Which of the following is NOT a feature of T cells?
- A. They recognize three-dimensional structures of a pathogen
- B. Their receptors possess specificity
- C. Their receptors have one antigen-binding site
- D. Their antigen receptors are never secreted
Correct Answer: A
Rationale: The correct answer is A because T cells do not recognize three-dimensional structures of a pathogen. T cell receptors interact with processed antigen fragments presented by MHC molecules on antigen-presenting cells. Choice B is correct because T cell receptors possess specificity for antigens. Choice C is incorrect because T cell receptors have multiple antigen-binding sites. Choice D is incorrect as T cell receptors can be secreted as soluble forms.
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A client is in the hospital and has received two doses of an angiotensin-converting enzyme for hypertension. When the nurse answers the client's call light, the client presents an appearance as shown below: What action by the nurse takes is most appropriate?
- A. Administer epinephrine 1:1000, 0.3 mg IV push immediately.
- B. Apply oxygen by facemask at 100% and a pulse oximeter.
- C. Ensure a patent airway while calling the Rapid Response Team.
- D. Reassure the client that these symptoms will go away.
Correct Answer: C
Rationale: The correct action by the nurse is to ensure a patent airway while calling the Rapid Response Team (Choice C). This is because the client is showing signs of angioedema, a potential adverse reaction to angiotensin-converting enzyme (ACE) inhibitors. Angioedema can lead to airway compromise and respiratory distress, hence ensuring a patent airway is crucial. Additionally, calling the Rapid Response Team will allow for immediate medical intervention and monitoring of the client's condition.
Choice A (Administer epinephrine) is incorrect as epinephrine is not the first-line treatment for angioedema associated with ACE inhibitors. Choice B (Apply oxygen) is not sufficient to address the potential airway compromise. Choice D (Reassure the client) is inappropriate as the client's condition requires immediate action to address the potential airway obstruction.
What receptor is targeted in Grave's disease, a Type V hypersensitivity reaction?
- A. Insulin receptor
- B. Thyroid-stimulating hormone (TSH) receptor
- C. Complement receptor
- D. CD4 receptor
Correct Answer: B
Rationale: The correct answer is B: Thyroid-stimulating hormone (TSH) receptor. In Grave's disease, autoantibodies bind to and activate the TSH receptor on thyroid cells, leading to hyperthyroidism. This is a Type II hypersensitivity reaction. Insulin receptor (A) is not involved in Grave's disease. Complement receptor (C) is not the target in this condition. CD4 receptor (D) is primarily involved in T cell activation, not in Grave's disease.
Hfr strains of bacteria:
- A. do not have an 'F' (fertility) factor.
- B. have an 'F' factor plasmid.
- C. have an 'F' factor integrated in the bacterial chromosome.
- D. transfer the genetic information to other bacteria with ow frequency.
Correct Answer: C
Rationale: The correct answer is C because Hfr strains of bacteria have the F factor integrated into their bacterial chromosome. This integration allows for the transfer of genetic material during conjugation. This integration results in a high frequency of genetic information transfer to recipient cells, which is a characteristic of Hfr strains.
Choice A is incorrect because Hfr strains do have the F factor, but it is integrated into their chromosome, not absent. Choice B is incorrect because Hfr strains do not just have an F factor plasmid; it is integrated into the chromosome. Choice D is incorrect because Hfr strains actually transfer genetic information with high frequency, not low frequency.
A patient identified as HIV antibody–positive 1 year ago manifests acute HIV infection but does not want to start antiretroviral therapy at this time. What is an appropriate nursing intervention for the patient at this stage of illness?
- A. Assist with end-of-life issues
- B. Provide care during acute exacerbations
- C. Provide physical care for chronic diseases
- D. Teach the patient about immune enhancement
Correct Answer: D
Rationale: Immune enhancement strategies, such as nutrition and stress reduction, can help maintain health until the patient decides to initiate ART.
Which of the following is NOT true? The meeting of naïve T cells and dendritic cells:
- A. Is facilitated by the presence of naïve B cells
- B. Occurs in the paracortex of lymph nodes
- C. Is facilitated by movement of the T cell along connective tissue networks
- D. May supply the T cell with activation Signal 1
Correct Answer: A
Rationale: The correct answer is A because the meeting of naïve T cells and dendritic cells is not facilitated by the presence of naïve B cells. Naïve T cells interact with dendritic cells in the paracortex of lymph nodes, not with naïve B cells. The movement of T cells along connective tissue networks aids in their interaction with dendritic cells, and this interaction may supply the T cell with activation Signal 1, which is essential for T cell activation. Overall, the incorrect choices (B, C, and D) are actually true statements regarding the meeting of naïve T cells and dendritic cells, making them incorrect options.