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.
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Context: Human breast tumors are heterogeneous and consist of phenotypically diverse cells. Breast cancer cells with a CD44+/CD24- phenotype have been suggested to have tumor-initiating properties with stem cell-like and invasive features, although it is unclear whether their presence within a tumor has clinical implications. There is also a large heterogeneity between tumors, illustrated by reproducible stratification into various subtypes based on gene expression profiles or histopathological features. We have explored the prevalence of cells with different CD44/CD24 phenotypes within breast cancer subtypes.', 'Double-staining immunohistochemistry was used to quantify CD44 and CD24 expression in 240 human breast tumors for which information on other tumor markers and clinical characteristics was available. Gene expression data were also accessible for a cohort of the material.', 'A considerable heterogeneity in CD44 and CD24 expression was seen both between and within tumors. A complete lack of both proteins was evident in 35% of the tumors, while 13% contained cells of more than one of the CD44+/CD24-, CD44-/CD24+ and CD44+/CD24+ phenotypes. CD44+/CD24- cells were detected in 31% of the tumors, ranging in proportion from only a few to close to 100% of tumor cells. The CD44+/CD24- phenotype was most common in the basal-like subgroup--characterized as negative for the estrogen and progesterone receptors as well as for HER2, and as positive for cytokeratin 5/14 and/or epidermal growth factor receptor, and particularly common in BRCA1 hereditary tumors, of which 94% contained CD44+/CD24- cells. The CD44+/CD24- phenotype was surprisingly scarce in HER2+ tumors, which had a predominantly CD24+ status. A CD44+/CD24- gene expression signature was generated, which included CD44 and alpha6-integrin (CD49f) among the top-ranked overexpressed genes.\Question: Does the CD44+/CD24- phenotype is enriched in basal-like breast tumors?
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We demonstrate an association between basal-like and particularly BRCA1 hereditary breast cancer and the presence of CD44+/CD24- cells. Not all basal-like tumors and very few HER2+ tumors, however, contain CD44+/CD24- cells, emphasizing that a putative tumorigenic ability may not be confined to cells of this phenotype and that other breast cancer stem cell markers remain to be identified.


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Context: To assess the effect of six different enteral diets on the gut barrier.', 'Laboratory study.', 'University hospital, Germany.', '70 Specific pathogen free female Crl:CDR BR rats.', 'For 7 days, 6 groups of rats were fed orally with standard chow (n = 15); total parenteral nutrition solution (oral TPN, n = 15); elemental diet (ED, n = 10); nutrient-defined diet (NDD, n = 10); or the NDD supplemented with uracil (NDD+uracil, n = 10), or fibre (NDD+fibre, n = 10).', 'Bacterial translocation to mesenteric lymph nodes, numbers of Gram negative enterobacteria and total aerobic bacteria in the caecum, and intestinal concentrations of secretory IgA.', 'The incidence of bacterial translocation was significantly increased in the groups given oral TPN, ED, NDD, and NDD+uracil compared with the group given chow. Only NDD+fibre resulted in a similar degree of translocation to that in the chow group. All groups in which there was increased translocation had a highly significant overgrowth of aerobic bacteria in the caecum, mainly by Gram negative enteric organisms. The secretory IgA concentration was reduced in the group that had been given oral TPN, and that in the ED and NDD+uracil groups was similar to that in the chow group. NDD and NDD+fibre were associated with higher intestinal concentrations of secretory IgA than chow.\Question: Is fibre an essential ingredient of enteral diets to limit bacterial translocation in rats?
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Fibre-free enteral diets do not protect the gut antimicrobial barrier whatever else is in them. The superiority of early enteral as opposed to parenteral nutrition after injury may, therefore, not be the result of a specific protective effect on the gut barrier. The supplementation of commercial enteral diets with bulk fibre should be tested in clinical trials.


question:
Context: Cardiac carcinoma is the most common subtype of gastric cancer and its incidence has increased in recent years. The current chemotherapeutic drugs exhibit limited effectiveness and significant side effects in patients. Maslinic acid (MA) exerts an anti-tumor activity on a wide range of cancers and has no significant side effect; however, the anti-tumor effect of MA on cardiac carcinoma has not yet been explored.', 'MTT assays, tumor xenograft animal model, immunoblotting, MMP assessment and flow cytometry were performed in this study.', 'MA was able to suppress the viability of cardiac carcinoma cells in both a time- and dose-dependent manner. This natural compound exhibited no cytotoxicity in normal cells. Its inhibitory effect on tumor growth was further confirmed in a mouse model. Mechanistically, MA induced the activation of p38 MAPK in cardiac carcinoma cells and, in turn, changed their mitochondrial membrane potential (MMP). Finally, caspase cascades were activated by a series of cleavages, leading to apoptosis in cardiac cancer cells. Inhibition of p38 MAPK signaling was able to rescue the effect of MA on cardiac carcinoma cells.\Question: Does maslinic acid activate mitochondria-dependent apoptotic pathway in cardiac carcinoma?
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Our data demonstrated that natural compound, MA, suppressed the growth of cardiac carcinoma by inducing apoptosis via the p38 MAPK/mitochondria/caspase pathway. MA and its derivatives may be promising anti-tumor agents for cardiac carcinoma treatment in the future. (Supplemental Figures available here.).