Engenharia de Células e Tecidos/Engenharia Celular e de Tecidos
Cell and Tissue Engineering/Cellular and Tissue Engineering
June, 24th 2011
Name:___________________________________________________
Degree: ________________________
Number: _______________________
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Grading: 0.375/20 per each multiple choice question. Each wrong question penalizes 0.075/20. Choose THE
BEST answer.
Group I
1. A bone marrow transplant may need 1010 cells which occupy a volume of (cell diameter = 10
µm):
a) 5.2 L
b) 5.2 mL
c) 5.2 µL
d) 5.2 nL
2. __________ are used in _______________ in which resolution limit is about ______. Choose
the appropriate set to complete blanks.
a) quantum dots/bright field microscopy/200 nm
b) fluorescent dyes/transmission electron microscopy/0.2nm
c) electron-dense “dyes”/transmission electron microscopy/0.2nm
d) electron-dense “dyes”/scanning electron microscopy/0.2nm
3. Fluorescence microscopy shows:
a) very high spatial resolution when cells are cut in very thin slices
b) a spatial resolution limit of 0.2 nm with some fluorescence techniques (4Pi, STED, STORM)
c) different lateral and axial spatial resolution with some fluorescence techniques (4Pi, STED,
STORM)
d) poor temporal resolution
4.
a)
b)
c)
d)
Techniques to purify cells and organelles from organs and tissues:
are commonly based on strategies to weaken the ECM
are rarely immunologically based
do not depend on the cell and/or tissue type
start with cells/tissues in an appropriate buffer at 37ºC
5.
a)
b)
c)
d)
All biomembranes show: Choose the FALSE statement
protein flip-flop
lipid lateral movement
different lipid composition in both leaflets
protein lateral movement
6.
a)
b)
c)
d)
The microtubules
result from the assembling of actin G and F to form their walls
polymerize and depolymerize to allow cell crawling (motility)
polymerize and depolymerize during flagellar beating
do not depolymerize during vesicular trafficking
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7.
a)
b)
c)
d)
Collagens
form fibrils but not networks
have a diameter of 1.5 µm
are synthesized mostly by fibroblasts
do not bind to fibronectin nor to laminin
8.
a)
b)
c)
d)
GPCRs directly interact with:
adenylate cyclase
protein G
phospolipase C
all of the above
9. The Ca2+/calmodulin complex regulates ___________ involved in the control of _________.
Choose the appropriate set to complete blanks.
a) protein G/translation
b) protein kinases/ transcription
c) phosphatases/translation
d) cAMP phosphodiesterase/vasodilation
10. Identify the following tissues
A
B
C
a)
b)
c)
d)
A) fibrous cartilage; B) brown adipose; C) neurons
A) stratified squamous epithelium; B) dense connective; C) fibrous cartilage
A) dense connective; B) white adipose; C) hyaline cartilage
A) dense connective; B) hyaline cartilage; C) white adipose
11.
a)
b)
c)
d)
The protein secretory pathway have at least the following components
cytosolic ribosomes/rough endoplasmic reticulum/secretory vesicles
rough endoplasmic reticulum/cis Golgi/ lysosomes
rough endoplasmic reticulum / lysosomes/secretory vesicles
rough endoplasmic reticulum /nucleus/secretory vesicles
12. About adipose tissues. Indicate the FALSE statement
a) thermogenin dissipates the proton electrochemical gradient
b) adipocytes stores mainly triglycerides
3
c)
d)
13.
a)
b)
c)
d)
are poorly metabolic active
are highly vascularized
About nerve tissue
is found only in the brain and spinal cord
neurons interact only with other neurons
glial cells are only responsible for neuron support
connections are called synapses
14. Synapses
a) releases neurotransmitters to the synaptic cleft which triggers the action potential in the
postsynaptic neuron
b) are structural (physical) connections for communication between neurons and other neurons
or cells
c) are always excitatory
d) is the functional mechanism of opening/closing of voltage gated Na+ and K+ channels
15. About mechanisms of morphogenesis:
a) mesenchyme to ephitelium and ephitelium to mesenchyme cells interactions are not
important
b) tissue formation and morphogenesis are opposite processes
c) embryogenesis and organogenesis are not morphogenic processes
d) diffusible signals, cell-ECM and cell-cell contacts are only important if proceed on a
characteristic time scale
16.
a)
b)
c)
d)
The Rayleigh Criterion defines the
number of apertures in an optical system
magnification attainable by an optical system
depth of field attainable by an optical system
resolution of an optical system
17. What distinguishes confocal optical microscopy from conventional (widefield) optical
microscopy?
a) Confocal microscopy produces spatially filtered images whereas widefield microscopy does
not
b) Confocal microscopy works only in transmission whereas widefield microscopy can work both
in transmission and reflection conditions
c) Confocal microscopy allows producing tomographic reconstructions but has lower resolution
than widefield microscopy
d) Confocal microscopy produces images with lower contrast than widefield microscopy
18. In scanning electron microscopy high resolution images presenting chemical contrast are
obtained using as signal
a) Auger electrons
b) Secondary electrons
c) Backscattered electrons
d) X-ray photons
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19.
a)
b)
c)
d)
Which methods are best suited for mechanical testing of single cells?
