instruction:
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.
question:
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.
answer:
Does production of infectious human immunodeficiency virus type 1 require depletion of APOBEC3G from virus-producing cells?


question:
In chronic pain, increased activity from intact or damaged peripheral nerve endings results in an enhanced response in central pain transmission systems, a mechanism known as central sensitization. Central sensitization can also be invoked in human experimental models. Therefore, these models may be useful to characterize novel analgesics in humans. The anticonvulsant gabapentin has demonstrated efficacy in patients with neuropathic pain, but its mode of action remains unclear. This study examined the effects of gabapentin on signs of central sensitization (brush and pinprick hyperalgesia) in a human model of capsaicin-evoked pain, using a gabapentin dosing regimen similar to that used in the clinic. The aims were to determine whether gabapentin, dosed in a manner similar to that used in the clinic, affected the various components of central sensitization and to assess the utility of this model for characterizing novel analgesics.', 'Intradermal capsaicin (100 microg/20 microl) was administered in the volar forearm of 41 male human volunteers to induce pain and clinical signs of central sensitization. Gabapentin (titrated to 2,400 mg daily) or placebo was given orally for 15 days in a randomized, double-blind, parallel-group design. The capsaicin test was conducted at baseline and after gabapentin or placebo. Endpoints were the size of areas of brush-evoked allodynia (with cotton gauze) and pinprick hyperalgesia (with von Frey filament), and the intensity of ongoing brush- and pinprick-evoked pain.', 'Gabapentin significantly reduced the area of brush allodynia compared with placebo (P </= 0.05) and insignificantly attenuated the area of pinprick hyperalgesia. Gabapentin had no significant effect on spontaneous and evoked pain intensity.
answer:
Does chronic oral gabapentin reduce elements of central sensitization in human experimental hyperalgesia?


question:
The purpose of this study was twofold: 1) to evaluate the effectiveness of a school-based physical activity intervention, Action Schools! BC (AS! BC), for maintaining academic performance in a multiethnic group of elementary children, and 2) to determine whether boys and girls' academic performance changed similarly after participation in AS! BC.", 'This was a 16-month cluster randomized controlled trial. Ten schools were randomized to intervention (INT) or usual practice (UP). One INT school administered the wrong final test, and one UP school graded their own test, so both were excluded. Thus, eight schools (six INT, two UP) were included in the final analysis. Children (143 boys, 144 girls) in grades 4 and 5 were recruited for the study. We used the Canadian Achievement Test (CAT-3) to evaluate academic performance (TotScore). Weekly teacher activity logs determined amounts of physical activity delivered by teachers to students. Physical activity was determined with the Physical Activity Questionnaire for Children (PAQ-C). Independent t-tests compared descriptive variables between groups and between boys and girls. We used a mixed linear model to evaluate differences in TotScore at follow-up between groups and between girls and boys.', 'Physical activity delivered by teachers to children in INT schools was increased by 47 min x wk(-1) (139 +/- 62 vs 92 +/- 45, P < 0.001). Participants attending UP schools had significantly higher baseline TotScores than those attending INT schools. Despite this, there was no significant difference in TotScore between groups at follow-up and between boys and girls at baseline and follow-up.
answer:

Does school-based physical activity compromise children 's academic performance?