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: L-Carnosine inhibits senescence of somatic cells and displays anticancer activity. Here we analyzed if L-carnosine (20 mM) retards senescence of human peritoneal mesothelial cells (HPMCs) and inhibits progression of ovarian cancer cells.', 'Experiments were performed with primary HPMCs established from patients undergoing abdominal surgery and with three ovarian cancer cell lines: A2780, OVCAR-3 and SKOV-3.', 'L-Carnosine retards senescence of HPMCs plausibly via inhibition of mitochondria-related oxidative stress. Prolonged exposure of HPMCs to L-carnosine prevented senescent HPMC-dependent exacerbation of cancer cell adhesion, migration, invasion and proliferation, which may be linked with decreased secretion of various pro-cancerogenic agents by HPMCs. Cancer cells exposed directly to L-carnosine displayed reduced viability, increased frequency of apoptosis and unaltered proliferation.\Question: Does l-Carnosine prevent the Pro-cancerogenic Activity of Senescent Peritoneal Mesothelium Towards Ovarian Cancer Cells?

SOLUTION: L-carnosine may be a valuable anticancer drug, especially in the context of prevention and therapy of intraperitoneal ovarian cancer metastasis.

PROBLEM: Context: Intracellular pathogens have developed elaborate strategies for silent infection of preferred host cells. Chlamydia pneumoniae is a common pathogen in acute infections of the respiratory tract (e.g. pneumonia) and associated with chronic lung sequelae in adults and children. Within the lung, alveolar macrophages and polymorph nuclear neutrophils (PMN) are the first line of defense against bacteria, but also preferred host phagocytes of chlamydiae.', 'We could show that C. pneumoniae easily infect and hide inside neutrophil granulocytes until these cells become apoptotic and are subsequently taken up by macrophages. C. pneumoniae infection of macrophages via apoptotic PMN results in enhanced replicative activity of chlamydiae when compared to direct infection of macrophages, which results in persistence of the pathogen. Inhibition of the apoptotic recognition of C. pneumoniae infected PMN using PS- masking Annexin A5 significantly lowered the transmission of chlamydial infection to macrophages. Transfer of apoptotic C. pneumoniae infected PMN to macrophages resulted in an increased TGF-ss production, whereas direct infection of macrophages with chlamydiae was characterized by an enhanced TNF-alpha response.\Question: Does chlamydia pneumoniae hide inside apoptotic neutrophils to silently infect and propagate in macrophages?

SOLUTION: Taken together, our data suggest that C. pneumoniae uses neutrophil granulocytes to be silently taken up by long-lived macrophages, which allows for efficient propagation and immune protection within the human host.

PROBLEM: Context: After formation of the linear heart tube a chamber-specific program of gene expression becomes active that underlies the formation of the chamber myocardium. To assess whether this program is recapitulated in in vitro differentiated embryonic stem cells, we performed qualitative and quantitative analyses of cardiogenesis in vivo and in vitro.', 'Gene expression profiles were made by in situ hybridisation and real-time PCR and electrophysiological profiles by patch clamp analyses of cardiomyocytes derived from time series of differentiating HM1 mouse embryonic stem cells and from embryonic and adult mouse hearts.', 'In embryoid bodies the in situ patterns of expression of alpha-myosin heavy chain, myosin light chain 2a and sarcoendoplasmic reticulum calcium ATPase 2a were similar to that of the heart muscle-specific marker gene cardiac troponin I. Myosin light chain 2v was expressed in part of the cardiac troponin I-expressing area, indicating heterogeneity within the cardiac cell population. Atrial natriuretic factor expression, indicative of the chamber-type program, could only very occasionally be detected by in situ hybridisation. Quantitative reverse transcriptase PCR showed that all cardiac genes, most notably atrial natriuretic factor, were expressed at relatively low levels, similar to those in embryonic hearts at embryonic day 8.75-9. Analysis of the electrophysiological characteristics of embryonic stem cell-derived cardiomyocytes showed an increase of the upstroke velocity and a shorter duration of the action potential during prolonged differentiation in vitro. When embryonic mouse heart compartments of embryonic day 12.5 were used as a reference, the electrophysiological characteristics of a substantial part of the embryonic stem cell-derived cardiomyocytes were most reminiscent to those observed in the embryonic outflow tract.\Question: Do cardiomyocytes derived from embryonic stem cells resemble cardiomyocytes of the embryonic heart tube?

SOLUTION:
Together, these data suggest that most cardiomyocytes acquired by differentiation of embryonic stem cells maintain a phenotype reminiscent of that of the cardiomyocytes of the primary heart tube, and hardly any myocytes develop a chamber myocardial phenotype.