PURPOSE: Aggregatibacter actinomycetemcomitans is associated with localized aggressive periodontitis. It produces cytolethal distending toxin (CDT), which induces cell cycle arrest in the G2/M phase. The CDT holotoxin is composed of CdtA, CdtB, and CdtC. CdtB has structural homology to human DNase I and is an active component of the CDT complex acting as a DNase. In particular, the pattern homology seen in the CdtB subunit has been associated with specific DNase I residues involved in enzyme catalysis, DNA binding, and metal ion binding. So, to study the functions and regulation of recombinant CdtB, we made up a quantity of functional recombinant CdtB and tested it in relation to the metal ion effect. MATERIALS AND METHODS: We constructed the pET28a-cdtB plasmid from A. actinomycetemcomitans Y4 by genomic DNA PCR and expressed it in the BL21 (DE3) Escherichia coli system. We obtained the functional recombinant CdtB by the refolding system using the dialysis method and then analyzed the DNase activity and investigated the metal ion effect from plasmid digestion. RESULTS: The recombinant CdtB subunit was expressed as the inclusion bodies. We were able to obtain functional recombinant CdtB subunit using refolding system. We confirmed that our refolded recombinant CdtB had DNase activity and was influenced by the metal ions Mg2+ and Ca2+. CONCLUSION: We suggest that the factors influencing recombinant CdtB may contribute to CDT associated diseases, such as periodontitis, endocarditic, meningitis, and osteomyelitis.
Aggressive Periodontitis ; Bacterial Toxins ; Catalysis ; Cell Cycle Checkpoints ; Deoxyribonuclease I ; Deoxyribonucleases ; Dialysis ; DNA ; Edetic Acid ; Escherichia coli ; Humans ; Inclusion Bodies ; Ions ; Meningitis ; Osteomyelitis ; Periodontitis ; Plasmids ; Polymerase Chain Reaction

The aim of the present study was to investigate the distribution of periodontally hopeless teeth in patients who had not been treated. Five hundred nineteen teeth of 163 patients who had visited at the Department of Periodontology, Chonbuk National University Hospital during the period from January 1999 to July 2001 were selected as a periodontally hopeless tooth. Selection criteria were as follows: 1) probing pocket depth more than 8mm, 2) tooth mobility of degree III, 3) radiographic bone loss more than 75%. The contralateral tooth to a hopeless tooth (experimental tooth) was designated as a control tooth. Between the experimental and control tooth, differences in probing pocket depth, tooth mobility and amount of radiographic bone loss were examined as well as correlation. The results showed that hopeless teeth were most frequently found in the maxillary first molar position and least frequently in the maxillary canine position. Differences between experimental and control teeth were 2mm in probing depth, 1 degree in tooth mobility, and 20% in amount of bone loss (p<0.01). The periodontal conditions between the experimental and control teeth showed correlation in general, however, statistical significances were found in posterior teeth positions. Within limitations of this study, it can be concluded that local factors may play a role in deterioration of periodontal disease along with symmetrical character of periodontal disease.
Humans ; Jeollabuk-do ; Molar* ; Patient Selection ; Periodontal Diseases ; Tooth ; Tooth Mobility

