TASK DEFINITION: In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
PROBLEM: Context: Non-viral gene transfer efficiency is low as compared to viral vector systems. Here we describe the discovery of new drugs that are capable of enhancing non-viral gene transfer into mammalian cells using a novel two-stage screening procedure.', 'First, potential candidates are preselected from a molecular library at various concentrations by a semi-automated yeast transfection screen (YTS). The maximal transfection efficiency of every positive drug is subsequently determined in independent experiments at the optimal concentration and compared to the inhibitory effect of the drug on cell growth (IC50). In a subsequent mammalian cell transfection screen (MTS), the maximal transfection efficiency and the IC50 are determined for all preselected drugs using a human cell line and a luciferase reporter gene construct.', 'Employing our novel system we have been able to identify a new class of transfection enhancers, the tricyclic antidepressants (i.e. doxepin, maprotiline, desipramine and amoxapine). All positive drugs enhanced gene transfer in both yeast and human cell lines, but lower concentrations were sufficient for mammalian cells. With a triple combination of doxepin, amoxapine and chloroquine we obtained a transfection efficiency that exceeded that of chloroquine, one of the best-known transfection enhancers of mammalian cells, by nearly one order of magnitude.\Question: Does novel two-stage screening procedure lead to the identification of a new class of transfection enhancers?

SOLUTION: Non-viral gene transfer efficiency can be increased significantly using new transfection enhancers that are identified by a novel, semi-automated two-stage screening system employing yeast cells in the first and specific human target cells in the second round.

PROBLEM: Context: Tyrphostin AGL-2043 is a potent tricyclic quinoxaline inhibitor of PDGF beta-receptor tyrosine kinase (PTK), Kit, and Flt3. We have shown previously that selective inhibition of PDGF beta-receptor PTK by tyrphostins markedly reduces SMC proliferation and migration in vitro, reduces neointima formation in balloon-injured porcine femoral arteries, and reduces neointimal stenosis in stented porcine coronary arteries when administered intramurally within biodegradable nanoparticles. The present study was designed to determine the effect of AGL-2043 delivered from a stent-based, biodegradable polymeric coating on neointima formation in the porcine coronary artery model.', 'Stents coated with biodegradable, polylactic/glycolic acid (PLGA) polymer, with (n=13) or without (n=11) 180 mcg AGL-2043 were implanted into the proximal LAD of 24 Sinclair mini-pigs (34+/-4 kg) to achieve a 1.1:1 stent/artery diameter ratio. The delivery of drug from stent to tissue was confirmed by high-performance liquid chromatography. After 28 days, histomorphometric analysis showed that in-stent stenosis in animals treated with AGL-2043 was reduced by 50% (51+/-21% versus 26+/-10%, p=0.001), the absolute neointimal area was reduced by 44% (2.38+/-1.04 versus 1.31+/-0.43 mm(2), p=0.004), and the absolute luminal area was increased by 57% (2.19+/-1.09 versus 3.39+/-0.59 mm(2), p=0.003). There were no significant differences between control and AGL-2043 in injury score (1.24+/-0.11 vs. 1.15+/-0.12, p=0.07) or inflammation score (1.19+/-0.35 vs. 1.07+/-0.33, p=0.41). Moreover, the difference in % in-stent stenosis between control and treated animals remained highly significant even after normalizing the % stenosis to the degree of injury (p=0.0008) or to the inflammation score (p=0.001). Mortality for this study was zero. Tissue concentration in segments 1 cm proximal and distal to the stents, were negligible or zero at 1 h, 24 h, and 4 weeks after stent implantation.\Question: Does tyrphostin AGL-2043 eluting stent reduce neointima formation in porcine coronary arteries?

SOLUTION: Stent-based delivery of tyrphostin AGL-2043 from a biodegradable polymeric coating reduces in-stent neointimal hyperplasia in porcine coronary arteries by 50% after 28 days and preserves lumen area. Long-term studies should be the next step in testing applicability to the human interventional setting.

PROBLEM: Context: To identify the minocycline anti-inflammatory and antiapoptotic mechanisms through which it is believed to exert spinal cord protection during aortic occlusion in the rabbit model.', 'An animal model of aortic occlusion-related spinal cord ischemia. Randomized study with a control group and pre-ischemia and post-ischemia escalating doses of minocycline to high-dose minocycline in the presence of either hyperglycemia, a pro-apoptotic maneuver, or wortmannin, a specific phosphatidylinositol 3-kinase antagonist.', 'Tertiary medical center and school of medicine laboratory.', 'Laboratory animals-rabbits.', 'Balloon obstruction of infrarenal aorta introduced via femoral artery incision.', 'Severe hindlimb paralysis (mean Tarlov score 0.36±0.81 out of 3) was observed in all the control group animals (9 of 11 with paraplegia and 2 of 11 with paraparesis) compared with 11 of 12 neurologically intact animals (mean Tarlov score 2.58±0.90 [p = 0.001 compared with control]) in the high-dose minocycline group. This protective effect was observed partially during a state of hyperglycemia and was completely abrogated by wortmannin. Minocycline administration resulted in higher neurologic scores (p = 0.003) and a shift to viable neurons and more apoptotic-stained nuclei resulting from reduced necrosis (p = 0.001).\Question: Does minocycline Effectively protect the Rabbit 's Spinal Cord From Aortic Occlusion-Related Ischemia?

SOLUTION:
In a rabbit model of infrarenal aortic occlusion, minocycline effectively reduced paraplegia by increasing the number of viable neurons in a dose-dependent manner. Its action was completely abrogated by inhibiting the phosphatidylinositol 3-kinase pathway and was inhibited partially by the pro-apoptotic hyperglycemia maneuver, indicating that the activation of cell salvage pathways and mitochondrial sites are possible targets of minocycline action in an ischemic spinal cord.