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.

Q: Context: Nicotinamide adenine dinucleotide (NAD(+)) and its phosphorylated form (NADP(+)) are key molecules in ubiquitous bioenergetic and cellular signaling pathways, regulating cellular metabolism and homeostasis. Thus, supplementation with NAD(+) and NADP(+) precursors emerged as a promising strategy to gain many and multifaceted health benefits. In this proof-of-concept study, we sought to investigate whether chronic nicotinamide riboside administration (an NAD(+) precursor) affects exercise performance.', 'Eighteen Wistar rats were equally divided in two groups that received either saline vehicle or nicotinamide riboside at a dose of 300mg/kg body weight/day for 21days via gavage. At the end of the 21-day administration protocol, both groups performed an incremental swimming performance test.', 'The nicotinamide riboside group showed a tendency towards worse physical performance by 35% compared to the control group at the final 10% load (9453s for the nicotinamide riboside group and 14559s for the control group; P=0.071).\Question: Does the NAD ( + ) precursor nicotinamide riboside decrease exercise performance in rats?

A: Our results do not confirm thepreviously reported ergogenic effect of nicotinamide riboside. The potentially negative effect of nicotinamide riboside administration on physical performance may be attributed to the pleiotropic metabolic and redox properties of NAD(+) and NADP(+).
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Q: Context: Urothelial carcinoma associated 1 (UCA1) functions as an oncogene, which promotes cancer cell proliferation, invasion, and metastasis, and is responsible for drug resistance. This study aimed to determine the expression level of UCA1 in ovarian cancer and to further investigate its clinical significance.', 'The expression levels of UCA1 in ovarian cancer and normal ovaries were determined by quantitative real-time PCR. The relationship between UCA1 expression and clinical features and the prognostic value of UCA1 for overall survival were examined.', 'UCA1 expression in ovarian cancer tissues was significantly upregulated compared with normal ovarian tissues. High UCA1 expression was related to lymph node metastasis, FIGO stage, and response to chemotherapy. Kaplan-Meier analysis demonstrated that high UCA1 expression was associated with poorer overall survival in patients with ovarian cancer. Cox proportional hazards analysis showed that high UCA1 expression was an independent prognostic marker of poor outcome. This effect remained significant in the further stratification analysis.\Question: Does uCA1 overexpression predict clinical outcome of patients with ovarian cancer receiving adjuvant chemotherapy?

A: Our findings provided the first evidence that UCA1 may serve as an indicator of response to chemotherapy and prognosis of ovarian cancer. UCA1 may play an important role in the progression of ovarian cancer.
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Q: Context: Porphyromonas gingivalis infection induces apoptosis inhibition in gingival epithelial cells; however, it is not fully understood which bacterial effectors are involved in this process. The aim of this study is to evaluate whether the P.gingivalis lipopolysaccharide (LPS), specifically the O-antigen region, affects adherence, invasion, viability and apoptosis of gingival epithelial cells.', "Gingival epithelial cells (OKF6/TERT2 line) were infected by different freshly prepared P.gingivalis clinical isolates, obtained from subjects with chronic periodontitis (CP3 and CP4) and healthy individuals (H1 and H3). Periodontitis and healthy isolates show differences in O-antigen production, as healthy isolates lack the O-antigen region. In addition, cells were infected by a site-specific mutant lacking the O-antigen portion. After 24h postinfection, cell proliferation, viability and apoptosis were evaluated by Trypan blue, MTS and annexin V assays, respectively. Bacterial invasion, adhesion and proliferation were measured by gentamicin/metronidazole protection assays. Finally, toll-like receptor (TLR)2 and TLR4 mRNA expression was evaluated by quantitative reverse transcription-polymerase chain reaction. Statistical analysis was performed using ANOVA, Tukey's or Dunnett's tests (p<0.05).", 'At 24h postinfection, strains lacking the O-antigen region (healthy isolates and O-antigen ligase-deficient strain) were unable to increase proliferation and viability, or decrease apoptosis as compared with strains producing intact LPS (periodontitis isolates and reference strain). However, the presence of the O-antigen neither contributed to changes in the ability of the bacteria to adhere to or invade cells, nor to intracellular survival. The presence of O-antigen also increased the expression of TLR4 (nearly sixfold), which correlated with inhibition of apoptosis.\Question: Is the Porphyromonas gingivalis O antigen required for inhibition of apoptosis in gingival epithelial cells following bacterial infection?

A:
The O-antigen region of P.gingivalis LPS is required to increase gingival epithelial cell viability upon infection by bacteria and this increase is attributable to a reduction in apoptosis. Moreover, although bacterial internalization is required, the effects observed are not due to alterations in P.gingivalis adherence, invasion or intracellular survival. Interestingly, inhibition of apoptosis correlates with increased TLR4 expression, suggesting a role for TLR4 in this process.
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