instruction:
In this task, you are given an abstract of article. Your task is to generate label "True" if abstract is structured, otherwise generate "False". A structured abstract is composed of a topic sentence (or key sentence), relevant supporting sentences, and a closing (or transition) sentence. This structure is key to keeping your abstract focused on the main idea and creating a clear and concise image.
question:
PURPOSE The goal of this study was to evaluate prospectively the engraftment rate, factors influencing engraftment, and predictability of clinical outcome of low-passage xenografts from patients with resectable pancreatic ductal adenocarcinoma (PDA) and to establish a bank of PDA xenografts. EXPERIMENTAL DESIGN Patients with resectable PDA scheduled for resection at the Johns Hopkins Hospital were eligible. Representative pieces of tumor were implanted in nude mice. The status of the SMAD4 gene and content of tumor-generating cells were determined by immunohistochemistry. Gene expression was carried out by using a U133 Plus 2.0 array. Patients were followed for progression and survival.
RESULTS A total of 94 patients with PDA were resected, 69 tumors implanted in nude mice, and 42 (61%) engrafted. Engrafted carcinomas were more often SMAD4 mutant, and had a metastatic gene expression signature and worse prognosis. Tumors from patients resistant to gemcitabine were enriched in stroma-related gene pathways. Tumors sensitive to gemcitabine were enriched in cell cycle and pyrimidine gene pathways. The time to progression for patients who received treatment with gemcitabine for metastatic disease (n = 7) was double in patients with xenografts sensitive to gemcitabine.
CONCLUSION A successful xenograft was generated in 61% of patients attempted, generating a pool of 42 PDA xenografts with significant biological information and annotated clinical data. Patients with PDA and SMAD4 inactivation have a better engraftment rate. Engraftment is a poor prognosis factor, and engrafted tumors have a metastatic gene expression signature. Tumors from gemcitabine-resistant patients were enriched in stromal pathways.
answer:
True

question:
OBJECTIVE The aim was to describe the sex and socioeconomic differences in patterns of physical activity at work and in leisure time of men and women aged 36 years, and to investigate factors in childhood and adolescence which predict high rates of participation in sports and recreational activities in later life.
DESIGN Data collected in childhood, adolescence, and at 36 years on members of a national prospective birth cohort study were used.
SETTING The population sample was resident in England, Scotland, and Wales. SUBJECTS A stratified sample of about 3500 men and women was studied regularly from birth until 43 years.
MEASUREMENTS AND MAIN RESULTS More men than women reported high rates of sports and recreational activities, gardening, and do-it-yourself. In contrast women reported higher rates of bicycling and walking. Higher levels of education were associated with frequent participation in sports. Individuals often engaged in one type of activity without necessarily engaging in other types. Those who were most active in sport had been above average at sports in school, more outgoing socially in adolescence, had fewer health problems in childhood, were better educated, and had more mothers with a secondary education than those who were less active.
CONCLUSIONS Studies that examine the relationship between physical activity and chronic disease should consider a broad range of pursuits rather than extrapolating from only one area of physical activity, and in their explanations should take account of the possible role of childhood characteristics. The findings suggest the importance of developing skills and habits in childhood as well as of encouraging healthier exercise habits in adults who may have had few opportunities or low motivation previously.
answer:
True

question:
GOALS We investigated whether measurement of serum levels of the microRNAs (miRNAs) miR-16, miR-195, and miR-199a, alone or in combination with conventional serum markers, can help to differentiate hepatocellular carcinoma (HCC) from chronic liver diseases (CLDs).
BACKGROUND Recent reports suggest a link between aberrant expression of miRNA, and HCC. STUDY This retrospective analysis was conducted using sera from 105 HCC patients, 107 CLD patients, and 71 normal control subjects. The miRNAs were measured using real-time reverse transcription-polymerase chain reaction. The conventional HCC markers -fetoprotein (AFP), lens culinaris agglutinin-reactive AFP (AFP-L3%), and des--carboxyprothrombin (DCP) were measured with commercial kits.
RESULTS Serum levels of miR-16 and miR-199a were significantly lower in HCC than in CLD patients or control subjects (P<0.01). As a single marker, miR-16 had the highest sensitivity for HCC, followed by miR-199a, AFP, DCP, AFP-L3%, and miR-195. The combination of miR-16, AFP, AFP-L3%, and DCP yielded the optimal combination of sensitivity (92.4%) and specificity (78.5%) for HCC, overall and when analysis was restricted to patients with tumors size smaller than 3 cm. As a second-line HCC marker, miR-16 yielded positive HCC predictions in 18 of the 26 (69.2%) HCC patients with negative results on all 3 conventional markers, most of whom had tumors size smaller than 3 cm; miR-16 was falsely positive in only 12 of 96 (12.5%) CLD patients.
CONCLUSIONS The addition of miR-16 to conventional serum markers improved sensitivity and specificity for HCC. Use of miR-16 for second-line testing in cases considered negative on the basis of conventional HCC markers should be explored in larger, prospective studies.
answer:
True