Nokea
APECED is a rare autoimmune disease caused by deficiency of
- A. CTLA-4
- B. AIRE
- C. Tregs
- D. TGF-β
Correct Answer: B
Rationale: The correct answer is B: AIRE. APECED (Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy) is caused by mutations in the AIRE gene. AIRE is responsible for regulating the expression of self-antigens in the thymus, crucial for the development of immune tolerance. Deficiency in AIRE leads to the production of autoantibodies and autoimmune manifestations.
Incorrect options:
A: CTLA-4 is involved in downregulating immune responses but is not directly linked to APECED.
C: Tregs (regulatory T cells) play a role in immune tolerance, but APECED is not directly caused by their deficiency.
D: TGF-β is a cytokine involved in immune regulation, but its deficiency does not lead to APECED.
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You are evaluating an HIV-positive patient who is receiving IV pentamidine (Pentam) as a treatment for Pneumocystis carinii pneumonia. Which information is most important to communicate to the physician?
- A. The blood pressure decreased to 104/76 during administration.
- B. The patient is complaining of pain at the site of the infusion.
- C. The patient is not taking in an adequate amount of oral fluids.
- D. Blood glucose is 55 mg/dL after the medication administration.
Correct Answer: D
Rationale: Pentamidine can cause hypoglycemia which is a serious and potentially life-threatening side effect. A blood glucose level of 55 mg/dL is critically low and requires immediate intervention. The other findings while important are less urgent and can be managed with standard nursing interventions.
The nurse is presenting a community education program related to cancer prevention. Based on current cancer death rates, the nurse emphasizes what as the most important preventive action for both women and men?
- A. Smoking cessation
- B. Routine colonoscopies
- C. Protection from ultraviolet light
- D. Regular examination of reproductive organs
Correct Answer: A
Rationale: Smoking cessation is the most significant preventive action because smoking is a leading cause of preventable cancer deaths.
A patient’s breast tumor originates from embryonal ectoderm. It has moderate dysplasia and moderately differentiated cells. It is a small tumor with minimal lymph node involvement and no metastases. What is the best description of this tumor?
- A. Sarcoma,grade II,T3 N4 M0
- B. Leukemia,grade I,T1 N2 M1
- C. Carcinoma,grade II,T1 N1 M0
- D. Lymphoma,grade III,T1 N0 M
Correct Answer: C
Rationale: This tumor is classified as a carcinoma, grade II, with a small size, limited lymph node involvement, and no metastases.
A segment of DNA that reads the same from forward and backward is called_____.
- A. Complementary DNA
- B. Palindromic DNA
- C. Copy DNA
- D. Transcribed DNA
Correct Answer: B
Rationale: The correct answer is B: Palindromic DNA. Palindromic DNA refers to a segment of DNA that reads the same from both directions. This property occurs when the nucleotide sequence on one strand of DNA is the reverse complement of the nucleotide sequence on the other strand. This symmetry allows the DNA sequence to be read the same forward and backward.
Incorrect choices:
A: Complementary DNA - Complementary DNA refers to a synthesized DNA strand that is complementary to a given DNA sequence.
C: Copy DNA - Copy DNA is not a commonly used term in molecular biology.
D: Transcribed DNA - Transcribed DNA refers to DNA that has been converted into RNA through the process of transcription, not DNA that reads the same forward and backward.
Which T cell type is involved in directly killing infected or foreign cells?
- A. Helper T cells
- B. Cytotoxic T cells
- C. Regulatory T cells
- D. Memory T cells
Correct Answer: B
Rationale: The correct answer is B: Cytotoxic T cells. Cytotoxic T cells are responsible for directly killing infected or foreign cells by releasing toxic substances that induce apoptosis in the target cells. This process helps eliminate the threats to the body.
Helper T cells (Choice A) assist in coordinating immune responses but do not directly kill cells. Regulatory T cells (Choice C) play a role in suppressing immune responses to prevent autoimmunity but do not kill infected cells. Memory T cells (Choice D) are primed for rapid response upon re-exposure to a specific antigen but do not directly kill cells. Therefore, the correct choice is B as cytotoxic T cells are specifically designed for cell killing.