Antibacterial effect of TiO2:Cu:Ag thin coatings on Pseudomonas strain measured by microbiological and ATP assays

The aim of this study is to investigate the antimicrobial properties of nanocomposite thin TiO₂:Cu:Ag films on Pseudomonas putida as a natural isolate and an opportunistic pathogen. Several different methods were used to compare the antibacterial effect of thin TiO₂:Cu:Ag layers obtained by radiofrequency magnetron sputter deposition against P. putida: optical density of the bacterial suspension, most probable number of survived cells, dehydrogenase activity inhibition, scanning electron microscopy images, atomic flame absorption spectroscopy, and adenosine triphosphate (ATP) luminescent assay. Optical density measurements and most probable plate count were in agreement and showed a strong bactericidal effect of the as‐deposited and only bacteriostatic effect of the annealed coatings with the same metal content on tested bacteria. As the metal quantity in the medium rises during the first hour of the experiment, it could be suggested that this is the main reason for cell death. ATP‐luminescent assay showed up to 18‐fold reduction of the signal. It was compared with other microbiological and biochemical assays to prove the strong antibacterial effect of nanocomposite thin TiO₂:Cu:Ag coatings with the possibilities of medical applications. Protection of medical devices against infections is a significant current challenge raised by an increasing number of medical devices‐associated infections and microbial resistance to conventional antibiotic and multidrug treatments. Deposition of antimicrobial coatings is one of the current approaches to mitigate the problem.     

Adenoviral vectors--how to use them in cancer gene therapy?

Gene therapy is most often described as a technique for introducing the foreign genetic material into cells with a correction of a dysfunctional gene as its final goal. Today, it is well known that cancer is one of the leading causes of mortality in the world. Besides classical methods for cancer treatment new strategies against cancer are needed. Although originally being designed as a treatment for monogenetic illness, soon after, gene therapy appeared as a potential new strategy in cancer therapy. One of the widely used vectors for cancer gene therapy is adenovirus. In this review we have described molecular biology of adenoviruses and basis for construction of adenoviral vectors. We have also described concepts for cancer gene therapy including their in vitro and in vivo application. Special attention is drawn toward retargeting of adenovirus as a new approach in vector design for cancer gene therapy, in order to restrict transgene expression in tumor tissue. This approach uses biophysical as well as genetic characteristics of tumor itself and its supporting tissue, allowing new "bypass" in cancer gene therapy.     

Familial Papillary Thyroid Carcinoma (FPTC): a Retrospective Analysis in a Sample of the Bulgarian Population for a 10-Year Period

In recent years, there are numerous reports indicating the presence of familial papillary carcinoma. Unfortunately, no genetic defect can be linked directly to the disease. In this study, we set the goal to make a retrospective analysis of the cases with papillary carcinoma in the Department of Endocrine Surgery for the past 10 years, to compare the characteristics of sporadic and familial forms of the disease and to find families with hereditary papillary carcinoma. The study included 810 patients treated for thyroid cancer in the Department of Endocrine Surgery, USBALE “Acad. Iv. Penchev” Hospital, between January 1, 2006 and December 31, 2015. We used chi square test to determine statistical significant difference. The data analysis and interpretation was performed on SPSS 20.0. Both groups had similar demographic distribution. We found that 587 patients have sporadic papillary carcinoma, while 147 have a relative with thyroid pathology in the first degree of kinship. In 8 patients, there was a blood relative with thyroid cancer. When we compared the two groups, we found statistically significant difference only in tumor size. There was no significant difference in aggressiveness of the thyroid cancer (multifocality and lymph node metastasis). When analyzing the results, we identified 147 patients with a family history of thyroid disease (20%). In 8 patients (5.44%), we found at least one relative with papillary thyroid carcinoma. However, our study does not demonstrate any difference in the aggressiveness of familial and sporadic papillary thyroid carcinoma.     

alpha(v)beta(3) Integrin-mediated drug resistance in human laryngeal carcinoma cells is caused by glutathione-dependent elimination of drug-induced reactive oxidative species

As a model for determination of the role of integrins in drug resistance, we used alpha(v)beta(3) integrin-negative human laryngeal carcinoma cell line (HEp2) and three HEp2-derived cell clones with a gradual increase of alpha(v)beta(3) integrin expression. The alpha(v)beta(3) integrin expression protects cells from cisplatin, mitomycin C, and doxorubicin. In HEp2-alpha(v)beta(3) integrin-expressing cells, the constitutive expression of Bcl-2 protein and the level of glutathione (GSH) were increased compared with HEp2 cells. Pretreatment of HEp2-alpha(v)beta(3) integrin-expressing cells with an inhibitor of GSH synthesis, buthionine sulfoximine (BSO), decreased the level of GSH and partially reverted drug resistance to all above-mentioned drugs, but it did not influence the expression of Bcl-2. Sensitivity to selected anticancer drugs did not change with overexpression of Bcl-2 in HEp2 cells, nor with silencing of Bcl-2 in HEp2-alpha(v)beta(3) integrin-expressing cells, indicating that Bcl-2 is not involved in resistance mechanism. There was no difference in DNA platination between HEp2 and HEp2-alpha(v)beta(3) integrin-expressing cells, indicating that the mechanism of drug resistance is independent of cisplatin detoxification by GSH. A strong increase of reactive oxidative species (ROS) formation during cisplatin or doxorubicin treatment in HEp2 cells was reduced in HEp2-alpha(v)beta(3) integrin-expressing cells. Since this increased elimination of ROS could be reverted by GSH depletion, we concluded that multidrug resistance is the consequence of GSH-dependent increased ability of alpha(v)beta(3)-expressing cells to eliminate drug-induced ROS.     

Human Adenovirus Type 26 Induced IL-6 Gene Expression in an αvβ3 Integrin- and NF-κB-Dependent Manner

The low seroprevalent human adenovirus type 26 (HAdV26)-based vaccine vector was the first adenovirus-based vector to receive marketing authorization from European Commission. HAdV26-based vaccine vectors induce durable humoral and cellular immune responses and, as such, represent a highly valuable tool for fighting infectious diseases. Despite well-described immunogenicity in vivo, the basic biology of HAdV26 still needs some refinement. The aim of this study was to determine the pro-inflammatory cytokine profile of epithelial cells infected with HAdV26 and then investigate the underlying molecular mechanism. The expression of studied genes and proteins was assessed by quantitative polymerase chain reaction, western blot, and enzyme-linked immunosorbent assay. Confocal microscopy was used to visualize HAdV26 cell uptake. We found that HAdV26 infection in human epithelial cells triggers the expression of pro-inflammatory cytokines and chemokines, namely IL-6, IL-8, IL-1β, and TNF-α, with the most pronounced difference shown for IL-6. We investigated the underlying molecular mechanism and observed that HAdV26-induced IL-6 gene expression is αvβ3 integrin dependent and NF-κB mediated. Our findings provide new data regarding pro-inflammatory cytokine and chemokine expression in HAdV26-infected epithelial cells, as well as details concerning HAdV26-induced host signaling pathways. Information obtained within this research increases our current knowledge of HAdV26 basic biology and, as such, can contribute to further development of HAdV26-based vaccine vectors.