Patients with septic shock are treated, among other drugs, with activated protein C. The purpose of this treatment is to

Correct Answer: C

Rationale: The correct answer is C: Resolve DIC. Activated protein C is used in septic shock to address the coagulopathy associated with DIC, a common complication. Activated protein C inhibits clotting factors and promotes fibrinolysis, helping to restore normal coagulation function. This treatment does not directly dampen the cytokine storm (choice A), raise blood pressure (choice B), or boost the immune response (choice D) in septic shock patients. It specifically targets the coagulation abnormalities seen in DIC, making choice C the most appropriate answer.

Correct Answer: A

Rationale: The correct answer is A: Passage through cultured cells. Attenuated vaccines are produced by weakening the pathogen through serial passages in cultured cells, reducing virulence while maintaining immunogenicity. Formaldehyde treatment (B) disrupts the pathogen's structure and is used for inactivated vaccines. The use of viral vectors carrying pathogen subunits (C) is a method for creating subunit vaccines, not attenuated vaccines. Therefore, D is incorrect as not all treatments lead to attenuated vaccines.

Correct Answer: B

Rationale: The correct answer is B: IgG. IgG plays a major role in opsonization by binding to antigens and marking them for phagocytosis. IgM is the first antibody produced in response to an infection but is not as effective in opsonization. IgA primarily protects mucosal surfaces. IgD is involved in the activation of B cells, not opsonization. In summary, IgG is the correct choice due to its specific role in opsonization compared to the other isotypes.

Correct Answer: D

Rationale: The correct answer is D because T cell development starts in the thymus while the naïve T cell activation by antigen occurs outside of the thymus. T cell development involves positive and negative selection, establishing MHC restriction, and interaction with thymic dendritic cells for maturation. Naïve T cells are activated by antigens in the periphery, not during T cell development in the thymus. Therefore, D is the correct answer as it does not align with the process of T cell development.

Correct Answer: D

Rationale: Step 1: Jenner observed milkmaids were protected from smallpox due to prior exposure to cowpox. Step 2: Jenner decided to inoculate a young boy with cowpox first. Step 3: Jenner then inoculated the boy with smallpox to test immunity. Step 4: The boy did not contract smallpox, demonstrating immunity. Step 5: Conclusion: Jenner proved cowpox exposure can make individuals immune to smallpox. Other choices are incorrect: A: The boy never contracted smallpox, not just because of the mild form of smallpox in the milkmaid. B: Inoculating with virulent smallpox first would not demonstrate cowpox immunity. C: Jenner did not just substitute cowpox for smallpox; he specifically tested immunity by exposing the boy to both viruses.