Test 1

1.

1 point

Which of the following is not a role of macrophages in the skin wound healing?

Initiate clot formation

Stimulate proliferation of epidermal cells

Promote initiation of angiogenesis

Promote formation of granulation tissue

Kill bacteria and clean up cellular debris

2.

1 point

Homing property of HSCs is mediated by:

SDF-1/CXCR4 interaction

BMP signaling

Activity of CDK inhibitors

HSCs do not possess homing property

Wnt signaling

3.

1 point

Which of the following growth factors exerts the least influence on proliferation of fibroblast?

PDGF

KGF

bFGF

EGF

TGF beta

4.

1 point

Which of the following transcription factors is not a master reprogramming factor that is required to maintain pluripotency of ESCs?

Oct4

PU.1

Sox2

Nanog

5.

1 point

ECM molecule that stores growth factors and releases them slowly is:

Laminin

Elastin

Fibronectin

Heparan sulfate

Tenascin

6.

1 point

Growth of hair is controlled by a number of growth factors. Which of the following signals from the dermal papilla induced the hair germ cells to proliferate during anagen?

Wnt

BMP-2

BMP-6

FGF-7

FGF-18

7.

1 point

Which phase of the hair cycle last longest period in the human scalp

All phases have similar length

Telogen

A and B

Anagen

Catagen

8.

1 point

Wound repair of the adult skin has multiple phases. Which of the following events does not take place during the structural repair?

Collagen remodeling

Coagulation

Formation of granulation tissue

Re-epithelialization

Migration and proliferation of fibroblasts

9.

1 point

Which of the following statement is false regarding re-epithelialization?

Keratin 14+ basal cell layer at the edge of the wound is the source of epidermal cells for re-epithelization

Epidermal keratinocyte proliferation is promoted by TGF alpha, EGF, and KGF released from keratinocytes, macrophages, and fibroblasts

While covering the wound surface, migrating epidermal cells undergo proliferation

Epidermal basal layer cells dissociate from the basement membrane by MMPs and plasmin

After covering, basal cells begin to synthesize a new basement membrane

10.

1 point

Fetal skin displays several properties different from the adult one. Which of the following is false regarding the wounded fetal skin?

No chondroitin sulfate synthesis

Low level of TGF-B3

Rapid wound closure and fast migration of fibroblasts to wound

Higher ratio of type III to type I collagen

Low granulation tissue formation thus no scar formation

11.

1 point

A key factor that induces downstream cascade reactions during hemostasis of skin repair is:

Fibrin

ADP

Thrombin

Serotonin

Factor VII

12.

1 point

Which of the following is true about epithelial cells of human intestinal villi and crypts?

Each villus contains 3500 cells and a crypt about 250 cells

Each crypt contains 4-6 stem cells at the base

Intestinal epithelial cells have about 4 day life span

1400 cells are shed per villus per day

All of the above are true

13.

1 point

Which of the following ECM molecules is not a proteoglycan?

Hyaluronic acid

Elastin

Chondroitin sulfate

Dermatan sulfate

Heparan sulfate

14.

1 point

Which of the following is true regarding pre-graft procedures for the hematopoietic stem cell transplantation?

Ablative procedure can be used for all age group

After chemotherapy/radiation, quiescent HSCs should be mobilized from the bone marrow into the circulation to be repopulated

Typically ablative procedure uses 200 cGy of total body irradiation to remove defective hematopoietic cells

Ablative procedure wipes out every bone marrow cell including quiescent HSCs

Non-myeloablative therapy increases incidence of grade III-V GVHD

15.

1 point

Human epidermis is a multilayered structure. Which of the following is the correct order of the epidermis from innermost to outermost?

Stratum basale → stratum granulosum → stratum spinosum → stratum corneum

Stratum corneum → stratum spinosum → stratum granulosum → stratum basale

Stratum corneum → stratum granulosum → stratum spinosum → stratum basale

Stratum basale → stratum spinosum → stratum granulosum → stratum corneum

Stratum basale → stratum corneum → stratum spinosum → stratum granulosum

16.

1 point

Molecules that can attract cells are called:

Receptors

Chemokines

Interferons

Signaling molecules

Interleukins

17.

1 point

Intestinal tract consists of four major layers. Which of the following is in the correct order from innermost lumen to outmost of the digestive tract?

Mucosa - muscle layers - submucosa - serosa

Mucosa - submucosa - muscle layers - serosa

Serosa - mucosa - submucosa - muscle layers

Serosa - mucosa - muscle layers - submucosa

Muscle layers - serosa - mucosa - submucosa

18.

