China
Africa
Explore chapters and articles related to this topic
Infection and Inflammation
Published in Michael Ljungberg, Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
Erik H. J. G. Aarntzen, Andor W. J. M. Glaudemans
Caution should be taken if radioactivity is retained in the lung beyond 30 minutes, but nevertheless is cleared within 3 hours, or when radioactivity in the liver is higher than in the spleen at any time point during the acquisition. Both conditions likely indicate cell damage, and the procedure should be considered to non-diagnostic. Normal biodistributions of radiopharmaceuticals has been summarized in Table 16.1 [48].
Serological Typing of HLA-A, -B, and -C Antigens
Published in M. Kam, Jeffrey L. Bidwell, Handbook of HLA TYPING TECHNIQUES, 2020
The cryopreservative DMSO is essential in the freezing mixture to prevent cell damage due to ice crystal formation. It is toxic to lymphocytes and should be added in a dropwise manner to lymphocyte suspensions with constant mixing. During the cryopreservation process, the heat of crystallization is generated at about -18°C, which may damage the lymphocytes. Consequently, the rate of freezing to -30°C is slow. This reduces the cell damage because the heat of crystallization is not released instantaneously but released over a period of time.
Hypoxia, Free Radicals, and Reperfusion Injury Following Cold Storage and Reperfusion of Livers for Transplantation
Published in John J. Lemasters, Constance Oliver, Cell Biology of Trauma, 2020
Ronald G. Thurman, Wenshi Gao, Henry D. Connor, Sigrid Bachmann, Robert T. Currin, Ronald P. Mason, John J. Lemasters
When cells can no longer recover after reoxygenation, irreversible hypoxic injury occurs. Dead cells are, by definition, irreversibly injured, but prior to the onset of cell death irreversible cell damage may occur. In anoxic cultured hepatocytes, the transition from reversible to irreversible injury and the onset of cell death seem to take place simultaneously. When blebs are resorbed upon reoxygenation prior to bleb rupture, reversible injury is indicated.13 In perfused liver, blebs also disappear after low-flow hypoxia followed by reflow; however, after reflow many blebs from intact livers are shed into the circulation instead of being resorbed.12 Shedding of blebs occurs as the bleb cytoplasm tries to withdraw through endothelial fenestrations. Release of blebs may be promoted by the difficulty of withdrawing through fenestrations, together with the shear force of fluid moving through sinusoids. Shedding of blebs apparently accounts for enzyme release by damaged livers in the absence of outright hepatic necrosis.12,18,19 In addition, blebbing occurs in many hepatic diseases and in the response of hepatocytes to many hepatotoxicants.20,21
Anaesthesia for a patient with Friedreich’s ataxia undergoing emergency tibia interlocking nail insertion
Published in Egyptian Journal of Anaesthesia, 2022
Friedreich's ataxia is a disorder that affects a gene (FXN) on chromosome 9, which produces an important protein (frataxin). Low frataxin levels lead to insufficient biosynthesis of iron–sulfur clusters that are needed for mitochondrial electron transport and iron metabolism. This leads to cell damage and degeneration. Degeneration occurs in sensory nerves more than motor nerves. Similar degenerative changes occur in cardiac cells and pancreatic cells causing left ventricular hypertrophy and dilatation and diabetes mellitus. Friedreich's ataxia is the most common inherited ataxia with a prevalence of 1 in 30,000–50,000 and a carrier frequency of 1 in 90–110. The classic Friedreich’s ataxia phenotype is due to a homozygous GAA (guanine, adenine, adenine) triplet repeat expansion in intron 1 of the frataxin gene [3–6].
Low dose gamma irradiation pretreatment modulates the sensitivity of CNS to subsequent mixed gamma and neutron irradiation of the mouse head
Published in International Journal of Radiation Biology, 2021
Alla V. Rodina, Yulia P. Semochkina, Olga V. Vysotskaya, Anastasia N. Romantsova, Aleksandr N. Strepetov, Elizaveta Y. Moskaleva
Most of the studies of the biological effects of LDIR demonstrate that human and animal cells change the activity of many biochemical and cellular systems in response to such an impact. In experiments investigating the possibility of using pre-irradiation at low doses to increase the radioresistance of the immune cells, controversial results were obtained (Gridley et al. 2010; Rizvi, Pecaut, Gridley 2011; Rizvi, Pecaut, Slater, et al. 2011; Gridley et al. 2013). In various studies, LDIR led both to the activation of adaptive mechanisms and to negative effects, including the formation of genomic instability in different types of cells (Brooks 2005; Tapio and Jacob 2007; Mothersill and Seymour 2012; Cortese et al. 2018; Azzam 2019). The existence of a threshold for the small doses of different types of ionizing radiation which could represent the boundary between the development of stochastic and deterministic effects is still in question. This threshold can vary depending on the type of cells and their radiosensitivity, and the final effect will result from both the degree of cell damage and their ability to repair damage. Therefore, the question of the danger level of LDIR is still open. In many studies, a pronounced radioadaptive response was observed after irradiation of animals in low doses, associated with an increase in life expectancy and suppression of carcinogenesis, but the data differed significantly since the indicators were influenced not only by the type of radiation, dose and dose rate and by the variety of cell types, tissues and organisms (Feinendegen et al. 2004, 2007; Schwartz 2007).
Effects of 27 natural products on drug metabolism genes in channel catfish (Ictalurus punctatus) cell line
Published in Xenobiotica, 2020
Zhenyue Wang, Yongtao Liu, Xiaohui Ai, Liqiao Zhong, Gang Han, Jinlong Song, Qiuhong Yang, Jing Dong
In order to examine whether the 27 natural products inhibited the growth of CC-K cells, we measured the cells viability by the MTT assay after treatment with the test compounds. Apart from schisandrin B, ginkgolide A and oxymatrine, which had no significant effect on cell viability at concentrations below 100 µM, 200 µM, and 2.5 mM, respectively (Table 1), the other 24 natural products had significant cytotoxic effects at the highest treatment concentrations. In addition, different degrees of cell damage were found such as cell contraction, morphology changes and eventually apoptosis in different concentrations of treatment groups. As shown in the figure below, the toxicity effects of curcumin on cells exhibited a dose-dependent inhibition at 24 h (Figure 1). The semi-lethal concentrations and IC50 plots (Supporting material) of 24 natural products were performed with GraphPad Prism software (version 8.0) (Table 1 and Figure 2). The no observed effect concentration levels of natural products were taken as the NOAEL. Then, the concentrations of the natural products used in subsequent work were under their highest safe concentration (Table 1).