Nokea
Which of the following molecules can function both as complement initiators and as opsonins?
- A. C3b
- B. C-reactive protein
- C. MBL
- D. All of the above
Correct Answer: D
Rationale: The correct answer is D, All of the above. C3b, C-reactive protein, and MBL can all function as complement initiators and opsonins. C3b is a key complement protein involved in both processes. C-reactive protein can activate complement and enhance phagocytosis. MBL can also activate complement and enhance phagocytosis by binding to pathogens. All choices can serve as both initiators of the complement cascade and as opsonins, making D the correct answer.
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The nurse is administering medications to a patient. Which medications should the nurse understand is being given to suppress C-reactive protein levels?
- A. Aspirin and steroids
- B. Antibiotics and diuretics
- C. Epinephrine and antihistamines
- D. Antihypertensives and antineoplastic agents
Correct Answer: A
Rationale: The correct answer is A: Aspirin and steroids. Aspirin is known to suppress C-reactive protein levels by inhibiting inflammatory pathways. Steroids also have anti-inflammatory properties that can lower CRP levels. Antibiotics, diuretics, epinephrine, antihistamines, antihypertensives, and antineoplastic agents do not have direct effects on CRP levels. It is important for the nurse to understand the mechanism of action of medications to ensure safe and effective administration.
All of the following are true about antibodies, EXCEPT which one?
- A. They fix complement.
- B. They occur on the surface of B-lymphocyte
- C. They predominate the primary immune response to antigen.
- D. have a single, defined amino acid sequence due to variability.
Correct Answer: D
Rationale: The correct answer is D because antibodies do not have a single, defined amino acid sequence due to variability in their structure. This variability is a result of somatic recombination and hypermutation.
A: Antibodies can fix complement, leading to the destruction of pathogens.
B: Antibodies are produced by B-lymphocytes and can occur on their surface as B-cell receptors.
C: Antibodies predominate the secondary immune response, not the primary response, as memory B-cells are generated during the primary response for a quicker and more robust secondary response.
A patient is scheduled to have a tunneled catheter placed for administration of chemotherapy for breast cancer. When preparing the patient for the catheter insertion, what does the nurse explain about this method of chemotherapy administration?
- A. Decreases the risk for extravasation at the infusion site
- B. Reduces the incidence of systemic side effects of the drug
- C. Does not become occluded as peripherally inserted catheters can
- D. Allows continuous infusion of the drug directly to the area of the tumor
Correct Answer: A
Rationale: Tunneled catheters reduce extravasation risks compared to peripheral lines by delivering medications centrally.
What is not true about Salmonella thyphimurium?
- A. It is the causal agent of "hamburger disease"
- B. It is the second most common cause of food poisoning
- C. It is able to induce its own uptake by manipulating the actin cytoskeleton of host cells
- D. It is able to survive inside the phagosomes by manipulating the host actin cytoskeleton
Correct Answer: A
Rationale: The correct answer is A: It is the causal agent of "hamburger disease." Salmonella typhimurium is not the causal agent of "hamburger disease." Instead, Escherichia coli O157:H7 is the primary causal agent of this particular foodborne illness. Salmonella typhimurium is commonly associated with causing salmonellosis. Therefore, choice A is incorrect. Choices B, C, and D are all true statements about Salmonella typhimurium. It is the second most common cause of food poisoning, it is able to induce its own uptake by manipulating the actin cytoskeleton of host cells, and it is able to survive inside the phagosomes by manipulating the host actin cytoskeleton.
The oxidation-reduction pairs X/XHâ‚‚ and Y/YHâ‚‚ have reduction potentials of -50 and +75 millivolts, respectively. This means that electrons would most likely be removed from ______ to reduce ______.
- A. XHâ‚‚, Y
- B. Y, XHâ‚‚
- C. YHâ‚‚, X
- D. Y, YHâ‚‚
Correct Answer: A
Rationale: The correct answer is A: XHâ‚‚, Y. This is because the reduction potential of -50 mV for X/XHâ‚‚ indicates that X is more likely to lose electrons compared to Y with a reduction potential of +75 mV. Therefore, electrons would be removed from XHâ‚‚ (X) to reduce Y. Choice B is incorrect because Y has a higher reduction potential than XHâ‚‚, so electrons would not be removed from Y to reduce XHâ‚‚. Choices C and D are also incorrect as they do not consider the relative reduction potentials of X/XHâ‚‚ and Y/YHâ‚‚.