• 한국가금학회지
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• 제22권1호
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• pp.31-42
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• 1995

This study was to investigate the effects of dietary linoleic acid(18:2\omega6, LA) and aipha-linolenic acid(18:3\omega3. \alpha-LNA) levels on brain development and fatty acid compositions of various lipid classes in the chicken embryo brain tissues. Thirty two ISA Brown layers, 52 weeks-old, were divided into four groups. Birds of each group were given corn-soybean meal based diets added with 1) safflower oil 8%, 2) safflower oil 6% + perilla oil 2%, 3) safflower oil 2% + perilla oil 6%, or 4) perilla oil 8%. Mter 15 days fed the diets. the layers were artificially inseminated to obtain fertile eggs. During the incubation. embryonic brains were sampled at 15th and 21st days. Fatty acid contents were quantitated by using heptadecanoic acid (17:0) as an internal standard. No significant differences in brain weight and in contents of various lipids such as phospholipid. triglyceride, cholesterol. cholesterol ester and free fatty acid in the tissues were found among the dietary groups (P<0.05). The ratios of AA/LA in the brain lipid classes were lowered as the dietary levels of perilla oil were increased. Higher LA was found in phosphatidylcholine(PC) than arachidonic acid (20:4\omega6. AA), meanwhile the level of LA was less than AA in phosphatidylethanolamine(PE). Docosahexaenoic acid(22:6\omega3, DHA) was the* major fatty acid in the tissue and its content in PE was 2.5~3 times higher than in PC. DHA level in the phospholipid reached at a peak (1.7~1.8 mg/brain) in dietary groups added with 6% or 8% perilla oil. suggesting that no more increase in that fatty acid level in the brain tissue could be obtained by consuming more \alpha-LNA, the major precursor of DHA.

• International Journal of Oral Biology
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• 제36권4호
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• pp.195-201
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• 2011

Matrix metalloproteinases (MMPs) have been implicated in tissue development and re-modeling. Dynamic morphological changes of tooth germs reflect involvement of these enzymes during odontogenesis. The present study was performed to investigate expression and localization of MMP-2 and MMP-9, which have been known to have type IV collagenase activities, in rat tooth germs at different developmental stages. MMP-2 expression was increased gradually in the tooth germs from cap to crown staged germs at both transcription and translation levels. The localization of this molecule was detected in secretory ameloblasts and preameloblasts. The strong immunoreactivities were occasionally seen along the basement membrane between ameloblasts (or preameloblasts) and odontoblasts (preodontoblasts). However, weak reactivity was detected in odontoblasts and reduced enamel epithelium. The level of MMP-9 expression in the tooth germs was higher in cap stage than in crown staged germs at both transcription and translation levels. They were strongly expressed in both ameloblasts and odontoblasts. Even though reduced enamel epithelium after enamel formation and inner enamel epithelium at the cap stage exhibited weak reactivity, strong reactivity was detected in dental follicles and perifollicular tissues surrounding cap staged germs. These results suggested that MMP-2 may involve degradation of the basement membrane during hard tissue formation, whereas MMP-9 might be involved in remodeling of follicular tissues.

• 한국산학기술학회논문지
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• 제10권9호
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• pp.2535-2544
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• 2009

뇌파연구는 비교적 안전하게 뇌상태에 관한 다양한 정보를 제공한다. 상담자나 피검자는 뇌파의 측정, 분석, 관리 등 일련의 과정에 대해 편리하게 사용자 TCO를 절감할 수 있어야 하고, 원하는 정보에 실시간 접근이 가능해야 한다. 기존 환경이 전문가의 판단에 따른 수작업 형태였다면, 본 논문이 제안한 시스템은 3-Tier 클라이언트/서버 IT기 술 및 BQT를 포함하는 뇌파기술을 융합하고 최적화시킨 스마트 뇌파케어시스템이다. 이 시스템은 편리한 웹 인터페이스를 통해 전 과정을 완전히 자동화하여 실시간서비스를 실현하였다. 본 연구로 개발된 이 시스템은 현재, 필드에서 서비스를 진행하고 있으며, DB에 수집된 자료는 연구자들에게 임상연구의 용도로 제공되고 있다.

