Nokea
Defensins are
- A. Cationic antimicrobial peptides
- B. Opsonins
- C. DAMPs
- D. Fatty acids
Correct Answer: A
Rationale: Defensins are cationic antimicrobial peptides that play a crucial role in the innate immune system by disrupting the microbial cell membrane. This property allows them to kill a wide range of pathogens. Option A is correct because it accurately describes the primary function of defensins.
Option B, opsonins, are proteins that enhance phagocytosis but are not specific to defensins. Option C, DAMPs, are damage-associated molecular patterns released by damaged cells and are not related to defensins. Option D, fatty acids, are not directly related to the antimicrobial properties of defensins.
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A patient in Russell traction with a Pearson attachment for a fracture of the tibia complains of intense pain at the fracture site. The nurse assesses a temperature of 102° F and increased swelling at the fracture site. Which complication do these findings suggest?
- A. Osteomyelitis
- B. Fat embolism
- C. Traction misalignment
- D. Nonunion of the fracture
Correct Answer: A
Rationale: The correct answer is A: Osteomyelitis. The combination of intense pain, increased swelling, elevated temperature, and presence of traction indicates an infection in the bone, suggesting osteomyelitis. This serious complication requires prompt treatment with antibiotics.
Incorrect choices:
B: Fat embolism - This typically presents with respiratory distress, petechiae, and neurological changes, not with localized pain and swelling.
C: Traction misalignment - This would cause a change in the alignment of the fracture but would not typically present with fever and localized signs of infection.
D: Nonunion of the fracture - Nonunion is a failure of the bone to heal, which would not typically present with the acute signs of infection seen in this case.
Which of the following statements accurately describe genetic testing (select all that apply)?
- A. Results of genetic testing may raise psychologic and emotional issues.
- B. An ethical issue that is raised with genetic testing is protection of privacy to prevent discrimination.
- C. Genetic testing of the mother can be used to determine an unborn child’s risk of having genetic conditions.
- D. An example of genetic testing that is required by all states is premarital testing of women for the hemophilia gene.
Correct Answer: B
Rationale: Genetic testing raises psychological and ethical concerns, helps assess risks in unborn children, and includes tests like BRCA1/BRCA2 mutation screening. Premarital hemophilia testing is not universally mandated.
Polyclonal antibodies made in response to a given antigen will be:
- A. Derived from multiple B cell clones
- B. A mixture of different affinities
- C. A mixture of different antibody classes
- D. All options are correct
Correct Answer: D
Rationale: Step-by-step rationale for why Answer D is correct:
1. Polyclonal antibodies are produced by multiple B cell clones in response to an antigen (Choice A).
2. These antibodies have varying affinities due to the diversity of B cell clones involved (Choice B).
3. Different antibody classes, such as IgM, IgG, IgA, etc., are produced by different B cells (Choice C).
4. Therefore, all options are correct as polyclonal antibodies exhibit these characteristics.
The researcher that postulated the existence of 'pattern recognition receptors' on innate cells was:
- A. Susumu Tonegawa
- B. Ilya Metchnikoff
- C. Charles Janeway
- D. Ralph Steinman
Correct Answer: C
Rationale: The correct answer is C: Charles Janeway. He proposed the existence of pattern recognition receptors on innate cells in the 1980s, leading to the development of the concept of innate immunity. Janeway's hypothesis revolutionized our understanding of immune responses by emphasizing the role of pattern recognition in detecting pathogens. Tonegawa is known for his work on immune diversity; Metchnikoff discovered phagocytes; and Steinman identified dendritic cells. Janeway's contribution to immunology specifically focuses on pattern recognition receptors, making him the correct choice for this question.
What is the diversity of pattern recognition receptors (PRRs) like?
- A. Highly diverse due to somatic recombination
- B. Limited because they are germline-encoded
- C. Constantly changing in response to infections
- D. Specific to individual antigens
Correct Answer: B
Rationale: The correct answer is B because pattern recognition receptors (PRRs) are encoded in the germline, meaning they are genetically determined and do not change during an individual's lifetime. This ensures consistency in detecting various pathogens across different individuals. Choices A, C, and D are incorrect because PRR diversity is not influenced by somatic recombination, does not change constantly in response to infections, and is not specific to individual antigens.