Browsing by Subject "metabolic activity"

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    Combined effects of soft drinks and nicotine on Streptococcus mutans metabolic activity and biofilm formation
    (J-STAGE, 2021-01) Mokeem, Lamia S.; Willis, Lisa H.; Windsor, L. Jack; Cook, N. Blaine; Eckert, George; Gregory, Richard L.; Cariology, Operative Dentistry and Dental Public Health, School of Dentistry
    The purpose of this study was to explore the effects of nicotine on the activity of Streptococcus mutans (S. mutans) in soft drinks. Regular soft drinks contain large proportions of high-fructose corn syrup (HFCS), which increases the activity of S. mutans resulting in high-caries risk compared with sugar-free soft drinks. Nicotine use exhibits a strong correlation with increased S. mutans biofilm formation. The soft drinks chosen were (Coca-Cola Classic, Diet Coke, Coca-Cola Zero Sugar, Caffeine-Free Coca-Cola, Caffeine-Free Diet Coke, Caffeine-Free Coca-Cola Zero Sugar). S. mutans was grown overnight in tryptic soy broth; nicotine was diluted in tryptic soy broth supplemented with 1.0% sucrose followed by soft drinks in dilution of 1:3. Total growth absorbance and biofilm growth were determined by spectrophotometry, absorbance measured to determine biofilm formation, and metabolic activity quantified. One-way ANOVA showed a considerable effect for HFCS and caffeine in the presence of nicotine and their interaction in all measures. Results showed sugar-free caffeinated colas demonstrated significant effect in inhibiting S. mutans biofilm formation and metabolic activity with nicotine. Nicotine-induced S. mutans increased biofilm formation and metabolic activity in the presence of HFCS and caffeine in soft drinks. In conclusion, smokers should consider sugar-free caffeinated versions to minimize the chance of developing dental caries dut to the reduction of biofilm formation.
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    Effect of Midtreatment PET/CT-Adapted Radiation Therapy With Concurrent Chemotherapy in Patients With Locally Advanced Non–Small-Cell Lung Cancer
    (American Medical Association, 2017-10-01) Kong, Feng-Ming; Ten Haken, Randall K.; Schipper, Matthew; Frey, Kirk A.; Hayman, James; Gross, Milton; Ramnath, Nithya; Hassan, Khaled A.; Matuszak, Martha; Ritter, Timothy; Bi, Nan; Wang, Weili; Orringer, Mark; Cease, Kemp B.; Lawrence, Theodore S.; Kalemkerian, Gregory P.; Radiation Oncology, School of Medicine
    IMPORTANCE Our previous studies demonstrated that tumors significantly decrease in size and metabolic activity after delivery of 45 Gy of fractionated radiatiotherapy (RT), and that metabolic shrinkage is greater than anatomic shrinkage. This study aimed to determine whether 18F-fludeoxyglucose–positron emission tomography/computed tomography (FDG-PET/CT) acquired during the course of treatment provides an opportunity to deliver higher-dose radiation to the more aggressive areas of the tumor to improve local tumor control without increasing RT-induced lung toxicity (RILT), and possibly improve survival. OBJECTIVE To determine whether adaptive RT can target high-dose radiation to the FDG-avid tumor on midtreatment FDG-PET to improve local tumor control of locally advanced non–small-cell lung cancer (NSCLC). DESIGN, SETTING, AND PARTICIPANTS A phase 2 clinical trial conducted at 2 academic medical centers with 42 patients who had inoperable or unresectable stage II to stage III NSCLC enrolled from November 2008, to May 2012. Patients with poor performance, more than 10% weight loss, poor lung function, and/or oxygen dependence were included, providing that the patients could tolerate the procedures of PET scanning and RT. INTERVENTION Conformal RT was individualized to a fixed risk of RILT (grade >2) and adaptively escalated to the residual tumor defined on midtreatment FDG-PET up to a total dose of 86 Gy in 30 daily fractions. Medically fit patients received concurrent weekly carboplatin plus paclitaxel followed by 3 cycles of consolidation. MAIN OUTCOMES AND MEASURES The primary end point was local tumor control. The trial was designed to achieve a 20% improvement in 2-year control from 34% of our prior clinical trial experience with 63 to 69 Gy in a similar patient population. RESULTS The trial reached its accrual goal of 42 patients: median age, 63 years (range, 45–83 years); male, 28 (67%); smoker or former smoker, 39 (93%); stage III, 38 (90%). Median tumor dose delivered was 83 Gy (range, 63–86 Gy) in 30 daily fractions. Median follow-up for surviving patients was 47 months. The 2-year rates of infield and overall local regional tumor controls (ie, including isolated nodal failure) were 82% (95% CI, 62%–92%) and 62% (95% CI, 43%–77%), respectively. Median overall survival was 25 months (95% CI, 12–32 months). The 2-year and 5-year overall survival rates were 52% (95% CI, 36%–66%) and 30% (95% CI, 16%–45%), respectively. CONCLUSIONS AND RELEVANCE Adapting RT-escalated radiation dose to the FDG-avid tumor detected by midtreatment PET provided a favorable local-regional tumor control. The RTOG 1106 trial is an ongoing clinical trial to validate this finding in a randomized fashion. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01190527