• BMB Reports
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• 제57권2호
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• pp.98-103
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• 2024

The mammalian sirtuin family (SIRT1-SIRT7) has shown diverse biological roles in the regulation and maintenance of genome stability under genotoxic stress. SIRT7, one of the least studied sirtuin, has been demonstrated to be a key factor for DNA damage response (DDR). However, conflicting results have proposed that Sirt7 is an oncogenic factor to promote transformation in cancer cells. To address this inconsistency, we investigated properties of SIRT7 in hepatocellular carcinoma (HCC) regulation under DNA damage and found that loss of hepatic Sirt7 accelerated HCC progression. Specifically, the number, size, and volume of hepatic tumor colonies in diethylnitrosamine (DEN) injected Sirt7-deficient liver were markedly enhanced. Further, levels of HCC progression markers and pro-inflammatory cytokines were significantly elevated in the absence of hepatic Sirt7, unlike those in the control. In chromatin, SIRT7 was stabilized and colocalized to damage site by inhibiting the induction of γH2AX under DNA damage. Together, our findings suggest that SIRT7 is a crucial factor for DNA damage repair and that hepatic loss-of-Sirt7 can promote genomic instability and accelerate HCC development, unlike early studies describing that Sirt7 is an oncogenic factor.

• 한국학교보건학회지
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• 제14권1호
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• pp.115-130
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• 2001

Dieting behaviors prevail among most women and are highly increasing among female adolescents who don't have to lose weight. The dieting behaviors of normal or low weight groups are highly related to the negative impact of health risk behaviors. We need a strategy for intervening in the dieting behaviors of relevant groups. With this background, a study was conducted to examine the current situation of dieting behaviors and related factors in middle school girls, and to provide guidelines for the relevant dieting group. This survey was carried out by self-questionnaires passed out to 901 middle school girls from 3 middle schools in Seoul. Data were collected from April 10th, 2000 to April 17th, 2000 and 794 respondents' data were finally selected for analysis. The instruments of this study were Shin's scale for effects of mass-media, Birleson's depression self-rating scale translated by shim, Rosenberg's self-esteem scale, Smilkstein's Family APGAR score translated by Yoon, Kim's school-related adjustment scale. The credibility of instruments was 0.41~0.83 in the pilot study and 0.70~0.86 in the main study. The summary of results was as follows: 1. The general characteristics of respondents were analyzed. In comparison of grade and dieting behaviors, the subjects of the group perceived that their body image was obeser than their real body image and their ideal body image was slenderer than their current body image. A dieter's body image was seriously distorted. 2. The dieting behaviors were analyzed. The Subjects' BMI was within the normal to low range -- they didn't have to lose weight. But actually 47.3% of the respondents were dieters. Their main dieting methods were exercise(71.8%), computer games(64.9%) such as DDR and pump, and intake reduction(64.1%). Most dieters were using desirable methods such as exercise and intake control. But unhealthy methods such as saunax, smoking and harmful drug-use were also used by a few dieters. The main reason for dieting was attractiveness. The chief resources of dieting methods were mass-media(67.8%), friends(64.3%), and parents & relatives(35.1%). Only a few subjects obtained the information from health professionals. While they were trying to lose weight, 42.1% of the subjects experienced side effects such as dizziness(45.0%), apathy(20.5%), appetite loss(18.5%), amenorrhea and the irregularity of the menstrual cycle(16.6%). 3. The relationship between dieting behaviors and factors was analyzed. Dieting behaviors were significantly related to the experience of menarche, the experience of dating with heterosexuals, perceived body image, self-esteem, depression, family's relationship, school instruction-related adjustment, school life-related adjustment, and the effect of mass-media. After that, the multiple logistic regression was used. The analysis revealed that dating, perceived body image, the experience of menarche and the effect of mass media were significant factors. In conclusion, strategies for preventing irrelevant dieting behaviors are urgently required to enhance female adolescents' ability to choose the right information from countless others and to recognize their optimum body image.

