Unit 3 - Formative 3 D4 Thursday

Front 1

A 25 year old woman had recently returned from a trip to the Rocky Mountains. She had been traveling with a group of campers, who had obtained their drinking water from a lake. A few days after returning home, she presented to her internist suffering from profuse watery diarrhea, crampy epigastric pain and foul smelling flatulence.
A permanent trichrome stain revealed some oval protozoan trophozoites. The broad anterior end contained a concave area covering half the ventral surface. The structure of the parasite gave the appearance of a “smiling face”. Rare cysts, having four nuclei, and characteristic median bodies and longitudinal fibers were also seen. Organism?

Back 1

Giardia lamblia (flagellate); transmissted through cysts in water

Fat rich ghirardelli chocolates for fatty stools of Giardia!

Front 2

You note oval cysts under the microscope from a patient stool sample. You also see the presence of trophozoites Organism?

Back 2

Giardia lamblia; causes giardiasis (bloating, flatulence, foul smelling fatty diarrhea - often seen in campers/hikers)

Front 3

A 3- year old girl was brought to her pediatrician by her mother who was concerned about the child’s diarrhea of 1 week’s duration. She had also vomited several times. The girl attended a day care center while her mother was at work. The pediatrician ordered stool specimens for culture for enteric pathogens and a routine O & P examination. No enteric pathogens were isolated in culture. Microscopic exam was negative for O & P. No parasites were detected in the smears stained with trichrome. What kind of stain should be performed now?

Back 3

Acid fast to detect for cysts

Front 4

Acid fast stain reveals pinkish red 4-6 um oval structures. What protozoan is responsible for the patient's illness?

Back 4

Cryptosporidium

*ACID FAST CYSTS

Front 5

A patient presents with severe diarrhea. The patient is notable for a history of AIDS. Acid fast stains reveal cysts in the stool. Organism?

Back 5

Cryptosporidium

Front 6

a patient presents with intermittent watery diarrhea with blood and pus. A stool sample reveals LARGE ciliated trophozoites. You note that there is a bean shaped macronucleus. Organism?

Back 6

Balantidium Coli

Front 7

A patient presents with numerous bloody stools per day and right upper quadrant pain and fever. Direct wet mounts reveals motile trophozoites with ingested RBCs. Also noted is the presence of cysts with 4 nuclei. Organism?

Back 7

Entamoeba histolyica; RBC in cytoplasm of entamoeba; transmitted via cysts in water

RING AND DOT PATTERN

Front 8

A 19-year-old woman who had recently returned from a semester of schooling in costa Rica had been suffering from crampy abdominal pain and diarrhea for just over a week. Stool cultures where ordered and standard O & P examination was performed. Microscopic examination revealed several types of nematode eggs. These eggs had thick shells and were oval, with some being more broadly oval than others . Several eggs had a nubby out covering (a) while others lacked the outer covering (b). Golden brown eggs on wet preparation!

Back 8

Ascaris lumbricoides

Larvae emerge in small intestine; travel to lungs (pneumonitis); swallowed a second time to mature in intestine; larvae mature to adults and produce eggs which pass into feces

Front 9

A patient has a bout of unexplained diarrhea and abdominal pain. There is also pneumonitis and abdominal pain. Stool reveals filariform larvae.

Back 9

Strongyloides stercoralis

Front 10

What are characteristics of the filariform larvae of Stronglyoides?

Back 10

Notched tail; more prominent esophagus

Front 11

49-year-old man underwent a routine outpatient colonoscopy. His medical history was unremarkable and the laboratory findings were normal. Colonoscopy showed a long, slender, white worm in the cecum against the ileocecal valve. One end of the parasite was embedded in relatively normal mucosa (Fig. 4A). The parasite was carefully retrieved by forceps. Microscopically, the parasite was consistent with a female adult worm with a prominent uterus (Fig. 4B). Numerous barrel-shaped eggs with mucoid plugs at both ends were detected in the uterus (Fig. 4C). A microscopic evaluation revealed a moderate eosinophilic infiltration in the lamina propria of the adjacent colonic mucosa (Fig. 4D). On the stool examination subsequently performed, barrel-shaped eggs with mucoid plugs eggs were detected. He was treated with albendazole for 3 days.

Back 11

Ileal-cecal location indicates trichuris trichirua (whipworm); since worms are embedded in intestinal wall it's unusual to see them in the stool; EGGS in stool (eggs look like footballs with bumps at each end)

Front 12

What is unique about the life cycle of trichuris trichiura?

Back 12

Slow life cycle; don't penetrate tissue so no lung involvement or eosinophil elevation

Front 13

How are schistosoma mansoni infections aquired?

Back 13

Skin penetration by cercariae released from fresh water snails

Front 14

A patient presents with hepatosplenomegaly with large accumulation of ascitic fluid in the peritoneal cavity. Likely organism? Organism

Back 14

Schistosomiasis infection; skin penetration by cercariae released from freshwater snails

Front 15

A patient presents with dermatitis, cough, hepatitis, fever, malaise, abdominal pain and liver tendernis. Dysentery (ab pain diarrhea + blood in stool) was also present. Organism?

Back 15

Schistosomiasis infection; skin penetration by cercariae released from freshwater snails

Front 16

At what receptors do diphenoxylate and loperamide act?

Back 16

Mu receptors in myenteric plexus; hyperpolarize cholinergic neurons involved in motility (this allows more time for intestinal and colonic water absorption)

Front 17

What should you note when administering diphenoxylate or loperamide with other drugs?

Back 17

Since these drugs are opioid agonists, you have to be note that this will increase the oral bioavailability of drugs taken after administration

Front 18

Which drug is basically dietary fiber?

Back 18

Psyllium (metamucil); absorbs excess water, swells into a gel, and stimulates peristaltic activity

Front 19

Which drug can be used for both diarrhea and constipation?

Back 19

Psyllium (metamucil);

can absorb excess water (diarrhea) but also stimulate secretion (swells, stimulates motility)

Front 20

When administering psyllium (metamucil) for diarrhea what must you coadminister?

Back 20

oral fluids, because it can cause constipation

Front 21

What is cholestyramine used for?

Back 21

Bile induced diarrhea due to bile acid malabsorption

also an adjunct to antimicrobials for toxin producing bacterial enteritis

Front 22

Which two organisms produce enterotoxins cholestyramine can bind to?

Back 22

C. diff/E. coli

Front 23

Considering cholestyramine binds bile and prevents its reabsorption, what is a predictable side effect of cholestyramine use?

Back 23

It can cause malabsorption of fat soluble nutrients, vitamins, tetracyclines and aggravate steatorrhea induce diarrhea

Front 24

A patient presents with diarrhea. You note he has a black tongue and black stools. Which medication might he have taken?

Back 24

Bismuth subsalicylate (pepto-bismol)