PURPOSE: Most of studies dealing with abfractions are limited to the buccal surfaces of the teeth. In this study, we analyzed the cause for abfraction by investigating the incidence of palatal side abfractions in maxillary posterior teeth. MATERIALS AND METHODS: We investigated a total of 3193 maxillary posterior teeth by an intraoral examination, model observation, and observation of virtual model fabricated using model scanning. We recorded the results and classified them depending on the type of teeth, age, gender, and side of arches. We also performed Chi-square test to evaluate the statistical significance among the groups (α = 0.05). RESULTS: The incidence of palatal side abfraction of the maxillary molars (10.8%) was higher than the premolars (6.8%), and among them, the incidence of the 1st molars (39.1%) were the highest. The incidence of palatal side abfraction increased with age and was statistically significant (P < 0.05). There was no statistical significance in the difference by gender (P > 0.05); in the case of arches, left arch showed higher incidence and it was statistically significant (P < 0.05). CONCLUSION Palatal side abfraction in maxillary posterior teeth was frequently observed in the maxillary 1st molars, and the incidence increased with age. This result suggests that the main reason for abfraction is due to occlusal force.

Inflammation is a protective mechanism against pathogens, but if maintained continuously, it destroys tissue structures. Aggregatibacter actinomycetemcomitans is a gram-negative, facultative anaerobic bacterium often found in severe periodontitis. A. actinomycetemcomitans invades epithelial cells and triggers inflammatory response in the immune cells. In this study, we investigated the effect of water-soluble rosehip extract on A. actinomycetemcomitans-induced inflammatory responses. A human monocytic cell line (THP-1) was differentiated to macrophages by phorbol 12-mystristate 13-acetate treatment. The cytotoxic effect of extract was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The effects of extract on bacterial growth were examined by measuring the optical densities using a spectrophotometer. THP-1-derived macrophages were infected A. actinomycetemcomitans after extract treatment, and culture supernatants were analyzed for cytokine production using enzyme-linked immunosorbent assay. Protein expression was measured by western blotting. Extract was not toxic to THP-1-derived macrophages. A. actinomycetemcomitans growth was inhibited by 1% extract. The extract suppressed A. actinomycetemcomitans-induced tumor necrosis factor-α, interleukin (IL)-1β, and IL-8 production. It also decreased mitogen-activated protein kinase (MAP kinase) and nuclear factor-κB (NF-κB) phosphorylation. Moreover, the extract inhibited the expression of inflammasome components, including nucleotide-binding oligomerization domain-like receptor pyrin domain-containing protein 3, Absent in Melanoma 2, and apoptosis associated speck-like protein containing a CARD. And cysteine-aspartic proteases-1 and IL-1β expression were decreased by the extract. In summary, extract suppressed A. actinomycetemcomitans growth and decreased inflammatory cytokine production by inhibiting activation of MAP kinase, NF-κB, and inflammasome signaling. Rosehip extract could be effective in the treatment of periodontal inflammation induced by A. actinomycetemcomitans infection.

BACKGROUND: Periodontitis is an inflammatory disease characterized by the breakdown of tooth-supporting tissues, leading to tooth loss. Aggregatibacter actinomycetemcomitans are major etiologic bacterium causing aggressive periodontitis. Ursodeoxycholic acid (UDCA), a hydrophilic gall bladder acid, has been used as an effective drug for various diseases related to immunity. The aim of this study was to investigate the effect of UDCA on the inflammatory response induced by A. actinomycetemcomitans. METHODS: A human acute monocytic leukemia cell line (THP-1) was differentiated to macrophage- like cells by treatment with phorbol 12-mystristate 13-acetate (PMA) and used for all experiments. The cytotoxic effect of UDCA was examined by MTT assay. THP-1 cells were pretreated with UDCA for 30 min before A. actinomycetemcomitans infection and the culture supernatant was analyzed for various cytokine production by ELISA. The effect of UDCA on bacterial growth was examined by measuring optical densities using a spectrophotometer. RESULTS: UDCA showed no cytotoxic effect on THP-1 cells, up to 80 µM Ed highlight: Please confirm technical meaning. UDCA pretreatment inhibited the A. actinomycetemcomitans-induced IL-1β, TNF-α, and IL-17A secretion in a dosedependent manner. UDCA also inhibited IL-21 production at 60 µM. The production of IL-12 and IL-4 was not influenced by A. actinomycetemcomitans infection. CONCLUSION: These findings indicate that UDCA inhibits the production of inflammatory cytokines involved in innate and Th17 immune responses in A. actinomycetemcomitans-infected THP-1-derived macrophages, which suggests its possible use for the control of aggressive periodontitis.
Aggregatibacter actinomycetemcomitans* ; Aggregatibacter* ; Aggressive Periodontitis ; Cell Line ; Cytokines ; Enzyme-Linked Immunosorbent Assay ; Humans ; Interleukin-12 ; Interleukin-17 ; Interleukin-4 ; Leukemia, Monocytic, Acute ; Macrophages ; Periodontitis ; Tooth Loss ; Urinary Bladder ; Ursodeoxycholic Acid*

