If you measure the ability of cytotoxic T cells from an HLA-B27 person to kill virus X-infected target cells, which one of the following statements is CORRECT?

Correct Answer: B

Rationale: The correct answer is B: Only virus X-infected cells of HLA-B27 type will be killed. This is because cytotoxic T cells recognize antigens presented by HLA molecules. In this case, the cytotoxic T cells from an HLA-B27 person will specifically target virus X-infected cells that display antigens on HLA-B27 molecules. Choice A is incorrect because not all virus X-infected cells will be killed, only the ones with specific HLA molecules. Choice C is incorrect as not all HLA-B27 cells will be killed, only the virus-infected ones. Choice D is incorrect as the question specifically mentions virus-infected cells, not all HLA-B27 cells.

Correct Answer: D

Rationale: The correct answer is D: protect the body against pathogens. White blood cells are a vital part of the immune system and play a key role in defending the body against infections and diseases caused by pathogens such as bacteria, viruses, and other harmful substances. They do this by identifying and destroying pathogens through various mechanisms like phagocytosis and producing antibodies. Choice A (transport oxygen to body cells) is incorrect because the function of transporting oxygen is primarily carried out by red blood cells. Choice B (produce hormones that regulate cell communication) is incorrect as white blood cells do not produce hormones for this purpose. Choice C (carry glucose to body cells) is incorrect because the transportation of glucose is mainly performed by the bloodstream and facilitated by insulin.

Correct Answer: C

Rationale: The correct answer is C: Standard precautions. Standard precautions are essential to prevent transmission of HIV, which spreads through blood and body fluids. These precautions include hand hygiene, personal protective equipment, safe injection practices, and proper disposal of sharps. Airborne precautions (choice A) are not necessary for HIV, as it is not transmitted through the air. Contact precautions (choice B) only during wound care are not sufficient, as HIV can be transmitted through various body fluids, not just wounds. Droplet precautions (choice D) are not appropriate for HIV, as it is not primarily spread through respiratory droplets. Therefore, standard precautions are the most effective and comprehensive approach to prevent HIV transmission.

Correct Answer: B

Rationale: The correct answer is B, as rifampin can cause skin and/or urine discoloration, turning them reddish-orange. This is a common side effect known as rifampin-induced discoloration. Choice A is incorrect because blurry vision is an adverse effect of ethambutol, not rifampin. Choice C is incorrect as rifampin does not improve hearing. Choice D is incorrect as sunlight sensitivity is not associated with rifampin. Therefore, understanding the potential side effect of skin discoloration is crucial for patient education regarding the new prescription for rifampin.

Correct Answer: B

Rationale: The correct answer is B because it demonstrates therapeutic communication by clarifying and restating the client's concern, showing empathy and understanding. This approach helps the client feel supported and encourages open communication with their partner. Choice A is incorrect because healthcare providers are not required by law to disclose a patient's HIV status without their consent, as it violates patient confidentiality under HIPAA. Choices C and D are incorrect as they do not address the importance of open communication and may lead to potential harm by withholding vital information. Overall, response B is the most appropriate as it promotes trust, honesty, and understanding in the client-nurse relationship.