• Journal of Korean Neurosurgical Society
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• 제53권6호
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• pp.337-341
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• 2013

Objective : After spinal cord injury (SCI), functional and structural reorganization occurs at multiple levels of brain including motor cortex. However, the underlying mechanism still remains unclear. The current study was performed to investigate the alterations in the expression of the main regulators of neuronal development, survival and death, in the brain following thoracic contusive SCI in a mouse model. Methods : Eight-week-old female imprinting control region mice (n=60; 30-35 g) were used in this study. We analyzed the expression levels of regulators such as brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), nerve growth factor (NGF) and histone deacetylase (HDAC) 1 in the brain following thoracic contusive SCI. Results : The expression of BDNF levels were elevated significantly compared with control group at 2 weeks after injury (p<0.05). The expression of NGF levels were elevated at 2, 4 weeks compared with control group, but these difference were not significant (p>0.05). The GDNF levels were elevated at 2 week compared with control group, but these differences were not significant (p>0.05). The difference of HDAC1 levels were not significant at 2, 4 and 8 weeks compared with control group (p>0.05). Conclusion : These results demonstrate that the upregulation of BDNF may play on important role in brain reorganization after SCI.

• 한국지능시스템학회논문지
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• 제16권3호
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• pp.372-377
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• 2006

본 논문에서, 우리는 뇌파를 이용하여 사용자의 감정을 인식하는 감정인식 모델을 제안한다. 사용자의 감정을 인식하기 위해서는 우선 생체 데이터나 감정 데이터를 포함한 뇌파의 정량적인 데이터를 획득하는 방법이 필요하며 다음으로 획득된 뇌파를 통하여 현재 사용자의 감정 상태를 규명하는 패턴인식 기법이 중요한 문제가 된다. 본 논문에서는 뇌파를 통하여 현재 사용자의 감정 상태를 규명하고 인식할 수 있는 패턴인식 기법으로 Multi Layer Perceptron(MLP)을 사용한 패턴인식 기법을 사용한다. 본 논문에서 제안한 감정인식 모델의 실험을 위하여 특정 공간 내에서 여러 피험자의 감정별 뇌파를 측정하고, 측정된 뇌파로 집중도 및 안정도를 도출하여 유의미한 데이터로 감정 DB를 구축한다. 감정별 DB를 본 논문에서 제안한 감정인식 모델로 학습한 후 새로운 사용자의 뇌파로 현재 사용자의 감정을 인식한다. 마지막으로 피험자의 수와 은닉 노드의 수에 따른 인식률의 변화를 측정함으로서 뇌파를 이용한 감정인식 모델의 성능을 평가한다.

• 대한방사성의약품학회지
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• 제7권2호
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• pp.79-84
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• 2021

Radiopharmaceuticals are important for tumor diagnosis and therapy. To deliver a radiotracer at the desired target excluding non-targeted tissues is difficult The development of a targeted tracer that has a good clearance profile while maintaining high biostability and biocompatibility is key to optimizing its biodistribution and transport across biological barriers. Improving the hydrophilicity of radiotracers by PEGylation can reduce serum binding, allowing the tracer to circulate without retention and reducing its affinity for non-targeted tissues. In this study, we synthesized a new benzamido tracer (SnBz-PEG₃₆) with the introduction of a low molecular weight polyethylene glycol unit (PEG₃₆, ~2,100 Da). The tumor targeting efficiency and biodistribution of [¹³¹I]-Bz-PEG₃₆ or radiotracer-loaded liposomes were evaluated after their administration to normal mice or mouse tumor models including CT26 (xenograft) and 4T1 (xenograft and orthotopic). Most of the radiotracer was cleared out rapidly (1-24 h post-administration) through the kidney and there was little tumor uptake.

• Molecules and Cells
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• 제39권5호
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• pp.395-402
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• 2016

Identifying Hoxc8 target genes is at the crux of understanding the Hoxc8-mediated regulatory networks underlying its roles during development. However, identification of these genes remains difficult due to intrinsic factors of Hoxc8, such as low DNA binding specificity, context-dependent regulation, and unknown cofactors. Therefore, as an alternative, the present study attempted to test whether the roles of Hoxc8 could be inferred by simply analyzing genes frequently coexpressed with Hoxc8, and whether these genes include putative target genes. Using archived gene expression datasets in which Hoxc8 was differentially expressed, we identified a total of 567 genes that were positively coexpressed with Hoxc8 in at least four out of eight datasets. Among these, 23 genes were coexpressed in six datasets. Gene sets associated with extracellular matrix and cell adhesion were most significantly enriched, followed by gene sets for skeletal system development, morphogenesis, cell motility, and transcriptional regulation. In particular, transcriptional regulators, including paralogs of Hoxc8, known Hox co-factors, and transcriptional remodeling factors were enriched. We randomly selected Adam19, Ptpn13, Prkd1, Tgfbi, and Aldh1a3, and validated their coexpression in mouse embryonic tissues and cell lines following $TGF-{\beta}2$ treatment or ectopic Hoxc8 expression. Except for Aldh1a3, all genes showed concordant expression with that of Hoxc8, suggesting that the coexpressed genes might include direct or indirect target genes. Collectively, we suggest that the coexpressed genes provide a resource for constructing Hoxc8-mediated regulatory networks.