BACKGROUND: Smoking prevention and anti-smoking education in schools must be designed and planned according to age and sex as well as the type of schools and their smoking status. But the current education programs do not consider these factors. This study, therefore, aims to evaluate the actual status of the smoking prevention and anti-smoking education in Korea and to find present recommendations for an effective and, systematic education. METHODS: We surveyed 15,310 teen-age students attending middle schools and high schools in such cities as Seoul, Incheon, Bucheon, Mokpo, and Pohang and smaller areas in the vicinity of these cities from June 1 to 15, 2005. Self-survey was done by the health education teacher of each school. It contained questions about the general disposition of respondents, their smoking habits, and awareness programs on prevention and cessation of smoking. We used SPSS 12.0 for chi-square-test to analyze the collected data. RESULTS: The most prevailing form of anti-smoking education was "video". Most of the students surveyed said that the fourth or fifth grade of elementary school will be a good starting point for anti-smoking education. Only 39.6% of students who were educated by the current smoking prevention and anti-smoking program answered that it was "helpful" and 29.6% was "satisfied". Higher percentage of middle school students said that they either tried to quit smoking ('pre-contemplation') or had no intention of doing it ('termination-fail') after having been involved in the anti-smoking education program, while high school students turned out to be more oriented towards 'contemplation' and 'termination-success'. CONCLUSION: Some students were found to begin smoking even at an early grade in elementary school. Most adolescents knew about the danger of smoking, but current smokers had a low educational satisfaction. The real target of such education programs, however, should be focused on higher grade students in elementary schools and middle school students, because data show that smoking rate increases explosively among these students.
Adolescent ; Surveys and Questionnaires ; Education* ; Gyeonggi-do ; Gyeongsangbuk-do ; Health Education ; Humans ; Incheon ; Intention ; Jeollanam-do ; Korea ; Seoul ; Smoke* ; Smoking Cessation ; Smoking*

The purpose of this study was to evaluate in vitro the effects during subgingival calculus removal using Nd:YAG laser. The study group was consisted of 30 teeth with advanced periodontal disease extracted before the start of periodontal therapy. The specimens were divided into 8 different groups : 1) untreated control 2) scaling and root planing only 3) laser treated using 150mJ/pulse, 1sec, 5sec, contact mode 4) laser treated using 200mJ/pulse, 5sec, contact mode 5) laser treated using 150mJ/pulse, 1sec, non-contact mode 6) laser treated using 200mJ/pulse, 5sec, non-contact mode 7) laser treated using 150mJ/pulse, 1sec, contact mode with water irrigation 8) laser treated using 200mJ/pulse, 5sec, contact mode with water irrigation. All specimens were prepared for evaluation by scanning electron microscopy(SEM). Specimens from Group 2 exhibited a smear layer of scale like texture with parallel instrument tracks resulting from curet use. Specimens treated by contact mode, Group 3 and 4 featured surface changes not observed in controls such as charring, randomly distributed pitting and crater formation, and melting down of the tooth material and calculus. Specimens treated by noncontact mode, Group 5 and 6 featured similar surface changes observed in contact mode. However, the differences between contact and non-contact groups not significant. Specimens treated by contact mode with water irrigation, Group 7 and 8 featured slight surface change compared to other groups. The results suggested that Nd: YAG laser did not completely remove the subgingival calculus but was possible the application as adjunctive method.
Calculi* ; Freezing ; Lasers, Solid-State ; Periodontal Diseases ; Root Planing ; Smear Layer ; Tooth ; Trout ; Water

