Biomedical subjects

Svetlana Farrell

Publications and source records attributed to Svetlana Farrell.

5 recordsLinked to original sources

PubMed2006

Oral malodor reduction by a combination of chemotherapeutical and mechanical treatments.

Bacterial proliferation and plaque accumulation on the surface of the tongue are major factors contributing to oral malodor. In this research, we used subjective and objective methods to evaluate the breath benefit of a triclosan-containing dentifrice (Blend-a-Med Complete Night) with and without tongue brushing in a randomized, examiner-blinded, three-period crossover clinical trial. Twenty-nine adults (mean age 40.2 years) with morning malodor were randomly assigned to a treatment sequence: triclosan dentifrice, triclosan dentifrice plus tongue brushing, and a control dentifrice (Crest Cavity Protection). The subjects used each product four times in 27 h with a 2-day wash-out period between treatments. Halimeter measurements were taken at baseline and at 3, 24 and 27 h. Subject questionnaire data assessing the breath quality were collected at 24 and 27 h. Both triclosan regimens showed significant improvement in oral malodor (p < 0.03) relative to the control. Significant (p = 0.035) malodor benefit was observed when tooth brushing with triclosan dentifrice was supplemented with tongue brushing. The triclosan dentifrice was associated with significant improvement (p < 0.05) in morning mouth feel and feeling of clean and fresh breath during the day relative to the control. There were no adverse events reported. The triclosan dentifrice was effective against overnight and daytime oral malodor. Supplementing routine brushing with tongue brushing resulted in additional breath improvement and breath benefits of the triclosan dentifrice were first-person noticeable.

Adult↗

PubMed2006

Comparative plaque removal efficacy of a dual-action power toothbrush and a manual tooth: effects by tooth type.

PURPOSE: To evaluate the plaque removal efficacy of a dual action power toothbrush (Crest SpinBrush Pro Clean) relative to an ADA reference manual toothbrush. In addition to overall plaque removal, emphasis was put on plaque reduction around the gingival margin, interproximal areas of the tooth and in the posterior segment of the dentition. METHODS: The study was a randomized, examiner-blind, two-treatment, four-period, crossover design. After an informed consent, 50 healthy volunteers were randomized to four treatment sequences and used each toothbrush twice according to their assigned treatment sequence. At every visit, plaque removal was assessed at baseline and after a single brushing using the Rustogi-modified Navy Plaque Index that allows estimation of interproximal plaque and plaque at the gingival margin. Self-reported and examiner-observed adverse events were collected at every visit. Mean Plaque Index (MPI) scores were calculated for the whole mouth, gingival region, interproximal region and different areas of the dentition using an analysis of covariance for crossover design with baseline plaque score as the covariate. RESULTS: 49 subjects provided complete data and were included in the analysis. Baseline MPI scores were not significantly different between the groups for any investigated tooth region or dentition area. Following a single brushing, the power toothbrush provided a reduction of 43% (P< 0.001) for the whole mouth MPI, 43% (P< 0.001) for the gingival margin MPI and 65% (P< 0.001) for the interproximal MPI relative to a manual brush. Use of the power toothbrush resulted in a significant reduction of whole-mouth and gingival margin MPI across all areas of the dentition compared to a manual toothbrush (P< 0.001). The power toothbrush also had superior interproximal plaque removal efficacy compared to the manual toothbrush for molars (P< 0.001, with 118% greater removal score). Both brushes were well tolerated.

Adult↗

PubMed2005

Immunoassay for B. globigii spores as a model for detecting B. anthracis spores in finished water.

