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.

Ex Input:
Context: Hypoxia is associated with human non-small cell lung cancers (NSCLC), which are highly resistant to chemotherapy. The hypoxia inducible factor (HIF) as a transcription factor in response to hypoxia indicates that it could be a novel, tumor-specific target for anticancer therapy. We hypothesized that disruption of HIF pathway through lentiviral vector-mediated HIF-1alpha RNA interference (RNAi) could reverse the hypoxia-induced resistance to chemotherapy.', 'We transfected Human NSCLC cell lines, SPCA1 and A549 with HIF-1alpha specific RNAi lentiviral vectors as well as controls. HIF-1alpha silenced cells [SPCA1/HIF-1alpha(-) and A549/HIF-1alpha(-)] were screened by blasticidin. They were incubated in 19 or 0.5% O2 for 16 h followed by the assessment of chemosensitivity to cisplatin and doxorubicin with MTT and clonogenic assays. Quantitative RT-PCR and Western blot analysis were used to detect the expressions of HIF-1alpha mRNA and protein, respectively. Moreover, flow cytometry was used to monitor the expression of P-glycoprotein.', 'Exposure of SPCA1 and A549 cells to 0.5% O2 significantly increased resistance to cisplatin and doxorubicin, in contrast to cells incubated in normoxia. Transduction of SPCA1 with HIF-1alpha RNAi vector resulted in sequence specific silencing with 87.2 and 84.6% decreases of HIF-1alpha mRNA transcription and 97.3 and 94.8% of protein expressions in normoxia and hypoxia, respectively. Correspondingly, they are 89.2, 89.9% and 97.2, 88.4% decreases in A549 cells. Hypoxia-induced resistance to cisplatin and doxorubicin were reversed in SPCA1/HIF-1alpha(-) and A549/HIF-1alpha(-) cells. There was no significant P-glycoprotein increase induced by hypoxia in NSCLC cells.\Question: Is hypoxia-induced resistance to cisplatin and doxorubicin in non-small cell lung cancer inhibited by silencing of HIF-1alpha gene?

Ex Output:
Our studies demonstrated that hypoxia-induced chemoresistance to cisplatin and doxorubicin in NSCLC cells is through the HIF pathway. MDR1 regulation may not be involved in hypoxia-induced chemoresistance. Combining delivery of HIF-1alpha RNAi lentiviral vector with cisplatin-related chemotherapy regimens may enable us to develop more effective strategy for NSCLC therapy.


Ex Input:
Context: Globally, heterosexual intercourse is the primary route of HIV-1 (HIV) transmission. It follows that mechanisms that protect against HIV infection are likely operative at the genital mucosa. In HIV-resistant Kenyan sex workers who are highly exposed to HIV infection yet remain uninfected, protection correlates with HIV-specific immune responses and genetic factors. However, these factors do not entirely explain this model of natural immunity to HIV. We hypothesized that protection may be mediated by innate immune proteins in the genital tract of HIV-resistant sex workers.', 'The genital proteome of mucosal secretions from HIV-resistant women was examined using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry. Cervical lavage samples were collected from 315 HIV-resistant, HIV-uninfected and HIV-infected commercial sex workers.', 'Univariate analysis identified a 6 kDa biomarker of HIV resistance in genital secretions from these women. This protein was identified by tandem mass spectrometry as elafin and was found to be overexpressed in HIV-resistant women compared with HIV-uninfected (P = 0.001) and infected (P = 0.002) women. The elevated levels of elafin/trappin-2 in HIV-resistant women were confirmed using ELISA. The prospective association of elevated cervicovaginal elafin/trappin-2 levels with protection from HIV acquisition was then confirmed in an independent cohort of high-risk female sex workers.\Question: Does elevated elafin/trappin-2 in the female genital tract is associate with protection against HIV acquisition?

Ex Output:
Using a unique proteomics approach in a large scale, cross-sectional cohort study, we identified elafin/trappin-2 as a novel innate immune factor, which is highly associated with resistance. This association was confirmed within an independent, prospective cohort study. Genital tract elafin/trappin-2 levels constitute a natural correlate of HIV protection in humans.


Ex Input:
Context: Current conceptualizations of drug reinforcement assume that drug-taking behavior is a consequence of the contingent, temporal relationship between the behavior and drug reward. However, stimulant drugs also potentiate the rewarding effects of other reinforcers when administered noncontingently.', 'These studies were designed to determine whether noncontingent nicotine enhances the reinforcing properties of a nonpharmacological reinforcer and whether this direct effect facilitates operant behavior within the context of a nicotine self-administration procedure.', 'Rats self-administered nicotine or food, or received noncontingent nicotine, saline, or food either with or without a response-contingent, unconditioned reinforcing visual stimulus (VS).', 'Noncontingent nicotine, whether delivered as discrete injections based on a pattern of self-administered nicotine or as a continuous infusion, increased response rates maintained by the VS. There were no significant differences in responding by animals that received contingent compared with noncontingent nicotine when a VS was available. This increase was not observed in the absence of the VS or as a consequence of noncontingent food delivery. Operant behavior was equally attenuated and reinstated by the removal and subsequent replacement of contingent and noncontingent nicotine. Nicotine supported self-administration in the absence of response-contingent, nicotine-paired stimuli; however, response rates were drastically reduced compared with nicotine self-administration with the VS.\Question: Is operant responding for a visual reinforcer in rats enhanced by noncontingent nicotine : implications for nicotine self-administration and reinforcement?

Ex Output:

Nicotine influences operant behavior in two ways: by acting as a primary reinforcer when it is contingent upon behavior, and by directly potentiating the reinforcing properties of other stimuli through a nonassociative mechanism. Nicotine self-administration and smoking may be largely dependent upon this later action.