Twenty-Month Monitoring of Humoral Immune Response to BNT162b2 Vaccine: Antibody Kinetics, Breakthrough Infections, and Adverse Effects.

BACKGROUND: Vaccination is one of the most effective life-saving medical interventions, and the introduction of SARS-CoV-2 vaccines was intended to prevent the serious implications of COVID-19. The objectives of the study were (i) to observe the humoral immune response to the BNT162b2 vaccine and SARS-CoV-2 infection (mainly breakthrough infections), (ii) to demonstrate the persistence of anti-SARS-CoV-2 antibodies over time in relation to the number of received vaccine doses and the course of infection, and (iii) to determine the adverse effects after primary vaccine doses. METHODS: To assess the humoral response, IgG and IgA anti-S1 antibodies were quantified by ELISA assays. In total, the tests were carried out seven times in almost two years. RESULTS: We demonstrated strong immunogenicity (compared to levels before primary vaccination, 150- and 20-fold increases in IgG and IgA, respectively) of the BNT162b2 vaccine. Over time, we observed a systematic decline in antibody levels, which may have contributed to breakthrough infections. Although they caused seroconversion similar to the booster, antibody levels in such patients fell more rapidly than after re-vaccination. On the other hand, in individuals who did not receive booster(s) and who did not present breakthrough infection, anti-SARS-CoV-2 antibodies returned to pre-vaccination levels after 20 months. The most commonly recognized adverse effects were injection site redness and swelling. CONCLUSION: Vaccination is highly effective in preventing the most severe outcomes of COVID-19 and should be performed regardless of prior infection. Booster doses significantly enhance anti-SARS-CoV-2 antibody levels and, in contrast to those obtained by breakthrough infection, they remain longer.

Case Report of COVID-19 after Full Vaccination: Viral Loads and Anti-SARS-CoV-2 Antibodies.

The introduction of effective vaccines against SARS-CoV-2 is expected to prevent COVID-19. However, sporadic cases of infection in vaccinated persons have been reported. We describe a case of a double-dose vaccinated woman with COVID-19. All stages of infection were observed, from no identification of virus, then the start of the infection, a high viral load, coming out of viraemia, and finally no detection of the virus. Despite the high viral load, the woman demonstrated mild COVID-19 symptoms, manifested only by a sore throat. The antibody results showed that she produced both post-infectious and post-vaccination immune responses. Phylogenetic analysis of the obtained viral genome sequence indicated that the virus belonged to the UK SARS-CoV-2 lineage B.1.1.7 (GR 501Y.V1; 20I/S:501Y.V1; Alpha variant).

N-Nitrosodimethylamine Contamination in the Metformin Finished Products.

A GC-MS/MS method with EI ionization was developed and validated to detect and quantify N-nitrosodimethylamine (NDMA) and seven other nitrosamines in 105 samples of metformin tablets from 13 different manufactures. Good linearity for each compound was demonstrated over the calibration range of 0.5-9.5 ng/mL. The assay for all substances was accurate and precise. NDMA was not detected in the acquired active pharmaceutical ingredient (API); however, NDMA was detected in 64 (85.3%) and 22 (91.7%) of the finished product and prolonged finished product samples, respectively. European Medicines Agency recommends the maximum allowed limit of 0.032 ppm in the metformin products. Hence, 28 finished products and 7 pronged dosage products were found to exceed the acceptable limit of daily intake of NDMA contamination. The implications of our findings for the testing of pharmaceutical products are discussed.

Selenized Plant Oil Is an Efficient Source of Selenium for Selenoprotein Biosynthesis in Human Cell Lines.

Selenium is an essential trace element which is incorporated in the form of a rare amino acid, the selenocysteine, into an important group of proteins, the selenoproteins. Among the twenty-five selenoprotein genes identified to date, several have important cellular functions in antioxidant defense, cell signaling and redox homeostasis. Many selenoproteins are regulated by the availability of selenium which mostly occurs in the form of water-soluble molecules, either organic (selenomethionine, selenocysteine, and selenoproteins) or inorganic (selenate or selenite). Recently, a mixture of selenitriglycerides, obtained by the reaction of selenite with sunflower oil at high temperature, referred to as Selol, was proposed as a novel non-toxic, highly bioavailable and active antioxidant and antineoplastic agent. Free selenite is not present in the final product since the two phases (water soluble and oil) are separated and the residual water-soluble selenite discarded. Here we compare the assimilation of selenium as Selol, selenite and selenate by various cancerous (LNCaP) or immortalized (HEK293 and PNT1A) cell lines. An approach combining analytical chemistry, molecular biology and biochemistry demonstrated that selenium from Selol was efficiently incorporated in selenoproteins in human cell lines, and thus produced the first ever evidence of the bioavailability of selenium from selenized lipids.

