Nokea
The release of IL-8 at an infection site specifically induces
- A. Increase of adhesion molecules on local endothelial cells
- B. Local recruitment of neutrophils
- C. Systemic effects, including fever
- D. Increase of acute-phase proteins
Correct Answer: B
Rationale: The correct answer is B because IL-8 is a chemokine that specifically functions to recruit neutrophils to the site of infection. Neutrophils are crucial for fighting off pathogens. A: Increase of adhesion molecules on local endothelial cells is not directly induced by IL-8. C: Systemic effects, including fever, are typically mediated by other cytokines like IL-1 and IL-6. D: Increase of acute-phase proteins is not the primary role of IL-8 in the immune response.
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Neurons are
- A. Cells specialized for carrying signals
- B. The functional units of the nervous system
- C. consists of A cell body, Dendrites and Axons
- D. all above
Correct Answer: D
Rationale: The correct answer is D because neurons are specialized cells that carry signals, making them the functional units of the nervous system. Neurons consist of a cell body, dendrites, and axons, fulfilling the criteria mentioned in options A, B, and C. Therefore, option D encompasses all the essential characteristics of neurons, making it the correct choice. Options A, B, and C individually do not fully capture the comprehensive nature of neurons, as they only cover specific aspects of what neurons are, whereas option D encompasses all the correct statements regarding neurons.
Patients with septic shock are treated, among other drugs, with activated protein C. The purpose of this treatment is to
- A. Dampen the cytokine storm
- B. Raise the blood pressure
- C. Resolve DIC (disseminated intravascular coagulation)
- D. Boost the immune response
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.
What is a primary characteristic of modern immunology?
- A. It relies solely on innate immunity concepts
- B. It builds on the pioneering work of Jenner, Pasteur, and others
- C. It focuses exclusively on tissue healing
- D. It is an ancient field of study with minimal current advancements
Correct Answer: B
Rationale: The correct answer is B because modern immunology indeed builds on the groundbreaking contributions of scientists like Jenner and Pasteur. Their work laid the foundation for understanding concepts like vaccination and immune responses. Choice A is incorrect because modern immunology encompasses both innate and adaptive immunity. Choice C is incorrect as immunology extends beyond tissue healing to include immune responses to pathogens and self-cells. Choice D is incorrect as immunology is a rapidly evolving field with significant advancements in understanding immune mechanisms and developing new treatments.
What outcome would you least expect if the amount of template in a PCR fell significantly below the optimal amount?
- A. non-specific amplification
- B. increased yield
- C. Allelic drop-out (some alleles fail to amplify)
- D. Longer targets amplify poorly or fail
Correct Answer: B
Rationale: The correct answer is B: increased yield. If the amount of template in a PCR falls significantly below the optimal amount, it would be expected to result in a decreased yield rather than an increased yield. The template is essential for DNA amplification in PCR, and a lower amount would lead to fewer copies being produced. Non-specific amplification (choice A) can occur if there is too much template or incorrect primer annealing. Allelic drop-out (choice C) is likely to happen if there is insufficient template present to amplify all alleles. Longer targets amplifying poorly or failing (choice D) is also a common outcome when template concentration is low. Therefore, the least expected outcome would be an increased yield as that goes against the principle of PCR amplification.
What antibody mediates Type I hypersensitivity?
- A. IgA
- B. IgE
- C. IgG
- D. IgM
Correct Answer: B
Rationale: The correct answer is B: IgE. In Type I hypersensitivity reactions, IgE antibodies are involved. Firstly, upon initial exposure to an allergen, B cells produce IgE antibodies specific to that allergen. IgE antibodies then bind to mast cells and basophils. Upon subsequent exposure to the same allergen, it cross-links the IgE antibodies on mast cells and basophils, leading to degranulation and release of inflammatory mediators like histamine. This results in the symptoms of Type I hypersensitivity reactions.
Choice A (IgA) is incorrect because IgA is mainly involved in mucosal immunity. Choice C (IgG) is incorrect because while IgG can be involved in Type II and Type III hypersensitivity reactions, it is not the primary antibody in Type I hypersensitivity. Choice D (IgM) is incorrect because IgM is typically involved in the primary immune response, not in Type I hypersensitivity reactions.