Optical tweezers, atomic force microscopy and tensile testing
Atomic force microscopy, torsion testing and micropipette aspiration
Atomic force microscopy, micropipette aspiration and optical tweezers
Flow cytometry, atomic force microscopy and micropipette aspiration
20.
a)
b)
c)
d)
What is the correct order for increasing Young’s modulus?
Tooth enamel, bone, wood, living cells
Living cells, tooth enamel, bone, wood
Wood, bone, living cells, tooth enamel
Living cells, wood, bone, tooth enamel
21.
a)
b)
c)
d)
Which type of filaments is believed to behave as tensile element in the cell?
Microtubules
Intermediate filaments
Actin filaments
Collagen
22.
a)
b)
c)
d)
What are the ultimate goals of third generation biomaterials?
Biological inertness and biocompatibility,
Bioactivity and biodegradation
Stimulation of specific responses at tissue architecture level
Stimulation of specific cellular responses at molecular level
23. Indicate a general disadvantage of natural polymers when compared with synthetic polymers
in the context of tissue engineering applications?
a) Difficult to tune properties
b) Absence/low cellular stimulation
c) Lack of biocompatibility
d) Absence/low biodegradation
24.
a)
b)
c)
d)
What are the characteristics of thermoplastic synthetic polymers?
Little crosslinking, ductile, cannot be softened by heating.
Little crosslinking, ductile, soften with heating
Large crosslinking, hard and brittle, cannot be softened by heating
Moderate cross-linking, non linear elasticity, cannot be softened by heating
25. Which processing method cannot be used to prepare porous and/or textured 3-D polymeric
scaffolds?
a) Computer-aided “ink-jet” 3D printing
b) Phase separation
c) Foaming
d) (Soft) lithography micropatterning
26. Scaffolds for tissue engineering in vivo, should
a) include biological factors to avoid undesirable vascularization of new formed tissue
b) high degree of interconnectivity, with high surface area to promote cell adhesion
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c) cylindrical pores with well defined structure with a pore size smaller than 1 micrometer
d) made of non-degradable polymers
27. Select the table that provides the best relation between (i) Material chemical-physical
properties and (ii) Parameter/ technique:
Option a)
Material chemical-physical Parameter/
properties
technique
Hydrophobicity
Youngs modulus
Elasticity
AFM
Degradation rate
Contact angle
Roughness
Weight loss
Material chemical
physical properties
Hydrophobicity
Elasticity
Degradation rate
Roughness
Option c)
Material chemical physical Parameter/
properties
technique
Hydrophobicity
AFM
Elasticity
Youngs modulus
Degradation rate
Weight loss
Roughness
Contact angle
Material chemicalphysical properties
Hydrophobicity
Elasticity
Degradation rate
Roughness
Option b)
Parameter/ technique
Youngs modulus
Contact angle
Weight loss
AFM
Option d)
Parameter/ technique
Contact angle
Youngs modulus
Weight loss
AFM
28.
a)
b)
c)
d)
In animal cell culture, a characteristic cell growth curve can display a plateau phase because
cells reach confluence, occupying all available surface area
nutrient depletion and metabolite accumulation occurs
both (a) and (b) are true if the cells are anchorage-dependent
none of the above is true
29.
a)
b)
c)
d)
In animal cell culture Glutamine
is exclusively a carbon source
is exclusively a nitrogen source
can be a source of both carbon and nitrogen
is highly stable at physiological pH in liquid media
30. Considering scale-up strategies in animal cell culture, one of the limitations of the culture as
“Cell aggregates” is
a) the existence of diffusional limitations to nutrient and metabolic by-product mass transfer
b) the large number of homogenous aggregates formed
c) the ability to use suspension bioreactors only
d) cannot be cultivated in rotating bioreactors
31. Animal serum contains important components such as growth factors and adhesion factors
that can be key to successful tissue culture, but present some disadvantages which do not
include
a) batch-to-batch variability
b) risk of contaminations (mycoplasma and viral)
c) increased costs of production compared to specialized serum-free formulations, but
downstream separation is easier
d) potential regulatory hurdles, envisaging the clinical application of cultured cells
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32. Macroporous microcarriers (pore diameter > 30-50 micrometers) are applicable to animal cell
culture for
a) suspension cells only
b) adherent cells only
c) both adherent and suspension cells
d) cellular aggregates only
33.
a)
b)
c)
d)
The Rotary Cell Culture System (RCCS) is a device
designed to grow cells/tissues under a microgravity environment
that uses a plastic bag on a rocking platform
based on fluidized-bed technology
none of the above is true
34. Mammalian cells have become the predominant system for the production of recombinant
proteins for therapeutic applications due to
a) the ability to produce proteins with proper folding and post-translation modifications
b) the capacity to metabolize inorganic nitrogen
c) the ability to be cultivated exclusively as anchorage-dependent cells
d) none of the above is true
35.
