Nokea
What chemical in poison ivy is responsible for triggering contact dermatitis?
- A. Histamine
- B. Urushiol oil
- C. Lipopolysaccharide (LPS)
- D. C3a
Correct Answer: B
Rationale: The correct answer is B: Urushiol oil. Urushiol oil is the allergen in poison ivy that triggers contact dermatitis. When urushiol oil comes into contact with the skin, it can cause an allergic reaction leading to redness, itching, and inflammation. Histamine (choice A) is a compound released by the body in response to allergens but is not the specific chemical in poison ivy. Lipopolysaccharide (LPS) (choice C) is a component of the outer membrane of certain bacteria and not present in poison ivy. C3a (choice D) is a complement protein involved in the immune response but not related to poison ivy dermatitis.
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A client with AIDS is terminally ill and wants to name a person as a beneficiary to his life insurance in exchange for immediate cash. What is the term that best describes this arrangement?
- A. Power of attorney
- B. Beneficiary settlement
- C. Viatical settlement
- D. Life insurance guardianship
Correct Answer: C
Rationale: A viatical settlement allows a terminally ill client to sell their life insurance policy for immediate cash naming a beneficiary.
The release of IL-8 at an infection site specifically induces
- A. Increase of adhesion molecules on local endothelial cells
- B. Local recruitment of neutrophils
- C. Systemic effects, including fever
- D. Increase of acute-phase proteins
Correct Answer: B
Rationale: The correct answer is B because IL-8 is a chemokine that specifically functions to recruit neutrophils to the site of infection. Neutrophils are crucial for fighting off pathogens. A: Increase of adhesion molecules on local endothelial cells is not directly induced by IL-8. C: Systemic effects, including fever, are typically mediated by other cytokines like IL-1 and IL-6. D: Increase of acute-phase proteins is not the primary role of IL-8 in the immune response.
One of the most significant factors in determining when to start antiretroviral therapy in a patient with HIV infection is:
- A. Whether the patient has high levels of HIV antibodies
- B. Confirmation that the patient has contracted HIV infection
- C. The patient’s readiness to commit to a complex, lifelong, uncomfortable drug regimen
- D. Whether the patient has a support system to help manage the costs and side effects of the drugs
Correct Answer: C
Rationale: Patient adherence is critical for successful antiretroviral therapy. Ensuring the patient is prepared to follow the regimen long-term improves outcomes.
What type of cells do natural killer (NK) cells target?
- A. Bacterial cells
- B. Virus-infected and cancerous cells
- C. Plasma cells
- D. Self-antigens
Correct Answer: B
Rationale: Natural killer (NK) cells target virus-infected and cancerous cells because they have the ability to recognize abnormal cells through activating receptors. These cells can identify changes in surface markers associated with viral infection or cancer, leading to their destruction. NK cells do not target bacterial cells (choice A), plasma cells (choice C), or self-antigens (choice D) as these are not typically recognized as threats by the immune system. NK cells play a crucial role in immune surveillance against abnormal cells, making choice B the correct answer.
Which of the following statements is NOT true
- A. During T cell development the decision to become a CD4 or a CD8 positive cell is a random event
- B. During T cell differentiation the decision to become a TH1 or a TH2 cell CD4+ is a random event
- C. TH2 CD4+ cells secrete IL-4
- D. IL-10 is TH2 polarizing cytokine
Correct Answer: B
Rationale: The correct answer is B: During T cell differentiation, the decision to become a TH1 or a TH2 cell CD4+ is not a random event. This is because T cell differentiation into TH1 or TH2 cells is guided by specific signals from the environment, such as cytokines present during activation. TH1 cells are induced by IL-12 and IFN-gamma, while TH2 cells are induced by IL-4. This process is not random but rather a result of specific signaling cues.
A: During T cell development, the decision to become a CD4 or a CD8 positive cell is not a random event. It is determined by interactions with thymic stromal cells and the T cell receptor.
C: TH2 CD4+ cells do secrete IL-4, so this statement is true.
D: IL-10 is not a TH2 polarizing cytokine; rather, it is known to have regulatory functions in immune responses.