Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

[EX Q]: Context: Androgen-independent prostate cancer is today an incurable disease, but increased understanding of the mechanisms for the transition into an androgen-independent state may increase the possibilities for more efficient strategies in the future.', 'An androgen-independent subline, LNCaP-19, to the androgen-dependent prostate cancer cell line LNCaP was developed in vitro under standard culture conditions. The characteristics of LNCaP-19 regarding androgen responsiveness, PSA, and VEGF secretion was studied in vitro. The growth in vivo and the microvessel density (MVD) of the tumors were studied after inoculation in nude mice.', 'LNCaP-19 grows equally well in dextran-charcoal stripped FBS (DCC-FBS) as in normal FBS, and rapidly gives rise to tumors in both intact and castrated mice, indicating a true androgen-independent growth. The PSA secretion from LNCaP-19 cells was lower than from LNCaP cells, while the VEGF level was comparable to the secretion from LNCaP cells without androgen stimulation. The MVD was increased in the LNCaP-19 tumors, and the vessels also displayed a changed morphology with exclusively small microvessels without lumen.
Answer: LNCaP-19 shows characteristics resembling those of androgen-independent prostate cancer. An increased MVD and changed vessel morphology in the tumor, makes it an interesting model system for studies regarding angiogenesis in the context of the acquisition of androgen independence.
[EX A]: Is transition of an androgen-dependent human prostate cancer cell line into an androgen-independent subline associated with increased angiogenesis?

[EX Q]: Context: Thailand has the lowest incidence of gastric cancer in the world. Helicobacter pylori infection, a low serum pepsinogen I/II ratio, and interleukin (IL)-1beta-511 polymorphisms are suspected to be risk factors for gastric cancer.', 'A total of 167 Thais, comprising 56 cancer patients and 111 volunteers without cancer, underwent an esophagogastroduodenoscopic examination and three fixed-point biopsies; a cancer tissue biopsy was also done, and blood samples were collected. The subjects without cancer were divided into normal subjects and chronic gastritis patients. IL-1beta-511 polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism, and the serum levels of pepsinogen I and II were determined by a radioimmunoassay. Helicobacter pylori IgG antibody and tissue pathology were tested in all groups.', 'The pepsinogen I/II ratio was significantly lower in the gastric cancer group than in the normal and chronic gastritis groups [odds ratio (OR), 2.3; 95% confidence interval (CI), 1.10-4.80; P = 0.025]. Gastric cancer patients were positive for the H. pylori IgG antibody more frequently than negative (OR, 2.946; 95% CI, 1.4-6.39; P = 0.005). However, only 15 (27%) cancer patients were both positive for H. pylori IgG antibody and had low serum pepsinogen I/II. The C/C genotype was found more frequently in the gastric cancer group than in the group with a normal gastric mucosa (OR, 0.64; 95% CI, 0.50-0.81; P = 0.014).
Answer: A low serum pepsinogen I/II ratio combined with positivity for H. pylori IgG, and a IL-1beta-511 C/C genotype may be independent risk factors for gastric cancer in Thais.
[EX A]: Are helicobacter pylori infection in combination with the serum pepsinogen I/II ratio and interleukin-1beta-511 polymorphisms independent risk factors for gastric cancer in Thais?

[EX Q]: Context: The aim of the study was to verify early and definitive outcome of radioiodine therapy in patients with Graves' disease, administering 131I calculated dose to pursue euthyroidism.", "We retrospectively analyzed 639 patients affected by Graves' disease and treated by one or more 131I calculated doses. Results dose by dose are reported. As to the first administration, outcome is related to parameters used to calculate dose and to patients' available features. Failures and hypothyroidism onset are evaluated.", 'A mean dose of 10 mCi shows great effectiveness: 75% of patients were cured after one administration, 88% after two. Of the failures, 84.1% occurred in a mean time of 0.340.23 years and were more frequent for larger glands, accelerated intra-gland radioiodine turnover, ophtalmopathy, administration of antithyroid drugs until 131I therapy. Of hypothyroid patients, 39.8% were diagnosed within the first year. After a sharp initial rise, hypothyroidism occurred at a slower rate, with estimated yearly increases of 3.8% until 10 years and of 1.8% later. In still followed up patients, euthyroidism was observed in about half the population after 10 years and in a third after 25 years.
Answer: 131I can be the first line treatment for Graves' disease in small-medium thyroids. Calculated doses can achieve a high amount of long term euthyroid patients. Similar results could be expected by fixed doses of 10 mCi.
[EX A]:
Is 131I therapy and Graves ' disease in a long term observation : euthyroidism a suitable goal . Our experience?