Writing the Methods and Results Sections
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An example of this suggested structure is shown below.
Responses of Normal, Premalignant, and Malignant Human Bronchial Epithelial (HBE) Cells to Deguelin
To determine whether deguelin could be a potential lung cancer chemopreventive agent, we first examined its effects on the growth of normal, premalignant, and malignant HBE cells . The growth of premalignant and malignant HBE cell lines was inhibited by deguelin in a dose- and time-dependent manner (Fig. 2A). After testing a range of concentrations from 10 -9 M to 10 -7 M , we determined that the IC 50 for deguelin was less than 10 -8 M . Deguelin had minimal effect on the growth of normal HBE cells. Of all the cell lines, premalignant 1799 cells, which represent the earliest stage in the lung cancer model, were the most sensitive to deguelin, with exposure to 10 -7 M deguelin for 1 day decreasing cell growth by 67.1% (95% CI, 64.1% to 70.1%). Because BEAS-2B cells have only a few of the properties of premalignant HBE cells in vivo, we also tested the effects of deguelin on cells from another immortalized cell line, HB56B. Dose- and time-dependent growth-inhibitory effects of deguelin in these cells were also detected (Fig. 2A). These results suggest that deguelin preferentially inhibited growth of premalignant HBE cells. (Adapted from Chun KH et al. Effects of deguelin on the phosphatidylinositol 3-kinase/Akt pathway and apoptosis in premalignant human bronchial epithelial cells. J Natl Cancer Inst 95:291 – 302, 2003. Reprinted with permission.) A similar structure can also sometimes be used in clinical articles, with the following exception: For clinical articles, there is usually no need for an opening sentence that reminds readers of the intervention or analysis you performed.
Verb Tense
In the Results section, as in the Methods section, use the past tense . For example, “Serum levels of Her -2/neu correlated with disease-free survival.”; “PCR analysis showed that 3 genes were expressed.... ” Some authors use the present tense in the Results section, but this is incorrect. In scientific writing, by convention, present tense is reserved for describing established facts (for exam ple, “DNA has a double-helix structure.”) and general conclusions (for example, at the end of an
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