No abstract

Brain tumors are one of the most common causes of cancer-related deaths around the world. Angiogenesis is critical in high-grade malignant gliomas, such as glioblastoma multiforme. Objective: The aim of this study is to comparatively analyze the angiogenesis-related genes, namely VEGFA, VEGFB, KDR, CXCL8, CXCR1 and CXCR2 in LGG vs. GBM to identify molecular distinctions using datasets available on The Cancer Genome Atlas (TCGA). Methods: DNA sequencing and mRNA expression data for 514 brain lower grade glioma (LGG) and 592 glioblastoma multiforme (GBM) patients were acquired from The Cancer Genome Atlas (TCGA), and the genetic alterations and expression levels of the selected genes were analyzed. Results: We identified six distinct KDR mutations in the LGG patients and 18 distinct KDR mutations in the GBM patients, including missense and nonsense mutations, frame shift deletion and altered splice region. Furthermore, VEGFA and CXCL8 were significantly overexpressed within GBM patients. Conclusions: VEGFA and CXCL8 are important factors for angiogenesis, which are suggested to have significant roles during tumorigenesis. Our results provide further evidence that VEGFA and CXCL8 could induce angiogenesis and promote LGG to progress into GBM. These findings could be useful in developing novel targeted therapeutics approaches in the future.

Microbial and chemical contamination is one of the biggest environmental problems since exposure to pathogenic microorganisms, such as food poisoning bacteria and their biological by-products, are often associated with disease and allergic reactions. Paenibacillus lautus is an aerobic or facultative anaerobic opportunistic bacterial pathogen, which is found in a variety of sources. In this study, we isolated and characterized P. lautus from Niğde Province, which is a wastewater disposal area and therefore presents a great source of contamination. The bacterial isolate was grown, colony morphology and Gram-reactions were observed. Bacteria were identified by 16S rDNA sequencing analysis, which was performed using DNA samples isolated from pure cultures and amplified by polymerase chain reaction (PCR). Sequencing results were compared against known bacterial strains using BLAST (Basic Local Alignment Search Tool) across databases. Antibiotic resistance against 20 different antibiotics and heavy metal resistance against different concentrations of zinc, copper, iron, cobalt, chromium and silver containing compounds were tested via disk diffusion method. Inhibition zones were examined and minimum inhibitory concentrations were recorded. Our results indicated that P. lautus was resistant to a certain set of antibiotics, while it was sensitive against others. Similarly, the bacteria were resistant against high concentrations of most metals tested. In summary, this study provided the first data regarding the isolation and characterization of Paenibacillus lautus strain from a local source in Turkey, which will account as preliminary data and guide our future efforts to fight against microbial contaminations.

Recently nanotechnology has become an integral part of modern biomedical applications. Accordingly, nanoparticles are considered as promising components for the development of innovative tags, probes, biosensors and carrier molecules for drug delivery. Spherical colloidal gold nanoparticles (AuNPs) are prime candidates to be utilized for these purposes due to their useful physical properties. However, in order for the gold nanoparticles to be used in nanomedicine, their biological properties should be extensively studied as well. Therefore, in this paper we chemically synthesized gold nanoparticles and studied their physical and biological characteristics to determine their potential use in medicine. Gold nanoparticles were synthesized by the reduction of chloroauric acid (HAuCl4) solution with sodium citrate. The physical properties of the AuNPs were determined by UV–vis spectrophotometer and Zetasizer readings. The antimicrobial activity of the newly synthesized gold nanoparticles on Escherichia coli, Salmonella infantis, Salmonella kentucky, Salmonella typhimurium, Salmonella enteritidis, Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Bacillus subtilis and Candida albicans were investigated via disk diffusion method. We found that the AuNPs were monodisperse, stable and not prone to aggregation with an average size of 22.12 nm and an emission band at 522 nm. The disk diffusion tests revealed that the gold nanoparticles did not have a significant growth inhibitory effect on the pathogens tested. In conclusion, here we showed the successful synthesis of gold nanoparticles by a safe and non-toxic method. Furthermore, our evaluation of the antimicrobial activity of these nanoparticles suggests that these molecules could be considered as biologically safe molecules for future medical applications.

Stem cells give rise to almost 200 different cell types that are present in a mammalian organism. In spite of the fact that these distinct cell types have different functions and morphologies, they descend from a common ancestor cell and essentially share the same DNA. The underlying cause for the rise of specific cell types is not genetic differences; it is mostly due to how the genetic information is interpreted. The epigenome, which consists of several degrees of regulatory mechanisms, dictates the gene expression profile of a certain type of cell. Eukaryotic DNA is packaged into chromatin, folded and compacted which in turn affects its functionality as certain regions of DNA will not be accessible whereas some other regions will be easier to access for effect or proteins and modifiers to bind. The chromatin dynamics are modulated by several machineries including but not limited to histone PTMs and their variants, DNA methylation and RNA interference, which have crucial roles in regulating stem cell differentiation, cell fate determination and lineage specification.