instruction:
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.
question:
Context: To investigate the independent relationship of individual- and area-level socio-economic status (SES) with the presence and severity of visual impairment (VI) in an Asian population.', 'Cross-sectional data from 9993 Chinese, Malay and Indian adults aged 40-80 years who participated in the Singapore Epidemiology of eye Diseases (2004-2011) in Singapore. Based on the presenting visual acuity (PVA) in the better-seeing eye, VI was categorized into normal vision (logMAR≤0.30), low vision (logMAR>0.30<1.00), and blindness (logMAR≥1.00). Any VI was defined as low vision/blindness in the PVA of better-seeing eye. Individual-level low-SES was defined as a composite of primary-level education, monthly income<2000 SGD and residing in 1 or 2-room public apartment. An area-level SES was assessed using a socio-economic disadvantage index (SEDI), created using 12 variables from the 2010 Singapore census. A high SEDI score indicates a relatively poor SES. Associations between SES measures and presence and severity of VI were examined using multi-level, mixed-effects logistic and multinomial regression models.', 'The age-adjusted prevalence of any VI was 19.62% (low vision = 19%, blindness = 0.62%). Both individual- and area-level SES were positively associated with any VI and low vision after adjusting for confounders. The odds ratio (95% confidence interval) of any VI was 2.11(1.88-2.37) for low-SES and 1.07(1.02-1.13) per 1 standard deviation increase in SEDI. When stratified by unilateral/bilateral categories, while low SES showed significant associations with all categories, SEDI showed a significant association with bilateral low vision only. The association between low SES and any VI remained significant among all age, gender and ethnic sub-groups. Although a consistent positive association was observed between area-level SEDI and any VI, the associations were significant among participants aged 40-65 years and male.\Question: Do composite Measures of Individual and Area-Level Socio-Economic Status Are Associated with Visual Impairment in Singapore?
answer:
In this community-based sample of Asian adults, both individual- and area-level SES were independently associated with the presence and severity of VI.


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Context: Intrathecal magnesium sulfate coinfusion with morphine increases antinociception in normal rats; however, because magnesium also delays the onset of tolerance, it is not clear whether this additional antinociception is a result of potentiated analgesia or tolerance abatement. We examined the antinociceptive interaction of intrathecal (IT) bolus magnesium sulfate and morphine in morphine naive rats and those with mechanical allodynia after a surgical incision. After intrathecal catheter implantation, rats were given preinjections of magnesium or saline, followed by injections of morphine or saline. In morphine naïve rats, IT bolus magnesium sulfate 281 and 375 microg followed by IT morphine 0.25 or 0.5 nmol enhanced peak antinociception and area under the response versus time curve two-to-three-fold in the tail-flick test as compared with morphine alone. Likewise, in rats with incisional pain, IT bolus magnesium sulfate 188 and 375 microg followed by morphine 0.5 nmol reduced mechanical allodynia, whereas morphine 0.5 nmol alone did not. This study suggests that IT magnesium sulfate potentiates morphine at a spinal site of action.\Question: Does magnesium sulfate potentiate morphine antinociception at the spinal level?
answer:
Magnesium sulfate potentiates morphine analgesia when coadministered intrathecally in normal rats, and in an animal model of mechanical allodynia after a surgical incision. These results suggest that intrathecal administration of magnesium sulfate may be a useful adjunct to spinal morphine analgesia.


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Context: Preexisting gastroesophageal reflux disease (GERD) and esophageal motility disorders may affect the outcome of laparoscopic adjustable gastric banding (AGB).', 'Prospective cohort study.', 'Tertiary referral center.', 'Between January 1, 1996, and December 31, 2002, AGB procedures were performed in 587 patients (mean body mass index, 46.7 [calculated as weight in kilograms divided by the square of height in meters]). The study population was composed of patients with preoperative GERD (assessed by a symptom-score questionnaire) and was divided into group 1 (those with preoperative GERD symptoms only) and group 2 (those with preoperative and postoperative GERD symptoms).', 'Laparoscopic AGB was performed according to the pars-flaccida technique.', 'All patients underwent preoperative and annual postoperative symptom scoring, endoscopy, esophageal barium swallow tests, esophageal manometry, and 24-hour pH monitoring.', 'Mean follow-up time was 33 months (range, 12-49 months). A total of 164 patients (27.9%) were diagnosed as having preoperative GERD symptoms. In 112 (68.3%) of these patients GERD symptoms vanished postoperatively (group 1), whereas 52 patients (31.7%) remained symptomatic after undergoing laparoscopic AGB implantation (group 2). Preoperatively, group 2 patients showed significantly poorer esophageal body motility compared with group 1 patients (20.8% vs 12.8% defective propagations; P = .007). In group 2 the mean symptom scores for dysphagia (0.4 vs 0.9) and regurgitation (0.6 vs 1.4) deteriorated significantly following laparoscopic AGB implantation, respectively. Eighteen patients (34.6%) in group 2 developed esophageal dilatation.\Question: Do prevalent esophageal body motility disorders underlie aggravation of GERD symptoms in morbidly obese patients following adjustable gastric banding?
answer:

Adjustable gastric banding provides a sufficient antireflux barrier in most of the obese patients with GERD. However, in patients with preoperatively defective esophageal body motility, AGB may aggravate GERD symptoms and esophageal dilatation. Alternative bariatric surgical procedures should be considered in these patients.