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.

Input: Consider Input: Context: Severity of rheumatoid arthritis and progression of radiographic joint damage have decreased over the last decades.', 'To examine whether this trend is attributable to an underlying trend towards milder disease or to improved treatment.', 'The study used an inception cohort of patients with early rheumatoid arthritis seen at the Wichita Arthritis Center, Wichita, Kansas, USA, since 1973 and monitored prospectively since their first clinic visit through clinical, radiographic, laboratory, demographic and self-reported data. The radiographic disease progression in patients with disease onset in the 1970s, 1980s and 1990s was compared using a multivariate regression model for longitudinal data. The analysis was adjusted for differences in baseline predictors, type of disease-modifying antirheumatic drugs (DMARDs) and steroid use.', '418 patients with rheumatoid arthritis with radiographic follow-up were included. Patients in earlier decades used fewer DMARDs, had longer disease durations and higher tender joint counts at their first visit. Other important predictors of disease progression did not differ significantly between decades of disease onset. The unadjusted rates of radiographic progression differed between decades (analysis of variance, p = 0.01), with a significant trend towards less radiographic progression in more recent times (trend, p<0.001). However, after adjusting for DMARD use, steroid use and baseline predictors, differences between decades vanished (analysis of variance, p = 0.40) and the trend towards less radiographic progression disappeared (trend, p = 0.45).\Question: Are progression of radiographic joint damage in different eras : trends towards milder disease in rheumatoid arthritis attributable to improved treatment?

Output: These results suggest that the observed trend towards milder disease in rheumatoid arthritis is attributable to more effective antirheumatic treatment and not to a secular trend.

Input: Consider Input: Context: Nonviral vectors based on polyethylenimine (PEI) usually contain an excess of PEI that is not complexed to DNA. Since unbound PEI contributes to cellular and systemic toxicity, purification of polyplexes from unbound PEI is desirable.', 'Size exclusion chromatography (SEC) was used to purify PEI polyplexes of free PEI. Transfection properties of purified polyplexes and the effect of free PEI on gene delivery were studied in vitro and in vivo after systemic application into mice.', 'SEC did not change the size and zeta-potential of polyplexes. Independent of the amount of PEI used for complex formation, purified PEI polyplexes had the same final PEI nitrogen/DNA phosphate ratio of 2.5. Notably, purified PEI polyplexes demonstrated low cellular and systemic toxicity. High transfection efficiency was achieved with purified polyplexes at high DNA concentrations (8-15 microg/ml). At low DNA concentrations (2-4 microg/ml) gene transfer with purified particles was less efficient than with polyplexes containing free PEI both in vitro and in vivo. Mechanistic studies showed that free PEI partly blocked cellular association of DNA complexes but was essential for the following intracellular gene delivery. Adding free PEI to cells treated with purified particles with a delay of up to 4 h resulted in significantly enhanced transfection efficiency compared with non-purified particles or purified particles without free PEI.\Question: Does purification of polyethylenimine polyplexes highlight the role of free polycations in gene transfer?

Output: This study presents an efficient method to remove free PEI from PEI polyplexes by SEC. Our results from transfection experiments demonstrate that free PEI substantially contributes to efficient gene expression but also mediates toxic effects in a dose-dependent manner. Purified polyplexes without free PEI have to be applied at increased concentrations to achieve high transfection levels, but exhibit a greatly improved toxicity profile.

Input: Consider Input: Context: Treating hyperglycaemia in hospitalized patients has proven to be beneficial, particularly in those with obstructive vascular disease. In a cohort of patients undergoing resection for oesophageal carcinoma (a group of patients with severe surgical stress but a low prevalence of vascular disease), we investigated whether early postoperative hyperglycaemia is associated with increased incidence of infectious complications and prolonged in-hospital stay.', 'Postoperative glucose values up to 48 hours after surgery were retrieved for 151 patients with American Society of Anesthesiologists class I or II who had been previously included in a randomized trial conducted in a tertiary referral hospital. Multivariate regression analysis was used to define the independent contribution of possible risk factors selected by univariate analysis.', 'In univariate regression analysis, postoperative glucose levels were associated with increased length of in-hospital stay (P < 0.001) but not with infectious complications (P = 0.21). However, postoperative glucose concentration was not found to be an independent risk factor for prolonged in-hospital stay in multivariate analysis (P = 0.20).\Question: Is early postoperative hyperglycaemia a risk factor for infectious complications and prolonged in-hospital stay in patients undergoing oesophagectomy : a retrospective analysis of a prospective trial?
Output: Our data indicate that postoperative hyperglycaemia is more likely to be a risk marker than a risk factor in patients undergoing highly invasive surgery for oesophageal cancer. We hypothesize that patients with a low prevalence of vascular disease may benefit less from intensive insulin therapy.