instruction:
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.
question:
Context: Plasma high-density lipoprotein (HDL) level is inversely correlated with the risk of atherosclerosis. However, the cellular mechanism by which HDL exerts antiatherogenic actions is not well understood. In this study, we focus on the lipid components of HDL as mediators of the lipoprotein-induced antiatherogenic actions.', 'HDL and sphingosine 1-phosphate (S1P) stimulated the migration and survival of human umbilical vein endothelial cells. These responses to HDL and S1P were almost completely inhibited by pertussis toxin and other specific inhibitors for intracellular signaling pathways, although the inhibition profiles of migration and survival were different. The HDL-stimulated migration and survival of the cells were markedly inhibited by antisense oligonucleotides against the S1P receptors EDG-1/S1P1 and EDG-3/S1P3. Cell migration was sensitive to both receptors, but cell survival was exclusively sensitive to S1P1. The S1P-rich fraction and chromatographically purified S1P from HDL stimulated cell migration, but the rest of the fraction did not, as was the case of the cell survival.\Question: Does high-density lipoprotein stimulate endothelial cell migration and survival through sphingosine 1-phosphate and its receptors?
answer:
HDL-induced endothelial cell migration and survival may be mediated by the lipoprotein component S1P and the lipid receptors S1P1 and S1P3.

question:
Context: To determine whether repeat administration of an adenovector (Ad) into the eye results in efficient gene delivery and to test whether transgenes can be expressed from an adenovector expression system in the presence of preexisting, neutralizing anti-Ad antibodies.', 'To assess the efficiency of repeated gene delivery of an adenovector expression system, C57Bl/6 mice received one, two, or three injections (intravitreal [IVT] or periocular [PO]) of AdNull.11D (empty cassette) at 2-week intervals, followed by a single AdLuciferase (AdL.11D) IVT or PO injection. Mice were killed approximately 24 hours after AdL.11D injection and the eyes were enucleated and stored until assayed. Serum samples were also analyzed to determine whether repeated IVT or PO injections lead to induction of neutralizing antibodies directed against an adenovector delivery system. To determine whether preexisting neutralizing anti-Ad antibodies would block transgene expression, mice were preimmunized with one, two, or three intramuscular (IM) injection(s) of AdNull.11D (1 x 10(9) particle units [pu]). Fourteen days later, when systemic anti-Ad antibody titers were expected to exist, mice were given a single AdL.11D injection (IVT or PO) and killed, and the eyes and serum collected.', 'These studies show that multiple injections at 2-week intervals with adenovectors (IM, IVT, or PO) did not prevent transgene expression in the eye. Moreover, measurement of neutralizing anti-Ad antibody titers revealed that measurable anti-Ad antibody titers in mice did not ablate transgene expression.\Question: Does repeated administration of adenovector in the eye result in efficient gene delivery?
answer:
These studies suggest that transgene expression after repeated adenovector administration into the eye is feasible and repeated injections, whether given IVT or PO, do not lead to an immediate increase in neutralizing anti-Ad antibody titers. Moreover, preimmunization of mice by systemic exposure to adenovector, does not block transgene expression in the eye. These studies indicate that repeat administration of adenovectors (IVT and PO) into the eye can be considered in designing future clinical trials and that the pre-existence of neutralizing anti-Ad antibodies probably does not mitigate activity.

question:
Context: While tumor infiltrating lymphocytes (TIL) have been shown to independently predict survival in primary colorectal cancer, the prognostic implications of TIL in resectable colorectal cancer liver metastases (CRCLM) have not been previously defined. This study examines the correlation between TIL numbers and survival following hepatic resection.', 'We studied patients who survived <or=2 or >or=10 years following CRCLM resection. Immunohistochemistry was performed on tissue microarrays (TMAs) to determine the number of T cells within CRCLM. Correlation between TIL frequency and <or=2 or >or=10 year survival was determined while controlling for established prognostic factors.', 'Of 162 patients, 104 survived <or=2 years and 58 survived >or=10 years. Independent correlates of 10-year survival following CRCLM resection included a high number of CD8 T cells, a low number of CD4 T cells, and a clinical risk score of <or=2 (P < 0.001). Among 10-year survivors, 31% of patients had a high number of CD8 T cells compared with 8% for <or=2 year survivors (P < 0.01). Surprisingly, only 22% of 10-year survivors had a high number of CD4 T cells, in contrast to 69% of those who died within 2 years (P < 0.001). The combination of CD8 and CD4 T cell counts was a more powerful predictor of survival than either marker alone.\Question: Does t cell infiltrate predict long-term survival following resection of colorectal cancer liver metastases?
answer:
CRCLM T cell number is an independent correlate of long-term survival following liver resection. We conclude that CRCLM TIL analysis represents a potentially powerful prognostic tool which will require further validation prior to broad application.