The process of somatic hypermutation:
- A. Can lead to the formation of antibodies with higher affinity for the antigen
- B. Occurs mainly in the CDR regions of immunoglobulin heavy and light chain genes
- C. Occurs in germinal centres
- D. All of the above are correct
Correct Answer: D
Rationale: The correct answer is D because somatic hypermutation can lead to the formation of antibodies with higher affinity for the antigen by introducing point mutations in the variable regions of immunoglobulin genes. This process mainly occurs in the complementarity-determining regions (CDRs) of immunoglobulin heavy and light chain genes, which are critical for antigen binding. Somatic hypermutation takes place in the germinal centers of secondary lymphoid organs, where B cells undergo rapid proliferation and selection based on antigen binding affinity. Therefore, all the statements in choices A, B, and C are correct, making option D the right answer.
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What is a characteristic disease associated with Type III hypersensitivity?
- A. Grave's disease
- B. Goodpasture's syndrome
- C. Systemic lupus erythematosus (SLE)
- D. Contact dermatitis
Correct Answer: C
Rationale: The correct answer is C: Systemic lupus erythematosus (SLE). In Type III hypersensitivity, immune complexes form and deposit in tissues, leading to inflammation and tissue damage. SLE is a classic example of a Type III hypersensitivity reaction where these immune complexes deposit in various organs causing systemic inflammation and damage. Graves's disease (A) is an example of Type II hypersensitivity, where autoantibodies target cell-surface receptors. Goodpasture's syndrome (B) is a Type II hypersensitivity disease affecting the kidneys and lungs. Contact dermatitis (D) is a Type IV hypersensitivity reaction mediated by T cells, not involving immune complexes. Therefore, the correct answer is C as it aligns with the characteristic disease associated with Type III hypersensitivity.
When the patient asks about the late effects of chemotherapy and high-dose radiation, what areas of teaching should the nurse plan to include when describing these effects?
- A. Third space syndrome
- B. Secondary malignancies
- C. Chronic nausea and vomiting
- D. Persistent myelosuppression
Correct Answer: B
Rationale: Late effects of chemotherapy and radiation include secondary malignancies due to long-term cellular damage.
T regulatory cells are NOT
- A. Generated in the thymus upon expression of Foxp3
- B. Generated in the periphery in response to cytokines
- C. Able to inhibit effector T cells
- D. Able to cause immunity
Correct Answer: D
Rationale: The correct answer is D because T regulatory cells are known to suppress immune responses and promote immune tolerance, which is opposite to causing immunity. Choice A is incorrect because T regulatory cells are indeed generated in the thymus upon expression of Foxp3. Choice B is incorrect as T regulatory cells can also be generated in the periphery in response to cytokines. Choice C is incorrect as T regulatory cells are known to inhibit effector T cells to regulate immune responses.
The patient is transferring from another facility with the description of a sore on her sacrum that is deep enough to see the muscle. What stage of pressure ulcer does the nurse expect to see on admission?
- A. Stage I
- B. Stage II
- C. Stage III
- D. Stage IV
Correct Answer: D
Rationale: Stage IV pressure ulcers involve full-thickness tissue loss, exposing muscle, tendon, or bone.
Which of the following statements is NOT true? The SARS coronavirus
- A. Caused an epidemic in 2003 that registered 10% mortality rate
- B. Caused an acute infection of the lungs classified as acute respiratory distress syndrome
- C. Is also the causal agent of MERS (Middle East Respiratory Syndrome)
- D. Is thought to have been transmitted from bats to civets and from civets to humans
Correct Answer: C
Rationale: The correct answer is C because the statement that SARS coronavirus is also the causal agent of MERS is false. MERS (Middle East Respiratory Syndrome) is caused by a different coronavirus called MERS-CoV. SARS-CoV caused the 2003 epidemic with a 10% mortality rate, which aligns with statement A. Statement B is correct as SARS-CoV does cause an acute infection of the lungs known as acute respiratory distress syndrome. Statement D is also true as SARS-CoV is believed to have been transmitted from bats to civets and then to humans. Therefore, the incorrect statement is C.