Cerebral edema early stroke or hypoxia, cardiac arrest, and pseudotumor cerebri. During an ischemic stroke, a lack of oxygen and glucose leads to a breakdown of the sodium-calcium pumps on brain cell membranes, which in turn results in a massive buildup of sodium and calcium intracellularly. This causes a rapid uptake of water and subsequent swelling of the cells. It is this swelling of the individual cells of the brain that is seen as the main distinguishing characteristic of cytotoxic edema, as opposed to vasogenic edema, wherein the influx of fluid is typically seen in the interstitial space rather than within the
Tissue residue the exposure media. In general, tissue residue approaches are used for chemicals that bioaccumulate or for bioaccumulative chemicals. The majority of these substances are organic compounds that are not easily metabolized by organisms and have long environmental persistence. Examples of these chemicals include: polychlorinated dibenzodioxins, furans, biphenyls, DDT and its metabolites, and dieldrin. The use of tissue residues in assessing toxicity and bioaccumulation may also be referred to as the tissue residue-effects approach (TRA), critical body residue (CBR) or tissue residue-based toxicity tests. Historically, aquatic toxicology toxicity tests have focused on water-based approaches where concentration of a toxicant is determined