HEME-ONCOLOGY-1
A 53-year-old woman with rheumatoid arthritis comes to the physician for a follow-up examination one week after being discharged from the hospital. While she was in the hospital, she received acetaminophen and erythropoietin. This patient most likely has which of the following additional conditions?
Anemia of chronic disease
An investigator is studying mechanisms of oxygen storage in skeletal muscle. Biopsy specimens of the soleus muscle are obtained from resting marathon runners and sprinters. Compared to muscle tissue obtained from the sprinters, muscle tissue from the marathon runners is more likely to show an increased concentration of a protein that corresponds to which of the following oxygen dissociation curves?
D on the diagram
An investigator is studying the effects of tissue hypoxia on skeletal muscles. Skeletal muscle hypoxia is induced by decreasing oxygen delivery to peripheral tissues. Which of the following is most likely to achieve this desired effect?
Decrease the serum 2,3-bisphosphoglycerate concentration
A 55-year-old woman comes to the physician because of a 6-month history of worsening shortness of breath on exertion and fatigue. She has type 1 diabetes mellitus, hypertension, hypercholesterolemia, and chronic kidney disease. Her mother was diagnosed with colon cancer at the age of 65 years. Her blood pressure is 145/92 mm Hg. Examination shows conjunctival pallor. Laboratory studies show: Hemoglobin9.2 g/dLMean corpuscular volume88 μm3Reticulocyte count0.6 %SerumFerritin145 ng/mLCreatinine3.
Decreased erythropoietin production
A 27-year-old man comes to the physician for a follow-up evaluation. Two days ago, he was involved in a physical altercation and sustained a bruise on his left arm and an injury to his left shoulder. Initially, there was a reddish-purplediscoloration on his left upper arm. A photograph of the left upper arm today is shown. Which of the following enzymes is most likely responsible for the observed changes in color?
Heme oxygenase
An investigator is studying the changes that occur in the oxygen-hemoglobin dissociation curve of different types of hemoglobin under various conditions. The blood obtained from a male infant shows decreased affinity for 2,3-bisphosphoglyceric acid. Which of the following is the most likely composition of the hemoglobin molecule in this sample?
α2γ2
A 16-year-old girl is brought to the emergency department because of lethargy and headache for the past 6 hours. Three days ago, she was started on dapsone and rifampin for the treatment of tuberculoid leprosy. Her pulse is 115/min and respirations are 12/min. Physical examination shows bluish discoloration of the lips and nail beds. A venous blood sample appears chocolate-colored and does not change color when exposed to oxygen. Compared to a healthy child, arterial blood gas analysis in this p
C on the diagram
A 46-year-old woman comes to the physician for a follow-up examination after a Pap smear showed atypical squamous cells. A colposcopy-directed biopsy of the cervix shows evidence of squamous cell carcinoma. The malignant cells from this lesion are most likely to drain into which of the following group of lymph nodes?
Internal iliac
A 63-year-old man comes to the physician because of an 8-month history of progressively worsening fatigue and shortness of breath on exertion. During this time, he has noticed blood in his stool on 5 separate occasions. Physical examination shows pale conjunctivae. His hemoglobin concentration is 8.9 g/dL and mean corpuscular volume is 65 μm3. Further analysis of this patient's arterial blood is most likely to show which of the following sets of findings?
D on the diagram
An investigator is conducting a study on hematological factors that affect the affinity of hemoglobin for oxygen. An illustration of two graphs (A and B) that represent the affinity of hemoglobin for oxygen is shown. Which of the following best explains a shift from A to B?
Increased body temperature
Six hours after birth, a newborn boy is evaluated for tachypnea. He was delivered at 41 weeks' gestation via Caesarian section and the amniotic fluid was meconium-stained. His respiratory rate is 75/min. Physical examination shows increased work of breathing. X-rays of the abdomen and chest show no abnormalities. Echocardiography shows elevated pulmonary artery pressure. He is started on an inhaled medication that increases smooth muscle cGMP, and there is immediate improvement in his tachypnea
Oxidization of Fe2+ to Fe3+
A 4-year-old girl is brought to the physician because of diarrhea and vomiting for 5 days. Vaccinations are up-to-date. She appears pale and irritable. Her vital signs are within normal limits. Examination shows petechiae on her trunk and extremities. Abdominal examination shows diffuse abdominal tenderness with hyperactive bowel sounds. The remainder of the exam shows no abnormalities. Laboratory studies show: Hemoglobin8 g/dLLeukocyte count17,000/mm3Platelet count49,000/mm3SerumCreatinine1.6 m
Escherichia coli infection
A 65-year-old man comes to the physician because of a 6-month history of progressive fatigue and abdominal pain. Physical examination shows pale mucous membranes and splenomegaly. Hemoglobin concentration is 9.1 g/dL and leukocyte count is 3,400/mm3. Peripheral blood smear shows nucleated red blood cells and teardrop poikilocytosis. A Janus kinase 2 gene mutation is present. Which of the following is the most likely underlying mechanism of this patient's condition?