1 point

Which of the following is not a problem associated with the use of iPS cells for clinical applications?

Mutagenesis by integration of retroviral vectors

Low efficiency of programming

Decreased differentiation potential during reprogramming

Formation of malignancy

Slow reprogramming process

19.

1 point

The state of LT-HSCs is regulated by the osteoblasts through several molecular interactions. Which of the following is not an interaction between the osteoblasts and HSCs?

KitL and c-Kit

Integrin and fibronectin

Jagged-1 and Notch

Ang-1 and Tie-2

20.

1 point

Many molecular factors are involved in the restoration of damaged blood vessels during the formation of granulation tissue. Which of the following is false?

Endothelial cells are stabilized by interaction with pericytes, which is mediated by Ang1 binding to Tie2 receptor

Thrombin cleaves protease-activated receptor to activate endothelial cells

In the presence of VEGF, the endothelial cells secrete proteases that degrade the basement membrane of the blood vessel, allowing division of endothelial cells

Proliferating endothelial cells form cords that express PECAM and integrins

Pericytes synthesize Ang2, which competes with Ang1 for binding to Tie2, allowing tight interaction of pericytes to the endothelium

21.

1 point

The most abundant type of collagens in the unwounded dermal matrix of adult is:

Type IV Collagen

Type VI Collagen

Type I Collagen

Type VIII Collagen

Type III Collagen

22.

1 point

Intestinal stem cells differentiate into several types of epithelial cells. Which of the following is not derived from intestinal stem cells?

Enteroendocrine cell

Pneumocytes

Paneth cell

Goblet cell

Enterocyte

23.

1 point

LT-HSCs are pluripotent stem cells in the bone marrow. Which of the following is not true about LT-HSCs?

Express unique cell surface markers such as SLAM and CD49f

Express CXCR4

Chromatin is dense

One in every 100,000 cells of the bone marrow is LT-HSC

The cell size is relatively bigger than other cells

24.

1 point

During embryogenesis, blood precursor cells called hemangioblasts begin to form in:

Yolk sac mesoderm

Amniotic membrane

Bone marrow

Spleen

All of the above

25.

1 point

Transplantation of ESCs may accompany risks. Which of the following is not likely to happen?

Tumor formation

Chromosomal abnormalities

Incorrect differentiation

Inappropriate localization

Hyperacute rejection

26.

1 point

Epithelial stem cells are found in the ____ layer of the epidermis

Stratum spinosum

Stratum basale

Stratum granulosum

Stratum lucidum

Stratum corneum

27.

1 point

Which of the following is not true regarding general characteristics of regeneration?

Phylogenically invertebrates or lower vertebrates have less powerful regeneration ability than higher vertebrates

Ontogenically early embryos possess better regenerative capability than adults

In high vertebrates, regeneration response of musculoskeletal tissue is better than the one of neural tissue

Bigger tissue is much more difficult to regenerate than smaller one because bigger one requires more time and energy

28.

1 point

The challenge of allogeneic hematopoietic stem cell transplantation for treatment of leukemia is:

To enhance Graft vs. Host Disease but prevent Graft vs. Leukemia effect

To decrease both Graft vs. Host Disease and Graft vs. Leukemia effect

To increase both Graft vs. Host Disease and Graft vs. Leukemia effect

To suppress Graft vs. Host Disease without losing Graft vs. Leukemia effect

29.

1 point

Which of the following cells are not involved in the formation of granulation tissue?

Fibroblasts

Endothelial cells

Macrophages

Osteoblasts

Epidermal keratinocytes

30.

1 point

The human epidermis contains several different types of cells except:

Merkel cells

Melanocytes

Enterocytes

Keratinocytes

Langerhans cells

31.

1 point

Which of the following is an anti-adhesive glycoprotein?

Laminin

Heparan sulfate

Fibronectin

Tenascin

Collagens

32.

1 point

Which growth factor regulates proliferation of TA cells negatively in the crypt?

IGF-1

TGF beta

IGF-2

IL-4

33.

1 point

Repair of a skin wound involves interaction between a number of different types of cells, ECM molecules, and growth factors. Which of the following cells produces PDGF and TGF beta to attract inflammatory cells during the initial phase of adult skin wound healing?

Platelets

Endothelial cells

Fibroblasts

Injured nerve cells

None of the above

34.

