Quiz 49 And 50 Flashcards
What symptoms can be seen in a patient infected with entamoeba histolytica?
Patient with bloody diarrhea and liver tenderness
Describe the trophozoite of E. histolytica.
“Cart-wheel” distribution of chromatin in the nucleus; ingested RBCs
What does the third pharyngeal pouch give rise to?
Inferior parathyroids and thymus
What pouch are the superior parathyroids derived from?
Fourth pharyngeal pouch
What is the embryonic structure that gives rise to muscles of facial expression?
Second pharyngeal pouch
What artery can be involved in temporal (giant cell) arteritis, resulting in blindness?
Ophthalmic artery
What microorganism is responsible for progressive multifocal leukoencephalopathy? What cells are affected?
JC virus (a polyomavirus) infects oligodendroglial cells; eosinophilic intranuclear inclusions represents JC virus
What population is susceptible to PML?
Patients with AIDs; reactivation in immunosuppressed hosts
Multifocal lesions in the hemispheric or cerebellar white matter
PML
What transmits borrelia burgdorferi?
Ixodes scapularis
What diseases might one see bone marrow expansion in the calvarium? Why?
Sickle cell anemia and thalassemia major; both diseases result in chronic anemia - requiring compensatory hematopoiesis in the flat bones of the skull
“Crew-cut” or “hair on end” appearance is seen on radiograph, what diseases should be on the differential?
Sickle cell anemia and thalassemia major
What is thalassemia major?
Homozygous Beta thalassemia; severely deficient or absent B-globin chain
What is the point mutation resulting in sickle cell anemia?
Valine for glutamate at the 6th position of the beta-globin chain
What is the MOA of lactulose in regards to inhibiting ammonia absorption?
Lactulose is broken down but colonic bacteria; breakdown products acidify the colon, favoring protonation of NH3 to form NH4+; the positive charge prevents it from diffusing across into the blood stream and is therefore excreted
What is the MOA of the toxin produced by Enterotoxigenic E. coli?
Activate adenylate or guanylate cyclase, resulting in overproduction of cAMP, leading to diarrhea
What E. coli commonly infects travelers?
ETEC
What strain of E. coli is associated with consuming undercooked hamburger?
EHEC; has shiga like toxin that produces bloody diarrhea and HUS; associated with strain O157;H7
What is the characteristic findings of blood counts and peripheral smears in hairy cell leukemia?
Pancytopenia; hairy cells are seen - positive for tartrate-resistant acid phosphatase (TRAP)
When are smudge cells seen?
Chronic lymphocytic leukemia
What cell surface markers are found to be positive in hairy cell leukemia?
CD19, CD20, CD25 & CD11c (monocyte-associated antigens) and Surface IgG
What is the treatment for hairy cell leukemia?
2-chlorodeoxyadenosine
What organism gives rise to abdominal rash known as “rose spots”
Salmonella enterica subspecies typhi
What type of climate is Yersinia enterocolitica usually associated with? Why?
Colder climates - organism can be grown well at 4 degrees celcius.
What organism causes pseudoappendicitis? What age group?
Yersinia enterocolitica; older children/young adults
How does yersinia enterocolitica present in very young children?
Febrile, bloody, pussy diarrhea
Clavicles are formed via what type of fetal bone formation?
Intramembranous ossification
What type of inheritance pattern is seen in G6PD?
X-linked recessive
What drugs can cause oxidative distress to RBCs in a patient with G6PD?
Dapsone, primaquine (antimalarial) and sulfonamides
What part of the colon is usually affected by diverticulitis?
Distal (left) colon; but in severe cases can extend up to the cecum (mimics acute appendicitis)
What is the inheritance pattern of Fragile X syndrome?
X-linked; trinucleotide repeat expansion CGG
What cardiac disorders are seen in Fragile X syndrome?
Mitral valve prolapse and aortic root dilatation
ring-enhancing lesion seen on CT in a child with headache and fever
Brain abscess
Ring enhancing lesion on CT in a patient with HIV
Toxoplasmosis; esp with CD4 count <100
What is the most common cause of bacterial brain abscess in children?
Recurrent otitis media
What are the most common pathogens of otitis media?
S. Pneumonia, H. Influenza, moraxella catarrhalis
What regions of the brain are most affected by complications from middle-ear infections?
Cerebellar and temporal lobes
What rash can be seen in secondary syphilis?
Rash on palms and soles
What is the causative organism of syphilis?
T. Pallidum
What is the morphology of T. Pallidum?
Spirochete; a thin spirillar prokaryote that is motile (via internal flagellum)
What results from an injury to the lower trunk of the brachial plexus?
Clawing of all digits;
What structures are affected in thoracic outlet syndrome?
Lower trunk of the brachial plexus and subclavian artery
Why can one see total claw hand in a lower trunk brachial plexus injury?
Loss of lumbrical function/innervation
What is a first line treatment in diabetic gastroparesis?
Prokinetic agents
What is the MOA of metoclopramide?
Dopamine receptor blocker
What type of medications can give rise to pseudoparkinsonism?
Dopamine antagonists
What is Monckeber arteriosclerosis? What symptoms result?
Medial calcific sclerosis (calcifications in the media of small-medium arteries); no symptoms result as lumen diameter does not change
What labs can aid in the diagnosis of carcinoid syndrome?
Elevated serum chromogranin A and 5 hydroxyindoleacetic acid (5HIAA)
What cardiac affects can result from carcinoid syndrome?
Right sided heart failure secondary to tricuspid valve stenosis and endocardial fibrosis caused by serotonin’s action
Cells in the lung can break down serotonin
What is the MOA of octreotide in regards to carcinoid tumors?
Synthetic somatostatin analog that binds to receptors on the carcinoid tumor
What antibiotic can result in grey baby syndrome?
Chloramphenicol
What is the MOA of chloramphenicol?
Inhibits ribosomal peptidyl transferase.
What drug class is used in treatment of BPH?
Alpha-1 antagonists
What infection causes thickening of the meninges?
Tertiary syphilis
What region of the brain is exquisitely sensitive to hypoxic damage?
Hippocampus
What region of the brain is important in developing new information?
Hippocampus
Damage to the hippocampus produces what deficit?
Inability to form new memories (anterograde amnesia)
What is SVC syndrome? When does one see it?
SVC syndrome is characterized by obstruction of the venous return resulting in facial and arm edema, JVD. Over 85% of cases are related to malignancy (SCC or squamous cell carcinoma)
What is the MOA of clarithromycin?
Binds to 50S ribosomal subunit; blocks protein synthesis
What are the affects of macrolides on the CYP system?
Inhibit CYP3A4
What is the affect of rifampin on the CYP system?
Potent hepatic enzyme induce
Describe the defense mechanism of splitting.
Objects or people are either “all bad” or “all good”; the world is pictured in extreme terms
What results due to Rh incompatibility?
Erythroblastosis fetalis
What are the consequences of erythroblastosis fetalis?
Anemia with high output HF, edema, and elevated unconjugated bilirubin
In erythroblastosis fetalis, the high serum bilirubin can result in damage to what?
CNS - esp the basal ganglia; process known as kernicterus