The fibroblasts are the principal cells in the periodontal ligament of periodontium. As the periodontal ligament fibroblasts (PDLF) show similar phenotype with osteoblasts, the PDLF are thought to play an important role in alveolar bone remodeling. Cell-to-cell contacted signaling is crucial for osteoclast formation. Recently it has been reported that PDLF enhance the bone resorbing activity of osteoclasts differentiated from hematopoietic preosteoclasts. The aims of this study were to clarify the mechanism of PDLF-induced osteoclastogenesis and 2) whether we can use preosteoclast cell line instead of primary hematopoietic preosteoclast cells for studying the mechanism of PDLF-induced osteoclastogenesis. Osteoclastic differentiation of mouse macrophage cell line RAW264.7 was compared with that of mouse bone marrow-derived M-CSF dependent cell (MDBM), a well-known hematopoietic preosteoclast model, by examining, 1) osteoclast-specific gene expression such as calcitonin receptor, M-CSF receptor (c-fms), cathepsin K, receptor activator nuclear factor kappa B (RANK), 2) generation of TRAP(+) multinucleated cells (MNCs), and 3) generation of resorption pit on the OAASTM plate. RAW264.7 cultured in the medium containing of soluble osteoclast differentiation factor (sODF) showed similar phenotype with MDBM-derived osteoclasts, those are mRNA expression pattern of osteoclast-specific genes, TRAP(+) MNCs generation, and bone resorbing activity. Formation of resorption pits by osteoclastic MNCs differentiated from sODF-treated RAW264.7, was completely blocked by the addition of osteoprotegerin (OPG), a soluble decoy receptor for ODF, to the sODF-containing culture medium. The effects of PDLF on differentiation of RAW264.7 into the TRAP(+) multinucleated osteoclast-like cells were examined using coculture system. PDLF were fixed with paraformaldehyde, followed by coculture with RAW264.7, which induced formation of TRAP(+) MNCs in the absence of additional treatment of sODF. When compared with untreated and fixed PDLF (fPDLF), IL-1beta-treated, or lipopolysaccharide- treated and then fixed PDLF showed two-fold increase in the supporting activity of osteoclastogenesis from RAW264.7 coculture system. There were no TRAP(+) MNCs formation in coculture system of RAW264.7 with PDLF of no fixation. These findings suggested that we can replace the primary hematopoietic preosteoclasts for RAW264.7 cell line for studying the mechanism of PDLF-induced osteoclastogenesis, and we hypothesize that PDLF control osteoclastogenesis through ODF expression which might be enhanced by inflammatory signals.
Animals ; Bone Remodeling ; Cathepsin K ; Cell Line ; Coculture Techniques ; Fibroblasts* ; Gene Expression ; Humans* ; Macrophage Colony-Stimulating Factor ; Macrophages ; Mice ; NF-kappa B ; Osteoblasts ; Osteoclasts ; Osteoprotegerin ; Periodontal Ligament* ; Periodontium ; Phenotype ; RANK Ligand ; Receptors, Calcitonin ; RNA, Messenger

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal neoplasms affecting the gastrointestinal tract. The main sites for GIST are the stomach and small intestine but they can also occur in the rectum, albeit rarely. We report a 58-year-old woman who presented with hematochezia. Endoscopically, a submucosal tumor with mucosal ulceration was located approximately 2 cm from the anal verge. The pelvic CT and MRI scanning findings demonstrated a large low-density lesion with intraluminal growth from the lower rectum and an absence of tumor infiltrations to other organs. The patient underwent an abdominoperineal resection of the rectum. A histopathological examination showed fascicular proliferation of spindle shaped cells. The mitotic rate was more than 30 mitotic figures per 50 high-power fields. A immunohistochemical examination revealed most of the tumor cells to be positive for the c-kit protein, CD34 and SMA (alpha-smooth muscle action). The tumor was diagnosed as a GIST of the rectum.
Female ; Humans

BACKGROUND: Percutaneous mitral balloon valvuloplasty (PMV) has been proposed as an alternative to surgery for selected patients with symptomatic mitral stenosis. The presence of mild mitral regurgitation (MR) in mitral KERN=5535>stenosis is usually not considered as a contraindication for the procedure. But, the results of PMV in the subgroup KERN=>of patients with concomitant mild MR are unknown. Accordingly, this study evaluates the clinical outcome of a consecutive series of patients with mitral stenosis and mild MR undergoing PMV. METHODS: Between August 1992 and December 1996 we attempted to dilate the mitral valves of 43 consecutive patients with symptomatic mitral stenosis. Mean age of the group was 45.9+/-10.6 years and 37 patients were women. They were divided into two groups according to the presence or absence of mild MR before the procedure. Clinical feature, inital result, complication were compared. RESULTS: 1) Age, gender, symptomatic status, and atrial fibrillation were similar in both groups. 2) Patients with MR had more thickened valve (2.50+/-0.33 vs 1.84+/-0.55, p=0.048) and subvalvular tissue (2.55+/-0.73 vs 1.88+/-0.73, p=0.015), higher echocardiographic score (8.44+/-1.01 vs 7.08+/-1.65, p=0.004). 3) Mitral valve area gain on the first day after PMV was smaller in patients with MR(p=0.008). 4) The success rate of PMV, the incidence of severe MR after PMV, and the restenosis rate on 6 month were similar in both groups. CONCLUSION: Although the PMV in patients with mild MR obtained smaller increments in mitral valve area compared to those without MR, they showed similar immediate and short-term results after PMV.
Atrial Fibrillation ; Balloon Valvuloplasty* ; Echocardiography ; Female ; Humans ; Incidence ; Mitral Valve ; Mitral Valve Insufficiency* ; Mitral Valve Stenosis*

