Patient-Specific Quality Assurance
Ben Mijnheer in Clinical 3D Dosimetry in Modern Radiation Therapy, 2017
In vivo is Latin for “within the living” and denotes the use of a whole, living organism for specific purposes. Consequently, many different types of in vivo measurements are possible in radiation oncology. In vivo dosimetry in radiotherapy means the measurement of the radiation dose “within the living,” i.e., the dose received by a living object during irradiation, as opposed to ex vivo or in vitro dose measurements in a phantom simulating that object. As discussed in Section 18.2.1, point detectors are often used to determine the entrance and exit in vivo dose, whereas electronic portal imaging devices (EPIDs) are frequently used to determine the transit (transmission) in vivo dose. These transit in vivo measurements using EPIDs can be analyzed by making a comparison at the EPID level or in the patient, as discussed in Chapter 7. Although the first approach is also based on an in vivo measurement and may, for instance, provide useful information about anatomical changes in a patient, this approach does not provide quantitative information about the dose “within the living.” According to the nomenclature introduced earlier, this approach will therefore not be considered as in vivo dosimetry. Only measurements during patient treatment providing quantitative information about the actual dose received by the patient can according to this definition be considered as in vivo patient dosimetry and is the topic of this chapter.
Challenges in Delivering Gene Therapy
Yashwant Pathak in Gene Delivery, 2022
Gene therapy usually has two main ways of delivery: in vivo and ex vivo. Another name for these delivery systems would be “direct delivery” for in vivo and “cell-based delivery” for ex-vivo delivery. In in vivo, the work performed, in this instant the delivery of gene therapy, is performed within the natural condition of the organism or quite literally within the organism. Ex-vivo refers to the opposite, which would be outside the living organism [6]. Ex-vivo can almost be compared to that of invitro. Invitro, refers to the work within a set environment, such as a test tube. Ex-vivo gene therapy would use the concept of invitro, as ex-vivo refers to cells being taken out of the body and then transduced with the gene in a test tube, invitro, and then simply readministered to the body, where the gene expression can start to occur. Below in the figure is a summary of direct and cell-based delivery (Figure 1.3).
Recent Developments in Bioresponsive Drug Delivery Systems
Deepa H. Patel in Bioresponsive Polymers, 2020
Molecular imaging is a powerful tool to visualize and characterize biological processes at the cellular and molecular level in vivo. Molecular imaging involves the noninvasive visualization and quantitative detection of biomolecules in vivo by means of target-specific probes [38–41]. Valuable applications of molecular imaging are accurate disease detection, phenotyping, and staging by gathering information on molecular pathways underlying biological and cellular processes in the diseased tissue. Hence, molecular imaging is likely to play a pivotal role in the stratification of patients for personalized treatment. Furthermore, molecular imaging is clinically relevant in the discovery and development of drugs and for the real-time assessment of the efficacy of drug therapy [42, 43]. Further, it can contribute to improved interventions by image-guided drug delivery and image-guided surgery [44–47].
Circulating cell-free mitochondrial DNA in brain health and disease: A systematic review and meta-analysis
Published in The World Journal of Biological Psychiatry, 2022
Sarah Sohyun Park, Hyunjin Jeong, Ana C. Andreazza
Two investigators (SP and HJ) independently screened the titles and abstracts of all studies from the search. The following criteria was used to screen all articles from the initial search: (i) a cross-sectional, case–control or longitudinal study in humans with measurements of ccf-mtDNA; (ii) the study included both disease (cases) and non-disease healthy (controls) participants; and (iii) the study reported ccf-mtDNA concentrations using mean and standard deviation (SD), the sample size, and p-values. Studies were excluded if they met the following criteria: (i) no measurement of ccf-mtDNA in humans; (ii) no healthy control (HC) group; (iii) a review paper, book chapter or comments; (iv) an in vivo or in vitro study; or (v) the author failed to reply when requested for additional information.
The need for consensus guidelines to address the mixed legacy of genetic damage assessments for radiofrequency fields
Published in International Journal of Radiation Biology, 2023
Kenneth R. Foster
In 2016 the American Statistical Association published a statement that expresses the caution of statisticians about NHST and p-value (Wasserstein and Lazar 2016): …A conclusion does not immediately become ‘true’ on one side of the divide [of statistical significance] and ‘false’ on the other. Researchers should bring many contextual factors into play to derive scientific inferences, including the design of a study, the quality of the measurements, the external evidence for the phenomenon under study, and the validity of assumptions that underlie the data analysis. The statistically significant increases in genetic damage, albeit with modest effect size, in several in vivo studies is striking. Perhaps in vivo studies simply present more opportunities for experimental error than in vitro studies, or perhaps something more interesting is occurring. These studies should be redone with more rigorous quality controls, i.e. complaint with OECD guidelines. There is no point in doing studies that are intended to inform health risk assessments that do not meet current standards of quality. Simply listing statistically significant results without an appropriate evaluation of study quality and synthesis of evidence across related studies is neither reliable nor informative.
A review on the effects of extremely low frequency electromagnetic field (ELF-EMF) on cytokines of innate and adaptive immunity
Published in Electromagnetic Biology and Medicine, 2019
Hanie Mahaki, Hamid Tanzadehpanah, Naghi Jabarivasal, Khosro Sardanian, Alireza Zamani
By exposing the body through external stimuli, the dependence of various body systems responses cannot be fully defined by in vitro experiments. Thus, in vivo studies are better matched for considering the general effects of experiment on a living subject. Table 2 presents in vivo studies on the effects of ELF-EMF on cytokines of the innate immune system. Zhang et al. showed that plasma levels of nuclear factor kappa B, TNF-α IL-6, and IL-1β in workers of a power plant were decreased after ELF-EMF exposure with frequency ranging from 5 to 32,000 Hz and density ranging from 0.1 nano Tesla (nT) to 32 mT (D. Zhang et al., 2017). According to our previous research, 100 µT ELF-EMFs increased the level of phytohemagglutinin (PHA)-activated IL-6 in cultures of the spleen and blood of rats, while its production in serum was unchanged. The level of IL-12 in serum was decreased, while the PHA-stimulated IL-12 levels in the spleen and blood cultures were not altered. IL-12 is produced usually by dendritic and macrophage cells. It acts as a primary mediator with early innate immune responses to intracellular microbes. (Salehi et al., 2013). In this regard, in our unpublished study, the effects of 1 and 100 µT ELF-EMF enhanced serum level of IL-10 of not-stimulated rat, while they did not change the release of IL-10 in human serum albumin-incomplete Freund adjuvant (HSA-IFA)-stimulated of rat. Serum level of TNF-α was decreased after exposures to 100, 500, and 2000 µT ELF-EMF in non-stimulated of rat. TNF-α was also decreased in (HSA-IFA)-stimulated of rat after exposure to 100 µT ELF-EMF.
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