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Flashcards in BB Lec - Current Trends Deck (54):
1

Creating RBCs in the laboratory

(blood pharming)

2

mechanism for forming O-type RBCs

The use of enzymes that remove the carbohydrate moieties of the A and B antigens

3

Current research on blood substitutes is focused on two areas:

hemoglobin-based oxygen carriers (HBOCs) and per- fluorocarbons (PFCs)

4

Originally developed to be used in trauma situations such as accidents, combat, and surgery,

RBC substitutes

5

are intimately involved in primary hemostasis,

Platelets

6

interaction of platelets and the vascular endothelium in halting and preventing bleeding following vascular injury.

hemostasis

7

cellular fragments derived from the cytoplasm of megakaryocytes present in the bone marrow.

Platelets

8

They do not contain a nucleus

Platelets

9

platelet DNA found in__

mitochondria

10

average diameter of platelets

2 to 4 μm

11

normal plt count

150,000 to 350,000 per μL

12

how many days do PLT circulate

9-12 days

13

how much plt is sequestered in the microvasculature of the spleen as functional reserves.

30% of the platelets

14

Used to treat bleeding as associated with thrombocytopenia

PLT

15

Efficacy of transfused platelets: estimated from __

CORRECTED COUNT INCREMENT

16

CORRECTED COUNT INCREMENT estimates what of platelets?

Efficacy of transfused platelets:

17

measured after transfusion; does not evaluate or assess the function of the transfused plt

CCI

18

Transfused prophylactically to increase the circulating platelet count in hematology-oncology thrombocytopenic patients to prevent bleeding secondary to drug or radiation therapy

PLT

19

utilized in some instances to treat other disorders in w/c platelets are qualitatively or quantitatively defective because of genetic reasons

PLT

20

MAJOR PROBLEM whenplatelet transfusions were given as freshly drawn whole blood or platelet-rich plasma

circulatory overload

21

Today, platelets are prepared as (2)

concentrates from whole blood
by apheresis

22

The 2007 National Blood Collection and Utilization Survey found that only ??% of platelet doses in the United States were whole blood derived (WBD).

17

23

still remain as the primary means of treating thrombocytopenia

Platelets

24

Storage limit of PLT

5 DAYS

25

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

26

loss of plt quality and viability

Plt storage lesion:

27

assoc with loss of membrane integrity

Absence of platelet swirling:

28

During the storage of PCs in plasma, the principal buffer is

bicarbonate

29

PLT routinely stored at what temp with continuous agitation (primarily flatbed and circular agitators for up to 5 days).

20°C to 24°C,

30

In the United States, platelets are being stored WHERE, unless a platelet additive solution is used.

in a 100% plasma medium

31

Initially, platelets were stored at ___, based on the successful storage of RBCs at this temperature range

1°C to 6°C

32

what happens to PLT when stored at 1-6C?

becomes spherical from discoid

33

loss of PLT shape at 1-6c is due to

microtubule assembly

34

a study by _______ showed that cold storage at 1°C to 6°C resulted in a marked reduction in platelet in vivo viability, manifested as a reduction in in vivo life span, after only 18 hours of storage. This study also identified for the first time that 20°C to 24°C (room temperature) should be the preferred range, based on viability results.

Murphy and Gardner

35

aside from the temp considerations, platelets must also be ___ during storage

agitated

36

has been shown to facilitate oxygen transfer into the platelet bag and oxygen consumption by the platelets.

agitation

37

what happens when pH was reduced from 6.8 to 6.2

platelets progressively changed shape from disks to spheres

38

The ___ being used for storage were identified as being responsible for the fall in pH because of their limiting gas transfer properties for oxygen and carbon dioxide

containers

39

1st generation containers

polyvinyl chloride (PVC) containing phthalate plasticizer

40

2nd gen containers

PVC or polyolefin plastic

41

For most PVC containers,_____ used to increase gas transport

alternative plasticizers

42

two alternative plasticizers

trimellitate & citrate based a

43

____ is determined by measuring pre-transfusion and post-transfusion platelet counts (1 hour and/or 24 hours) and expressing the difference based on the number of platelets transfused (corrected count increment)

Platelet viability

44

The observation of the ____ caused by discoid platelets when placed in front of a light source has been used to obtain a semi-qualitative evaluation of the retention of platelet viability properties in stored units

swirling phenomenon

45

indicates the capacity of platelets to circulate after infusion without premature removal or destruction.

Viability

46

Platelets have a life span of ??days after release from megakaryocytes.

8 to 10

47

is defined as the ability of viable platelets to respond to vascular damage in promoting hemostasis.

Function

48

Company developing the technology of blood typeconversion

ZymeQuest

49

Company awarded the contract to develop a system to produce O negative RBCs

Arteriocyte

50

Blood substitutes areas of research

Hemoglobin-based oxygen carriers
Perfluorocarbons (PFCs)

51

How much platelet is discarded by blood supplier or hospital blood bank

Approx 30% of platelet inventory

52

Identified as being responsible for the fall of pH of PLT due to their limiting gas transfer properties for oxyen and carbon dioxide

Containers for storage

53

Disadvantages of culture methods for detection of bacterial contamination of PLT

Product loss due to sampling
False negative results
Costs
Delay in product release, further reducing already short shelf-life
Logistical problems of culturing WBD platelets

54

The major concern associated with storage of platelets at 20°C to 24°C is the ?

potential for bacterial growth

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