• Asian Pacific Journal of Cancer Prevention
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• 제15권18호
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• pp.7589-7595
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• 2014

Apurinic/apyrimidinic endonuclease 1 (APEX1) is a multifunctional protein which plays a central role in the BER pathway. APEX1 gene being highly polymorphic in cancer patients and has been indicated to have a contributive role in Apurinic/apyrimidinic (AP) site accumulation in DNA and consequently an increased risk of cancer development. In this case-control study, all exons of the APEX1 gene and its exon/intron boundaries were amplified in 530 breast cancer patients and 395 matched healthy controls and then analyzed by single-stranded conformational polymorphism followed by sequencing. Sequence analysis revealed fourteen heterozygous mutations, seven 5'UTR, one 3'UTR, two intronic and four missense. Among identified mutations one 5'UTR (rs41561214), one 3'UTR (rs17112002) and one missense mutation (Ser129Arg, Mahjabeen et al., 2013) had already been reported while the remaining eleven mutations. Six novel mutations (g.20923366T>G, g.20923435G>A, g.20923462G>A, g.20923516G>A, 20923539G>A, g.20923529C>T) were observed in 5'UTR region, two (g.20923585T>G, g.20923589T>G) in intron1 and three missense (Glu101Lys, Ala121Pro, Ser123Trp) in exon 4. Frequencues of 5'UTR mutations; g.20923366T>G, g.20923435G>A and 3'UTR (rs17112002) were calculated as 0.13, 0.1 and 0.1 respectively. Whereas, the frequency of missense mutations Glu101Lys, Ser123Trp and Ser129Arg was calculated as 0.05. A significant association was observed between APEX1 mutations and increased breast cancer by ~9 fold (OR=8.68, 95%CI=2.64 to 28.5) with g.20923435G>A (5'UTR), ~13 fold (OR= 12.6, 95%CI=3.01 to 53.0) with g.20923539G>A (5'UTR) and~5 fold increase with three missense mutations [Glu101Lys (OR=4.82, 95%CI=1.97 to 11.80), Ser123Trp (OR=4.62, 95%CI=1.7 to 12.19), Ser129Arg (OR=4.86, 95%CI=1.43 to 16.53)]. The incidence of observed mutations was found higher in patients with family history and with early menopause. In conclusion, our study demonstrates a significant association between germ line APEX1 mutations and breast cancer patients in the Pakistani population.

• Restorative Dentistry and Endodontics
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• 제31권5호
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• pp.371-377
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• 2006

이 연구의 목적은 확대하기 전 근관에서 전자근관장 측정 시의 정확성을 평가하고 확대된 근관에서 파일의 크기에 따른 네 가지 전자근관장 측정기의 정확성을 비교하기 위한 것이다. 발치된 치아 10개를 #10파일을 이용하여 치아의 실제길이를 측정하였다 현미경에서 25배 확대 하에 #10 파일이 치근단공을 넘어 해부학적 치근단공에 이를 때까지 전진하여 디지털 캘리퍼로 측정하였다. Root ZX, Bingo 1020, SmarPex, e-Magic Finder를 알지네이트를 이용한 인체 재현 모델을 이용하여 #10 파일로 apex 표시등에서 측정하였다 (S10). #45까지 핸드 파일로 확대한 다음 #10, #40 파일을 이용하여 전자근관장을 측정하였다. 실제 길이와 각각 측정값의 차이를 계산하여 L10, L40으로 정의하고 기계간의 비교는 one-way ANOVA통계처리하고, Scheffe's multiple range test로 사후 검증하였고, 같은 기계 안의 L10, L40은 Student's t-test로 비교하였다. 본 연구의 실험 조건 하에서, 측정값의 정확도가 기계간에 차이를 보였고, 파일의 크기는 측정값의 정확도에 영향을 주지 못하며, e-Magic Finder는 이 실험 조건하에서 다른 기계에 비해 가장 정확하였다.