BACKGROUND: Periodontitis is generally a chronic disorder characterized by the breakdown of tooth-supporting tissues. P. gingivalis, a Gram-negative anaerobic rod, is one of the major pathogens associated with periodontitis. Frequently, P. gingivalis infection leads to cell death. However, the correlation between P. gingivalis–induced cell death and periodontal inflammation remains to be elucidated. Among cell deaths, the death of immune cells appears to play a significant role in inflammatory response. Thus, the aim of this study was to examine P. gingivalis–induced cell death, focusing on autophagy and apoptosis in THP-1 cells. METHODS: Human acute monocytic leukemia cell line (THP-1) was used for all experiments. Autophagy induced by P. gingivalis in THP-1 cells was examined by Cyto ID staining. Intracellular autophagic vacuoles were observed by fluorescence microscopy using staining Acridine orange (AO); and 3-methyladenine (3-MA) was used to inhibit autophagy. Total cell death was measured by LDH assay. Cytokine production was measured by an ELISA method. RESULTS: P. gingivalis induced autophagy in an MOI-dependent manner in THP-1 cells, but 3-MA treatment decreased autophagy and increased the apoptotic blebs. P. gingivalis infection did not increase apoptosis compared to the control cells, whereas inhibition of autophagy by 3-MA significantly increased apoptosis in P. gingivalis-infected THP-1 cells. Inhibition of autophagy by 3-MA also increased total cell deaths and inflammatory cytokine production, including IL-1β and TNF-α. CONCLUSION: P. gingivalis induced autophagy in THP-1 cells, but the inhibition of autophagy by 3-MA stimulated apoptosis, leading to increased cell deaths and pro-inflammatory cytokines production. Hence, the modulation of cell deaths may provide a mechanism to fight against invading microorganisms in host cells and could be a promising way to control inflammation.
Acridine Orange ; Apoptosis ; Autophagy ; Blister ; Cell Death* ; Cell Line ; Cytokines ; Enzyme-Linked Immunosorbent Assay ; Humans ; Inflammation ; Leukemia, Monocytic, Acute ; Macrophages ; Methods ; Microscopy, Fluorescence ; Periodontitis ; Porphyromonas gingivalis* ; Porphyromonas* ; Vacuoles

Periodontitis is generally a chronic disorder characterized by breakdown of tooth-supporting tissues, producing dentition loss. Porphyromonas gingivalis (P. gingivalis), a Gram-negative anaerobic rod, is one of the major pathogens associated with periodontitis. Neutrophils are first line defense cells in the oral cavity that play a significant role in inflammatory response. Xylitol is a known anti-caries agent and has anti-inflammatory effects. In this study, we conducted experiments to evaluate anti-inflammatory effects of xylitol on P. gingivalis infected neutrophils for possible usage in prevention and treatment of periodontal infections. P. gingivalis was intraperitoneally injected and peritoneal lavage was collected for cytokine determination. For in vitro study, neutrophils were collected from mouse peritoneal cells after zymosan injection or bone marrow cells. Neutrophils were stimulated with live P. gingivalis and ELISA was used to determine the effect of xylitol on P. gingivalis induced cytokine production. IL-1β, IL-6, TNF-α concentration and neutrophil population in the peritoneal lavage was increased in P. gingivalis-infected mouse. Peritoneal cells infected with live P. gingivalis revealed significantly increased production of IL-1β, IL-6 and TNF-α at multiplicity of infection of 10. Neutrophils from bone marrow and peritoneal lavage revealed increased production of IL-1β, IL-6 and TNF-α. Xylitol significantly mitigated P. gingivalis induced cytokine production in neutrophils. Findings indicate that xylitol is an anti-inflammatory agent in neutrophils infected with live P. gingivalis, that suggests its use in periodontitis management.
Animals ; Bone Marrow ; Bone Marrow Cells ; Dentition ; Enzyme-Linked Immunosorbent Assay ; In Vitro Techniques ; Inflammation ; Interleukin-6 ; Mice ; Mouth ; Neutrophils ; Periodontitis ; Peritoneal Lavage ; Porphyromonas gingivalis ; Porphyromonas ; Xylitol ; Zymosan

