The MMR (Measles, MUMPs, Rubella) vaccine has been the object of controversy after a report (lately declared fraudulent) of an association with development of:

Correct Answer: B

Rationale: The correct answer is B: Autism. The controversy surrounding the MMR vaccine and autism emerged from a fraudulent report that falsely claimed a link between the two. Numerous scientific studies have since debunked this association, confirming the safety of the MMR vaccine. Autism is a neurodevelopmental disorder with a complex etiology, involving genetic and environmental factors, but not vaccines. Choices A, C, and D are incorrect as there is no proven causal link between the MMR vaccine and multiple sclerosis, encephalitis, or epilepsy.

Correct Answer: B

Rationale: The correct answer is B: Linear. T cells recognize linear epitopes, which are sequences of amino acids displayed in a linear fashion on the antigen's surface. This recognition occurs through the T cell receptor binding to the linear epitope. Conformational epitopes (A) involve multiple amino acid residues brought together in a specific three-dimensional structure. Epitopes on the antigen surface (C) are correct, but not all T cell epitopes are necessarily on the surface. Epitopes buried inside the antigen (D) are not accessible to T cell receptors for recognition. Thus, the correct choice is B due to the linear presentation of epitopes for T cell recognition.

Correct Answer: B

Rationale: The correct answer is B because there are no reports of the Black Death dating back to 1000 B.C. The Black Death specifically refers to the pandemic outbreak of the bubonic plague in the 14th century. The first recorded pandemic of the Black Death occurred in the 14th century, not in 1000 B.C. The other choices are incorrect because A is true as the Black Death did devastate Europe in the 14th century, C is true as plague is still present in some countries, and D is true as plague can be treated with antibiotics if caught early.

Correct Answer: D

Rationale: The correct answer is D: Peptidoglycan. Peptidoglycan is a structural component of bacterial cell walls and does not directly contribute to the pathogenicity or virulence of the bacterium. Flagella aid in motility and colonization, effector proteins manipulate host cells, and toxins damage host tissues, all of which are virulence factors. Peptidoglycan is essential for maintaining cell shape and integrity but does not directly enhance the ability of the bacteria to cause disease.

Correct Answer: D

Rationale: The correct answer is D because NLRP3 is not found in complex with pro-caspase 1 in resting, non-activated cells. Inflammasome formation requires assembly of NLRP3 with ASC and pro-caspase 1. Choices A, B, and C are correct statements because activation of receptors like TLRs can trigger inflammasome formation, extracellular ATP can induce inflammasome formation, and environmental triggers such as asbestos can also lead to inflammasome activation.