Flashcards in 11: transplantation Deck (18):
neurons have to? cell replacement techniques represent? clinical implications for?
have to carry out function for entire life, aren't replaced if damaged. one of the advanced methods by which we can ameliorate dysfunction of lesioned/damaged brain. NDDs like AD, PD for which no adequate medical treatments are avail
5 essential elements of neuronal transplantation?
donor age. host age. vascularization. immunologic factors. target access.
transplanted tissues survive best when from active stage of embryogenesis
old age drastically reduces survival and fiber outgrowth of graft
vasculrization for neuronal transplantation?
development of adequate blood supply to the graft is one of the most important factors determining graft survival
brain: immunologically? leads to? survival of graft enhanced by?
brain is an immunologic privileged site, leads to delyaed immune response to grafted tissue. by using immunosupressants
target access for neuronal transplantation? where should you always put the graft?
appropriate target area influences graft survival + growth of grafted tissues. always place at terminal area/target site, not the site of cellular origin
3 methods of neuronal transplantation
transplantation of: embryonic tissues, genetically modified cells, polymer-encapsulated cells
transplanation of embryonic tissues: what
solid pieces of tissues in preformed cavity or cell suspension of embronic tissues injected into target area
transplanation of embryonic tissues: 2 advantages + disadvantages
A: good graft survival, regulated release. D: ethical issues, limited avail of fetal tissue
transplanation of genetically modified cells: two cell types? mos commonly used method?
primary cells + immortalized cells. most commonly used: retroviral infection, which yields high levels of transgene incorporation
transplanation of genetically modified cells: 2 advantages + disadvantages
A: trasnplantation of specific genes. no ethical issues. D: unregulated secretion. poor survival of graft
transplanation of genetically modified cells: two classes of genes usually used
grwoth factors: cells genetically modified to produce GDNF, prevents degeneration of DA neurons (for PD). affected NT enzymes: cells genetically modified to produce TH, L-DOPA can ameliorate deficits in PD
transplantation of polymer encapsulated cells: is what? comprises what? what cells?
delivers growth factors/NTs to discrete brain areas. a selective barrier that allows free transport of low but not high MW agents. encapsulated PC12 cells, for animal models of PD
produces NA + DA. immortalized rat chromaffin cell that releases NA + DA. used for transplantation of polymer encapsulated cells for animal model of PD
transplantation of polymer encapsulated cells: 3 adv? 1 disadv?
use of unmatched tissue, no danger of tumor formation, can be retrieved in case of detrimental effects. D: unregulated secretion
2 animal models of PD
unilateral lesion of nigrostriatal pathway with 6 -hydroxydopamine. bilateral lesion of nigrostriatal pathways with MPTP