Phagocytosis is a fundamental process in which phagocytes capture and ingest foreign particles including pathogenic bacteria. Several oral pathogens have anti-phagocytic strategies, which allow them to escape from and survive in phagocytes. Impaired bacteria phagocytosis increases inflammation and contributes to inflammatory diseases. The purpose of this study is to investigate the influences of various agents on oral pathogenic phagocytosis. To determine phagocytosis, Streptococcus mutans, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis were stained with 5-(and-6)-carboxyfluorescein diacetate succinimidyl ester (CFSE), and was measured using flowcytometery and confocal microscopy. The influencing factors on phagocytosis were evaluated through the pretreatment of ROS inhibitor (N-acetyl-L-cysteine (NAC)), lysozyme, potassium chloride (KCI) and adenosine triphosphate (ATP) in THP-1 cells. Expression of pro-inflammatory cytokines was determined by enzyme-linked immunosorbent assay (ELISA). The phagocytosis of various bacteria increased in a MOI-dependent manner. Among the tested bacteria, phagocytosis of P. gingivalis showed the highest fluorescent intensity at same infection time. Among the tested inhibitors, the NAC treatment significantly inhibited phagocytosis in all tested bacteria. In addition, NAC treatment indicated a similar pattern under the confocal microscopy. Moreover, NAC treatment significantly increased the bacteria-induced secretion of IL-1β among the tested inhibitors. Taken together, we conclude that the phagocytosis occurs differently depending on each bacterium. Down-regulation by ROS production inhibited phagocytosis and lead increased of oral pathogens-associated inflammation.
Adenosine Triphosphate ; Aggregatibacter actinomycetemcomitans ; Bacteria ; Cytokines ; Down-Regulation ; Enzyme-Linked Immunosorbent Assay ; Fusobacterium nucleatum ; Inflammation ; Macrophages ; Microscopy, Confocal ; Monocytes ; Muramidase ; Phagocytes ; Phagocytosis ; Porphyromonas gingivalis ; Potassium Chloride ; Streptococcus mutans ; United Nations

Objective: An essay test is difficult to carry out because of the effort for hand scoring and the concerns about inter-rater reliability, even though the use of a rubric can increase inter-rater reliability. This study examined the feasibility of an essay test in medical school students and whether the use of a rubric increases inter-rater reliability. Methods: An essay test was given to 51 undergraduate students in the third grade of emergency medicine clinical clerkship. Three raters assessed the essay test independently with a prepared rubric immediately after the test. They then did the same essay test without a rubric three months later. The researchers compared the Pearson’s correlation coefficients between raters. The researchers analyzed the validity comparing the correlation coefficient between the essay test and previous multiple-choice questions (MCQ) and feasibility by acceptance. Results: Fifty-one students took the essay test. The Pearson’s correlation coefficient using rubric between raters 1 and 2, 1 and 3, and 2 and 3 were 0.898 (P<0.001), 0.896 (P<0.001), and 0.856 (P<0.001), respectively. Without a rubric, the correlation coefficients were 0.838 (P<0.001), 0.888 (P<0.001), and 0.824 (P<0.001), respectively. The new essay test showed a positive correlation (0.367) with the previous MCQ, and the evidence for validity and feasibility was acceptable. Conclusion In this study, the rubric did not increase the inter-rater reliability of the essay test. On the other hand, the inter-rater reliability was higher than 0.8, even without a rubric. In addition, the essay test showed evidence of validity and feasibility.

