Role of Nitric Oxide Synthase in Normal Brain Function and Pathophysiology of Neural Diseases

Nitric oxide synthase has three isoforms; according to their roles and tissues or cells they are involved. Neuronal NOS (nNOS) takes place in neuronal signalling, endothelial NOS (eNOS) takes place in vasodilation and inducible NOS (iNOS) takes place in immune responses. nNOS and eNOS are dominant but all isoforms have various roles in the central nervous system. nNOS and eNOS separately or together works in healthy brain during cognitive processes and in unhealthy brain during the pathology of related diseases. These roles were shown by inhibitor applied or by transgenic animal model studies and also by investigating the diseases at the molecular level. Besides, it is possible to say that iNOS has roles in some neurological pathologies creating immune responses. Three different isoforms mainly serve in different systems so there are lots of researchers from various disciplines working collaterally not knowing the others related works about NOSs. Because of this, a comprehensive chapter will be valuable for neuroscientists working with either healthy or unhealthy brains. The purpose of this chapter is to gather an overview of NOSs duties during the normal processes of the brain like learning and memory formation and abnormal processes such as depression, schizophrenia and brain cancers

Toxicity of β-Lactam Antibiotics: Pathophysiology, Molecular Biology and Possible Recovery Strategies

Beta (β)-lactam antibiotics are wide-spectrum antibiotics used for various bacterial infections. The aim of this chapter is to summarize the knowledge about the toxicity of β-lactam antibiotics and issues associated to their inappropriate use. This review has highlighted that β-lactam antibiotics are a group of products that have a chemical structure characterized by a β-lactam ring and are one of the most common antibacterial agents. However, due to the inappropriate use including abuse and misuse, resistance to the β-lactam antibiotics is currently a global crisis. Moreover, even when used appropriately, they have been linked to triggering allergic reactions like urticaria, bronchoconstriction, also severe conditions like immune-mediated haemolytic anaemia and intravascular haemolysis. It is known that some β-lactam antibiotics are neurotoxic, some are nephrotoxic, some are genotoxic and some are toxic to urogenital system. Several factors are involved in the occurrence of toxic effects including the dosage and renal status. Several strategies are possible to overcome β-lactam antibiotics-triggered toxicity, including rational prescribing, substitution combination and phage therapy which seems promising. Public health education for clinical teams and patients is essential in ensuring that this group of antibiotics are retained in therapeutics

LuxCDE-luxAB-based promoter reporter system to monitor the Yersinia enterocolitica O : 3 gene expression in vivo

It is crucial to understand the in vitro and in vivo regulation of the virulence factor genes of bacterial pathogens. In this study, we describe the construction of a versatile reporter system for Yersinia enterocolitica serotype O:3 (YeO3) based on the luxCDABE operon. In strain YeO3-luxCDE we integrated the luciferase substrate biosynthetic genes, luxCDE, into the genome of the bacterium so that the substrate is constitutively produced. The luxAB genes that encode the luciferase enzyme were cloned into a suicide vector to allow cloning of any promoter-containing fragment upstream the genes. When the obtained suicide-construct is mobilized into YeO3-luxCDE bacteria, it integrates into the recipient genome via homologous recombination between the cloned promoter fragment and the genomic promoter sequence and thereby generates a single-copy and stable promoter reporter. Lipopolysaccharide (LPS) O-antigen (O-ag) and outer core hexasaccharide (OC) of YeO3 are virulence factors necessary to colonization of the intestine and establishment of infection. To monitor the activities of the OC and O-ag gene cluster promoters we constructed the reporter strains YeO3-P-oc::luxAB and YeO3-P-op1::luxAB, respectively. In vitro, at 37 degrees C both promoter activities were highest during logarithmic growth and decreased when the bacteria entered stationary growth phase. At 22 degrees C the OC gene cluster promoter activity increased during the late logarithmic phase. Both promoters were more active in late stationary phase. To monitor the promoter activities in vivo, mice were infected intragastrically and the reporter activities monitored by the IVIS technology. The mouse experiments revealed that both LPS promoters were well expressed in vivo and could be detected by IVIS, mainly from the intestinal region of orally infected mice.Peer reviewe

High Throughput Characterization of Adult Stem Cells Engineered for Delivery of Therapeutic Factors for Neuroprotective Strategies

