What is blood comprised of?
Erythrocytes - RBCs
T Lymphocytes - specialized cell mediated immune responses
B Lymphocytes - antibody-mediated immune responses
Platelets - Thrombocytes
Macrophages - general phagocytic cells and accessory cells
Granulocytes - 3 types: Neutrophils (anti-bacterial), Eosinophils (anti-parasitic) and Basophils (anti-inflammatory)
What are 2 types of haematopoietic stem cells?
Totipotent stem cells - can permanently reconstitute the entire blood and immune cell produce systems but account for less thatn 0.1% of cells in the bone marrow.
Pluripotent stem cells - less general but can still differentiate into several cells lines (multipotential). They generate progenitor cells which are lineage-restricted and usually produce only one mature blood cell type.
What are 2 types of pluripotent stem cells?
CFU-E: produces erythroblasts and synthesizes haemoglobin
BFU-E: burst forming unit erythroid
What is haemapoietic Colony-forming Assay?
This process clones haematopoietic progenitor cells in suspension on semisolid media.
First, the marrow plug is removed from the bone then converted into single cell suspension by pipetting up and own to dissociate the tissue
Mix the dissociated cells with agar and conventional medium and place in Petri dishes (semisolid with growth factors is needed in order for growth to occur)
Primary cultures are maintained in growth medium for 1-3 weeks until cells form in culture
Pick colonies off agar, fix and stain in order to identify
What is long-term bone marrow cultures?
Contain a complex arrangement of different cell types from haematopoietic tissue
Culturing whole bone marrow maintains the relationship between the stroma and the stem cells -> with approproate interaction can get the proliferation of steam cells and progenitor cells for several weeks
What is allogenic bone marrow transplantation?
Allogenic transplantation is the transfer of bone marrow from one person to another
What problems are associated with allogenic bone marrow transplantation?
- Need to sufficiently suppress the patient's immune system so that it will not reject the transplanted stem cells
- Donor stem cells may recognize the recipient as 'foreign and cause lethal tissue and organ damange known as graft versus host disease
What is autologous transplantation?
First bone marrow from a patient that is cryopreserved. The patient is then treated with chemotherapy or radiation therapy. The frozen sample is thawed and injected into the patient's veins where it will find its way back into the veins.
What are some advantages and disadvantages from autologous transplantation?
There is no need to find a compatible bone marrow donor.
Need to seperate health stem cells from malignant celsl if the patient's bone marrow contains cancer cells
What are some uses of umbilical cord blood?
Umbilicord blood contains pluripotent stem cells that can be collected at birth and cryopreserved
What is the ultimate stem cell?
The unfertilized egg but after a few divisions, it loses its potential to become all types of cells because it gains differentiated functions.
How do adult stem cells go through self-renewal?
- both daughter cells are identical to the parent (symmetrical division)
- one daughter cell is identical to the parent (stem cell) and the other daughter cell will differentiate (asymmetrical division)
What are some cells that have potential for transplantation?
B-islet cells of pancrease can be transplated to produce insulin for diabetics
Brain neurons - eventually can be used by brains damaged by Parkinson's, stroke or head injury victims
Chondrocytes or osteoblasts - cells of cartilage or bone might be used for cartilage or bone repair and replacement
Hepatocytes - treats liver damage
Spermatogonia - progenitors of spermatocytes