3/24 - UW 21 Flashcards
(49 cards)
What are the 3 most common brain tumors in children?
- Pilocytic astrocytomas
- Medullobalstomas
- Ependymomas
What is the most common location for pilocytic astrocytomas?
Cerebellum
A child presenting with a cerebellar mass with both solid and cystic components, showing Rosenthal fibers on microscopy is indicative of what tumor?
Pilocytic astrocytoma
What is the most common location for Medulloblastomas?
Cerebellum (vermis) almost exclusively
What is the most common malignant brain tumor in children?
Medulloblastoma
What brain tumor in children shows sheets of small blue cells with hyperchromatic nuclei and scant cytoplasm in the cerebellum?
Medulloblastoma
Where are Ependymomas found?
In the ependymal lining of the ventricles, may obstruct CSF flow
What is absorbed primarily in the ileum?
Bile, B12
What proteins facilitate the “Rolling” phase of leukocyte accumulation?
L-selectin on neutrophils, E- or P-selectin on endothelial cells
How do the “Tight adhesion and crawling” phases of leukocyte accumulation happen?
Neutrophils use by [CD18beta2 integrins (Mac-1/LFA-1)]
to attach to
[Intercellular adhesion molecule-1 (ICAM-1)] on endothelial cells
What molecule facilitates the “Transmigration” (final) phase of leukocyte accumulation?
Platelet endothelial cell adhesion molecule 1 (PECAM-1)
What type of inheritance are the 3 leukocyte adhesion deficiency (LAD) syndromes?
Rare, AR
What causes leukocyte adhesion deficiency (LAD) syndrome?
CD18 defect, no pus, delayed umbilical detachment
What complication of subarachnoid hemorrhage can present 4-12 days later with new onset confusion/focal neuro deficit?
Vasospasm due to impaired brain autoregulation
How do you prevent vasospasms post-subarachnoid hemorrhage
Nimodipine (selective Ca channel blocker)
Why would you hyperventilate a patient with cerebral edema?
Hyperventilation causes hypocapnea, which decreases cerebral blood flow
Unexplained medical symptoms with excessive health care use are characteristic of what?
Somatic symptom disorder
What is the best first step in management of Somatic Symptom Disorder?
Regular scheduled visits with the same PCP
What is the TTAGGG repeat at the 3’ end of chromosomes?
Telomeres, added by Telomerase
What is the RNA template used by telomerases?
TERC template (built into the telomerase enzyme)
What type of cells have active telomerases?
Stem cells (e.g. embryonic, epidermal, bone marrow)
What does the proto-oncogene Ras encode?
G protein that activates the MAPK pathway, affecting downstream transcription
What is the mechanism for nitrite antidote for CN?
Nitrites convert Hgb to metHgb, which is worse for O2 carrying, but better for CN sequestration, preventing it from damaging the mitochodrial ETC
What is kinesin?
Microtubule associated motor protein that functions in anterograde transport of intracellular vesicles towards the (+) end