Selenitetriglycerides-Redox-active agents.

BACKGROUND: Human prostate cancer (hPCa) is the most commonly diagnosed cancer in elderly men and is the second leading cause of male cancer death. Data from epidemiological, eco-environmental, nutritional prevention and clinical trials suggest that selenium Se(IV) can prevent prostate cancer. Selol, a new organic semisynthetic derivative of Se(IV), is a mixture of selenitetriglycerides. This mixture is non-toxic and non-mutagenic, and after po treatment - 56-times less toxic (in mice) than sodium selenite. It exhibits strong anti-cancer activity in vitro in many cancer cell lines and can overcome the cell resistance to doxorubicin. Selol seems a promising compound for prostate cancer therapy. MATERIALS AND METHODS: The aim of the present study is the evaluation of Selol's influence on intracellular redox state (Eh) of prostatic tumors and the liver in androgen-dependent hPCa-bearing mice, and extracellular redox state in serum of these mice. RESULTS AND CONCLUSIONS: The anticancer activity of Selol involves perturbation of the redox regulation in the androgen dependent hPCa (LNCaP) cells, but not in healthy cells. After Selol treatment, intracellular Eh has increased in tumors from -223 mV to -175 mV, while in serum it has decreased (-82 mV vs -113 mV). It shows significant changes Eh in the extra- and intracellular environment. The difference decreases from 141 mV to 62 mV. The changes suggest that a tumor cell was probably directed toward apoptosis. This is exemplified in a significant decrease in cancer tumor mass by approx. 17% after the three weeks of Selol administration.

Comparison of selected gene expression profiles in sensitive and resistant cancer cells treated with doxorubicin and Selol.

AIM OF THE STUDY: Cellular resistance is strongly correlated with the risk of failure in doxorubicin (DOX) treatment, and the knowledge of the mechanisms of resistance and its possible modulation is still very limited. MATERIAL AND METHODS: In this study, we assessed the effect of 5% Selol and DOX on the expression of genes that affect cell proliferation in the resistant KB-V1 and sensitive HeLa cell lines, using RT2 ProfilerTM PCR Array matrix "Human Cancer Drug Resistance and Metabolism" (SABiosciences). RESULTS: We showed that HeLa and KB-V1 cell lines, characterised by varying susceptibility to DOX, have different genetic profiles as regards the studied genes. KB-V1 cells show overexpression of MYC and BCL2 genes, which encode proteins with anti apoptotic properties. Selol, when used in KB-V1 cells, reduced the expression of MYC and BCL2 genes, suggested as a new therapeutic target in the treatment of cancers resistant to cytostatic drugs. CONCLUSIONS: The results suggest that Selol could be used as a modulator that enhances the cytotoxic effects of doxorubicin, particularly in cells resistant to this drug.

The influence of Selol on the expression of oxidative stress genes in normal and malignant prostate cells.

Selol is a mixture of selenitriglycerides, obtained by the chemical modification of sunflower oil, which contain selenium at the +4 oxidation state. The aim of the present study was to describe the changes in the expression of genes related to oxidative stress caused by Selol in prostate cells: both normal (PNT1A) and malignant (LNCaP). The changes in gene expression in PNT1A and LNCaP cell lines under the influence of Selol were measured using a 96-well RT(2) Profiler ™PCR Array: Human Oxidative Stress and Antioxidant Defense, which arrayed 84 genes functionally involved in the cellular oxidative stress response. Based on the obtained data, LNCaP cells exhibited a significantly lower potential for antioxidant defence when compared to PNT1A cells. The response of the malignant LNCaP cells to exposure to Selol was significantly different from that of the normal PNT1A cells, especially after 48 h of incubation. In the case of LNCaP cells, Selol causes down-regulation of the expression of many vital genes. Under in vitro conditions, the efficacy of Selol slightly changes with increasing concentration, but significantly increases when the incubation time is lengthened.