TASK DEFINITION: Given a passage classify if the passage has a definite objective/aim/goal or not. Output '1' if the passage has a defininte objective/aim/goal and output '0' if the passage does not have a definite objective/aim/goal.
PROBLEM: Although trastuzumab improves the outcome of patients with human epidermal growth factor receptor\xa02 (HER2)-overexpressing gastric or gastroesophageal junction adenocarcinoma (collectively referred to as "gastroesophageal adenocarcinoma"; GEA), no clinical response is observed in a substantial population of patients. A predictive biomarker of trastuzumab response is required. The aim of this study was to evaluate whether the hyperactivation of the downstream phosphatidylinositol 3-kinase pathway, due to phosphatase and tensin homolog (PTEN) loss or PIK3CA mutations, could provide trastuzumab resistance in GEA.', 'Expression of HER2 and PTEN, and PIK3CA gene mutations were screened in 264 surgically resected GEA specimens. The effects of PTEN knockdown on the response to trastuzumab on cell viability, HER2 downstream signaling, apoptosis, and cell cycle were evaluated in HER2-overexpressing NCI-N87 gastric adenocarcinoma and OE19 esophageal adenocarcinoma cell lines. Inhibition of xenograft tumor growth by trastuzumab was investigated in OE19 cells with or without PTEN knockdown. The PTEN expression and objective response were analyzed in 23 GEA patients who received trastuzumab-based therapy.', 'PTEN loss was identified in 34.5\xa0% of HER2-overexpressing GEA patients, whereas PIK3CA mutations were rare (5.6\xa0%). Trastuzumab-mediated growth suppression, apoptosis, and G

SOLUTION: 0

PROBLEM: Intact myelin, which normally surrounds axons, breaks down in Wallerian degeneration following axonal injury and during neurodegenerative diseases such as multiple sclerosis. Clearance of degenerated myelin by phagocytosis is essential since myelin impedes repair and exacerbates damage. CR3 (complement receptor-3) is a principal phagocytic receptor in myelin phagocytosis. We studied how tyrosine kinase Syk (spleen tyrosine kinase) and cofilin control phagocytosis of degenerated myelin by CR3 in microglia and macrophages. Syk is a non-receptor tyrosine kinase that CR3 recruits to convey cellular functions. Cofilin is an actin-depolymerizing protein that controls F-actin (filamentous actin) remodeling (i.e., disassembly and reassembly) by shifting between active unphosphorylated and inactive phosphorylated states.', 'Syk was continuously activated during prolonged phagocytosis. Phagocytosis increased when Syk activity and expression were reduced, suggesting that normally Syk down regulates CR3-mediated myelin phagocytosis. Levels of inactive p-cofilin (phosphorylated cofilin) decreased transiently during prolonged phagocytosis. In contrast, p-cofilin levels decreased continuously when Syk activity and expression were continuously reduced, suggesting that normally Syk advances the inactive state of cofilin. Observations also revealed inverse relationships between levels of phagocytosis and levels of inactive p-cofilin, suggesting that active unphosphorylated cofilin advances phagocytosis. Active cofilin could advance phagocytosis by promoting F-actin remodeling, which supports the production of membrane protrusions (e.g., filopodia), which, as we also revealed, are instrumental in myelin phagocytosis.

SOLUTION: 0

PROBLEM: Among the essential biological roles of bone marrow-derived cells, secretion of many soluble factors is included and these small molecules can act upon specific receptors present in many tissues including the nervous system. Some of the released molecules can induce proliferation of Schwann cells (SC), satellite cells and lumbar spinal cord astrocytes during early steps of regeneration in a rat model of sciatic nerve transection. These are the major glial cell types that support neuronal survival and axonal growth following peripheral nerve injury. Fibroblast growth factor-2 (FGF-2) is the main mitogenic factor for SCs and is released in large amounts by bone marrow-derived cells, as well as by growing axons and endoneurial fibroblasts during development and regeneration of the peripheral nervous system (PNS).', 'Here we show that bone marrow-derived cell treatment induce an increase in the expression of FGF-2 in the sciatic nerve, dorsal root ganglia and the dorsolateral (DL) region of the lumbar spinal cord (LSC) in a model of sciatic nerve transection and connection into a hollow tube. SCs in culture in the presence of bone marrow derived conditioned media (CM) resulted in increased proliferation and migration. This effect was reduced when FGF-2 was neutralized by pretreating BMMC or CM with a specific antibody. The increased expression of FGF-2 was validated by RT-PCR and immunocytochemistry in co-cultures of bone marrow derived cells with sciatic nerve explants and regenerating nerve tissue respectivelly.

SOLUTION:
0