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: This study was conducted to determine if there was an increase in the urinary excretion of fluoride, after the use of fluoride mouth rinses in children.', 'The sample consisted of 58 children aged 5-8 years, randomly selected, residents in non-fluoridated water areas. Urine samples were collected prior to mouthwash and also 2 hours after use. The control sample, which received no treatment, consisted of 16 children of equivalent age and from the same community. Urinary excretion of fluoride was analysed by determining the pH, creatinine, F- ion and fluoride (mg)/creatinine (g) (F/Cr) ratio in urine. Results In the studied sample, the mean F/Cr ratio before fluoride mouth rinse was 0.26 mg/g and it rose to 1.58 mg/g 2 hours after mouth rinse. This difference of 1.33 mg/g was statistically highly significant (p<.001). In the control group no significant changes occurred. The average 2 hours afterward F/Cr ratios were 0.29 and 0.27 respectively (p=0.426).\Question: Does renal excretion of fluoride after fluoride mouth rinse in children?

A: After the use of a fluoride mouthwash, in children, there is a statistically significant increase of fluoride ion in urine, which can be attributed to the application of this product.
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Q: Context: Circulation on blood extracorporeally through plastic tubing activates several pathways including systemic inflammation and oxidative stress. These phenomena are suspected to participate to neurological and cardiovascular side effects observed in the patients under cardiopulmonary bypass (CPB). A direct relationship, in diabetic patients, between hyperglycemia and morbidity and mortality has been established. However, it is still unclear whether perioperative hyperglycemia has a direct effect on adverse events in cardiac surgery. The purpose of this study was to determine the influence of hyperglycemia on inflammation and oxidative stress in patients under CPB during cardiac surgery.', 'Control patients (n=17) and diabetic (type 2) patients (n=13) were included in this study. Blood samples were drawn before, during and after the CPB. Oxidative stress was evaluated in the plasma by direct and indirect approaches. Direct detection of ascorbyl radicals was assessed by electron spin resonance spectroscopy. An index: ascorbyl radical/vitamin C ratio is an indicator of the degree of oxidative stress taking place in the plasma. Oxygen radical absorbing capacity (ORAC) values were used as measurement of antioxidant capacity of the plasma. To determine inflammation profile of patients, we measure the evolution of plasma concentration of interleukin 8 (IL-8).', 'During cross clamping and post-CPB, the index ascorbyl radical/vitamin C is increased; the value of the index is more significant in diabetic patients. Concomitantly, ORAC values decreased in all the patients during cross clamping (p<0.05). Results concerning inflammatory index showed that IL-8 levels increased during the CPB.\Question: Is [ Oxidative stress exacerbated in diabetic patients during cardiopulmonary bypass ]?

A: In conclusion, the current study indicates that a systemic oxidative stress occurs during CPB and post-CPB periods and that in patients with type 2 diabetes mellitus, the systemic oxidative stress was increased.
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Q: Context: The activation of matrix metalloproteinases (MMPs) is a critical event for disruption of the blood-brain barrier (BBB) during cerebral ischemia. Among the MMPs, MMP-2, and MMP-9 expression were reported to be significantly elevated after the onset of ischemia. The aim of this study was to investigate which one is more significant for BBB disruption in the photothrombotic cerebral ischemia.', 'Male Sprague-Dawley rats weighing 250-300 g received focal cerebral ischemia by photothrombosis. MMP-2 and MMP-9 activities were assessed by gelatin zymography at various times from 2 h to 7 days. The BBB integrity was assessed using Evans blue dye with a spectrophotometric assay.', 'The Evans blue extravasation was increased within 2 h after cerebral ischemia, and was maximal at 12 and 24 h after the injury, and then gradually decreased. MMP-9 protein activity was detected as early as 2 h after the focal ischemic event; it rapidly increased at 6 h after ischemia, and reached a maximum level 48 h after the ischemic event. Thereafter, the MMP-9 level abruptly decreased and returned to the baseline at 72 h after the insult. By contrast, the MMP-2 protein activity was up-regulated at 6 h after the focal ischemic insult, and reached a maximum level at 72 h after the event. The elevated MMP-2 levels persisted for 7 days after the injury.\Question: Is early activation of matrix metalloproteinase-9 associated with blood-brain barrier disruption after photothrombotic cerebral ischemia in rats?

A:
The early activation of MMP-9 was correlated with the increase in the permeability of the BBB. Our findings suggest that MMP-9 is the key factor involved in BBB disruption and subsequent brain injury after photothrombotic cerebral ischemia in rats.
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