Flashcards in BB Lec - Current Trends Deck (54)
Creating RBCs in the laboratory
mechanism for forming O-type RBCs
The use of enzymes that remove the carbohydrate moieties of the A and B antigens
Current research on blood substitutes is focused on two areas:
hemoglobin-based oxygen carriers (HBOCs) and per- fluorocarbons (PFCs)
Originally developed to be used in trauma situations such as accidents, combat, and surgery,
are intimately involved in primary hemostasis,
interaction of platelets and the vascular endothelium in halting and preventing bleeding following vascular injury.
cellular fragments derived from the cytoplasm of megakaryocytes present in the bone marrow.
They do not contain a nucleus
platelet DNA found in__
average diameter of platelets
2 to 4 μm
normal plt count
150,000 to 350,000 per μL
how many days do PLT circulate
how much plt is sequestered in the microvasculature of the spleen as functional reserves.
30% of the platelets
Used to treat bleeding as associated with thrombocytopenia
Efficacy of transfused platelets: estimated from __
CORRECTED COUNT INCREMENT
CORRECTED COUNT INCREMENT estimates what of platelets?
Efficacy of transfused platelets:
measured after transfusion; does not evaluate or assess the function of the transfused plt
Transfused prophylactically to increase the circulating platelet count in hematology-oncology thrombocytopenic patients to prevent bleeding secondary to drug or radiation therapy
utilized in some instances to treat other disorders in w/c platelets are qualitatively or quantitatively defective because of genetic reasons
MAJOR PROBLEM whenplatelet transfusions were given as freshly drawn whole blood or platelet-rich plasma
Today, platelets are prepared as (2)
concentrates from whole blood
The 2007 National Blood Collection and Utilization Survey found that only ??% of platelet doses in the United States were whole blood derived (WBD).
still remain as the primary means of treating thrombocytopenia
Storage limit of PLT
The two main reasons for the 5-day shelf-life for platelets are
>bacterial contamination at incubation of 22°C
>loss of platelet quality during storage (known as the platelet storage lesion
loss of plt quality and viability
Plt storage lesion:
assoc with loss of membrane integrity
Absence of platelet swirling:
During the storage of PCs in plasma, the principal buffer is
PLT routinely stored at what temp with continuous agitation (primarily flatbed and circular agitators for up to 5 days).
20°C to 24°C,