TASK DEFINITION: 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.
PROBLEM: 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?

SOLUTION: 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.

PROBLEM: Context: The current standard of care for glioblastoma (GBM) involves a combination of surgery, radiotherapy, and temozolomide chemotherapy, but this regimen fails to achieve long-term tumor control. Resistance to temozolomide is largely mediated by expression of the DNA repair enzyme MGMT; however, emerging evidence suggests that inactivation of MSH6 and other mismatch repair proteins plays an important role in temozolomide resistance. Here, we investigate endogenous MSH6 mutations in GBM, anaplastic oligodendroglial tumor tissue, and corresponding brain tumor-initiating cell lines (BTIC).', 'MSH6 sequence and MGMT promoter methylation were determined in human tumor samples and BTICs. Sensitivity to temozolomide was evaluated in vitro using BTICs in the absence and presence of O(6)-benzylguanine to deplete MGMT. The influence of MGMT and MSH6 status on in vivo sensitivity to temozolomide was evaluated using intracranial BTIC xenografts.', 'We identified 11 previously unreported mutations in MSH6 in nine different glioma samples and six paired BTIC lines from adult patients. In addition, MSH6 mutations were documented in three oligodendrogliomas and two treatment-naive gliomas, both previously unreported findings. These mutations were found to influence the sensitivity of BTICs to temozolomide both in vitro and in vivo, independent of MGMT promoter methylation status.\Question: Do novel MSH6 mutations in treatment-naive glioblastoma and anaplastic oligodendroglioma contribute to temozolomide resistance independently of MGMT promoter methylation?

SOLUTION: These data demonstrate that endogenous MSH6 mutations may be present before alkylator therapy and occur in at least two histologic subtypes of adult glial neoplasms, with this report serving as the first to note these mutations in oligodendroglioma. These findings broaden our understanding of the clinical response to temozolomide in gliomas.

PROBLEM: Context: The cost effectiveness of preoperative localization in cases of primary hyperpara-thyroidism has not been established. We analyzed the potential savings in operative time after localization with technetium 99m (99mTc) sestamibi scan.', 'Thirty-three patients had localization of a solitary adenoma with 99mTc-sestamibi. Measurement was made of the time required for adenomectomy, unilateral neck exploration (UNE), unilateral neck exploration and confirmation of one contralateral parathyroid gland (UNEC), or bilateral neck exploration (BNE).', 'The total operative time in minutes was 76.4 +/- 18.8 for adenomectomy; 87.5 +/- 20.4 for UNE; 105.6 +/- 25.0 for UNEC; and 117.9 +/- 26.7 for BNE. The time difference was significant between adenomectomy versus UNE, UNEC, and BNE. There were also significant time differences between UNE versus UNEC and BNE.\Question: Do analysis of savings in operative time for primary hyperparathyroidism using localization with technetium 99m sestamibi scan?

SOLUTION:
The preoperative localization of a solitary parathyroid adenoma may optimize operative time with UNE, saving approximately 30 minutes.