TASK DEFINITION: Given a passage, 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.
PROBLEM: The human immunodeficiency virus Vif protein overcomes the inhibitory activity of the APOBEC3G cytidine deaminase by prohibiting its packaging into virions. Inhibition of APOBEC3G encapsidation is paralleled by a reduction of its intracellular level presumably caused by the Vif-induced proteasome-dependent degradation of APOBEC3G.', 'In this report we employed confocal microscopy to study the effects of Vif on the expression of APOBEC3G on a single cell level. HeLa cells dually transfected with Vif and APOBEC3G expression vectors revealed efficient co-expression of the two proteins. Under optimal staining conditions approximately 80% of the transfected cells scored double-positive for Vif and APOBEC3G. However, the proportion of double-positive cells observed in identical cultures varied dependent on the fixation protocol and on the choice of antibodies used ranging from as low as 40% to as high as 80% of transfected cells. Importantly, single-positive cells expressing either Vif or APOBEC3G were observed both with wild type Vif and a biologically inactive Vif variant. Thus, the lack of APOBEC3G in some Vif-expressing cells cannot be attributed to Vif-induced degradation of APOBEC3G. These findings are consistent with our results from immunoblot analyses that revealed only moderate effects of Vif on the APOBEC3G steady state levels. Of note, viruses produced under such conditions were fully infectious demonstrating that the Vif protein used in our analyses was both functional and expressed at saturating levels.

SOLUTION: Does production of infectious human immunodeficiency virus type 1 require depletion of APOBEC3G from virus-producing cells?

PROBLEM: The current American Joint Committee on Cancer Seventh Edition (AJCC7) pathologic staging for esophageal adenocarcinoma (EAC) is derived from data assessing the outcomes of patients having undergone esophagectomy without neoadjuvant treatment and has unclear significance in patients who have received multimodality therapy. Lymph nodes with evidence of neoadjuvant treatment effect without residual cancer cells may be observed and are not traditionally considered in pathologic reports, but may have prognostic significance.', 'All patients who underwent esophagectomy after completing neoadjuvant therapy for EAC at our institution between 2006 and 2012 were reviewed. Slides of pathologic specimens were reexamined for locoregional treatment-response nodes lacking viable cancer cells but with evidence of acellular mucin pools, central fibrosis, necrosis, or calcifications suggesting prior tumor involvement. Kaplan-Meier survival functions were estimated, and Cox proportional hazards regression models were used to compare staging models.', 'Ninety patients (82 men) underwent esophagectomy after neoadjuvant therapy for EAC (mean age, 61.8 ± 8.9 years). All patients received preoperative chemotherapy, and 50 patients also underwent preoperative radiotherapy. Median Kaplan-Meier survival was 55.6 months, and 5-year survival was 35% (95% confidence interval, 19% to 62%). A total of 100 treatment-response nodes were found in 38 patients. For patients with limited nodal disease (62 ypN0-N1), the presence of treatment-response nodes was associated with significantly worse survival (p = 0.03) compared with patients lacking such nodes. Adjusting for patient age and AJCC7 pathologic stage showed the presence of treatment-response nodes significantly increased the risk of death (hazard ratio, 2.7; 95% confidence interval, 1.1 to 6.9; p = 0.04). When stage-adjusted survival was modeled, counting treatment-response nodes as positive nodes offered a better model fit than ignoring them.

SOLUTION: Is neoadjuvant treatment response in negative nodes an important prognosticator after esophagectomy?

PROBLEM: Individuals with diabetes and individuals with serious mental illness are more likely than the general population to die prematurely. The study examined the impact of diabetes on mortality among 197 individuals with co-occurring psychotic and substance use disorders who participated in a randomized controlled study of integrated mental health and substance abuse treatment.', 'The authors examined Medicaid claims for evidence of diabetes and applied survival analyses to examine whether time from study entry until death was different for individuals with and without evidence of diabetes.', 'Of individuals with co-occurring psychotic and substance use disorders, 21% had evidence of diabetes. In a 12-year period, 41% of those with evidence of diabetes died compared with 10% of those without evidence of diabetes.

SOLUTION:
Do relationship between diabetes and mortality among persons with co-occurring psychotic and substance use disorders?