• Restorative Dentistry and Endodontics
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• 제25권3호
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• pp.435-445
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• 2000

The purpose of this study was to compare the leakage of four different obturation techniques in conjunction with immediate apical barrier of ${\beta}$-tricalcium phosphate(TCP) in teeth with open apex. Eighty single-rooted human premolar teeth were prepared and sectioned horizontally, so maximum diameter in apex was 4mm. Apical defects that were similar to open apex, were created with #1/2 round bur and SF104R bur. The apical foramen were opened to a size 80 file extended 3mm beyond the apex. The teeth were placed into the oasis block soaked saline to simulate periapical tissue often associated with pulpless teeth and received apical barriers consisting of TCP followed by obturation using lateral condensation technique, vertical condensation technique, continuous wave technique and thermoplasticized gutta-percha injection technique. Two unobturated teeth served as positive and negative controls. Teeth were immersed in resorcinol-formaldehyde resin for S days at $4^{\circ}C$, and the resin was allowed to polymerize completely for 4 days at room temperature. Teeth were then sectioned horizontally at 1.5mm(level 1), 2.5mm(level 2) and 3.5mm(level 3) from the apex, and examined under a stereomicroscope at ${\times}40$ magnification. The photographs were taken at ${\times}40$ magnification of the filling in each level and scanned. The leakage length in tooth/resin interface was measured at each of the three levels. Each ratio of leakage was obtained by calculating the ratio of the leakage length of canal wall infiltrated with resin to the total length of the canal and was analyzed statistically(One-way ANOVA and Scheffe test). The result were as follows : 1. At the level 1, there was the least leakage in the thermoplasticized gutta-percha injection technique group(group 4), but there was statistically significant(p<0.05). 2. At the level 2, there was the least leakage in the thermoplasticized gutta-percha injection technique group(group 4), and the most leakage in the continuous wave technique group(group 3). There was statistically significant difference between the thermoplasticized gutta-percha injection technique group and the continuous wave technique group(p<0.05). 3. At the level 3, there was the least leakage in the thermoplasticized gutta-percha injection technique group(group 4), but there were no statistically significant differences between other groups(p>0.05). These results suggest that thermoplasticized gutta-percha injection technique which had 1mm apical gutta-percha matrix after the formation of TCP apical barrier, can demonstrate favorable apical sealing.

• 한국응급구조학회지
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• 제20권1호
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• pp.83-94
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• 2016

Purpose: This study aimed to assess defibrillator pad positioning by the general public and healthcare providers during basic life support (BLS) renewal education (RE). Methods: A total 130 subjects performed defibrillation using an automated external defibrillator (AED) equipped with electrode pads developed by the researchers and male resuscitation manikins, in order to assess electrode pad placement (EPP) before BLS RE. Subjects included 54 Healthcare providers (HP) and 76 members of the general public (GP). Results: The apex EPP was positioned in the risk area (RA), more than 5 cm distant from the area recommended, by 63.2% of the GP (n = 48). The apex EPP was positioned in the RA by 44.4% of the HP (n = 23). The distance from the apex (GP $5.27{\pm}2.21cm$, HP $4.18{\pm}1.71cm$) was statistically significant, using Student's t-test. Conclusion: For both GP and HP, apex EPP was significantly in error. Thus, to prevent defibrillation failures, EPP education and practice for GP and HP in all BLS education programs should be improved, and incorrect Korean cardiopulmonary resuscitation guidelines and related literature should be revised and corrected.

• 한국임상보건과학회지
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• 제6권1호
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• pp.1089-1096
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• 2018

Purpose: To investigate the corneal thickness and anterior chamber depth (ACD) of eyes with Keratoconus in the Korean population with the Pentacam. Methods: The subjects consisted of 84 eyes from Keratoconic adults aged 7-59 years during 2010. The thinnest area, apex zone, and pupil centre of the corneal thickness were measured using the Pentacam pachymetry. ACD value was also measured with Pentacam. Results: There was a statistically significant relationship between thickness of the cornea at the apex area and the pupil centre (p=0.0001). However, there was no statistical difference (p>0.5) in the mean thickness of thinnest area, apex zone, pupil centre of cornea between right eye and left eye. Also, correlation between ACD and corneal thickness in all subjects had no statistical differences (p>0.05) in all subjects. Conclusion: These results suggested that the regional thickness of cornea and ACD with Pentacam can provide correct and useful diagnostic information of the morphology of Keratoconus for the RGP contact lens and diagnosis of abnormal corneal refraction surgery.

