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: The blasticidin S resistance gene (bsr) is a selectable marker used for gene transfer experiments. The bsr gene encodes for blasticidin S (BS) deaminase, which has a specific activity upon BS. Therefore, its expression is supposed to be harmless in cells. The work reported on herein consisted of experiments to verify a possible toxicity of bsr on mammalian cells, which include several cell lines and primary cultures.', 'Murine keratinocyte BALB/MK and human primary keratinocyte cells transduced with the retroviral vector LBmSN, which has an improved expression system of bsr, namely bsrm, died in five days after the transduction. Meanwhile the control vector LBSN, which expresses bsr, did not provoke cell death. The lethal activity of bsrm was observed only in human keratinocytes and BALB/MK cells among the cell types tested here. Death appears to be mediated by a factor, which is secreted by the BALB/MK transduced cells.\Question: Is over expression of the selectable marker blasticidin S deaminase gene toxic to human keratinocytes and murine BALB/MK cells?

A: By our study we demonstrated that the expression of bsrm gene is toxic to human keratinocytes and BALB/MK cells. It is likely over expression of BS deaminase gene is responsible for the death.
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Q: Context: Surgery has been the gold standard in the treatment of adult pyloric stenosis (APS). The introduction of proton pump inhibitors (PPIs) in 1989 revolutionised the treatment of peptic ulcer disease and its complications.', 'We carried out a prospective study to evaluate the effectiveness of PPIs as an alternative to surgery for treatment of APS. Six consecutive patients admitted with a diagnosis of adult peptic pyloric stenosis between November 1999 and August 2002 were studied. The diagnosis was confirmed with endoscopy. All patients were commenced on a twice-daily dose of intravenous PPI. This was changed to oral treatment after 2 days. Main outcome measures evaluated were resolution of symptoms on PPIs and failure of medical therapy.', 'There were five females and one male. Median age at diagnosis was 72 years (range, 30-90 years). Median duration of symptoms was 2 weeks (range, 1-5 weeks). Of the patients, five had a history of peptic ulcer disease. Complete resolution was achieved in 5 patients (83%). Median duration for resolution of symptoms was 9 days (range, 5-14 days). All patients were changed to oral PPIs after 2 days. One patient did not respond to oral therapy and required surgical intervention (pyloroplasty). Median follow-up was 26 months (range, 6-48 months). There was no recurrence of symptoms. All patients were discharged on low-dose PPI.\Question: Is proton pump inhibition a feasible primary alternative to surgery and balloon dilatation in adult peptic pyloric stenosis ( APS ) : report of six consecutive cases?

A: This study supports the view that proton pump inhibitors are a safe and feasible alternative to surgery in adult pyloric stenosis secondary to peptic ulcer disease.
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Q: Context: We previously reported omega-3 polyunsaturated fatty acids (n-3PUFAs) supplementation does not reduce atrial fibrillation (AF) following coronary artery bypass graft (CABG) surgery. The aim of the present study is to evaluate the impact of n-3 PUFAs on electrocardiogram (ECG) atrial arrhythmic markers and compare with expression of gap-junction proteins, Connexins.', 'Subset of clinical trial subjects with right atrial sampling during CABG surgery included. Twelve-lead ECG performed at recruitment and at surgery [after supplementation with n-3 PUFA (∼1.8 g/day) or matched placebo] for ∼14 days. Electrocardiograms analysed for maximum P-wave duration (P-max) and difference between P-max and minimum P-wave duration, P-wave dispersion (PWD). Right atrial specimens analysed for expression of Connexins 40 and 43 using real-time quantitative polymerase chain reaction (qPCR) and western blot. Serum levels of n-3 PUFA at baseline, at surgery, and atrial tissue levels at surgery collated from file. Postoperative AF was quantified by analysing data from stored continuous electrograms. A total of 61 patients (n-3 PUFA 34, Placebo 27) had ECG analysis and AF burden, of which 52 patients (26 in each group) had qPCR and 16 (8 in each group) had western blot analyses for Connexins 40 and 43. No difference between the two groups in ECG parameters or expression of Connexin 40 or 43. P-wave dispersion in the preoperative ECG independently predicted occurrence of AF following CABG surgery.\Question: Do omega-3 fatty acids alter P-wave parameters in electrocardiogram or expression of atrial connexins in patients undergoing coronary artery bypass surgery?

A:
Omega-3 polyunsaturated fatty acids supplementation does not alter pro-arrhythmic P-wave parameters in ECG or connexin expression in human atrium with no effect on the incidence of AF following CABG surgery.
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