1 point

Cells or structures that are found in the dermis are

Hair follicles

Sebaceous oil glands

Sweat glands

Fibroblast cells

All of the above

35.

1 point

There are evidences that the hair bulge contains EpSCs. These stem cells can be identified using:

Long-term BrdU labeling

Keratin-15 promoter-LacZ transgenic mice

Lgr5 promoter-EGFP transgenic mice

None of the above can detect stem cells

All of the above three (A-C) can identify stem cells

36.

1 point

Stem cell therapies can lead to some problems. Which stem cell transplantation approach would bypass the immunorejection and bioethical issues with maintaining pluripotency?

Natural ESCs

Designer ESCs

iPS cells

Adult SCs

A and B

37.

1 point

___ layer is a term focusing on the arrangement state of cells. It refers to the outer cell layer of the body in which cell are tightly arranged together.

Ectodermal

Stromal

Epithelial

Epidermal

Mesenchymal

38.

1 point

After skin injury, the first response is hemostasis. Which is not a major mechanism to stop bleeding and seal off the vessels?

Vasoconstriction induced by thromboxane A2

Formation of a fibrin clot by thrombin

Triggering diapedesis

Formation of a scab by dehydration of the clot surface

Formation of platelet clumps by ADP

39.

1 point

Androgenetic alopecia is typically caused by:

Abnormal level of estradiol

Increased sensitivity of hair follicles to testosterone

Low level of dihydrotestosterone

Low level of testosterone

Increased sensitivity of hair follicles to dihydrotestosterone

40.

1 point

Which of the following natural cellular turnover involves stem cells?

Shedding epidermal keratinocytes of the skin

Hair replacement

Sloughing epithelial cells on villi of the small intestine lining

Replacement of blood cells

All of the above

41.

1 point

Organoids are miniature organs created on the 3D ECM using stem/progenitor cells in vitro. Which of the following is the purpose of organoid use

To understand development and physiology of organs

To understand onset and process of disease

To test efficacy and toxicity of drugs

To replace abnormal or malfunctioned organs possibly combined with gene editing

All of the above

42.

1 point

In the hematopoietic stem cell transplantation for the treatment of advanced leukemia, which of the following tissues/organs is the best as a cell source in terms of relapse and survival rate?

Bone marrow

Umbilical cord blood

Peripheral blood

Adipose tissue

A and C

43.

1 point

After wounding, the distal portion of injured nerves degenerate within 1-2 days, and then regenerates over the next 2 weeks. Which of the following is true about roles that injured nerves play during the skin wound repair?

To cause degranulation of mast cells to release histamine and cytokines

To increases vascular permeability

To attract neutrophils and macrophages

To increase fibroblast activity

All of the above

44.

1 point

Which of the following current strategies for regenerative medicine is considered as the true regeneration?

Use of biometric devices and organ transplants

Cell transplantation

Implantation of bio-artificial tissues or organs

Inhibition of scarring and simultaneous promotion of new tissue formation by permissive factors directly at the site of injury

All of the above are considered as the true regeneration

45.

1 point

The dermal ECM plays many roles except:

To promote differentiation of keratinocyte

Reservoir for growth factors

To regulate intercellular communication

To segregate tissues from one another

To provide support and anchorage for cells

46.

1 point

SIS can be prepared from:

Large intestine

Serosa layer of the intestine segment

Swine intact skin

Submucosa layer of the small intestine

Mucosa layer of the stomach

47.

1 point

Which of the following is not true about fibronectin?

Synthesized by connective tissue cells

Serves as substrates to which cells can adhere

Binds to integrin

Promotes the substrate adhesion of cells

Gives tensile strength to the matrix

48.

1 point

One of problems in cell transplantation for treatment after the second degree burn injury is the formation of serous fluid blisters between the wound and transplanted epidermal cells. To solve this issue, which of the following is the best way?

Applying cell suspension of primary keratinocytes and epidermal stem cells by spraying

Applying cultured epidermal stem cells by direct injection

Using a bioartificial dermal matrix

Applying epidermal sheet containing concentrated keratinocytes

49.

1 point

Ideal cells for transplant

Should be easy to expand to large numbers

Have not senesced

Must possess a developmental plasticity

Have to be rejection proof

All of the above

50.

1 point

Stem cell niche is the microenvironment supporting stem cells. Which of the following is not a component of the bone marrow stem cell niche?

Red blood cell

Mesenchymal stem cell

Endosteal osteoblast cell

Fibroblast stromal cell

Sinusoidal endothelial cell