• 대한의용생체공학회:의공학회지
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• 제11권2호
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• pp.217-226
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• 1990

This paper presents a new algorithm that extracted lung region in X-ray and enhanced the region. With a lung region that was extracted by histogram threshold value, it was diffi cult to detect perfect lung boundary. Therefore we presented perfect lung boundary detection method using apex detection and apex region restoration. Also, by applying modified equalization algorithm and presented function to inside of lung region, we want to give help to automatic diagnosis In X-ray chest image. Presented main line trace algorithm gave good result in detection of lung boundary And, as apex detection method using lung row and column gray level average value found more correct place of lung than the rpethod of prior algorithm, we succeeded perfect lung region detection, Also, presented function that had lung region's gray level distribution characteristic was very effective to image enhancement.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.399-402
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• 1997

It is important to find a accurate root canal length or successful endodontic therapy. By X-ray method takes a long time and difficult in a curved canal. After developed electronic apex locator has allowed to measure the root canal length with easy, in a short time also in a curved canal. But most electronic apex locators have the disadvantage which is too short reading or sometimes the measurement itself becomes impossible if there are electrolytes in the canal. To overcome this drawback, impedance ratio method has been developed. In this study, we have developed frequency dependent electronic apex locator to minimize the interference of electrolytes. And based on that also some error in clinic use, we added the other method. Difference of two signals which are used in calculation of impedance ratio was can be represent the status of root canal fluid. As a result, using impedance ratio method and auto-calibration by voltage difference method can reduce the measurement error.

• 대한치과의사협회지
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• 제55권1호
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• pp.42-52
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• 2017

The purpose of this study is to evaluate the preferred method of root canal length determination and the apical limit for canal instrumentation among endodontic teachers of dental school. A questionnaire on the preferred method of root canal length determination and the apical limit for canal instrumentation was designed and distributed to endodontic teachers of various dental schools. The response rate was 90%. The most preferred method of root canal length determination was Electronic apex locator (EAL)(89%). The most favoured apical limit for canal instrumentation was 0.5 to 1.0 mm short of the radiographic apex(78%). The most preferred method of using EAL was that the working length is taken at 'APEX' mark and then distracted 0.5mm from that length.(41%). When there is no agreement between radiographic measurement and EAL measurement, 74% of respondents chose the length of EAL measurement. The majority of endodontic teachers from Korean dental schools preferred EAL to radiograph method in determining root canal length.

• Restorative Dentistry and Endodontics
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• 제22권2호
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• pp.809-819
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• 1997

The purpose of this study was to develop an accurate frequency-dependent type apex locator. To compensate the impedence differences of different canal contents, voltage differences were pre-measured and stored for saline, HOsb1/$2O_2$ and NaOCl. The circuit was adjusted to recognize the different voltages of each solution, thereby the machine could automatically compensate the voltage differences. In the process of this study, the following informations were observed. 1. Most stable apical reading was obtained at 500Hz and 10kHz. 2. There were no differences in accuracy among three different frequency types, sign wave, triangular wave and rectangular wave(p>0.05). 3. Before the compensation of voltage differences, saline, H2O2 and NaOCl showed different readings at the apex even with the frequency-type (p<0.05). 4. After compensating the voltage difference, the accuracy was enhanced from + 0.42 to +0.32 in H2O2(p<0.05), from -0.34 to -0.12 in NaOCl(p<0.05).

• 치과방사선
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• 제25권2호
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• pp.501-511
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• 1995

The purpose of this study was to evaluate the position and shape of mental foramen in periapical radiographs. For this study, periapical radiographs of premolar areas were obtained from the 200 adults. Accordingly, the positional and shape changes of mental foramen were evaluated. The authors obtained radiographs according to changes in radiation beam direction in periapical radiographs of premolar areas, and then evaluated the positional and shape changes of mental foramen. The following results were obtained: 1. Shapes of mental foramen were observed elliptical(34.3％), round or oval(28.0％), unidentified(25.5％) and diffuse(12.2％) type in descending order of frequency. 2. Horizontal positions of mental foramen were most frequently observed at the 2nd premolar area(55.3％), the area between the 1st premolar and 2nd premolar(39.6％), the area between the 2nd premolar and 1st molar(3.4％), the 1st premolar area(1.0％), the area between the canine and 1st premolar(0.7％) in descending order of frequency. 3. Vertical positions of mental foramen were most frequently observed at the inferior to apex(67.1％), and at apex(24.8％), overlap with apex(6.4％), superior to apex(1.7％) in descending order of frequency. 4. Shapes of mental foramen were more obviously observed at the upward 10° positioned periapical radiographs. And according to the changes of horizontal and vertical position, they were observed similar to normally positioned periapical radiographs.