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The Emergence of Nanomedicine: A Vast Industry
Published in Paula V. Messina, Luciano A. Benedini, Damián Placente, Tomorrow’s Healthcare by Nano-sized Approaches, 2020
Paula V. Messina, Luciano A. Benedini, Damián Placente
Diagnostic tools: in vitro methods: In this category are grouped those nano-systems that can help to identify the occurrence of a disease as soon as possible. Screenable markers to work directly on genes and genetic samples. In nuclear biology and molecular biology, a marker gene is a gene used to determine if a nucleic acid sequence has been successfully inserted into an organism’s DNA. They are used in ultra-sensitive labelling and, detection technologies; high throughput arrays and multiple analyses. Contrast agents like nanoparticle labels and imaging devices that make possible graphical representations of the patient’s condition by imaging observation.
Plant Biotechnology
Published in Firdos Alam Khan, Biotechnology Fundamentals, 2020
To select only cells that have incorporated the new genes, the genes coding for the desired trait are fused to a gene that allows selection of transformed cells, so-called marker genes. The expression of the marker gene enables the transgenic cells to grow in the presence of a selective agent, usually an antibiotic or an herbicide, while cells without the marker gene die. One of the most commonly used markers is the bacterial aminoglycoside-3′ phosphotransferase gene (APH(3′)II), also referred to as neomycin phosphotransferase II (NPTII). This gene codes for an enzyme that inactivates the antibiotics kanamycin, neomycin, and G418 through phosphorylation. In addition to NPTII, several other antibiotic resistance genes have been used as selective markers, such as hygromycin phosphotransferase gene conferring resistance to hygromycin. Another group of selective markers is herbicide tolerance genes. Herbicide tolerance has been obtained through the incorporation and expression of a gene that either detoxifies the herbicide in a manner similar to that of the antibiotic resistance gene products or a gene that expresses a product that acts like the herbicide target but is not affected by the herbicide. Herbicide tolerance may not only serve as a useful trait for selection in the development of transgenic plants but also has some commercial interest. Transformations of plant protoplasts, cells, and tissues are usually only useful if they can be regenerated into whole plants. The rate of regeneration varies greatly not only among different species but also between cultivars of the same species. Besides the ability to introduce a gene into the genome of a plant species, regeneration of intact, fertile plants out of transformed cells or tissues is the most limiting step in developing transgenic plants (Figure 6.9).
The effects of thymoquinone on DNA damage, apoptosis and oxidative stress in an osteoblast cell line exposed to ionizing radiation
Published in Radiation Effects and Defects in Solids, 2021
Osman Yılmaz, Veysel Yüksek, Sedat Çetin, Semiha Dede, Taylan Tuğrul
Studies have reported that radiation exposure leads to oxidative stress in the skeletal system, oxidative stress reduces the osteogenic activity in osteoblast cell lines, and oxidative-stress-regulating genes such as Sod, Gpx and CAT regulate the osteogenic expression and proliferation in osteoblast cell lines (38–40). Considering the statistical results of the measurement values obtained after IR application in this study, at the end of 72 h, in the IR group, there was an approximately 2.4-fold increase in the expression of the Sod-1 gene in comparison to the control group. According to these results, as the Sod-1 expression increasing at the end of 72 h was an indication of increasing free oxygen radicals, it may be stated that IR causes oxidative stress. In addition to this effect, it was determined that TQ applications both before and after IR application for the 72-hour incubation period brought the oxidant–antioxidant marker gene expression levels close to those of the control group.
Diagnosis and management of implant debris-associated inflammation
Published in Expert Review of Medical Devices, 2020
Stuart B. Goodman, Jiri Gallo, Emmanuel Gibon, Michiaki Takagi
Osteoprotegerin (OPG) is a natural soluble decoy protein that has the ability to inhibit the Receptor Activator of NF-κB Ligand (RANKL). In a mouse calvarial model of osteolysis, Ulrich-Vinther et al. investigated a gene therapy drug using a recombinant adeno-associated virus (rAAV) to induce production of OPG in myocytes [113]. Titanium-implanted mice treated with the rAAV showed high levels of OPG and significantly decreased numbers of osteoclasts and bone resorption. Yang et al. [114] exposed implanted bone tissue, within established pouches in BALB/c mice, with UHMWPE particles. AAV encoding the human OPG gene (rAAV-hOPG) or the β galactosidase marker gene (rAAV-LacZ) was then injected into the air pouches. This resulted in significantly less mRNA expression of osteoclast markers in OPG-transduced pouches, compared with rAAV-LacZ-transduced pouches. The transduction and expression of OPG also considerably decreased the gene copies of the biologic RANK. Similar results were obtained by Kim et al. [115].
The potential for the use of gene drives for pest control in New Zealand: a perspective
Published in Journal of the Royal Society of New Zealand, 2018
Peter K. Dearden, Neil J. Gemmell, Ocean R. Mercier, Philip J. Lester, Maxwell J. Scott, Richard D. Newcomb, Thomas R. Buckley, Jeanne M. E. Jacobs, Stephen G. Goldson, David R. Penman
To illustrate a gene drive system based on Cas9, consider the situation of a release of a few GM insects that are homozygous for a dominant fluorescent protein marker gene (GFP) (Figure 1A). All the offspring from mating between GM insects and wild type will be fluorescent. Most likely these insects will mate with the numerous wild type insects in the environment. From these matings only half of the offspring will show fluorescence because of normal Mendelian inheritance. In the following generation, even fewer of the population will show fluorescence. Now consider a release of a few insects carrying the fluorescent protein marker gene linked to a Cas9-based gene drive (Figure 1B). The Cas9, gRNA and GFP marker gene are both within the recognition sequence for the Cas9. As for the first release, all the offspring from mating with wild type insects will be fluorescent (carrying GFP). In the germline of the first generation, expression of the Cas9 and gRNA will cause cleavage of its recognition site in the chromosome that does not contain the Cas9 (Figure 1C). Insertion of the Cas9 + gRNA + GFP genes will then occur via homology dependent repair (HDR). This repair process is likely to be near 100% efficient; all the gametes will contain a chromosome with the Cas9 and linked fluorescence gene. Thus, when the first generation insects mate with wild type insects all the offspring will be fluorescent. Further generations will lead to the marker gene being ‘driven’ into the population.