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.
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Question: The tumor necrosis factor (TNF) gene is located within the highly polymorphic major histocompatibility complex region, exhibiting the -308 GA promoter region polymorphism and six microsatellites (TNFa-f) spanning the region nearby the TNF locus.', 'In the present study, we evaluated the frequency of -308 GA and TNFa-e polymorphisms and respective haplotypes (in chromosomal sequence: TNFd-TNFe-308GA-TNFc-TNFa-TNFb), in 222 patients with AIDS, 52 of whom exhibited cytomegalovirus retinitis, and in 202 healthy HIV-negative individuals.', 'TNF microsatellite and single nucleotide polymorphism typings were performed by PCR followed by polyacrylamide gel electrophoresis.', 'The TNF-308A allele and the 4-3-G-2-7-1 haplotype were associated with susceptibility to AIDS, whereas the TNFb4 allele and the 3-3-G-1-11-4 haplotype were associated with protection against AIDS development. The TNFc2 allele and the 4-1-G-2-2-1 haplotype, which contains the TNFc2 allele, were associated with cytomegalovirus retinitis.

Answer: Are tumor necrosis factor region polymorphisms associated with AIDS and with cytomegalovirus retinitis?


Question: The local anesthetic properties of tetrodotoxin, a potent naturally occurring sodium channel blocker, have been recently reexamined. It was found that sciatic nerve block duration could be greatly increased and systemic toxicity greatly decreased if epinephrine was injected with tetrodotoxin. The mechanism that underlies epinephrine-mediated prolongation of tetrodotoxin nerve blocks is not known, but indirect evidence suggests that epinephrine may slow the clearance of tetrodotoxin from the site of injection. The authors hypothesized that tetrodotoxin causes vasodilatation at its injection site, which accelerates its systemic uptake, and that this vasodilatation is attenuated by coinjected epinephrine.', 'The radiolabeled microsphere technique was used to measure tissue blood flow in anesthetized rats before and after perisciatic injection of tetrodotoxin alone and in combination with epinephrine.', 'Tetrodotoxin, in a dose of 0.1 ml of a 60 microM solution, significantly increased blood flow in perisciatic muscle at the injected side compared with simultaneous contralateral control and ipsilateral preinjection baseline. Tetrodotoxin did not increase blood flow in the sciatic nerve. Coinjection of epinephrine with tetrodotoxin prevented tetrodotoxin-induced increases in perisciatic muscle blood flow over time and did not alter sciatic nerve blood flow. Arterial blood pressure was maintained with this dose of tetrodotoxin, although brain blood flow decreased. Coinjection of epinephrine with tetrodotoxin prevented decreases in brain blood flow. Higher doses of tetrodotoxin produced hypotension.

Answer: Does epinephrine prevent muscle blood flow increases after perineural injection of tetrodotoxin?


Question: To fully understand the cytotoxicity of after-degradation QDs, we synthesized CdS QDs and investigated its toxicity mechanism.', 'Biomimetic method was proposed to synthesize cadmium sulfide (CdS) QDs. Thereafter MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay was conducted to evaluate their cytotoxicity. To investigate the toxicity mechanism, we subsequently conducted intracellular reactive oxygen species (ROS) measurement with DCFH-DA, glutathione (GSH) measurement with DTNB, and cellular cadmium assay using atomic absorption spectrometer. Microsized CdS were simultaneously tested as a comparison.', "MTT assay results indicated that CdS QDs are more toxic than microsized CdS especially at concentrations below 40 microg/ml. While microsized CdS did not trigger ROS elevation, CdS QDs increase ROS by 20-30% over control levels. However, they both deplete cellular GSH significantly at the medium concentration of 20 microg/ml. In the presence of NAC, cells are partially protected from CdS QDs, but not from microsized particles. Additionally, nearly 20% of cadmium was released from CdS nanoparticles within 24h, which also accounts for QDs' toxicity.

Answer:
Do intracellular oxidative stress and cadmium ions release induce cytotoxicity of unmodified cadmium sulfide quantum dots?