Nokea
Langerhans cells, which play a role in defense against microbes, are located in the:
- A. epidermis
- B. dermis
- C. hypodermis
- D. subcutaneous layer
Correct Answer: A
Rationale: The correct answer is A: epidermis. Langerhans cells are a type of immune cell found in the epidermis, the outermost layer of the skin. They play a crucial role in the defense against microbes by capturing and presenting antigens to activate the immune system. The dermis (B), hypodermis (C), and subcutaneous layer (D) are located deeper in the skin and do not contain Langerhans cells. Therefore, the epidermis is the correct location for these immune cells to carry out their defensive functions.
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A 9 y.o. child has been taking antibiotics on account of bronchopneumonia for a long time. There appeared pain and burning in the area of mucous membrane of his lips and tongue. Objectively: mucous membrane of lips and tongue has caseous and grey plaques that can be easily removed by a spatula leaving hyperemia foci on their spot. Microscopic examination of the plaques revealed mycelium. What is the most probable diagnosis?
- A. Candidous cheilitis
- B. Exfoliative cheilitis
- C. Leukoplakia
- D. Contactant allergic cheilitis
Correct Answer: A
Rationale: The most probable diagnosis is A: Candidous cheilitis. Candidous cheilitis is a fungal infection caused by Candida species. In this case, the presence of mycelium on the plaques indicates a fungal infection. The symptoms of pain, burning, and grey plaques that can be easily removed leaving hyperemia are typical for Candidous cheilitis. Choice B (Exfoliative cheilitis) is characterized by scaling and peeling of the lips, not plaques with mycelium. Choice C (Leukoplakia) is a precancerous condition causing white plaques that cannot be easily removed. Choice D (Contactant allergic cheilitis) is an allergic reaction causing inflammation, not fungal plaques.
Sanitary important bacteria for control of air quality are:
- A. Alpha and beta-hemolytic streptococci
- B. Pseudomonas aeruginosa
- C. E. Coli
- D. Salmonella spp.
Correct Answer: B
Rationale: The correct answer is B: Pseudomonas aeruginosa. This bacterium is important for controlling air quality as it can degrade a wide range of organic compounds present in the air, helping to maintain a clean and healthy environment. Alpha and beta-hemolytic streptococci (Choice A) are not typically associated with air quality control. E. coli (Choice C) and Salmonella spp. (Choice D) are more commonly found in water and food sources, not air, making them incorrect choices for this question. Pseudomonas aeruginosa's ability to break down organic matter in the air makes it the most suitable option for maintaining sanitary air quality.
During sanitary and bacteriological examination of air in a drugstore it was revealed that the air had high concentration of sanitary meaningful microorganisms. What microorganisms are these?
- A. Staphylococcus aureus and hemolytic streptococcus
- B. Diphtheritic and tuberculous bacilli
- C. Colibacilli and blue pus bacilli
- D. Epidermal staphylococcus and Sarcina
Correct Answer: A
Rationale: The correct answer is A: Staphylococcus aureus and hemolytic streptococcus. These microorganisms are commonly found in high concentrations during sanitary and bacteriological examination of air in a drugstore due to their prevalence in the environment. Staphylococcus aureus and hemolytic streptococcus are known to be significant pathogens that can cause various infections in humans.
Rationale:
1. Staphylococcus aureus and hemolytic streptococcus are common pathogens found in the environment and can easily contaminate air in enclosed spaces like a drugstore.
2. Both microorganisms are considered to be of sanitary significance as they can cause infections and are indicators of poor hygiene and sanitation.
3. Diphtheritic and tuberculous bacilli (Choice B) are not typically associated with air contamination in a drugstore setting.
4. Colibacilli and blue pus bacilli (Choice C) are more commonly found in fecal
A patient with a productive cough and fever had a sputum smear revealing Gram-positive cocci in pairs with a capsule. What is the most likely causative agent?
- A. Streptococcus pneumoniae
- B. Klebsiella pneumoniae
- C. Neisseria meningitidis
- D. Staphylococcus aureus
Correct Answer: A
Rationale: The correct answer is A: Streptococcus pneumoniae. This bacterium is the most likely causative agent based on the description of Gram-positive cocci in pairs with a capsule. S. pneumoniae is known for its characteristic morphology and the presence of a capsule, which helps in evading the immune system. It commonly causes pneumonia, especially in patients with a productive cough and fever.
Incorrect choices:
B: Klebsiella pneumoniae typically presents with a mucoid capsule and is associated with pneumonia in immunocompromised individuals.
C: Neisseria meningitidis is a Gram-negative diplococcus and is more commonly associated with meningitis and septicemia.
D: Staphylococcus aureus is a Gram-positive cocci, but it does not typically present in pairs with a capsule and is more commonly associated with skin and soft tissue infections.
A 16-year-old adolescent was vaccinated with DTP. In eight days there was stiffness and pain in the joints, subfebrile temperature, urticarial skin eruption, enlargement of inguinal, cervical lymph nodes and spleen. What kind of allergic reaction is observed?
- A. Immunocomplex
- B. Hypersensitivity of immediate type
- C. Cytoxic
- D. Hypersensitivity of delayed type
Correct Answer: D
Rationale: The correct answer is D: Hypersensitivity of delayed type. The symptoms described occur 5-10 days after exposure to the antigen, consistent with a delayed hypersensitivity reaction. This type of reaction involves T cells and is characterized by cell-mediated immune response, leading to inflammation and tissue damage. Choices A, B, and C are incorrect because they are associated with different mechanisms of allergic reactions. Immunocomplex reactions (choice A) involve antigen-antibody complexes depositing in tissues, immediate hypersensitivity reactions (choice B) involve IgE-mediated mast cell degranulation, and cytotoxic reactions (choice C) involve antibodies targeting specific cells for destruction.