Browsing by Subject "Anti-infective agents"

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    In-vitro evaluation of the effectiveness of polyphenols based strawberry extracts for dental bleaching
    (Springer Nature, 2023-03-13) Kohli, Shivani; Bhatia, Shekhar; Banavar, Spoorthi Ravi; Al‑Haddad, Afaf; Kandasamy, Murugesh; Bin Qasim, Syed Saad; Kit‑Kay, Mak; Pichika, Mallikarjuna Rao; Daood, Umer; Medicine, School of Medicine
    To formulate a dental bleaching agent with strawberry extract that has potent bleaching properties and antimicrobial efficacy. Enamel specimens (3 × 3 × 2 mm3) were prepared. Quaternary Ammonium Silane (CaC2 enriched) was homogenized with fresh strawberries: Group 1: supernatant strawberry (10 g) extract < Group 2: supernatant strawberry (10 g) extract + 15%HA (Hydroxyapatite) < Group 3: supernatant strawberry (10 g) extract + 15% (HA-2%k21) < Group 4: supernatant strawberry (20 g) extract only (20 g strawberries) < Group 5: supernatant strawberry (20 g) extract + 15% HA < Group 6: supernatant strawberry (20 g) extract + 15% (HA-2%K21) < Group 7: In-office Opalescence Boost 35%. Single-colony lactobacillus was examined using confocal microscopy identifying bacterial growth and inhibition in presence of bleaching agents using 300 µL aliquot of each bacterial culture. Images were analysed by illuminating with a 488 nm argon/helium laser beam. Colour difference (∆E00) was calculated using an Excel spreadsheet implementation of the CIEDE2000 colour difference formula and colour change measured between after staining and after bleaching. Scanning electron microscope was used to image specimens. Raman spectra were collected, and enamel slices were used for STEM/TEM analysis. HPLC was used for strawberry extract analysis. Nano-indentation was performed and X-ray photoelectron spectroscopy. Antioxidant activity was determined along with molecular simulation. hDPSCs were expanded for Alamar Blue Analysis and SEM. Mean colour change was significantly reduced in group 1 compared to other groups (p < 0.05). CLSM showed detrimental effects of different strawberry extracts on bioflms, especially with antimicrobial (p < 0.05). Groups 1, 2 and 3 showed flatter/irregular surfaces with condensation of anti-microbial in group 3. In strawberry specimens, bands predominate at 960 cm-1. HPLC determined the strawberry extracts content. Molecular simulation verified interaction between calcium and polyphenol components. XPS peak-fitted high-resolution corresponding results of Ca2p3/2 and Ca2p1/2 for all k21 groups. Combination of 10 g strawberry extract supernatant and 15% (hydroxyapatite 2%k21) improved the whiteness and provided additional antimicrobial potential. The novel strawberry extract and antimicrobial based dental formulation had immediate bleaching effect without promoting significant changes in enamel morphology.
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    Lack of Consistent Malaria Incidence Hotspots in a Highland Kenyan Area During a 10-Year Period of Very Low and Unstable Transmission
    (American Society of Tropical Medicine and Hygiene, 2020-12) Hamre, Karen E.S.; Hodges, James S.; Ayodo, George; John, Chandy C.; Pediatrics, School of Medicine
    The use of spatial data in malaria elimination strategies is important to understand whether targeted interventions against malaria can be used, particularly in areas with limited resources. We previously documented consistent areas of increased malaria incidence in the epidemic-prone area of Kipsamoite in highland Kenya from 2001 to 2004. In this area and a neighboring subcounty (Kapsisiywa), malaria incidence decreased substantially in 2005, going from peak incidence of 31.7 per 1,000 persons in June 2004 to peak incidence of 7.4 per 1,000 persons in May 2005. Subsequently, the use of indoor residual spraying and artemisinin combination therapy malaria treatment led to a possible interruption of malaria transmission for a 13-month period from 2007 to 2008, after which the incidence returned to very low levels until an epidemic in April-July 2013. In the present study, we used novel kernel density estimation methods to determine whether areas of increased malaria incidence were consistent in six periods of peak incidence from 2003 to 2013, and to assess patterns of incidence in the period before versus. after the period of possible interruption. Areas of highest incidence differed during peak malaria transmission periods over the years 2003-2013, and differed before and after the potential malaria interruption. In this epidemic-prone region with very low malaria transmission, consistent malaria "hotspots" identified in a time of higher transmission are no longer present. Ongoing assessment of spatial malaria epidemiology to identify and target current areas of elevated malaria risk may be important in campaigns to control or eliminate malaria in epidemic-prone areas.
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    Monitoring, characterizing, and preventing microbial degradation of ignitable liquids on soil
    (2013) Turner, Dee Ann; Goodpaster, John V. (John Vincent); Michalski, Greg M.; Blacklock, Brenda J.; Siegel, Jay A.; Long, Eric C. (Eric Charles)
    Organic-rich substrates such as soil provide an excellent carbon source for bacteria. However, hydrocarbons such as those found in various ignitable liquids can also serve as a source of carbon to support bacterial growth. This is problematic for fire debris analysis as samples may be stored at room temperature for extended periods before they are analyzed due to case backlog. As a result, selective loss of key components due to bacterial metabolism can make identifying and classifying ignitable liquid residues by their chemical composition and boiling point range very difficult. The ultimate goal of this project is to preserve ignitable liquid residues against microbial degradation as efficiently and quickly as possible. Field and laboratory studies were conducted to monitor microbial degradation of gasoline and other ignitable liquids in soil samples. In addition to monitoring degradation in potting soil, as a worst case scenario, the effect of soil type and season were also studied. The effect of microbial action was also compared to the effect of weathering by evaporation (under nitrogen in the laboratory and by the passive headspace analysis of the glass fragments from the incendiary devices in the field studies). All studies showed that microbial degradation resulted in the significant loss of n-alkanes and lesser substituted alkylbenzenes predominantly and quickly, while more highly substituted alkanes and aromatics were not significantly affected. Additionally, the residential soil during the fall season showed the most significant loss of these compounds over the course of 30 days. To combat this problem, a chemical solution is to be immediately applied to the samples as they are collected. Various household and commercial products were tested for their efficacy at low concentrations to eliminate all living bacteria in the soil. Triclosan (2% (w/v) in NaOH) proved to be the most effective at preserving ignitable liquid residues for at least 30 days.