• 대한의생명과학회지
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• 제16권1호
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• pp.1-9
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• 2010

In order to understand the effects of all-trans-RA on palate development, RA was injected into the abdominal cavity of pregnant mice and then the embryos were taken in the following days and analyzed morphologically as well as molecular biologically. When RA was administered at the stage of E11 or E15, the overall craniofacial development was retarded. The length from jaw to eye was shortened, compared to that of normal group. When the E11 embryos were exposed to RA, cleft lip was also found along with the cleft palate. In vitro palate culture experiment also revealed that RA caused cleft palate. When RT-PCR was performed, early stage administration of RA at E11 inhibited the upregulation of Hoxa7 expression at E15 through E17. Whereas in control group, high level of Hoxa7 expression was detected in the palate of E15 to E17. In the case of Bax, the expression was decreased from E16, while remaining constant in control group. When TUNEL analysis was performed following the RA treatment at E15, TUNEL positive cells were detected in the mesenchymal cells as well as epithelial cells of palatal shelves of E16 and in E17 embryos. Whereas in normal control, TUNEL positive cells were observed mostly at the epithelium around the nasal cavity and oral cavity where rugae is made. These results altogether indicate that exposure to RA during palate development causes facial deformity including cleft palate and cleft lip by modulating the expression of homeotic genes such as Hoxa7 as well as an apoptosis-related gene, Bax, and thus malregulating the apoptosis.

• Journal of Photoscience
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• 제9권2호
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• pp.5-8
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• 2002

Photoperiodism is an important adaptive phenomenon in various physiological parameters including reproduction to cope with seasonal changes. Involvement of extraretinal photoreceptors in the photoperiodism in non-mammalian vertebrates has been well established. In addition, circadian clock system is known to be involved in the photoperiodic time measurement. The pathway consists of light-input system, time measurement system (circadian clock), gonadotropin releasing hormone (GnRH) production in the hypothalamus, luteinizing hormone (LH) and follicle stimulating hormone (FSH) production in the pituitary, and final gonadal development. Recently, several laboratories reported photopigments newly cloned in the pineal, eyes and deep brain in addition to already known visual pigments in the retina. These are pinopsin, parapinopsin, VA-opsin, melanopsin, etc. All these photopigments belong to the opsin family having retinal as the chromophore. However, the function of these photopigments remains unknown. I reviewed the studies on the location of the photopigments by immunocytochemistry. I also discussed the results on the action spectra for induction of gonadal development in relation with the location of the photoreceptors. Various physiologically active substances distribute in the vertebrate brain. Such substances are GnRH, GnIH, neuropeptide Y, vasoactive intestinal peptide, c-Fos, galanin, neurosteroids, etc. I summarized the immunhistochemical studies on the distribution and the photoperiodic changes of these substances and discussed the route from the deep brain photoreceptor to GnRH cells.

• Journal of Korean Neurosurgical Society
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• 제52권3호
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• pp.193-199
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• 2012

Objective : The objective of study is to evaluate the incidence of leptomeningeal carcinomatosis (LMC) in breast cancer patients with parenchymal brain metastases (PBM) and clinical risk factors for the development of LMC. Methods : We retrospectively analyzed 27 patients who had undergone surgical resection (SR) and 156 patients with whole brain radiation therapy (WBRT) as an initial treatment for their PBM from breast cancer in our institution and compared the difference of incidence of LMC according to clinical factors. The diagnosis of LMC was made by cerebrospinal fluid cytology and/or magnetic resonance imaging. Results : A total of 27 patients (14%) in the study population developed LMC at a median of 6.0 months (range, 1.0-50). Ten of 27 patients (37%) developed LMC after SR, whereas 17 of 156 (11%) patients who received WBRT were diagnosed with LMC after the index procedure. The incidence of LMC was significantly higher in the SR group compared with the WBRT group and the hazard ratio was 2.95 (95% confidence interval; 1.33-6.54, p<0.01). Three additional factors were identified in the multivariable analysis : the younger age group (<40 years old), the progressing systemic disease showed significantly increased incidence of LMC, whereas the adjuvant chemotherapy reduce the incidence. Conclusion : There is an increased risk of LMC after SR for PBM from breast cancer compared with WBRT. The young age (<40) and systemic burden of cancer in terms of progressing systemic disease without adjuvant chemotherapy could be additional risk factors for the development of LMC.