Viruses — MCQs

During a study on the immune system, an investigator isolates and labels T cells from the cortex of the thymus. The T cells that do not bind cortical epithelial cells expressing MHC molecules undergo apoptosis within 3–4 days. Which of the following best describes the T cells during this phase of differentiation?

A 16-year-old Mexican female presents with symptoms of the common cold after the patient's respiratory epithelial cells were infected with Rhinovirus. Due to the presence of the virus, her respiratory epithelial cells begin producing interferon. Which of the following is LEAST likely to be an outcome of the activation of the interferon response?

A researcher is studying the interactions between foreign antigens and human immune cells. She has isolated a line of lymphocytes that is known to bind antigen-presenting cells. From this cell line, she has isolated a cell surface protein that binds to class I major histocompatibility complex molecules. The continued activation, proliferation and survival of this specific cell line requires which of the following signaling molecules?

A previously healthy 6-year-old boy is brought to the physician because of a 3-day history of progressive rash. The rash started on his face and now involves the entire body. For the past week, he has had a cough and a runny nose. He is visiting from the Philippines with his family. He is in first grade and spends his afternoons at an after-school child care program. Immunization records are not available. His temperature is 39.5°C (103°F), pulse is 115/min, and blood pressure is 105/66 mm Hg. Examination shows generalized lymphadenopathy. There is an erythematous maculopapular, blanching, and partially confluent exanthem on his entire body. The remainder of the examination shows no abnormalities. Which of the following is most likely to confirm the diagnosis?

A 30-year-old woman who is 24-weeks pregnant presents to the emergency department with fever, painful urination, and headache. The patient's blood pressure is 111/67 mm Hg, the pulse is 95/min, the respiratory rate is 16/min, and the temperature is 38.3°C (101.1°F). Physical examination reveals bilateral tender inguinal lymphadenopathy and painful genital lesions. On closer inspection, the patient’s genital lesions contain clear fluid and measure 5–6 mm in diameter. What is the appropriate description of these lesions?

A 47-year-old man was brought in by his wife for progressively worsening memory and bizarre behavior over the past 2 months. The wife reports that he has been sleeping 15 hours a day, but is still complaining of fatigue. He frequently forgets important events such as his son’s graduation and left the stove running 2 days ago. During the encounter, the patient reports that “it is no longer worth living.” Past medical history is significant for a corneal transplant 7 years ago. Physical examination reveals depressed mood, healed surgical scar on the left neck, and sustained jerking of the left foot. Which of the following could have prevented this patient’s condition?

A 63-year-old woman visits her family physician because she has been experiencing difficulty to get her urine stream started in the past 8 months with many occasions needing extra effort to pass the urine. She describes the stream as intermittent and slow, and comments that she needs to go to the restroom again immediately after urinating. Her personal medical history is negative for malignancies, and all of her cytologies have been reported as normal. The only medication she takes is an angiotensin receptor blocker to treat essential hypertension diagnosed 5 years ago. Physical examination is unremarkable except for herniation of the anterior wall of the vagina that goes beyond the hymen. Which of the following types of incontinence is affecting the patient?

Five sets of PCR primers were designed and synthesized, one for each of the viruses listed below. The viral genomic material from each virus was extracted and added to a PCR reaction containing a DNA-dependent Taq polymerase with the corresponding primers. However, of the five PCR reactions, only one yielded an amplified product as detected by agarose gel. From which of the following viruses did the PCR product arise?

A 45-year-old male presents to the emergency room complaining of severe nausea and vomiting. He returned from a business trip to Nigeria five days ago. Since then, he has developed progressively worsening fevers, headache, nausea, and vomiting. He has lost his appetite and cannot hold down food or water. He did not receive any vaccinations before traveling. His medical history is notable for alcohol abuse and peptic ulcer disease for which he takes omeprazole regularly. His temperature is 103.0°F (39.4°C), blood pressure is 100/70 mmHg, pulse is 128/min, and respirations are 22/min. Physical examination reveals scleral icterus, hepatomegaly, and tenderness to palpation in the right and left upper quadrants. While in the examination room, he vomits up dark vomitus. The patient is admitted and started on multiple anti-protozoal and anti-bacterial medications. Serology studies are pending; however, the patient dies soon after admission. The virus that likely gave rise to this patient’s condition is part of which of the following families?

A homeless 45-year-old man presents to the emergency room in December complaining of malaise, body aches, chills, and fever. He reports that his symptoms started 4 days ago. His myalgias and chills have begun to resolve, but now he is starting to develop a dry cough, dyspnea, and a sore throat. He does not have a primary care provider and has not had any vaccinations in over 2 decades. He receives medical care from the emergency room whenever he is feeling ill. His temperature is 103°F (39.4°C), blood pressure is 130/70 mmHg, pulse is 115/min, and respirations are 22/min. On exam, he appears fatigued with mildly increased work of breathing. A chest radiograph is negative. A nasopharyngeal viral culture is positive for an orthomyxovirus. Upon further review of the patient’s medical record, he was diagnosed with the same condition 1 year ago in November. Which of the following mechanisms is responsible for pandemics of this patient’s disease?