Questions cluster 5, 6, 7 Flashcards
Current treatment options for bone defects include autologous tissue use such as bone grafts and bone flaps. Bone tissue engineering starting with stem cells is an attractive alternative, but what is the current limitation in bone tissue engineering?
Diffusion: cells on the inside of the bone will die because they have less oxygen and nutrients (limited to 200 micrometers). So TE products need to be vascularized to make larger constructs.
Name two applications of ceramic scaffolds and mention one ceramic subtype suitable for each application. Explain in a few words why that subtype is chosen.
- Aluminium oxide (Alumina) -> Hip arthroplasty, Facial reconstruction, Middle ear implants, Dental implants -> Almost bioinert
- Zirconia -> Hip arthroplasty, Dental implants, Joint replacement -> Bioinert
- Glasses and glass ceramics -> Facial reconstruction, Dental implants, Bone substitute -> Bioactive
- Calcium phosphates /Hydroxyapatite -> Orthopaedic implants, Bone substitute, Vertebral replacement -> Biodegradable (with exceptions!!!)
What is the seed region of the CRISPR/Cas system?
a) A sequence in the crRNA important for target genome recognition
b) A sequence in the trRNA required for target genome recognition
c) A sequence in the target genome, required for Cas9 activation
d) A sequence in the target genome, required for crRNA binding
a) A sequence in the crRNA important for target genome recognition
Name a strategy that can be applied to restore the lungs of patients with chronic obstructive pulmonary disease?
- Reversing airway epithelial remodeling with specific drugs.
- Stem cell therapy (i.e. with Mesenchymal stem/ stromal cells).
- Transplantation of a bioengineered lung.
Which types of differentiated intestinal cells are secretory cells (multiple answers possible)?
a) Paneth cells
b) Tuft cells
c) Enterocytes
d) Goblet cells
e) M cells
f) Enteroendocrine cells
a) Paneth cells
b) Tuft cells
d) Goblet cells
f) Enteroendocrine cells
What is the key difference between organ-on-chip technology and conventional tissue engineering?
a) Organs-on-chips contain no scaffolding materials
b) Tissue engineering is based on human cell material
c) Organs-on-chips are not made for use in the human body
d) Tissue engineering focuses on three-dimensional tissues
c) Organs-on-chips are not made for use in the human body
What is the graft material used in urethral reconstruction surgery in adults in a clinical setting?
a) Biomaterials (like decellularized small intestinal submucosa)
b) Synthetic scaffolds seeded with cells
c) Autologous grafts from oral mucosa
d) All of the above answers are correct.
c) Autologous grafts from oral mucosa
Mesenchymal Stem Cell (MSC) therapy is a promising strategy to treat neonatal brain injury. MSCs are not engrafted in the brain. Describe how MSCs are able to repair the neonatal injured brain.
MSCs migrate into the brain using chemotactic cues. They respond to the injured environment by enhancing the secretion of various factors (trophic factors, growth factors, cytokines). These secreted factors stimulate the endogenous NSCs to differentiate towards neurons and thereby enhance the endogenous neuroregenerative capacity of the brain. These neurons are engrafted at the site of the lesion and rebuild the injured areas of brain.
The presence of which type of T cells is usually associated with rejection of the grafted tissue?
a) CD8+ cytotoxic lymphocytes
b) CD4+ regulatory lymphocytes
c) CD4+ cytotoxic lymphocytes
d) none of them
a) CD8+ cytotoxic lymphocytes
Which of these immune cells subsets are found during the earliest phase after biomaterial implantation?
a) Polymorphonuclear neutrophils
b) T lymphocytes
c) Macrophages
d) Natural killer cells
a) Polymorphonuclear neutrophils
Which endothelial progenitor cell type is thought to become a structural part of newly formed blood vessels?
a) CFU-Hill
b) CAC
c) ECFC
d) All of the above
c) ECFC
What is the graft material used in urethral reconstruction surgery in adults in a clinical setting?
a) Biomaterials (like decellularized small intestinal submucosa)
b) Synthetic scaffolds seeded with cells
c) Autologous grafts from oral mucosa
d) All of the above answers are correct.
c) Autologous grafts from oral mucosa
Which 2 embryonic tissues interact to form the permanent kidney? And which of the 2 tissues branches into the other tissue during nephron formation?
Metanephric mesenchyme and ureteric bud.
The ureteric bud tissue branches into the
metanephric mesenchyme.
The removal of protein-bound toxins in the kidney is performed through
a) active transport mediated by proximal tubule epithelial cells
b) glomerular filtration
c) passive transport from blood into the filtrate
d) proteases in the loop of Henle
a) active transport mediated by proximal tubule epithelial cells
