01/06/15 - Gastrointestinal Flashcards
A 23yo “sun-worshipping” female presents to the ED with acute abdominal pain. She reports that she recently started a vegetarian Atkins diet. Her exam is normal. Labs reveal sodium of 129 and elevated urine porphobilinogen (Watson-Schwartz positive). What inherited erythrocyte disorder does she have?
A. Sickle Cell Disease
B. Acute Intermittent Porphyria
C. Fanconi’s Anemia
D. Porphyria Cutanea Tarda
B. Acute Intermittent Porphyria
AIP causes episodic abdominal pain with fasting (low carbohydrate state), but exhibits no photosensitivity. The other conditions would not be triggered by diet.
A 35yo woman diagnosed with rheumatoid arthritis is to be started on Methotrexate. She is to take a folate supplement to rescue the cells with the shortest G1 phase. What are they?
A. Her oocytes
B. Red blood cells
C. Neurons
D. Intestinal mucosal cells
D. Intestinal mucosal cells
None of the other lineages rapidly progress through the cell cycle. This is the only listed labile cell lineage.
The pancreas is derived from the ventral and dorsal pancreatic buds. The ventral bud is responsible for part of the head, the uncinate process, and what else?
A. Tail
B. Main pancreatic duct
C. Isthmus
D. Body
B. Main pancreatic duct
The tail, isthmus, and body are derived from the dorsal pancreatic bud.
A term newborn has not passed meconium or had a bowel movement. Upon performing a rectal exam, feces is robustly expelled. What is the diagnosis?
A. Hirschsprung’s disease
B. Imperforate anus
C. Necrotizing enterocolitis
D. Colon cancer
A. Hirschsprung’s disease
Aganglionosis of the colon causes stasis of feces and proximal dilation. Imperforate anus would be apparent on exam, and there is no indication of infection or neoplasm.
A 24yo is unaware of his or her Hep-B immunization status. His serology is negative for HBeAg and HBsAg but positive for HBsAb and HBcAb (IgG). What is his status?
A. Exposed, now recovered and immune.
B. Recently exposed, in window phase
C. Exposed, now in chronic infection
D. Immunized for Hep-B, but forgotten.
A. Exposed, now recovered and immune.
He is expressing IgG against both core and surface antibodies, which is protective. Recent exposure would not feature IgG, chronic infections would be antigen-positive, and HBcAb is not conferred by a vaccine.
A 45yo immigrant from Mexico is constipated and experiences acid reflux. His PMI is laterally displaced. CXR reveals enlarged heart, dilated colon, and pulmonary congestion. What arthropod transmitted his infection?
A. Anopheles mosquito
B. Ixodes tick
C. Reduviid bug
D. Sandfly
E. Tsetse fly
C. Reduviid bug
The disease is Chagas, characterized by acquired aganglionosis (megacolon, megaesophagus) and dilated cardiomyopathy. Anopheles transmits Plasmodia, Ixodes transmits Babesia+Borrelia, Sandfly transmits Leishmania, Tsetse fly transmits Trypanosoma
A 21yo unimmunized male presents with a 1-week history of fever, night sweats, sore throat, headache and fatigue. His cervical lymph nodes and spleen are enlarged and palpable. What is the structure of the responsible virus?
A. Linear dsDNA, enveloped
B. Linear dsDNA, no envelope
C. Linear dsRNA, enveloped
D. Segmented linear ssRNA, enveloped
A. Linear dsDNA with envelope
This is EBV, a member of the herpesviridae, of which all carry linear dsDNA and enveloped. Unenveloped dsDNA describes adenovirus, enveloped dsRNA describes reoviruses & rotaviruses, and enveloped ssRNA describes influenza
Dr. Franco presents to GI clinic with poor appetite and upset stomach. A biopsy reveals stomach hyperplasia and mucosal rigidity with sheets of atypical lymphocytes–a MALT lymphoma caused by H. Pylori. What lab tests will this organism reveal?