Fibrosis in the bone marrow
A 47-year-old woman with metastatic breast cancer who is undergoing chemotherapy comes to the physician for a follow-up exam. She reports extreme fatigue since beginning her chemotherapy regimen. Her pulse is 98/min, respirations are 16/min, and blood pressure is 132/84 mm Hg. Her hemoglobin is 10.4 g/dL, leukocyte count is 800/mm3 with 5% monocytes, and platelet count is 50,000/mm3. The patient is started on a new medication. One week later, serum studies show a hemoglobin of 10.6 g/dL, a leuko
Filgrastim
An investigator is studying the effect of overdoses on the affinity of hemoglobin for oxygen. An illustration with oxygen-hemoglobin dissociation curves in two settings is shown. Curve A shows the oxygen-hemoglobin dissociation curve of individual A with an overdose of a specific substance and an arterial pCO2 of 44 mm Hg. Individual A did not vomit following the substance overdose. Curve B shows the oxygen-hemoglobin dissociation curve of individual Bwho is healthy and has an arterial pCO2 of 4
Furosemide
A 27-year-old man comes to the emergency department because of abdominal pain, diarrhea, flushing, and generalized pruritus that began after playing soccer. He also has a 2-month history of fatigue. Physical examination shows pallor and dry mucous membranes. Bone marrow biopsy shows a dense infiltration of atypical leukocytes with basophilic granules; genetic analysis of these cells shows a mutation in the KIT gene. The patient is at greatest risk for which of the following complications?
Gastric ulceration
A 14-year-old boy is brought to the physician by his mother because of a 12-hour history of abdominal pain and dark urine. Three days ago, he developed a cough, sore throat, and rhinorrhea. Examination shows conjunctival pallor, scleral icterus, and mild splenomegaly. A peripheral blood smear shows small round inclusions within erythrocytes and several erythrocytes with semicircular indentations. The underlying cause of this patient's condition is most likely to also affect which of the followin
Generation of superoxide
A 1-year-old boy is brought to the physician by his mother because he has become increasingly pale over the past several months. He has otherwise been healthy. Apart from his maternal grandfather, who had a blood disorder and required frequent blood transfusions since birth, the rest of his family, including his parents and older sister, are healthy. Examination shows conjunctival pallor. Laboratory studies show: Hemoglobin7.7 g/dLMean corpuscular volume64.8 μm3SerumIron187 μg/dLFerritin306 ng
Glycine + succinyl-CoA → aminolevulinic acid
A 4-year-old boy with acute lymphoblastic leukemia is admitted to the hospital to undergo allogeneic bone marrow transplantation. Two weeks after the conditioning regimen is started, he develops a temperature of 38.5°C (101.3°F). Laboratory studies show: Hemoglobin8 g/dLLeukocyte count1400/mm3Segmented neutrophils15%Eosinophils0.5%Lymphocytes84%Monocytes1%Platelet count110,000/mm3 Which of the following is the most appropriate pharmacotherapy for this patient?
Granulocyte-macrophage colony-stimulating factor
An investigator compares the amount of oxygen delivered to the kidneys between healthy subjects and patients with ischemic renal injury. She measures the arterial oxygen content and estimates renal plasma flow rate by measuring para-aminohippurate (PAH) clearance. Which of the following additional measurements would suffice to accurately calculate the rate of oxygen delivery to the kidneys?