The artery of Percheron is a rare anatomical variant, in which a common trunk arises from one posterior cerebral artery and then branches to supply each of the thalami and the midbrain separately. Occlusion of this artery triggers a bilateral thalamic infarction. The most commonly reported clinical findings are an altered mental status, vertical gaze palsy, and memory impairment. A 51-year-old man was transferred to the emergency department with a sudden loss of consciousness after drinking alcohol. He appeared to be sleeping deeply. His wife insisted that he had not drunk a quantity of alcohol that would render him unconscious. Magnetic resonance imaging of the brain revealed an acute, bilateral, paramedian thalamic infarction. He was admitted and treated with antiplatelet agents. On the following day, four-vessel cerebral angiography revealed stenosis of the left, distal vertebral artery. Three weeks after admission, he was discharged with persistent hypersomnia, memory impairment, and behavioral changes.
Alcoholic Intoxication ; Arteries ; Brain ; Cerebral Angiography ; Coma* ; Constriction, Pathologic ; Disorders of Excessive Somnolence ; Drinking ; Eating* ; Emergency Service, Hospital ; Humans ; Infarction* ; Magnetic Resonance Imaging ; Memory ; Mesencephalon ; Middle Aged ; Paralysis ; Platelet Aggregation Inhibitors ; Posterior Cerebral Artery ; Spouses ; Thalamus ; Unconsciousness ; Vertebral Artery

OBJECTIVES: Heart rate variability (HRV) has gained recognition as a noninvasive marker of autonomic activity. HRV is considered a promising tool in various clinical scenarios. The optimal electrocardiogram (ECG) sampling frequency required to ensure sufficient precision of R–R intervals for HRV analysis has not yet been determined. Here, we aimed to determine the acceptable ECG sampling frequency range by analyzing ECG signals from patients who visited an emergency department with the chief complaint of acute intoxication or overdose. METHODS: The study included 83 adult patients who visited an emergency department with the chief complaint of acute poisoning. The original 1,000-Hz ECG signals were down-sampled to 500-, 250-, 100-, and 50-Hz sampling frequencies with linear interpolation. R–R interval data were analyzed for time-domain, frequency-domain, and nonlinear HRV parameters. Parameters derived from the data on down-sampled frequencies were compared with those derived from the data on 1,000-Hz signals, and Lin's concordance correlation coefficients were calculated. RESULTS: Down-sampling to 500 or 250 Hz resulted in excellent concordance. Signals down-sampled to 100 Hz produced acceptable results for time-domain analysis and Poincaré plots, but not for frequency-domain analysis. Down-sampling to 50 Hz proved to be unacceptable for both time- and frequency-domain analyses. At 50 Hz, the root-mean-squared successive differences and the power of high frequency tended to have high values and random errors. CONCLUSIONS: A 250-Hz sampling frequency would be acceptable for HRV analysis. When frequency-domain analysis is not required, a 100-Hz sampling frequency would also be acceptable.
Adult ; Electrocardiography* ; Emergencies ; Emergency Service, Hospital ; Heart Rate* ; Heart* ; Humans ; Poisoning ; Signal Processing, Computer-Assisted

Objectives: Oral streptococci play a significant role in the development of dental caries. Among them, Streptococcus mutans and Streptococcus sobrinus are the principal causative agents of dental caries. Rheum palmatum is a flowering plant of the family Polygonaceae with several known medicinal properties. However, its effects on oral streptococci have yet to be established. Therefore, we investigated the effects of Rheum palmatum for its potential use as an anticaries agent in inhibiting the growth of streptococci and preventing biofilm formation. Methods: Rheum palmatum extract was diluted with sterile distilled water to obtain various extract concentrations. Several strains of oral bacteria, including S. mutans and S. sobrinus, were treated with the varying concentrations. The effects of the extract on bacterial growth was examined using the viable cell count method. Glucan synthesis was measured using a spectrophotometer at 650 nm optical density. Crystal violet staining was also carried out to observe the effect of the extract on biofilm formation. Results: The growth of S. mutans and S. sobrinus was significantly inhibited by the Rheum palmatum solution at concentrations of 0.3% or more compared to the control group. The viable cell count results indicated that the number of bacterial colonies decreased 1.2-fold and 1.7-fold at concentrations of 1.25% and 2.5%, respectively, compared to the control group. Biofilm formation by S. mutans and S. sobrinus was suppressed more than 20-fold compared to the control group at extract concentrations of 1.25% or more. Conclusions The extract inhibited the growth of caries-causing bacteria, namely S. mutans and S. sobrinus. Furthermore, the extract inhibited the synthesis of glucan and biofilm formation by S. mutans and S. sobrinus. Therefore, this study suggests that the extract is a potential candidate as a therapeutic agent for controlling dental caries.