A 6-Week Oral Toxicity Study of Oral Cholera Vaccine in Sprague-Dawley Rats

The present study was carried out to examine the toxicity and target organs of oral cholera vaccine (OCV) after repeated oral administration in Sprague-Dawley rats for 6 weeks (3 administrations, once every 2 weeks). OCV is an inactivated oral cholera vaccine that contains Vibrio cholerae and confers protection against cholera caused by V. cholera serogroups O1 (Inaba and Ogawa serotypes) and O139 (strain 4260B). The animals were orally administered either OCV placebo (negative control) or OCV at a dose equivalent to 240 times the anticipated human dose. Throughout the administration period, no significant change was detected in clinical signs, body weight, food or water consumption, urinalysis results, hematological and clinical biochemistry test results, organ weights, necropsy, or histopathological examination results. Minor changes were found in hematological and clinical biochemistry tests; however, these changes were within normal ranges. The above results suggest that oral administration of OCV in rats did not induce any toxicologically meaningful changes, and the target organs could not be determined. This study was conducted in accordance with the guidelines established by Good Laboratory Practice (2009-183, KFDA, December 22, 2009) and the OECD Principles of Good Laboratory Practice (1997).

Correction of Caudal Septal Deformity via Open Approach / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Caudal septal deformities are surgically challenging disorders. A number of corrective programs have been described with variable success. Causes of frequent failure in correction of the caudal deformities have been conservatism and unrealistic dependence on incisional method such as cross hatching, and limited comprehension of the extrinsic and intrinsic forces causing caudal deformities. We reviewed and evaluated the surgical techniques for correction of the caudal septal deformities performed at our institution. SUBJECTS AND METHOD: A retrospective study was performed on 24 patients who underwent septal surgeries for severe caudal septal deformities between Feb 2001 to May 2004. With open approach, all deforming forces around the caudal septum were released and definite intraoperative correction was possible. RESULTS: All 24 patients showed definite improvement in terms of functional and anesthetic outcomes. Potential complications related with structural instability as well as other inherent complications of nasal surgery have not been encountered. CONCLUSION: For successful correction of the caudal septal deformities, completed exposure and releasing all the extrinsic forces around the caudal deformities via open rhinoplasty approach is desirable to avoid frequent recurrences.

A Case of MALT Lymphoma Showing Mikulicz Syndrome / 대한이비인후과학회지

Since Mikulicz's description of symptomless hypertrophy of the salivary gland and lacrimal gland, the term, Mikulicz syndrome, has been used to describe enlargement of the salivary gland with or without lacrimal gland involvement occurring in leukemia, lymphosarcoma, sarcoidosis, tuberculosis syphilis, etc. However, there are still a tremendous amount of confusion in the application of the term, Mikulicz syndrome. In Korea, there has been no reported case of Mikulicz syndrome to date. Internationally, it is also extremely rare to spot a reported case of the disease originating primarily from submandibular glands. We would like to report a case in which a 56 year old female patient was reported to have the disease ; she was diagnosed initially as benign lymphoepithelial lesion (BLL) by submandibular biopsy, but later confirmed by lacrimal gland biopsy to have mucosa associated lymphoid tissue (MALT).

Bacteriologic Evaluation of Peritonsillar Abscess / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Peritonsillar abscess (PTA) is a collection of pus lateral to tonsil and is located between the fibrous capsule of the palatine tonsil, usually at its upper pole, and the superior to the pharyngeal constrictor muscle. It frequently occurs as a complication of acute tonsillitis. Bacteriology including clinical characteristics in PTA were evaluated. SUBJECTS AND METHOD: Sixty-one patients with peritonsillar abscess, who visited National Medical Center from January 1997 through August 2001 were entered into the study. Each patient was asked to answer a questionnaire for clinical aspects of PTA. Needle aspirations were performed and pus was drained in all cases. Bacterial susceptibility to ampicillin, cephazoline, ciprofloxacin, erythromycin, tetracyclin, and vancomycin was tested on the ioslated bacteria. RESULTS: Among 61 cases, aerobes were isolated in 15 cases (24.6%) and anaerobes in 16 cases (26.2%). There was no significant difference in the culture positive rate of aerobes (p=0.767) and anaerobes (p=1.0) between antibiotics-medicated patients and nonmedicated patients. Among the cultured organisms, peptostreptococcus was the most common and the second most common was beta-hemolytic streptococcus. However, alpha-hemolytic streptococcus, an important pathogen considered in the previous study, was detected at 1.6%. CONCLUSION: Antibiotics medication was not a significant factor in culture positive rate in our study. Peptostreptococcus as an anaerobe and beta-hemolytic streptococcus as an aerobe were the major causes that contributed to the decreased state of peritonsillar abscess and culture positive rate of alpha-hemolytic streptococcus.