BACKGROUND/AIMS: Although many individual cases of toxic hepatitis have been reported in Korea, there are few comprehensive systematic studies on acute toxic hepatitis. The first aim of this study is to investigate the frequency and clinical characteristics of acute toxic hepatitis patients. The second aim of this study is to investigate the efficacy of steroid therapy for immunoallergic idiosyncrasy. METHODS: Between March 1998 and March 2004 forty eight patients were included in this study. The medical records were reviewed retrospectively. Acute toxic hepatitis was diagnosed by score of more than 3 in RUCAM criteria. All the patients were tested for hepatitis A, B and C. Other tests included antibodies to CMV and EBV, ANA, AMA and SMA. RESULTS: Seventy-three percent of the patients were female and the mean age of the patients was 47. Twenty cases of acute toxic hepatitis (42%) were related to prescribed medications. The other causes were herbs (35%) and traditional therapeutic preparations (23%). Common symptoms were jaundice (35%), fatigue (10%), fever (9%) and abdominal pain (9%). The biochemical pattern of hepatotoxicity was divided into three groups: hepatocellular (81%), mixed (13%), and cholestatic types (6%). Three patients who have prolonged and severe jaundice were classified into immunoallergic idiosyncrasy based upon clinical and histologic findings. Prednisolone was prescribed in all three cases whose bilirubin levels had been higher than 15 mg/dL for at least 7 days. Jaundice and the laboratory findings rapidly improved within 8 days since the treatment began. CONCLUSIONS: In a demographic point of view, most patients of acute toxic hepatitis were middle aged women. Jaundice was the most commonly observed symptom. Prescribed drugs were the most common cause of acute toxic hepatitis. Although most cases of toxic hepatitis will recover with supportive care after cessation of the causative agent, steroid treatment may be helpful for the patients with severe jaundice patients who have immunoallergic idiosyncrasy.
Prednisolone/therapeutic use ; Middle Aged ; Male ; Jaundice/drug therapy/etiology ; Humans ; *Hepatitis, Toxic/diagnosis/drug therapy/etiology ; Glucocorticoids/therapeutic use ; Female ; Adult ; Acute Disease

PURPOSE: To evaluate the frequency and imaging findings of various ventriculo-peritoneal shunt-relatedcomplications in pediatric patients with hydrocephalus. MATERIALS AND METHODS: We retrospectively reviewed 246plain radiographs, three shuntograms, 53 ultrasounds, 133 CT scans, and 24 MR images obtained before and after theventriculo-peritoneal shunt procedure in 33 pediatric patients with hydrocephalus. Using preoperative images, theetiology of the hydrocephalus was assessed. Changes in the size and shape of the ventricles, the location andcontinuity of shunt apparatus, and the presence of any abnormal enhancement, hemorrhage, edema or tissue loss, orother findings of complications, were analyzed on postoperative images; the frequency and imaging findings ofshunt-related complications such as shunt malfunction, infection, hemorrhage or isolated ventricle, andcomplications caused by overdrainage, were thus evaluated. The frequency of such complications was analyzedaccording to the etiology of the hydrocephalus, and in addition, medical records were reviewed and correlated withimaging findings. RESULTS: In 18 of the 33 patients(54%), a total of 31 complications was detected. These werepresent in four of five cases (80%) of hydrocephalus caused by meningitis and ventriculitis, seven of twelve (58%)intraventricular hemorrhage, two of four (50%) unknown cases, three of nine (33%) congenital malformations, one oftwo (50%) tumors, and one (100%) congenital infection. Shunt malfunction was most common(n=15), and wasaccompanied by findings of enlarged ventricles, periventricular and peritubal edema, and abnormal location of theshunt tube. Symptoms and signs of increased intracranial pressure were also noted. Subdural hemorrhage andinfection were present infour cases each;findings of infection were enhancement of the ventricular wall, meninges,and parenchyma, as well as sonographically noted intraventricular septation and increased ventricular wall echo.Isolated lateral ventricle (n=4) or 4th ventricle (n=1) was persistently distended in spite of the presence of ashunt tube within the other ventricle. Collapsed ventricles, thick calvarium, and symptoms of increasedintracranial pressure were helpful in the diagnosis of slit ventricle syndrome(n=1). Immediate postoperativeintraventricular and parenchymal hemorrhage were noted in one case each. CONCLUSION: Shunt-related complicationswere found on postoperative images in 54% of pediatric patients with hydrocephalus; the frequency was highest incases of hydrocephalus caused by infection. Shunt malfunction occurred most frequently and each complication hadvarious imaging findings. For the diagnosis of post-operative shunt-related complication, continuous follow-upstudies are therefore necessary.
Child* ; Diagnosis ; Edema ; Hematoma, Subdural ; Hemorrhage ; Humans ; Hydrocephalus* ; Infant* ; Intracranial Pressure ; Lateral Ventricles ; Medical Records ; Meningitis ; Retrospective Studies ; Skull ; Tomography, X-Ray Computed ; Ultrasonography