A. Urease-, Catalase-, Oxidase-
B. Urease-, Catalase-, Oxidase+
C. Urease-, Catalase+, Oxidase-
D. Urease-, Catalase+, Oxidase+
E. Urease+, Catalase-, Oxidase-
F. Urease+, Catalase+, Oxidase-
G. Urease+, Catalase+, Oxidase+
G. Urease+, Catalase+, Oxidase+
H. Pylori is urease positive (urea breath test), catalase positive & oxidase positive (microaerophilic)
Several people consume a quantity of chicken & rice from a restaurant. 6 hours later, they experience abdominal pain, vomiting, and (non-bloody) diarrhea. What treatment should be prescribed?
A. Bismuth, Tetracycline, Metronidazole & Amoxicillin
B. Ciprofloxacin
C. IV fluids & Tetracycline
D. Supportive treatment only
D. Supportive treatment only
The organism responsible is Bacillus Cereus (note the very short 6hr incubation); symptoms are caused by an enterotoxin rather than active infection, so antibiotics are not indicated.
While visiting Bangladesh, you develop severe diarrhea without abdominal pain. No leukocytes are present, but you experience enough electrolyte disturbance and dehydration to cause tachycardia and hypotension. What are you infected with?
A. Clostridium Difficile
B. Giardia Lamblia
C. Salmonella
D. Vibrio Cholerae
D. Vibrio Cholerae
Cholera toxin stimulates mucosal cAMP resulting in chloride secretion and massive “rice-water” stools, enough to kill if rehydration is not established. C-Diff generally follows antibiotic use, Giardia causes steatorrhea, and salmonella causes bloody diarrhea.
After swimming in freshwater lake in Texas, you develop nausea, vomiting, and behavioral changes. An LP diagnoses a rapidly progressive meningoencephalitis which kills you. What protozoa did you contract in the lake?
A. Cryptosporidium
B. Entamoeba histolytica
C. Leishmania donovani
D. Naegleria fowleri
D. Naegleria fowleri
Naegleria is classically transmitted from stagnant warm water through the cribriform plate and olfactory bulb. It is extremely fatal. Cryptosporidium presents with diarrhea, as does Entamoeba. Leishmania is transmitted by sandfly bite.
A 50yo man with a history of needlesticks presents jaundiced and ascitic. Liver panels show elevated indirect bilirubin. What virus did he contract as a 20yo?
A. Hepatitis A
B. Hepatitis C
C. Hepatitis D
D. Hepatitis E
B. Hepatitis C
Hepatitis C frequently causes chronic liver infection, especially in IVDUs or those receiving transfused blood products in the 80s. Hepatitis A & E are fecal-oral, acute infections, while Hepatitis D is only relevant in the presence of a concurrent Hepatitis B infection.
A week after a trip to Africa, you develop a fever and scleral icterus. Liver biopsy yields eosinophilic globules known as what?
A. Councilman bodies
B. Dohle bodies
C. Negri bodies
D. Pappenheimer bodies
A. Councilman bodies
Flaviviridae (Yellow fever - transmitted by mosquitoes) classically produce councilman bodies as a result of hepatocyte apoptosis. Dohle bodies are a reactive and basophilic feature of neutrophils, Negri bodies are seen in neurons (rabies), and pappenheimer bodies are ferruginous granules seen in the erythrocytes of those with SCD or sideroblastic anemia.
After months on a pasta-only diet, you develop chronic smelly diarrhea and fatigue. Small bowel biopsy shows villous atrophy. What do you have?
A. Abetalipoproteinemia
B. Celiac sprue
C. Lactase deficiency
D. Whipple’s disease
B. Celiac sprue
The history indicates a reaction to a gluten-rich food. Pasta does not contain dairy, abetalipoproteinemia would have presented sooner, and Whipple’s disease is characterized by PAS+ macrophages, not villous atrophy.
A 2yo presents with a 3-week history of daily fevers. She is emaciated and pale, with hepatosplenomegaly. Bone marrow biopsy shows macrophages engulfing RBCs. Diagnosis?
A. Acute lymphocytic leukemia
B. Ewing’s sarcoma
C. Hemophagocytic lymphohistiocytosis
D. Neuroblastoma
C. Hemophagocytic lymphohistiocytosis
The biopsy findings are a giveaway. ALL and neuroblastoma have similar presentations but different pathologic findings. Ewing’s sarcoma is a bone tumor.
