You have a patient who makes autoantibodies against his own red blood cells, leading to hemolysis. Which one of the following mechanisms is MOST likely to explain the hemolysis?

Correct Answer: D

Rationale: The correct answer is D because in autoimmune hemolytic anemia, activation of the complement system leads to the formation of membrane attack complexes (MAC) that directly lyse the red blood cells. This process is known as complement-mediated hemolysis. Perforins from cytotoxic T cells (Choice A) are involved in cell-mediated cytotoxicity but are not typically responsible for hemolysis of red blood cells. Neutrophils releasing proteases (Choice B) or interleukin-2 binding to its receptor on red cells (Choice C) are not mechanisms commonly associated with hemolysis in autoimmune hemolytic anemia.

Correct Answer: C

Rationale: The correct answer is C: being vaccinated against chicken pox. Vaccination stimulates the immune system to produce antibodies against the specific microbe, providing protection. Antibiotics (choice A) target bacteria, not viruses like chicken pox. While a well-balanced diet (choice B) supports overall health, it doesn't specifically stimulate the immune system against a microbe. Hormones in mother's milk (choice D) provide passive immunity but do not actively stimulate the immune system to produce antibodies. Vaccination is the most direct and effective way to stimulate the immune system for targeted protection.

Correct Answer: D

Rationale: Step 1: RAST testing is used to detect allergen-specific IgE antibodies in the blood. Step 2: Seasonal allergies are typically caused by exposure to specific allergens. Step 3: IgE is elevated in response to exposure to specific antigens, which matches the purpose of RAST testing. Step 4: IgG is not specific to allergies but is more related to various infections. IgM is for acute infections. IgA is for mucosal protection. Step 5: Therefore, the correct answer is D (IgE) as it aligns with the purpose of RAST testing and the client's symptom history.

Correct Answer: B

Rationale: The correct answer is B - A progressive, circular rash- often develops at the bite site, but can also develop at other sites such as the thighs and knees. This is the early manifestation of Lyme disease known as erythema migrans. The rash typically appears within 3-30 days after a tick bite and expands gradually. Double vision (Choice A) is associated with disseminated Lyme disease in the late stage. Severe joint swelling (Choice C) is not a common early symptom of Lyme disease. Chronic fatigue (Choice D) may occur in later stages but is not a specific early manifestation of Lyme disease.

Correct Answer: B

Rationale: Correct Answer: B Rationale: 1. Cleaning up blood spills with hot water is incorrect as it does not effectively kill HIV. Bleach solution is recommended. 2. Using gloves is essential for preventing exposure to blood and body fluids. 3. Immediate cleaning of spills is crucial to reduce the risk of transmission. 4. Hot water alone is not sufficient for disinfection. Summary: A: Hand washing is important, but using gloves for cleaning blood spills is more critical. C: Sharing utensils is not safe due to the risk of blood exposure. D: Gloves are necessary for routine care to prevent contact with bodily fluids.