A nurse recalls an example of an immune-complex-mediated disease is:

Correct Answer: C

Rationale: The correct answer is C: Serum sickness. Serum sickness is characterized by the formation of immune complexes in response to certain medications or proteins. These immune complexes can deposit in tissues, leading to inflammation and tissue damage. Bronchial asthma (Choice A) is a chronic inflammatory condition of the airways not primarily mediated by immune complexes. Contact dermatitis (Choice B) is a type IV hypersensitivity reaction mediated by T cells, not immune complexes. Rheumatoid arthritis (Choice D) is an autoimmune disease where antibodies target self-antigens, but it is not primarily mediated by immune complexes.

Correct Answer: B

Rationale: The correct instruction the nurse should provide is to avoid taking nitrates while on sildenafil (Viagra). Combining sildenafil with nitrates can result in severe hypotension due to additive vasodilatory effects. Choice A is incorrect because sildenafil can be taken with or without food. Choice C is incorrect as there is no specific requirement to take sildenafil at bedtime. Choice D is incorrect as taking sildenafil with milk has not been shown to enhance its absorption.

Correct Answer: B

Rationale: Hyperreflexia, or exaggerated reflexes, is a common sign of an upper motor neuron (UMN) lesion. An UMN lesion indicates damage to the central nervous system pathways that control movement. Hypotonia (choice A) refers to reduced muscle tone, which is more indicative of lower motor neuron lesions. Muscle atrophy (choice C) suggests long-standing denervation or disuse of muscles. Fasciculations (choice D) are involuntary muscle contractions that can be seen in lower motor neuron lesions, like in amyotrophic lateral sclerosis (ALS), rather than UMN lesions.

Correct Answer: A

Rationale: The correct answer is A: Increased risk of liver dysfunction. Testosterone therapy can lead to liver dysfunction, including cholestatic jaundice and hepatitis. This adverse effect necessitates monitoring of liver function tests during testosterone therapy. Choice B, increased risk of prostate cancer, is incorrect because testosterone therapy does not cause prostate cancer but is contraindicated in patients with known or suspected prostate cancer. Choice C, increased risk of bone fractures, is incorrect as testosterone therapy is actually associated with an increase in bone mineral density, reducing the risk of fractures. Choice D, increased risk of breast cancer, is incorrect because testosterone therapy in males does not increase the risk of breast cancer.

Correct Answer: C

Rationale: The correct answer is C. In assessing a child for migraines, asking about food allergies is least likely to yield data that will confirm or rule out migraines as the cause of his headaches. Food allergies are unrelated to the typical symptoms and triggers of migraines, such as family history, associated symptoms like nausea and vomiting, and pain-free intervals between headaches. Therefore, in this scenario, focusing on food allergies is less relevant for identifying migraines as the cause of the boy's headaches.

Correct Answer: C

Rationale: The correct answer is C. Hormonal contraceptives increase blood levels of clotting factors, particularly factors II, VII, IX, and X. This elevation in clotting factors can predispose individuals to thromboembolic events, including blood clots. Choices A, B, and D are incorrect because hormonal contraceptives do not have a significant effect on serum triglycerides and cholesterol, platelet levels, or causing direct injury to blood vessel linings as the primary mechanism for clot formation.

Correct Answer: B

Rationale: Cytotoxic T cells are the key players in cell-mediated immunity as they directly attack cells displaying specific antigens. Lymphokine-producing cells (Choice A) are involved in cytokine production, while Helper T cells (Choice C) assist in activating other immune cells. Macrophages (Choice D) are phagocytic cells that engulf and digest pathogens, but they are not the primary cells responsible for directly attacking cells with specific antigens in cell-mediated immunity.

Correct Answer: C

Rationale: The correct answer is C. Oral contraceptives can be less effective when taken with certain antibiotics as they may interfere with the effectiveness of the contraceptive. It is important for patients to be aware of this interaction to consider additional contraceptive methods during antibiotic therapy. Choices A and B are incorrect as no contraceptive method is 100% effective, and oral contraceptives typically require a period of time to reach full effectiveness. Choice D is incorrect as taking oral contraceptives with food does not significantly impact their effectiveness.

Correct Answer: A

Rationale: The correct answer is A: Use of nitrates. Sildenafil (Viagra) is contraindicated in patients taking nitrates due to the risk of severe hypotension. Nitrates and sildenafil both cause vasodilation, which can lead to a dangerous drop in blood pressure. Choice B (Use of antihypertensive medications) is incorrect because antihypertensive medications are not a critical contraindication for sildenafil use. Choice C (History of hypertension) is incorrect as it is not a contraindication for sildenafil; in fact, sildenafil is sometimes used in patients with hypertension. Choice D (History of peptic ulcer disease) is also incorrect as it is not a critical contraindication for sildenafil use.