Jong-Hoon Choi

In vitro antimicrobial activity of a chitooligosaccharide mixture against Actinobacillus actinomycetemcomitans and Streptococcus mutans

The purpose of this study was to evaluate the in vitro antibacterial activity of a chitooligosaccharide mixture (MW 2000-30000 Da) with a deacetylation degree of 91.5% against two representative oral pathogens, Actinobacillus actinomycetemcomitans and Streptococcus mutans. A 0.1% concentration of the chitooligosaccharides (derived from the exoskeletons of marine crustaceans) was used to estimate antibacterial activity. Approximately 2 logcolony forming units (CFU)/ml of A. actinomycetemcomitans were inactivated by 0.1% chitosan after 30 min, while 120 min exposure inactivated about 4.5 logCFU/ml of this organism. In contrast, the level of inactivation against S. mutans was less than 0.5 logCFU/ml after an exposure of up to 120 min. Electron microscopy showed that the exposure of A. actinomycetemcomitans to the chitooligosaccharides resulted in the disruption of cell membranes and that it could be considered for the treatment of periodontal diseases associated with A. actinomycetemcomitans.

Five highly informative X-chromosomal STRs in Koreans

The five X-chromosomal short tandem repeats (STRs) GATA172D05, HPRTB, DXS8377, DXS101 and HumARA were analyzed in 150 males and 150 females from Korea. Markers were amplified in a quadruplex and a monoplex PCR reaction with fluorescently labeled primers. For accurate and reproducible STR typing, sequenced allelic ladders were constructed and a Genotyper macro was programmed. Some differences were found on comparing the allele frequencies of Koreans with those of other populations in DXS8377, DXS101 and HumARA. The forensic efficiency parameters showed that the five X-linked STRs are highly informative for forensic application in Koreans.

Anti-inflammatory effects of licorice and roasted licorice extracts on TPA-induced acute inflammation and collagen-induced arthritis in mice.

The anti-inflammatory activity of licorice (LE) and roated licorice (rLE) extracts determined in the murine phorbol ester-induced acute inflammation model and collagen-induced arthritis (CIA) model of human rheumatoid arthritis. rLE possessed greater activity than LE in inhibiting phorbol ester-induced ear edema. Oral administration of LE or rLE reduced clinical arthritis score, paw swelling, and histopathological changes in a murine CIA. LE and rLE decreased the levels of proinflammatory cytokines in serum and matrix metalloproteinase-3 expression in the joints. Cell proliferation and cytokine secretion in response to type II collagen or lipopolysaccharide stimulation were suppressed in spleen cells from LE or rLE-treated CIA mice. Furthermore, LE and rLE treatment prevented oxidative damages in liver and kidney tissues of CIA mice. Taken together, LE and rLE have benefits in protecting against both acute inflammation and chronic inflammatory conditions including rheumatoid arthritis. rLE may inhibit the acute inflammation more potently than LE.

The diversity of dental patterns in the orthopantomography and its significance in human identification

The primary aim of this study was to evaluate the utility of orthopantomography for human identification. Three hundred orthopantomograms were randomly selected from those stored at Dental Hospital of Yonsei University in Seoul. Dental patterns observed in the orthopantomograms were converted into eight codes and their diversity was calculated. The diversity of dental patterns in the orthopantomogram data was 99.92% for full dentition and the diversity of mandible (99.28%) was slightly higher value than that of maxilla (98.22%). In the case of molars and premolars in both jaws, the diversity values ranged from 92.13% to 96.04%. It was founded that orthopantomography is a valuable means of personal identification not only based on full dentition but also when only the posterior teeth are available. The present study indicates that orthopantomography is excellent means of forensic identification.

Effect of sodium lauryl sulfate on recurrent aphthous stomatitis: a randomized controlled clinical trial.

OBJECTIVE To compare the effects of sodium lauryl sulfate (SLS)-free and SLS-containing dentifrice in patient with recurrent aphthous stomatitis (RAS). MATERIALS AND METHODS The design of this study was a double-blind crossover trial. The 90 subjects were divided into three groups: group I used SLS-free (a commercially available SLS-free dentifrice) and SLS-A (SLS-free + 1.5% SLS), group II used SLS-A and SLS-B (a commercially available 1.5% SLS-containing dentifrice), and group III used SLS-free and SLS-B. The subjects used one of the two assigned dentifrices for 8 weeks and then the other for the following 8 weeks. The order of the dentifrices used was selected at random, and there was a 2-week washout period between the two phases. The clinical parameters (number of ulcers, number of episodes, duration of ulcers, mean pain score) were compared between the two phases for each group. RESULTS The number of ulcers and episodes did not differ significantly between SLS-A, SLS-B, and SLS-free. Only duration of ulcers and mean pain score was significantly decreased during the period using SLS-free. CONCLUSION Although SLS-free did not reduce the number of ulcers and episodes, it affected the ulcer-healing process and reduces pain in daily lives in patients with RAS.