a)
b)
c)
In animal cell culture using stirred bioreactors
temperature control uses an immersion heater to assure 37ºC
the impeller typically used is a Rushton turbine
pH can be efficiently controlled using the CO2/HCO3- concentration within the gas/liquid
phase and/or by using base titration (e.g. NaOH)
d) agitation is not a controllable parameter
36. Murine, chimeric and humanized monoclonal antibodies are developed using the mouse
hybridoma technology which consists in fusing
a) B-cells with stem cells
b) B-lymphocytes with B-cells
c) B-lymphocytes with CHO cells
d) B-cells with myeloma cells
37. Presently, the large scale production of monoclonal antibodies for therapeutic applications is
typically produced using
a) hybridoma cells
b) microbial cells
c) chinese hamster ovary and myeloma cells
d) None of the above
38.
a)
b)
c)
d)
In gene therapy strategies the major advantage of using viral vectors over non-viral vectors is
their extremely low cytotoxicity
their high transduction efficiency
the easiness of chemical/physical modification
the unlimited size of the transgene carried by the virus
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39. After transfecting mammalian cells with non-integrative and non-replicative plasmids the
expression of the transgene will occur for
a) unlimited period of time, although the screening of the colonies is time-consuming and laborintensive
b) months/years under antibiotic pressure and its level depends on cell type, plasmid vector and
transfection method
c) a limited period of time
d) two weeks and is independent of the gene delivery methodology and cell type
40. One of the following statements is FALSE, which is it?
a) Human embryonic stem cells develop into teratomas when injected into
immunocompromised mice
b) The only totipotent stem cell is the fertilized egg
c) Human embryonic stem cells are derived from the inner cell mass/epiblast of the blastocyst
d) There are ongoing clinical trials worldwide using human embryonic stem cell-derived cells
41. Pluripotent stem cell fate can be controlled in vitro by engineering the extracellular
microenvironment. These strategies do not include
a) addition of specific soluble factors to culture medium
b) delivery of specific genes to stem cells using non-viral strategies
c) co-culture of stem cells with other cell types
d) control of physicochemical factors
42. How are designated the cell structures that occur during the in vitro monolayer neural
differentiation of pluripotent stem cells and that give origin to the cells of the central nervous
system?
a) Neurons, Astrocytes and Oligodendrocytes
b) Neural Tube
c) Neural Rosettes
d) Neural Crest Cells
43. Just one of the following statements about adult stem cells is TRUE, which is it?
a) Testis stem cells are unipotent
b) The renewal of the intestine epithelium is sustained by hematopoietic stem cells that
transdifferentiate into absorptive and secretory cells.
c) Bone remodeling is based on the activity of osteoblasts and osteoclasts, both with
hematopoietic origin
d) There is no stem cells in the adult brain
44. One of the following cells does not belong to the so-called “Hematopoietic Hierarchy”, which
is it?
a) Osteoclast
b) Red blood cell
c) Granulocyte
d) Glial cells
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45. Umbilical cord blood presents advantages in hematopoietic transplantation settings when
compared to adult sources such as
a) higher number of stem/progenitor cells
b) low Graft-versus-leukemia effect
c) low risk of Graft-versus-Host Disease
d) faster hematopoietic recovery
46. Just one of the following statements about human CD34 antigen is TRUE, which is it?
a) CD34 is a transmembranar glycoprotein expressed exclusively by human hematopoietic
progenitors
b) CD34 is a surface glycoprotein expressed by hematopoietic progenitors
c) CD34 is a glycoprotein expressed by human mesenchymal stem cells obtained from the bone
marrow
d) CD34 is a surface glycoprotein expressed exclusively by endothelial cells
47.
a)
b)
c)
d)
In this flow cytometry dot plot, the “highlighted” population corresponds to:
CD34+CD38+ cells
CD34-CD38+ cells
CD34+CD38- cells
CD34-CD38- cells
48. Considering a SWOT (Strengths, Weaknesses, Opportunities, and Threats) analysis for
bioreactor-based manufacture of tissue-engineered products, select the FALSE statement.
(a) Strength: Bioreactors enable consistent implementation of bioprocesses under controlled
culture conditions to maximize Tissue Engineering productivity
(b) Opportunity: Large regenerative medicine market provides opportunity for Tissue
Engineering-based products using bioreactor technology
(c) Threat: Implementation of bioreactor-based Tissue Engineering strategies can be constrained
or delayed by validation challenges inherent to automated processes (e.g. lack of appropriate
quality control)
(d) Opportunity: Innovative bioreactor technology is immediately implemented into clinics even
when mismatching with established regulatory standards (i.e. FDA or EMA)
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Group II
1. Please give examples of:
(a) A totipotent stem cell (at least one)
(b) A pluripotent stem cell (at least one)
(c) A multipotent adult stem cell (at least two)
2. Please give examples of bioreactor systems for:
(a) Hybridoma cell culture to produce monoclonal antibodies (at least two)
(b) Mesenchymal stem cell culture using microcarriers (at least two)
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