Distribution of oral pathogens in infections of endodontic origin / 대한치과보존학회지

It has been documented that periodontopathic bacteria are also implicated in endodontic infections. 16S rDNA gene-directed PCR was to examine the prevalence of periodontopathic bacteria including Actinobacillus actinomycetemcomitans (Aa), Prevotella intermedia (Pi), Prevotella nigrescens (Pn), Porphyromonas gingivalis (Pg), Porphyromonas endodontalis (Pe), and Treponema denticola (Td) in the root canals of 36 endodontically infected teeth having apical lesions with or without clinical symptoms like pain, swelling, and fistula. 1. In 36 infected root canals, most frequently detected bacterial species was Pg (61.1%), followed by Td (52.8%) and Pe (38.9%). 2. Of 36 infected root canals, Aa was detected in 6 canals (16.7%) of the teeth, all of which showed clinical symptoms. 3. Of 36 infected root canals, Pi and Pn were found in 4 (13.9%) and 5 (33.3%), respectively. Notably, prevalence of Pn in the symptomatic teeth was 50.0%. 4. One of black-pigmented anaerobic bacteria (BPB) including Pi, Pn, Pe, and Pg was detected in all of the teeth that showed pain or especially swelling but not fistula. It was, however, found that prevalence of BPB in the asymptomatic teeth or the teeth with fistula was only 40%. 5. Pe and Pg were detected in the teeth regardless of the presence or absence of symptoms. 6. Td was detected in the teeth regardless of the presence or absence of symptoms. High prevalence of BPB in the symptomatic teeth but low in the asymptomatic teeth suggests that BPB may play an important role in the pathogenesis of periapical lesions.

The canal system in the mesiobuccal root of the maxillary first molar / 대한치과보존학회지

This study is to investigate the canal system in the mesiobuccal root of the maxillry first molar. 61 maxillary first molars were randomly selected. Serial transverse sections were made perpendicular to the long axis of the mesiobuccal root. Each section was placed in 3% sodium hypochlorite for 24 hours and rinsed in water and dried. The resected surface was stained with 2% methylene blue dye and examined with stereomicroscope. 1. Canal configuration analysis showed that 36.1% of the specimen classified as type I, 16.4% as type II, 37.7% as type III and 9.8% as type IV. 2. Type II canal was merged in one canal within 1 to 4mm of the apex. 40% of type II canal converged at 2mm of the apex. 3. Type IV canal was divided into two canal within 2 to 4mm of the apex. 66.6% of type IV canal branched off at 2mm of the apex. 4. None of the sections had more than two main root canal. 5. 48.4% of the sections in 3mm with two canals contained an isthmusand more than 70% with two canals has isthmus at 4 to 5mm sections. 63.9% of the mesiobuccal root of maxillary first molar had two canaland 76.5% of sections with two canals in 5 MM had an isthmus. Because of this complexity the clinician should always search for extra canal carefullyand root canal system, including an isthmus, should be cleaned and shaped completelyand obturated three dimensionally for successful endodontic treatment.