Mesenchymal stem cells (MSCs) derived from bone marrow are a powerful cellular resource and have been used in numerous studies as potential candidates to develop strategies for treating a variety of diseases. The purpose of this study was to develop and characterize MSCs as cellular vehicles engineered for delivery of therapeutic factors as part of a neuroprotective strategy for rescuing the damaged or diseased nervous system. In this study we used mouse MSCs that were genetically modified using lentiviral vectors, which encoded brain-derived neurotrophic factor (BDNF) or glial cell-derived neurotrophic factor (GDNF), together with green fluorescent protein (GFP). Before proceeding with in vivo transplant studies it was important to characterize the engineered cells to determine whether or not the genetic modification altered aspects of normal cell behavior. Different culture substrates were examined for their ability to support cell adhesion, proliferation, survival, and cell migration of the four subpopulations of engineered MSCs. High content screening (HCS) was conducted and image analysis performed. Substrates examined included: poly-L-lysine, fibronectin, collagen type I, laminin, entactin-collagen IV-laminin (ECL). Ki67 immunolabeling was used to investigate cell proliferation and Propidium Iodide staining was used to investigate cell viability. Time-lapse imaging was conducted using a transmitted light/environmental chamber system on the high content screening system. Our results demonstrated that the different subpopulations of the genetically modified MSCs displayed similar behaviors that were in general comparable to that of the original, non-modified MSCs. The influence of different culture substrates on cell growth and cell migration was not dramatically different between groups comparing the different MSC subtypes, as well as culture substrates. This study provides an experimental strategy to rapidly characterize engineered stem cells and their behaviors before their application in longterm in vivo transplant studies for nervous system rescue and repair

Bacterial metagenome analysis of Mytilus galloprovincialis collected from Istanbul and Izmir coastal stations of Turkey

Dagdeviren, Elif Bozcal/0000-0003-2836-778XWOS: 000517314700002PubMed: 32072329Mytilus galloprovincialis is a marine mollusk belonging to the Bivalvia class. It has been distributed largely in Turkish shores and worldwide aquatic environments. Besides being known as an environmental pollution indicator, it is highly consumed as a food and has a high economic value. Due to their nutritional mechanisms by filtering water, they are affected by pollution in seawater and mussels can host-microbial diversity of environmental origin as well as pathogenic bacteria. Therefore, in this study, bacterial species found in Mediterranean mussels collected from the coastal stations of Istanbul [Rumeli Kavagi (RK), Kucukcekmece (KC)], and Izmir [(Foca (MF), Urla (MU)] were investigated and compared with microbiological and metagenomic analyses. According to microbiological analysis results, 34 mussel-associated Enterobacteriaceae and Vibrionaceae family members were identified. As a result of the culture-independent metagenomic analysis, taxonomic groups for each station were identified and compared based on Operational Taxonomic Unit data. For all stations, the most abundant bacterial genera were the unclassified bacterial genera. the total number of mussel-related total richness identified in all groups was 4889 (RK = 1605; KC = 1930; MF = 1508; and MU = 1125). According to the metagenomic data obtained in this study, different relative amounts of Lachnospiraceae and Bacteroidetes taxa groups were reported for all stations. the pathogenic bacterial genera identified by metagenomic analyses which may be significant for the public health are Arcobacter, Clostridium, Aeromonas, Vibrio, Escherichia_Shigella, Klebsiella, Campylobacter, Helicobacter, Pseudomonas, Morganella, Serratia, Corynebacterium, Enterococcus, Staphylococcus, Yersinia, Mycoplasma, Brucellaceae_unclassified, Pantoea, and Proteus.Istanbul University BAP unit [FBA-2018-30817]The authors received financial support from Istanbul University BAP unit for the project under FBA-2018-30817 code. Authors used the facilities of BM Labosis (Ankara, Turkey) for Sanger Sequencing. the meta-data analysis and numerical calculations reported in this paper were partially carried out at TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRUBA resources)

Dielectric properties of ZnO/PVDF flexible composites

The focus of this study is to make flexible ZnO/PVDF fibrous composites and to investigate their dielectric behavior. ZnO fibrous network is first produced by calcination and sintering of the precursor PVA/Zinc Acetate electrospun fiber mats. Composite making includes hot-pres melt-casting of ZnO fibrous nonwoven mat after sandwiched between solution cast PVDF films. SEM images of the nanocomposite show that fibrous network is affected during casting and turned into the ZnO short fibers, but remained well distributed/dispersed into PVDF. Processing the ZnO/PVDF flexible composite film facilitates successful handling, and enables measurements for dielectric properties, not practical on sole ZnO fibrous mat. Existence of the ZnO short fibers in the composite film increases the dielectric constant significantly while slight penalty on dielectric loss is measured compared to PVDF film alone

Pb(Zr,Ti)O3 nanofibers produced by electrospinning process

Lead zirconate titanate (PZT) nanofibers are obtained by electrospinning a sol-gel based solution and polyvinyl pyrrolidone (PVP) polymer, and subsequent sintering of the electrospun precursor fibers. The PVP content of the precursor solution is critical in the formation of the fully fibrous mats. Scanning electron microscope (SEM) is used to examine the morphology of the precursor fibers and annealed PZT nanofibers. The diameter of the precursor PZT/PVP green fibers have increased with the aging of the precursor solution along with an increase in the viscosity. The viscosity of 500 mPa results in successful fibrous mats, yielding green PZT/PVP fibers with a diameter of 400 nm. Thefiber mats are then sintered at 700C. X-ray diffraction (XRD) pattern of the annealed PZT fibers exhibits no preferred orientation and a pure tetragonal perovskite phase. Preparation of piezocomposites by infusion of epoxy into the nanofiber mat facilitates successful handling of the fragile mats and enables measurements of dielectric properties