PURPOSE: To evaluate the frequency and imaging findings of various ventriculo-peritoneal shunt-relatedcomplications in pediatric patients with hydrocephalus. MATERIALS AND METHODS: We retrospectively reviewed 246plain radiographs, three shuntograms, 53 ultrasounds, 133 CT scans, and 24 MR images obtained before and after theventriculo-peritoneal shunt procedure in 33 pediatric patients with hydrocephalus. Using preoperative images, theetiology of the hydrocephalus was assessed. Changes in the size and shape of the ventricles, the location andcontinuity of shunt apparatus, and the presence of any abnormal enhancement, hemorrhage, edema or tissue loss, orother findings of complications, were analyzed on postoperative images; the frequency and imaging findings ofshunt-related complications such as shunt malfunction, infection, hemorrhage or isolated ventricle, andcomplications caused by overdrainage, were thus evaluated. The frequency of such complications was analyzedaccording to the etiology of the hydrocephalus, and in addition, medical records were reviewed and correlated withimaging findings. RESULTS: In 18 of the 33 patients(54%), a total of 31 complications was detected. These werepresent in four of five cases (80%) of hydrocephalus caused by meningitis and ventriculitis, seven of twelve (58%)intraventricular hemorrhage, two of four (50%) unknown cases, three of nine (33%) congenital malformations, one oftwo (50%) tumors, and one (100%) congenital infection. Shunt malfunction was most common(n=15), and wasaccompanied by findings of enlarged ventricles, periventricular and peritubal edema, and abnormal location of theshunt tube. Symptoms and signs of increased intracranial pressure were also noted. Subdural hemorrhage andinfection were present infour cases each;findings of infection were enhancement of the ventricular wall, meninges,and parenchyma, as well as sonographically noted intraventricular septation and increased ventricular wall echo.Isolated lateral ventricle (n=4) or 4th ventricle (n=1) was persistently distended in spite of the presence of ashunt tube within the other ventricle. Collapsed ventricles, thick calvarium, and symptoms of increasedintracranial pressure were helpful in the diagnosis of slit ventricle syndrome(n=1). Immediate postoperativeintraventricular and parenchymal hemorrhage were noted in one case each. CONCLUSION: Shunt-related complicationswere found on postoperative images in 54% of pediatric patients with hydrocephalus; the frequency was highest incases of hydrocephalus caused by infection. Shunt malfunction occurred most frequently and each complication hadvarious imaging findings. For the diagnosis of post-operative shunt-related complication, continuous follow-upstudies are therefore necessary.
Child* ; Diagnosis ; Edema ; Hematoma, Subdural ; Hemorrhage ; Humans ; Hydrocephalus* ; Infant* ; Intracranial Pressure ; Lateral Ventricles ; Medical Records ; Meningitis ; Retrospective Studies ; Skull ; Tomography, X-Ray Computed ; Ultrasonography