• 한국방사선학회논문지
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• 제2권4호
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• pp.5-9
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• 2008

비산란 그리드는 X선 영상에서 산란방사선을 제거시키기 위해 사용되고, 그에 따라 X선 영상의 대조도를 향상 시킬 수 있다. 그러나 많은 경우 디지털 X선 영상에서는 그리드의 부적절한 샘플링으로 인해 moir$\acute{e}$ artifact를 발생 시키게 된다. 본 논문에서는 그리드 주파수, pixel pitch, 각도와 moir$\acute{e}$ artifact의 상관관계에 관하여 분석하고 실험으로 확인하였다. 실험을 위하여 4..0 - 8.5 까지의 6가지 탄소 그리드를 사용하여 $139{\mu}m{\times}139{\mu}m$ pixel size의 DDR system에서 실험을 하였다. 본 실험을 통하여 획득한 moir$\acute{e}$ artifact의 frequency는 이론적 계산값과 거의 같았고, 특히 그리드와 detector array의 각도에 따라 moir$\acute{e}$ frequency가 달라지는 것을 확인 할 수 있었다. 본 연구를 통한 moir$\acute{e}$ artifact에 대한 이론과 data는 향후 DR system에서 moir$\acute{e}$ artifact 제거에 큰 도움을 주리라 생각한다.

• 생명과학회지
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• 제20권7호
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• pp.1054-1065
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• 2010

생약복합물인 SH21B는 황금(Scutellaria baicalensis Georgi), 행인(Prunus armeniaca Maxim), 마황(Ephedra sinica Stapf), 석창포(Acorus gramineus Soland), 포황(Typha orientalis Presl), 원지(Polygala tenuifolia Willd), 하엽(Nelumbo nucifera Gaertner)의 혼합(비율 3:3:3:3:3:2:2)으로 이루어졌다. SH21B는 예로부터 한의학에서 비만의 치료에 사용되어 왔으나 자세한 분자적 메커니즘과 효능에 대한 연구는 이루어지지 않았다. 본 연구진은 선행연구를 통해 SH21B가 지방세포의 분화에서 adipogenesis (지방세포형성)와 관련된 유전자를 조절하여 중성지방의 축적을 억제함을 밝혔다. 본 연구에서는, microarray 기술을 이용하여 adipogenesis의 in vitro 모델인, 3T3-L1 세포에서 SH21B에 의한 지방세포형성 억제의 분자적 기작을 보다 상세하게 연구하고자 하였다. 전지방세포, 분화된 세포 그리고 SH21B에 의해 분화가 억제된 세포의 각각의 유전자 발현을 분석하기 위해 각 시료들에서 total RNA를 분리하여 cDNA를 합성한 후 microarray에 적용시켰다. 그 결과, 각각의 시료들의 비교에서 2배 이상의 유의한 발현 변화를 가지는 2,568개의 유전자를 확보하였다. 이 유전자들에 대해 Hierarchical clustering과 K-means clustering 분석을 진행하였고 서로 다른 양상을 가지는 9개의 군집(cluster)들을 분류하였다. 그 중, SH21B의 첨가에 의해 뚜렷하게 감소(cluster 4, cluster 6 및 cluster 9)하거나 반대로 뚜렷하게 증가(cluster 7와 cluster 8)하는 양상을 보이는 군집들을 따로 선별하여 그 군집들에 포함되어 있는 유전자들을 분석하였다. 선택 된 5개의 군집에는 지방세포형성과 세포증식에 관련된 유전자가 다수 포함되어 있었다. Cluster 4, cluster 6 그리고 cluster 9에는 peroxisome proliferator activated receptor gamma $\gamma$ ($PPAR{\gamma}$), CCAAT/enhancer binding protein $\alpha$ (C/$EBP{\alpha}$), sterol regulatory element binding transcription factor 1 (SREBF1), adiponectin (ADIPOQ), fatty acid synthase (FASN), lipoprotein lipase (LPL) 등의 지방세포형성 유도 및 관련 인자와 B-cell leukemia/lymphoma6 (BCL6), retinoblastoma 1 (RB1), cyclin-dependent kinase inhibitor 2C (CDKN2c), ras homolog gene family, member B (RHOB) 등의 많은 세포증식 억제 유전자가 포함되었다. 이와는 반대로, cluster 7과 cluster 8에는 $\beta$-catenin, cyclin D1 (CCND1), WNT1 inducible signaling pathway protein 2 (WISP2) 등과 같은 지방 세포형성 억제 조절자와 MARCKS-like1 (MARCKSL1), colony stimulating factor 1 (CSF1), discoidin domain receptor family, member 2 (DDR2), leukemia inhibitory factor receptor (LIFR) 등의 세포증식을 유도하는 조절자가 다수 포함되었다. 결론적으로, 이러한 결과들은 SH21B가 지방세포형성과 관련된 조절자 및 세포증식과 관련 된 조절자들의 유전자 발현을 조절하여 지방세포형성을 억제함을 제시한다.