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How does anemia develop in patients with chronic renal failure?

How does anemia develop in strict vegetarians?
What blood and bone marrow changes would you expect in acute appendicitis? Why?
What are the consequences of congenital spherocytosis?
What are the consequences of living in a high altitude area on eryhtropoiesis? Give one example of a pathologic condition that can give rise to the same phenomenon as above.

Answers:

CH

Chronic renal failure leads to anemia because of two things. First and most importantly, the kidneys are where the hormone erythropoetin is created. This is a hormone which is directly responsible for the stimulation of red blood cell formation from the bone marrow. When the kidney tissue dies, so does this hormone producing function and anemia results. Treatment for renal failure related anemia needs to include the administration of pharmacologic erythropoetin, which is marketed as “Procrit”. Secondly, renal failure necessitates dialysis. Although there is something called “peritoneal dialysis” which does not involve the blood directly, most people undergo “hemodialysis” which involves plugging into the vascular system and pumping blood through a filtration mechanism which mimics the action of the kidney. This is blood destructive even in the best of circumstances, and some blood is left behind in the tubing circuit. Banked blood is sometimes added to the circuit when people go in for their regular dialysis. Also, between dialysis sessions, people have to take in some water, and over a couple of days, this can result in dilution of the blood which contributes to the chronic anemia.
The concept of “strict vegetarian” means different things to different people, but the classic issue to talk about with total elimination of animal products from the diet is vitamin B12 deficiency. With B12 deficiency comes a failure to produce hemoglobin which leads to a macrocytic anemia. The red blood cells can form, but they’re basically large, empty and relatively devoid of oxygen carrying hemoglobin.
Appendicitis is basically a source of intra-abdominal infection. All infections (in normal people who can mount an immune response) are attended by increases in the white blood cell count. The concept of a white blood cell count is actually a little bit complicated because what you “count” is what is floating in the blood, while there are a substantial number of white cells which aren’t floating along, but instead are rolling along the blood vessel walls. The white blood cell count increases because the chemical signalling from the site of infection stimulates production of the short lived forms such as PMN’s (neutrophils) which when seen in the peripheral blood, have immature characteristics – indicating that the increased count is a result of increased marrow production and not just activation of the cells flowing along the blood vessel walls. I doubt that you’d be able to make a diagnosis from a marrow sample that this was going on, but I’m not a hematologist.
Hereditary spherocytosis is a classic medical school question, where an abnormal gene which codes for a protein called “anchorin” leads to the inability of red blood cells to form their normally flat/discoid shape. They “spherize” which makes them not as deformable and not as easily passed through capillaries. Spherocytosis leads to anemia by way of shortened red cell life and slow iron loss as a result. There is increased destruction of red cells in the spleen. Some people need splenectomies.
High altitude leads to high red cell counts because the system reads the low oxygen tension as being a result of insufficient oxygen carrying capacity in the blood. This stimulates erythropoesis.
I hope that helps.

AN

Anemia develops either becuase the body is unable to process the iron in one’s diet so as to assist the body in producing red blood cells or becuase one does not consume enough iron in one’s diet (usually the cause of anemia in vegetarians, which I learned from personal experience.)
With appendicitus, one would look for an increase in white blood cells as they attempt to fight off the infection of the same. The bone marrow would be producing more white cells in proportion to the red blood cells it was making. Bone marrow test are not usually used in diagnoising an appendicitus.
I can’t help with the third one but I will check back to see if someonelse answers it.
Living in a high altitude, one’s ability to process oxygen changes due to the lower level of the same in such places.
I would guess, though I may well be wrong, that any condition that restricted one’s breathing, thereby limiting the amount of oxygen processed by said person might result in similar problems and complications.

YO

You really ought to do your own homework.
Erythropoietin is produced in the kidneys. No beans, no erythropoietin.