Browsing by Author "Windsor, Jack"

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    Combined Effects of Soda Drinks and Nicotine on Streptococcus Mutans Metabolic Activity and Biofilm Activity
    (2019) Mokeem, Lamia Sami; Gregory, Richard; Cook, Norman Blaine; Windsor, Jack; Eckert, George
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    Nicotine Upregulates Coaggregation of Candida albicans and Streptococcus mutans
    (Wiley, 2017) Ashkanane, Ali; Gomez, Grace F.; Levon, John; Windsor, Jack; Eckert, George J.; Gregory, Richard L.; Biomedical and Applied Sciences, School of Dentistry
    Purpose Denture stomatitis is a condition of painless inflammation of denture-bearing mucosa. Reports indicate that nicotine, the major psychoactive ingredient in tobacco, increases growth of Streptococcus mutans and Candida albicans in denture biofilm. The purpose of this study was to determine the in vitro effects of nicotine on coaggregation of C. albicans with S. mutans. Material and Methods C. albicans strain ATCC 10231, S. mutans strain UA159 (ATTC 700610), and nicotine dilutions (ranging from 0 to 32 mg/ml) were used for this study. Both microorganisms were grown for 24 hours in dilutions of nicotine (0 to 32 mg/ml) made in tryptic soy broth (TSB) or TSB supplemented with 1% sucrose (TSBS; S. mutans) or yeast peptone dextrose broth (YPD; C. albicans). Suspensions of the nicotine-treated cells were prepared, mixed together and incubated for up to 24 hours to determine if there was an increase in coaggregation of nicotine-treated cells compared to the no nicotine control cells. Qualitative analysis of coaggregation was performed using a visual aggregation assay and light microscopic observation. A spectrophotometric assay was used to provide a quantitative analysis of the coaggregation. Results The visual aggregation assay indicated a significant increase in coaggregation between C. albicans and S. mutans with increasing incubation time (0 to 24 hours) and nicotine concentrations (0 to 4 mg/ml). Microbial growth in nicotine at 4 mg/ml demonstrated a significant increase in coaggregation after 24 hours of incubation. The numbers of coaggregated S. mutans/C. albicans cells exhibited a significant increase with incubation time and nicotine concentrations when the samples were examined microscopically. More coaggregation of S. mutans and C. albicans was observed with incubation time and increased nicotine compared to the 0 mg/ml nicotine group. There was a noticeable increase of coaggregation when cells were grown in TSBS compared to TSB. Absorbance of nicotine-treated cells (0.25 to 4 mg/ml) exhibited a decrease in values compared to 0 mg/ml at 0 hours of incubation, confirming increased coaggregation. Conclusion These results demonstrated the effect of nicotine in increasing the coaggregation of S. mutans with C. albicans. Coaggregation increased with incubation time and nicotine concentration. Coaggregation was increased with S. mutans grown in TSBS compared to TSB, suggesting that growth in sucrose media leads to an increase in receptors responsible for coaggregation.
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    The Effects of Two rhPDGF-BB Applications on Periodontal Ligament Cell’s Proliferation and VEGF Expression
    (2024) Velgis, Raziel; Windsor, L. Jack; John, Vanchit; Batra, Chadni; Batra, Chandni; John, Vanchit; Batra, Chandni; Windsor, Jack
    Background: Platelet derived growth factor (PDGF) has been shown since the late 1980s to play a major role in periodontal regeneration. PDGF has five isoforms and the isoform PDGF-BB has been found to be the most effective. Animal studies evaluating release kinetics of purified recombinant human platelet-derived growth factor (rh-PDGF-BB), demonstrated that 90% of rh-PDGF-BB was depleted from sites within 72 hours after implantation. Thus, the aim of this in-vitro study was to evaluate the effects of two rhPDGF-BB applications on periodontal ligament fibroblasts proliferation and VEGF expression. Materials & Methods: Periodontal ligament (PDL) cells were seeded in multiple 6 well plates and split into 3 groups. Group 1 served as a control that received no rh-PDGF-BB. Group 2 was given an initial dose of 10 ng/ml rhPDGF-BB on day 1 and none on day 3. Group 3 received a dose of 10 ng/ml rhPDGF-BB on day 1 and a second dose on day 3. On day 3, half of the plates were stopped and media collected was used for LDH, WST-1 and VEGF ELISA analysis for evaluation of VEGF expression, cellular proliferation and cytotoxicity. Plain media was then added to groups 1 and 2 while group 3 received media with rh-PDGF-BB. On day 6, the collected media was used for ELISA, WST-1 and LDH assays. Results: PDL cell proliferation was not significantly different between any group studied (p=0.689). VEGF expression was increased in group 2 and 3 on day 3 compared to group 1 (p=0.005). There was no difference between groups 1 and 2 on day 6 (p=0.977). Conclusion: The addition of rhPDGF-BB to PDL cells did not increase proliferation at any time point. A single application of rhPDGF-BB increased the expression of VEGF from PDL cells; however, an additional application did not significantly increase the expression of VEGF.