence of diagnostic kits: omnipak > Ultravist > melitrast > Triombrast. The method suggested for analysis of the influence of xenobiotics upon the antigen-antibody reaction can be used to reveal their possible side effects on the antigen-antibody complex formation in any particular case.

It was shown by the method of fluorescent probes that iodine-containing radiocontrast agents Triombrast > Omnipaque > Ultravist > Melitrast increase the content of intracellular Ca2+ in macrophages of the abdominal cavity of rats. Increase in the entry of Ca2+ from the external environment is the main factor of the change in the intracellular concentration of Ca2+ ions in the macrophages in interaction with radiocontrast agents.

The glycoprotein (15-18 kDa) antigen of Mycobacterium tuberculosis H37Rv was affinity isolated on the immunosorbent with monoclonal antibodies S4C1G4 (specific to M. tuberculosis H37Rv; Avdiyenko V. G., Kondrashov S.Yu, Lyashenko S.M.@Probl. Tuberk. 1996, v. 1, p. 6-8 (in Russian). This antigen and PPD (Batch RT 45, Stattens Seruminstitute, Denmark) that was a standard antigen were used for enzyme-linked immunosorbent assay (ELISA), by detecting serum IgG antibodies in patients with pulmonary tuberculosis, and control groups of patients with lung diseases other than tuberculosis (bronchitis and/or asthma, pneumonia) as well as healthy volunteers. The diagnostic parameters of specificity and sensitivity for titers and the same parameters for optic density (OD) (in serum dilution with maximum differences for groups of patients and donors) were compared. The new monoantigen method provided 86.11% specificity and 87.87% sensitivity, which were higher those obtained for optic density (63.89 and 80%, respectively). With PPD, the specificity and sensitivity were 58.04 and 78.78 (for the new titer method) versus 50 and 78.78% (OD data). The method error for titer determination was 10% and for standard OD determination was 27%. The new approach offers additional possibilities of enhancing the quality of ELISA for diagnosis of tuberculosis.

The mechanisms binding X-ray contrast media and magneto-resonance contrast media of various structure with human serum albumin and gamma-globulins were studied. Equilibrium dialysis showed that X-ray contrast media bind with blood plasma proteins, but magneto-resonance contrast media do not interact with these proteins. Electrostatic forces play a significant role in formation of complexes of X-ray contrast media with human blood serum albumin. With increase in the size of the molecule of the X-ray contrast media their affinity for the binding sites of this protein diminishes. The formation of complexes of X-ray contrast media with human blood plasma gamma-globulins occurs through hydrophobic interactions. Increase in the size of the molecules of these media reduces their affinity for the gamma-globulin binding sites.