The 2001 anthrax alarm in the US raised concerns about the Nation's preparedness to the threat of bioterrorism, and the demand for early warning systems that might be used in the case of a biological attack continues to grow. Here we develop an ultra-sensitive rapid detection method for B. globigii(BG) spores, the simulant of B. anthracis(BA) spores. BG spores were detected by a bead-based sandwich immunoassay with fluorescence detection. Paramagnetic Dynal beads were used as a solid support, primary antibody was attached to the beads by streptavidin-biotin coupling and the secondary antibody had an alkaline phosphatase (AP) enzyme label. Enzymatic conversion of fluorescein diphosphate (FDP) to fluorescein by AP was measured in real time with lambda(ex)= 490 nm and lambda(em)= 520 nm. The assay was linear from 2.6 x 10(3)-5.6 x 10(5) BG spores mL(-1), and the detection limit was 2.6 x 10(3) spores mL(-1) or 78 spores. All reagent concentrations and incubation times were optimized. The assay time from the moment the spores were introduced to the system was 30 min, and real-time fluorescence detection was done in less than 1 min. Formation of the BG spores-capture beads complex was confirmed by environmental scanning electron microscopy (ESEM). BG spores were detected successfully when doped into Cincinnati tap water to demonstrate the applicability of the developed method to detect the spores in non-buffered media.

Animals↗

PubMed2005

Bacillus globigii bugbeads: a model simulant of a bacterial spore.

Nonpathogenic microorganisms are often used as simulants of biological pathogens during the initial phase of detection method development. While these simulants approximate the size, shape, and cellular organization of the microorganism of interest, they do not resemble its surface protein content, a factor particularly important in methods based on immunorecognition. Here, we develop and detect an artificial bacterial spore--B. globigii (BG) Bugbead-a particle mimicking the antigenic surface of BG spores. Two methods of spore protein extraction were compared both quantitatively (by protein concentration assay) and qualitatively (by SDS-PAGE and Western blot): extraction by mechanical disruption and extraction by chemical decoating. The former method was more efficient in producing more protein and a greater number of antigens. BG Bugbeads were made by conjugating the extracted proteins to 0.8-microm carboxyl-coated polystyrene particles via carbodiimide coupling. BG Bugbeads were successfully detected by a bead-based enzyme-labeled immunoassay with fluorescence detection with a detection limit of 6.9 x 10(3) particles/mL. Formation of the Bugbead-capture bead complex was confirmed by ESEM. The concept of a harmless artificial spore can be applied to developing improved simulants for pathogenic spore-forming microorganisms such as B. anthracis, C. botulinum, and B. cereus, which can to be used for method validation, instrument calibration, and troubleshooting.

Antigens, Bacterial↗

PubMed2004

Bead-based immunoassays with microelectrode detection.

The suitability of a microelectrode as the detector for a small-volume, bead-based enzyme-labeled immunoassay for later use in a microfluidic device was investigated. The microelectrode helps to overcome consumption of the electroactive species by the electrode (depletion) that is encountered with macroelectrodes such as the rotating disk electrode (RDE) and allows the volume of the detection cell to be reduced. Microelectrodes also allow the chemical reactions to be monitored in real time due to the electrodes' close proximity to the assay site. A bead-based sandwich immunoassay for mouse IgG was developed with alkaline phosphatase (AP) as the enzyme label, p-aminophenyl phosphate (PAPP) as the enzyme substrate, and microelectrode detection. The diffusion coefficient of the product of enzymatic hydrolysis, p-aminophenol (PAP), was determined to be 7.2+/-0.9 x 10(-6) cm(2) s(-1). The detection limits were determined for free (0.52 ng mL(-1)) and bead-bound AP (10 ng mL(-1)). The number of binding sites for AP per bead was calculated to be 9.6 x 10(4) molecules/bead, and under saturation conditions the minimum detectable number of beads was 2500. Lower detection limits could be achieved with the microelectrode than the RDE while maintaining similar reproducibility. The microelectrode also made it possible to work with lower sample volumes (down to 10 microL) than with the RDE (minimum volume of 40 microL). Depletion of PAP was not observed with the microelectrode. The results obtained here with a microelectrode showed great promise for later use of microelectrodes in microfluidic devices with limited sample volumes. RDE detection cannot be used in a microfluidic system due to its complex set-up that includes a motor for rotation.

Alkaline Phosphatase↗