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.

[Q]: As HPV-induced cases of oral malignancy increase, it is important to understand the molecular differences between HPV positive and negative head and neck squamous cell carcinoma (HNSCC). PIWI-interacting RNAs (piRNAs) are a class of small non-coding RNAs aberrantly expressed in cancer. We analyzed global piRNA expression patterns to define the HNSCC piRNA transcriptome and assess whether HPV infection status associates with changes in piRNA levels.', 'A total of 498 HNSCC small RNA sequencing libraries were acquired from the Cancer Genomics Hub (cgHUB) Data Repository and a custom sequence analysis pipeline was developed to deduce piRNA expression from raw sequencing data. Expression matrices were aligned to clinicopathological features in order to analyze piRNA expression patterns across different HNSCC groups. The association of a piRNA signature with HPV-positive patient survival was evaluated using a Cox proportional hazard model.', 'Analysis of piRNA levels between HNSCC and non-malignant tissues revealed distinct expression patterns, with 87 piRNAs exclusively expressed in tumor samples. HPV infection status affected the expression of 41 of these piRNAs. Eleven (26.8%) piRNAs were significantly downregulated in HPV16/18 tumors compared to other HPV types. Remarkably, expression of a combination of five-piRNAs in HPV-positive HNSCC tumors was associated with worse overall survival.
[A]: Is hPV status associated with altered PIWI-interacting RNA expression pattern in head and neck cancer?


[Q]: The effects of exercise training on nocturnal blood pressure (BP) dipping status remain unclear. African Americans have the highest prevalence of nondippers compared with other racial/ethnic populations. In this 6-month study we tested the hypothesis that long-term aerobic exercise training would increase the levels of nocturnal BP dipping in African American nondippers.', 'We recruited African Americans who were nondiabetic, nonsmoking, and free from cardiovascular and renal disease. For this analysis, only African Americans with a nondipping profile, defined as those with the absence of a nocturnal decline in systolic or diastolic BP (<10% of daytime values), which was determined by ambulatory BP monitoring, were chosen. A pre-post design was used, with baseline and final evaluation including office blood pressure measurement, 24-h ambulatory blood pressure monitoring, fasted blood sampling, and graded exercise testing. Participants engaged in 6 months of supervised aerobic exercise training (AEXT). Following the AEXT intervention, there were significant increases in systolic BP dipping (baseline: 5.8±3.9% vs. final: 9.4±6.1%, P=0.0055) and pulse pressure dipping (baseline: -3.1±6.6% vs. final: 5.0±12.8%, P=0.0109). Of the 18 participants with a nondipping profile at baseline, eight were nonclassified as nondippers after the AEXT intervention. There were no significant changes in office systolic BP/diastolic BP values following the AEXT intervention.
[A]: Does chronic aerobic exercise improve blood pressure dipping status in African American nondippers?


[Q]: UV radiation induces damage to human skin. Protection of skin by an oral photoprotective agent would have substantial benefits. Objective We investigated the photoprotective effect of oral administration of an extract of the natural antioxidant Polypodium leucotomos (PL).', 'A total of 9 healthy participants of skin types II to III were exposed to varying doses of artificial UV radiation without and after oral administration of PL (7.5 mg/kg). At 24 hours after exposure the erythema reaction was assessed and paired biopsy specimens were obtained from PL-treated and untreated skin.', 'A significant decrease in erythema was found in PL-treated skin (P < .01). Histologically, PL-treated biopsy specimens showed less sunburn cells (P < .05), cyclobutane pyrimidine dimers (P < .001), proliferating epidermal cells (P < .001), and dermal mast cell infiltration (P < .05). A trend toward Langerhans cell preservation was seen.
[A]:
Does oral Polypodium leucotomos extract decrease ultraviolet-induced damage of human skin?