Specific Cytotoxicity of Targeted 177Lu and 212Pb-Based Radiopharmaceuticals.

Two radiopharmaceutical preparations were developed on the basis of artificial targeted polypeptide ZHER2 specific to HER2/neu tumor marker and radionuclides 177Lu (ZHER2-HSA-chelator-177Lu) or 212Pb (ZHER2-HSA-chelator-212Pb). The objective was to evaluate in vitro the cytotoxic activity of the targeted radiopharmaceuticals using two cultured human breast cancer cell lines with different expression of HER2/neu: SK-BR3 (high expression of HER2/neu) and MCF-7 (low expression of HER2/neu). It was shown that the cytotoxic effect of both preparations was significantly higher against the SK-BR-3 cells. The cytotoxicity correlated with the incubation period (it was higher after 72 h than after 24 h) and was significantly more pronounced in comparison with activity of radionuclide salts without a specific ligand. In vivo preclinical study of these pharmaceuticals seems to be very promising in animals with xenografted tumors showing high expression of HER2/neu marker.

[Methods for mathematical data processing in enzyme immunoassay. I. Theoretical bases].

The paper deals with the mathematical processing of enzyme immunoassay (EIA) data. The paper comprises two parts. Part 1 contains a brief comparative account of the basic ways of presenting experimental data and constructing a standard curve, as well as practical guidelines for choosing the mathematical methods for calculation of concentrations. The recommendations proposed in Part II are based on the comparative study of photometric equipment and software that is of common use in EIA diagnosis at the Russian clinical laboratories. The experiment imitates competitive analysis illustrates a relationship of the obtained clinical result to the choice of either mode of constructing the standard graph on the basis of the optic densities of calibration samples. The findings indicate that an incorrectly chosen method for data processing may make both a false rejection of the whole analysis on the basis of the erroneous calculation of the concentration of a test agent in the control serum and to underdiagnosis on the basis of the erroneous calculation of the concentration of a test agent in a patient's sample near the point of taking a medical decision.

[Blood sampling systems and interference in immunoassay].

Immunoassay interference caused by reagents (additives, excipients) incorporated in the blood sampling systems is undetectable by the conventional methods for intralaboratory quality control, by using reference substances. A large number of manufacturers and a great physicochemical variety of additives in the current vacuum and non-vacuum systems require that additional measures be made to monitor systemic errors in immunochemical studies. The review considers the mechanisms of this type of interference and the problems of its monitoring and prevention.

[Comparative analysis of serum analyte level measurements by commercial diagnostic kits from four manufacturers (Alkor-Bio, Roche, Diagnostic Products Corporation-DCP, and Bayer Corporation)]. / Sravnitel'nyi analiz opredeleniia kontsentratsii riada analitov v syvorotke krovi s ispol'zovaniem kommercheski dostupnykh naborov reagentov chetyrekh firm-proizvoditelei ("Alkor Bio", "Roche", "Diagnostic Products Corporation"-DCP i "Bayer Corporation").

Hydrocortisone, progesterone, testosterone, triiodothyronine, thyroxine, chorionic gonadotropin, prolactin, alpha-fetoprotein, luteinizing, follicle-stimulating, and thyrotropic hormones were measured in human sera and in Lyphochek Immunoassay Plus Control reference sera (Bio-Rad Laboratories, USA) using 4 commercial kits (Alkor Bio Inc. and Roche, automated analyzer Roche Cobas Core; DPC, automated analyzer Immulite; Bayer, automated analyzer ACS:180). Coordination and correlation between these kits was observed, the coordination decreasing in the series Alkor Bio/Bayer, Alkor Bio/Roche, and Alkor Bio/DPC.