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Reproductive Biotechnologies Applied to Artificial Insemination in Swine
Published in Juan Carlos Gardón, Katy Satué, Biotechnologies Applied to Animal Reproduction, 2020
Francisco Alberto García-Vázquez, Chiara Luongo, Gabriela Garrappa, Ernesto Rodríguez Tobón
Once the ejaculate is suitable for processing after this initial appreciation, the next step is the determination of spermatozoa concentration. Traditionally, the most used method to calculate the cell concentration has been the counting chambers such as Neubauer, Bürker, and Thoma (Althouse, 2007; Brito et al., 2016). Nowadays, this method has been surpassed by spectrophotometric techniques because manual counting is a slow process (Brito et al., 2016). In an ejaculate, the opacity depends on the number of cells among other elements of the SP that could interfere with the passage of the light through the sample. Therefore, it is recommendable to dilute a small sample for obtaining a more reliable result (depending extender, dilution rates from 1:4–1:25) (Althouse, 2007). Besides, errors in the evaluation can occur if the dilution is not correct or untimely reading (Althouse, 2007; Brito et al., 2016). CASA (Computerized Assisted Sperm Analysis) system can also be used to determine the concentration, although this system is more recommendable to assess sperm motility (Amann and Waberski, 2014; Brito et al., 2016), as will be explained later. Another method for cell counting is the flow cytometry, which allows rapid and automated counts of many cells. However, the use of flow cytometry is limited due to its high cost and the need for qualified personnel to manage the equipment and interpret the results (Brito et al., 2016).
Essential Oils in Cancer Therapy
Published in K. Hüsnü Can Başer, Gerhard Buchbauer, Handbook of Essential Oils, 2020
Carmen Trummer, Gerhard Buchbauer
Flow cytometry is a routinely used method to detect and measure physical and chemical characteristics of a population of cells. This method allows study of cellular populations with high precision. Some important measurable parameters are apoptosis (quantification, measurement of DNA degradation, caspase activity) and cell viability (Picot et al., 2012).
Use of Fluorescence as a Voltage Indicator in Mononuclear Cells*
Published in Richard C. Niemtzow, Transmembrane Potentials and Characteristics of Immune and Tumor Cell, 2020
Jeffrey L. Rossio, Richard C. Niemtzow
Fortunately, in the case of lymphoid cells, these problems seem to be manageable. The dyes, if carefully used, do not seem to induce hyperpolarization by themselves in lymphocytes. In addition, use of the fluorescence-activated flow cytometer (see later) allows the use of much lower dye concentrations than standard fluorescence photometry or visual fluorescence measurements. This decreases the contribution of the dye itself to cellular changes. To eliminate the ATP-poisoning effect of the dyes, which occurs by inhibition of mitochondrial respiration, cells can be provided with alternative energy sources to temporarily bypass the need for oxidative respiration. Fortunately, most dye measurements can be completed within about 10 min or so, allowing about 5 min to achieve stable fluorescence and up to 5 min to obtain a good reading of the fluorescence. Lymphocytes do not have large numbers of cytoplasmic mitochondria, so interference from potentials of mitochondrial membranes is probably minimal in these systems.
Sulfoxaflor insecticide exhibits cytotoxic or genotoxic and apoptotic potential via oxidative stress-associated DNA damage in human blood lymphocytes cell cultures
Published in Drug and Chemical Toxicology, 2023
Cebrail Sınacı, Ayla Çelik, Derya Yetkin, Sertan Çevik, Gizem Güler
In the flow cytometry, cells or particles in the liquid are passed through a chamber illuminated by laser light, and the stimuli given by the cells as they pass through the light are collected and analyzed. Here, the cells' physical properties such as size and granularity can be shown; antigenic structures on the cell surface or content can also be determined. Thus, information can be obtained about various properties of the cell, such as immune structure, DNA content, enzyme activity, cell membrane potential, and viability and apoptotic features of cells (Dunphy 2004, Atalay et al. 2018). It has been shown that it can analyze much more cells in a shorter time compared to light microscopy, and with this technique, an average of 10 000 cells can be evaluated in 20 seconds (Pozarowski et al. 2004, Toduka et al. 2012).
Dermal exposure to cobalt studied in vitro in keratinocytes – effects of cobalt exposure on inflammasome activated cytokines, and mRNA response
Published in Biomarkers, 2021
Maria Klasson, Magnus Lindberg, Håkan Westberg, Ing-Liss Bryngelsson, Kedeye Tuerxun, Alexander Persson, Eva Särndahl
The gating strategy to determine the activated cells during flow cytometry analysis is shown in Figure 4. FLICA 660 was used to measure the caspase-1 activity in HaCaT cells exposed for 24 hours and to 500 µM or 1 mM CoCl2. A significant increase in caspase-1 activity was detected in cells stimulated with 1 mM CoCl2 (Figure 3). Further, exposure of HaCaT cells to 1 mM CoCl2 showed a significant increase in caspase-1 activation compared to the unexposed cells when analysed by using the mixed model (OR 5.96; 95% CI 3.07–11.56), and the high exposure group (1 mM) showed a statistically significant increase of caspase-1 activity compared to the 500 µm (OR 2.81; CI 1.45–2.45). No significant difference was seen in the response between high and low calcium growth conditions (Table 3).
Monitoring immunomodulation in patients with sepsis
Published in Expert Review of Molecular Diagnostics, 2021
Evdoxia Kyriazopoulou, Evangelos J. Giamarellos-Bourboulis
Human Leukocyte Antigen-DR isotype (HLA-DR) is a Major Histocompatibility Complex (MHC) class II cell surface receptor on monocytes, macrophages, and dendritic cells. It participates in antigen presentation and it is encoded by the HLA-DRA gene. Abundance of HLA-DR on the surface of antigen-presenting cells is a sign of immune competence. In sepsis, HLA-DR downregulation is the best, so far, studied marker of sepsis-induced immunosuppression. Spleen biopsies harvested postmortem from septic patients revealed low HLA-DR expression of antigen-presenting cells [49]. Several studies have been performed on the role of HLA-DR expressed on monocytes for the detection of sepsis-induced immunosuppression (Table 3). It needs to be outscored that in some studies the expression of HLA-DR is provided as the absolute number of membrane receptors and in other studies as the percentage of monocytes expressing HLA-DR. Which is the most accurate expression of sepsis-induced immunosuppression remains to be defined. The real difference between the two measurements is that the percentage expression cannot preclude the density of the receptors on the cell membrane. A major limitation of both measurements is the requirement of flow cytometry technology.