Clinical assessment of oral malodor using autofluorescence of tongue coating

OBJECTIVES The aim of this study was to evaluate whether a new method using quantitative light-induced fluorescence-digital (QLF-D) was appropriate for the diagnosis of oral malodor by quantifying the fluorescence of tongue coating. METHODS This study examined 103 healthy subjects who have an oral malodor as a main complaint. The levels of oral malodor were measured by organoleptic scores (OLS) and volatile sulfur compound (VSC) levels. The fluorescent tongue coating images captured by QLF-D were quantified as the integrated fluorescence score (IF score) by multiplying the intensity and area of fluorescence. The correlations between the fluorescence parameters and OLS as well as VSC levels and the diagnostic accuracy of the IF score were evaluated. RESULTS The IF score of tongue coating showed a significant positive correlation with the OLS (r=0.54, p<0.01) and the VSC levels (r=0.49, p<0.01). This score was significantly differed with the level of oral malodor (p<0.001), and its AUC was 0.72 in identifying the patient with definite oral malodor (≥OLS 2). CONCLUSIONS A new method quantifying tongue coating fluorescence detected by QLF-D can be used to diagnose oral malodor and assess its severity in the clinical practice.

Alteration of Expression of Ca2+ Signaling Proteins and Adaptation of Ca2+ Signaling in SERCA2+/- Mouse Parotid Acini

Purpose The sarco/endoplasmic reticulum Ca2+-ATPase (SERCA), encoded by ATP2A2, is an essential component for G-protein coupled receptor (GPCR)-dependent Ca2+ signaling. However, whether the changes in Ca2+ signaling and Ca2+ signaling proteins in parotid acinar cells are affected by a partial loss of SERCA2 are not known. Materials and Methods In SERCA2+/- mouse parotid gland acinar cells, Ca2+ signaling, expression levels of Ca2+ signaling proteins, and amylase secretion were investigated. Results SERCA2+/- mice showed decreased SERCA2 expression and an upregulation of the plasma membrane Ca2+ ATPase. A partial loss of SERCA2 changed the expression level of 1, 4, 5-tris-inositolphosphate receptors (IP3Rs), but the localization and activities of IP3Rs were not altered. In SERCA2+/- mice, muscarinic stimulation resulted in greater amylase release, and the expression of synaptotagmin was increased compared to wild type mice. Conclusion These results suggest that a partial loss of SERCA2 affects the expression and activity of Ca2+ signaling proteins in the parotid gland acini, however, overall Ca2+ signaling is unchanged.

Plaque autofluorescence as potential diagnostic targets for oral malodor

Abstract. The aim of this study was to determine whether the degree of tongue and interdental plaque can be used to assess oral malodor by quantifying their fluorescence as detected using quantitative light-induced fluorescence (QLF) technology. Ninety-nine subjects who complained of oral malodor were included. The level of oral malodor was quantified using the organoleptic score (OLS) and the concentration of volatile sulfur compounds (VSCs). The fluorescence properties of tongue and interdental plaque were quantified as scores calculated by multiplying the intensity and area of fluorescence in QLF-digital images, and the combined plaque fluorescence (CPF) score was obtained by summing the scores for the two regions. The associations of the scores with malodor levels and the diagnostic accuracy of the CPF score were analyzed. The two plaque fluorescence scores and their combined score differed significantly with the level of oral malodor (p<0.001). The CPF score was moderately correlated with OLS (r=0.64) and VSC levels (r=0.54), and its area under the receiver operating characteristic curve was 0.77 for identifying subjects with definite oral malodor (OLS≥2). In conclusion, plaque fluorescence from tongue and interdental sites as detected using QLF technology can be used to assess the level of oral malodor.

Toothache Caused by Sialolithiasis of the Submandibular Gland

Received June 14, 2018 Revised August 10, 2018 Accepted August 13, 2018 Sialolithiasis is the most frequent disease of the salivary glands, causing swelling and/or pain of the affected site. We report a 44-year-old woman who presented with severe pain in the lower left second molar region without swelling. Sialoliths on her left submandibular gland were confirmed by radiographic examinations. After robot-assisted sialoadenectomy, the pain did not recur but remained facial paralysis and unaesthetic scar.