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.

Example Input: Context: Perls' stain is routinely used to demonstrate iron in liver biopsies. We tested the hypothesis that it may be unnecessary in cases, where no iron or another similar pigment was seen on the routine hematoxylin and eosin (H and E) stained section.", "The aim of this study was to evaluate the efficiency of H and E stain in demonstrating iron in liver biopsies as well as to determine the possibility of replacing Perls' stain with H and E stain.", "Two hundred pairs of slides of liver biopsies were taken from the archival files of the Department of Pathology from 2006 to 2011. Perls' and H and E slides were independently reviewed for the presence of iron.", "Hundred and one cases showed the presence of iron using H and E stain. 84 of 86 cases showed positive iron using both Perls' and H and E stains. Seventeen cases were positive using H and E stain but negative with Perls'. Only two cases did not show the presence of iron using H and E stain. Ninety-seven cases were negative using both Perls' and H and E stains. H and E stain showed a sensitivity, specificity, accuracy, positive predictive valve, and negative predictive value of 97.67%, 85.08%, 90.5%, 83.16%, and 97.98%, respectively.\Question: Do hematoxylin and eosin stain shows a high sensitivity but sub-optimal specificity in demonstrating iron pigment in liver biopsies?
Example Output: We demonstrate that the H and E stain is a sensitive method to detect iron pigment in liver biopsies, particularly when present in large quantities. A negative H and E stain might obviate the need for extra Perls' staining, thus saving costs and shortening report turn-around times.

Example Input: Context: In diabetics with end-stage renal disease (ESRD), risk of death has been reported to be non-constant after the first dialysis, and different outcomes have been observed between genders. We assessed the impact of type 2 diabetes (T2DM) on mortality in dialysis regarding its differential effect by gender using time-dependent analyses.', 'All T2DM and non-diabetic (no-DM) patients who started dialysis in two renal units in Lyon, France, between January 1, 1995, and December 31, 2007, were included. In multivariate analyses, the Cox model and Shoenfeld residual approach were used to assess the effect of T2DM on dialysis mortality by gender.', 'We included 235 T2DM (males: 57.9%) and 480 no-DM (males: 65.6%) patients. In males, the adjusted hazard ratio (aHR) for death in T2DM versus no-DM was 0.83 (p = 0.20) and was constant over time after the first renal replacement therapy (RRT) (p = 0.88). In females, aHR for death in T2DM versus no-DM patients was not constant over time (p = 0.002). It was 0.64 (p = 0.13) within the first year after the first RRT and 2.10 (p = 0.002) after the first year. Evolutions with time of these aHR by gender were significantly different (p = 0.009).\Question: Does the Impact of type 2 diabetes on mortality in end-stage renal disease patients differ between genders?
Example Output: T2DM was associated with death only in females. This association was not constant over time after the first dialysis.

Example Input: Context: Sildenafil (Viagra), an oral treatment for erectile dysfunction, has proved popular since its introduction in 1998. However, not all patients respond to this form of therapy. Consequently, this study investigated the efficacy of intracavernous alprostadil alfadex (EDEX/VIRIDAL) treatment in patients not responding to sildenafil.', 'In an open-label, multicenter study, patients with erectile dysfunction were treated with sildenafil for 4 weeks. The initial dose was 50 mg, which was increased to 100 mg if no response was achieved. Patients not responding to treatment, measured using the International Index of Erectile Function (IIEF) questionnaire, entered an alprostadil alfadex in-office titration phase, to determine the optimal dose, up to 40 microgram. A 6-week alprostadil alfadex at-home treatment phase followed.', 'In 67 patients who did not respond satisfactorily to sildenafil, the alprostadil alfadex at-home therapy resulted in improvements in questions 3 and 4 of the IIEF in 60 (89.6%) and 57 (85.1%) patients, respectively. The mean improvement in IIEF score for these patients was 2.75 and 2.63 for questions 3 and 4, respectively. The most common side effect was penile pain in 25 (29. 4%) of 85 patients treated with alprostadil alfadex in-office and at home.\Question: Is intracavernous alprostadil alfadex ( EDEX/VIRIDAL ) effective and safe in patients with erectile dysfunction after failing sildenafil ( Viagra )?
Example Output:
Alprostadil alfadex therapy can be used effectively and safely in men who fail initial therapy with sildenafil.