Toxic Responses of the Blood Flashcards
Due to the production rate of blood cells, they are susceptible to which two major modes of toxicity?
Cytoreductive and anti-mitotic chemicals that reduces cell numbers or prevent cell division.
WHat is the difference between primary and secondary hematotoxicity?
Primary toxicity directly deals with damage to blood tissues while secondary is a result of damage to another tissue that results in harm to blood cells.
What is erythrocytosis and what metal is capable if inducing this process?
Erythrocytosis in the increased production of red blood cells thereby increasing oxygen carrying capacity. This has been induced by cobalt, which is capable of inducing transcription of the erythropoietin gene.
What are the two fundamental ways to induce anemia?
Reduce the number of circulating RBCs via destruction or impair their synthesis.
How does plasma volume relate to anemia and erythrocytosis?
Increased plasma volume dilutes the RBC count, reduced plasma volume increased the relative concentration.
What is aplastic anemia and how is it categorized?
Aplastic anemia is a life-threatening disorder characterized by pancytopenia and bone marrow hypoplasia. There is predictable aplastic anemia that results from dose-response patterns to known substances (benzene and radiation). Then there is idiosyncratic that does not appear to be dose-responsive. The mechanism for this is unknown but suspected to involve the immune system.
What causes methemoglobinemia?
This is caused by an overwhelming exposure to an oxidizing substance that saturates the reductase system responsible for restoring methemoglobulin.
Why are infants more susceptible to methemoglobinemia than adults?
Infants ingest more water on a body weight basis, lower reductase activity than adults, and their GI tract (including flora) readily convert nitrate to the more potent nitrite.
A greenish hue to the skin indicates what type of hematotoxicity?
Hydrogen sulfide poisoning
Heinz bodies are the result of what mode of toxicity?
Oxidative stress in RBCs leading to denatured hemoglobin aggregates inside RBCs.
Why is acute (one time) exposure to cytotoxic agents unlikely to result in significant harm to stem cells that give rise to neutrophils?
Cell cycling of neutrophils is slow, resulting in a lag between exposure and the timing of cell division, so there is time to address the initial toxic insult.