Hematocrit
A 23-year-old man comes to the physician because of progressive pain, redness, and swelling of his left forearm. The symptoms began after he scratched his arm on a metal table 4 days ago. Examination of the left forearm shows a 2-cm, tender, erythematous, fluctuant lesion at the site of trauma. Incision and drainage of the lesion is performed and a small amount of thick, white liquid is expressed. Which of the following cytokines is involved in the recruitment of the primary cell type found in t
IL-8
An investigator who is studying a particular primary immunodeficiency disorder performs lymph node biopsies on patients with this disorder and compares the findings with those of healthy subjects. A photomicrograph of the cross-section of the lymph node obtained from a healthy volunteer is shown. The investigator notes that the region indicated by the arrow is absent in patients affected by the immunodeficiency disorder. Which of the following processes most likely occurs in this region?
Isotype switching
An investigator is studying the resting rate of oxygen consumption in the lower limbs of individuals with peripheral vascular disease. The rate of blood flow in a study subject's femoral vessels is measured using Doppler ultrasonography, and blood samples from the femoral vein and femoral artery are obtained. The blood samples are irradiated and centrifuged, after which the erythrocyte fractions from each sample are hemolyzed using 0.45% saline. Compared to the femoral vein, which of the followi
Lower chloride concentration
An investigator is studying the recycling of heme proteins in various cell types. Heat denaturation and high-performance liquid chromatography are used to carry out and observe the selective destruction of hemoglobin molecules in red blood cells. It is found that these cells are unable to regenerate new heme molecules. A lack of which of the following structures is the most likely explanation for this observation?
Mitochondria
A 67-year-old man with peripheral neuropathy comes to the physician for a follow-up examination after the results of serum protein electrophoresis showed monoclonal gammopathy. A complete blood count, serum creatinine, and serum electrolyte concentrations are within the reference ranges. A bone marrow biopsy shows 6% monoclonal plasma cells. Further analysis shows that class I major histocompatibility molecules are downregulated in these monoclonal plasma cells. The proliferation of these monocl
Natural killer cells
A 9-year-old boy is brought to the physician by his parents because of right-sided shoulder pain for 1 day. He has not had chills or sweating. At the age of 3 and 4, he was treated twice in the emergency department for painful swelling of his hands and feet. He emigrated with his family from Kenya 2 years ago. His temperature is 37.4°C (99.3°F), pulse is 96/min, and blood pressure is 123/82 mm Hg. Physical examination shows no tenderness, erythema, or joint swelling of the shoulder. Laboratory
Nuclear remnants in erythrocytes
A 3-year-old boy is brought to the emergency department because of worsening pain and swelling in both of his handsfor 1 week. He appears distressed. His temperature is 38.5°C (101.4°F). Examination shows erythema, swelling, warmth, and tenderness on the dorsum of his hands. His hemoglobin concentration is 9.1 g/dL. A peripheral blood smear is shown. The drug indicated to prevent recurrence of this patient's symptoms is also used to treat which of the following conditions?
Polycythemia vera
A 19-year-old man comes to the physician for evaluation of night sweats, pruritus, and enlarging masses in his right axilla and supraclavicular area for 2 weeks. Physical examination shows painless, rubbery lymphadenopathy in the right axillary, supraclavicular, and submental regions. An excisional biopsy of an axillary node is performed. If present, which of the following features would be most concerning for a neoplastic process?
Preponderance of lymphocytes with a single immunoglobulin variable domain allele
A 59-year-old woman with a history of chronic kidney disease comes to the physician for a 3-month history of easy fatiguability. Physical examination shows subconjunctival pallor. Her hemoglobin concentration is 8.9 g/dL, mean corpuscular volume is 86 μm3, and serum ferritin is 110 ng/mL. Treatment with erythropoietin is begun. A peripheral blood smear is obtained one week after treatment. A photomicrograph of the smear after specialized staining is shown. The prominent color of the intracellul
Ribosomal RNA
A 32-year-old man comes to the emergency department because of a wound in his foot. Four days ago, he stepped on a nail while barefoot at the beach. Examination of the plantar surface of his right foot shows a purulent puncture wound at the base of his second toe with erythema and tenderness of the surrounding skin. The afferent lymphatic vessels from the site of the lesion drain directly into which of the following groups of regional lymph nodes?
Superficial inguinal
An investigator is studying the function of different enzymes in various human cell types. A subset of normal human cells with an elevated intracellular concentration of bisphosphoglycerate mutase is harvested and isolated. Which of the following is most likely to be absent in these cells?
α-Ketoglutarate dehydrogenase