Tumor Transplantation and Imaging Flashcards
(21 cards)
Describe the In Vivo Hollow Fiber Assay.
Varying numbers of semipermeable hollow fibers, each fiber filled with a different tumor cell line, is implanted in a nude mouse.
What mutation renders natural killer cells nonfunctional?
Mutation in gamma c chain, ‘yc’
What age of zebrafish do not require immunosuppression if receiving xenotransplants?
Blastocyst to 48hpf
What is a characterization of tumors derived from cell lines?
Tend to be undifferentiated and homogenous with a diminished capacity for metastasis.
What type of tumors should be chosen for transplant? Cell concentration?
Actively dividing, nonulcerated. 10^6 cells/0.2 mL
How many cancer cells/volume should be injected SQ?
10^6-7 cells or a 3- to 5-mm fragment
Why is tumor palpation not recommended?
Risk of fatal hemorrhage from highly vascular tissues
What is the most common intracranially injected tumor? How many cells are needed?
Glioblastoma multiforme, the most malignant of the glioma class. 10^5-6 cells needed. Cells characterized as cancer stem cells (CSCs) need as few as 100 cells.
Why might tumors be implanted under the renal capsule?
Rich vascular supply may enhance tumor growth.
How are bladder tumors induced? What is a disadvantage of this method?
Bladder infused with antiseptic Cetavlon for 30 minutes, irrigated with saline, and filled with tumor suspension.
Seeding of tumor cells in ureter or urethra. Rats will show renal tumor growth due to vesicoureteral reflux
Describe fluoroscopy.
Modification of X-ray that is used to visualize the continuous movement of internal structures.
What is CT primarily used for?
Musculoskeletal
What does ultrasound require?
Direct contact of transducer probes with tissue surfaces and fluid interface for optimal signal contrast.
How is high-frequency ultrasound used?
Primarily to visualize tissue blood flow and cardiovascular physiology in rodents.
How does MRI work?
No radiation. Detects small differences in bulk physical properties of hydrogen nuclei aligned in high-strength magnetic fields. Contrast with magnetic (iron) and paramagnetic agents (gadolinium) used to assess blood flow
What type of MRI scanners are used for larger animals? Rodents?
Clinical: 1.5-3 Tesla
Rodents: Smaller bore, higher field. Up to 21T
Describe PET and SPECT.
Whole-body imaging using radioactive tracers. Can also induce CT to provide anatomical info for signal localization.
What type of wavelength penetrates better in tissue?
Longer wavelength (<650 nm)
What is a benefit of optoacoustic (photoacoustic) imaging?
Hybrid. Combines sensitivity of optical contrast with depth of ultrasound
How does optoacoustic imaging work?
Conversion of light energy to localized heat on absorption of light causes an elastic expansion that can be detected by ultrasound transducers. Often combined with US for anatomic information. Natural chromophores include melanin and hemoglobin