The canal system of mandibular incisors / 대한치과보존학회지

The purpose of this study is to identificate root canal system including ideal access placement, root curvature, canal configuration, incidence of isthmus in mandibular incisors for success of endodontic treatment. 200 mandibular incisors were selected. The ideal access placement was determimed as follows. The teeth were radiographed from mesiodistal and buccolingual views using intraoral dental film. The image was divided into coronal, middle and apical third using the proximal film. Straight line access was determined by measuring the faciolingual canal width and placing points at midway point between the buccal and lingual wall at the junction of the middle and apical third and at the juntion of coronal and middle third of the root canal. A line was drawn connecting these two points extending through the crown of the tooth. The point at which the line crossed the external crown surface was recorded as facial, incisal, lingual. Degree of root curvature was determined by Schneider Protractor Method. Both section method and clearing method were used in this study. By section method, 100 mandibular incisors were embedded in clear resin and transeverse serial sectioned at 0.5, 1.0, 2.0, 3.0, 4.0, 5.0mm level from root apex. The resected surfaces were stained by methylene blue and examined under x40 magnification with a stereomicroscope. By clearing method, 100 mandibular incisors were cleared in methysalicylate after decalcification with 10% nitric acid and evaluated under x18 magnification with a stereomicroscope. The results were as follows ; 1. 29% had the center of the plotted straight-line access facial to incisal edge, whereas 71% had straight-line access at the incisal edge. When incisal wear classified as extensive, the straight-line access was plotted on the incisal edge 95.5%. When incisal wear classified as slight/none, the straight-line access was plotted on the facial 65.9%. 2. Degree of curvature of main canal was straight or almost straight, and only 10% in buccolingual direction had a degree of curvature greater than 20 degrees and 5.5% in mesiodistal direction had. 3. In section method, canal configuration analysis showed that 51% of the specimen classified as type I, 27% as type II, 12% as type III, 10% as type IV. For thoses setions with two canals, the incidence of an isthmus was 26.7%, 64.3%, 79.2%, 96.3%, 97.4%, 97.6% at each level and highest in 3~5mm sections. 4. In clearing method, canal configuration analysis showed that 74% of the specimen classified as type I, 11% as type II, 6% as type III, 9% as type IV. These results suggested that traditional access from lingual should be moved as far toward the incisal as possible to locate and debride the lingual canal and root canal system should be cleaned, shaped completely and obturated three dimensionally for successful endodontic treatment.

Distribution of ion channels in trigeminal ganglion neuron of rat / 대한치과보존학회지

No abstract available.

Immunohistochemical study on the distribution of ion channels in rat trigeminal sensory nucleus / 대한치과보존학회지

No abstract available.

Effectiveness of customized master cone on apical sealing in various apical size of prepared root canals / 대한치과보존학회지

The purpose of this study is to evaluate the effectiveness of customized master cone on apical sealing in various apical size of prepared root canals, that is MAF(Master Apical File) and to know at which apical size the apical leakage is to be significantly reduced using customized master cone. 120 extracted single rooted premolars were divided into four groups according to their apical size(MAF), #30, 40, 50 and 60. And then, each group was subdivided into three in accordance with three obturation methods, lateral condensation with standardized master cone, lateral condensation with chloroform-dipped customized master cone, and continuous wave of obturation technique. Resorcinol-formaldehyde resin was used for the microleakage test of this study. Teeth were sectioned horizontally at 1.5mm(Level 1), 2.5mm(Level 2), and 3.5mm(Level 3) from the anatomical root apex using low speed microtome. All sections were examined under x40 magnification with a stereomicroscope, photographed, and then scanned. With the scanned images, resin-infiltrated area presenting the microleakage was calculated using SigmaScan/Image, and the ratio of leakage to the total root canal area of each group was analyzed statistically(one way ANOVA). The results were as follows; 1. In groups of MAF #30, there was no significant difference of mean leakage ratio among three obturation methods at all three levels. 2. In groups of MAF #40, the group using lateral condensation with customized master cone had the lowest mean leakage ratio at all three levels, but there was no significant difference among three obturation techniques. 3. In groups of MAF #50, the mean leakage ratio of the group using lateral condensation with standard master cone was the highest among those of three obturation techniques at level 1, and this difference was statistically significant(p<0.05). 4. In groups of MAF #60, the groups using lateral condensation with standard master cone had also the highest mean leakage ratio at all levels, but there was no significant difference at level 1 and 2. At level 3, the leakage of the group using lateral condensation with standard master cone was significantly higher than that of the group using continuous wave of obturation(p<0.05). The results of this study suggested that the obturation method using customized master cone or the continuous wave of obturation is more effective for apical sealing than that using standardized master cone when MAF is larger than #50.

A morphological study on residual alveolar ridges of edentulous jaws / 대한치과보철학회지

No abstract available.