143 research outputs found
에이퍼트 증후군 모델 마우스 얼굴 기형의 3차원 형태 분석을 통한 발병 기전 규명 및 치료법 제시
학위논문 (박사) -- 서울대학교 대학원 : 치의학대학원 치의과학과, 2021. 2. 류현모.Apert syndrome, caused by activating mutation in the FGFR2 gene commonly presents craniosynostosis, midface hypoplasia and respiratory problems. Unfortunately, the pathological mechanism and intrinsic contributing factor still remain unclear, and there is no cure but serial surgical treatment in the earliest stage of the patient’s life. In this study, we analyzed the causal factors of midface hypoplasia in Apert syndrome mouse model with three-dimensional morphometric analysis and histological assessment. Moreover, we suggested the therapeutic and surgical target for Apert syndrome treatment.
We used Fgfr2S252W/+ mice as a mouse model of Apert syndrome. In part 1, we found the premature fusion of anterior facial bones is the main contributing factor toward the anterior-posterior skull length shortening. The facial anomalies are closely related to the abnormal cranial base growth, which could possibly induce the airway obstruction. The inhibition of Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1), a downstream signaling enzyme of FGF/FGFR signaling, via genetic knockdown or use of a PIN1 inhibitor, juglone, attenuated the facial deformities in mouse model.
In part 2, we applied chondrocyte-specific Fgfr2S252W mutation in mice (Col2a1-cre; Fgfr2S252W/+) to examine the effect of cartilaginous component in the midface hypoplasia. These mice showed normal skull shape at birth, however, hypoplastic phenotypes were progressively evident. Especially, abnormal growth of nasal bone, vomer and ethmoid bone was notably presented, suggesting the involvement of altered nasal septal cartilage in the midface hypoplasia. Fgfr2S252W mutation on the septum chondrocytes accelerated hypertrophy and enlarged cellular size, finally, thickened and altered septal cartilage shape caused facial deformities.
In this study, we provided the pathological mechanisms for midface hypoplasia in Apert syndrome by detailed three-dimensional morphometric and histological analysis. Furthermore, we suggested targeting PIN1 and surgical correction of abnormal nasal septal cartilage as a treatment strategy for Apert syndrome patients. We expect these multidimensional observations and analyses on the mouse model of Apert syndrome could help the patients with syndromic craniosynostosis to reduce the risk of surgical process and have better prognosis.주로 FGFR2 돌연변이에 의한 FGF/FGFR 신호 증가로 인해 발생하는 에이퍼트 증후군 (Apert syndrome)은 대표적으로 두개골 조기 유합증 (craniosynostosis)과 중안모 저성장 (midface hypoplasia), 그로 인한 호흡 곤란 등의 증상을 나타낸다. 하지만 현재로서는 중안모 저성장의 정확한 발병 기전을 알지 못하며, 어린 시기부터 여러 차례에 걸친 수술 이외에는 치료 방법이 없는 실정이다. 본 연구에서는 에이퍼트 증후군의 마우스 모델 (Fgfr2S252W/+)을 사용하여, 3차원 형태 분석과 조직학적 분석을 통해 중안모 저성장을 일으키는 주요 원인을 파악하고자 한다. 또한 증상의 예방과 치료를 위한 약물 타겟 및 적절한 수술 방법을 제시하고자 한다.
Part 1에서는, Micro-CT로 촬영한 에이퍼트 마우스 두개안면부의 3차원적 형태 분석을 통해, 안면부를 구성하는 여러 봉합 (suture)의 조기 유합으로 인한 안면부의 길이 감소 및 형태 이상이 가장 두드러지게 나타나는 것을 확인하였다. 이러한 형태 변화는 두개저 (cranial base)의 휘어짐 현상과 밀접하게 연관되어 있으며, 이는 에이퍼트 증후군에서 나타나는 호흡 문제를 직접적으로 야기할 수 있는 요인으로 생각된다. 또한, FGF/FGFR 신호 전달 효소인 PIN1 (Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1)을 유전적 또는 약물학적으로 억제하여 에이퍼트 증후군 마우스 모델에서 나타나는 중안모 증상들이 호전되는 결과를 확인하였다.
Part 2에서는, 연골 특이적으로 FGFR2 돌연변이를 발현하는 마우스 모델을 사용하여 안면부를 구성하는 연골 조직의 성장 변화 및 중안모 발달에 미치는 영향을 살펴보고자 하였다. 해당 마우스에서는 관상 봉합 (coronal suture) 및 안면부를 구성하는 봉합의 조기 유합이 나타나지 않았지만, 여전히 중안모 성장 저하 증상이 나타났고, 특히, 비근점 (nasion)이 위로 솟아 오르는 현상, 앞위턱뼈 (premaxilla)와 보습뼈 (vomer) 사이의 유합, 벌집뼈 (ethmoid bone)의 형성 감소, 코뼈 휘어짐 증상이 두드러지게 나타났다. 해부학적으로 이들 골 조직은 비중격 연골 (nasal septal cartilage)을 중심으로 연결되어 있는데, 비중격 연골의 3차원 형태학적 분석을 통해 연골의 두께가 두꺼워지고 형태가 변형되어 비중격 만곡 (septal deviation)이 나타나는 것을 확인하였다. 이러한 비중격 연골의 두께 및 높이 증가는 연골을 구성하는 연골 세포의 비대 (hypertrophy) 증가로 인한 것으로 나타났다. 결과적으로, FGFR2 돌연변이에 의한 비중격 연골의 두께 증가 및 형태 변화는 안면부의 성장 저하를 일으키는 중심적인 역할을 하는 것으로 보인다.
본 연구에서는 다각적이고 자세한 3차원 형태 분석을 통해 에이퍼트 증후군의 마우스 모델에서 나타나는 중안모 저성장의 발병 기전을 분석하였다. 중안모 저성장의 주요 원인으로써, 안면을 구성하는 여러 봉합의 조기 유합과 두개저의 형태 변화, 그리고 비중격 연골 형태 변화를 제시하였고, 에이퍼트 증후군의 중안모 성장 저하 수술 과정에서의 적절한 수술 방법 전략을 제시할 수 있었다. 더불어, PIN1 억제로 인한 안면부 봉합의 조기 유합 증상 완화 효과를 보여줌으로써 에이퍼트 증후군의 약물 치료 타겟을 제시하였다. 따라서, 에이퍼트 증후군에서 나타나는 증상들을 다방면으로 분석한 본 연구의 결과가 에이퍼트 증후군의 증상 예방 및 완화, 중안모 성장 저하의 적절한 치료 방법과 시기를 결정하는데 응용 될 수 있을 것으로 기대한다.I. Literature reveiw 1
II. Purpose of study 14
III. Part1. PIN1 attenuation improves midface hypoplasia in a mouse model of Apert syndrome 15
IV. Part2. Role of septal cartilage on midface hypoplasia of Apert syndrome 68
V. Conclusion 129
VI. References 130
VII. 국문초록 145Docto
나노컨파인드 물의 유체 동역학적 성질
학위논문 (박사)-- 서울대학교 대학원 : 물리·천문학부(물리학전공), 2014. 2. 제원호.Most of the nano-metric confined space is filled with liquid water called nanoconfined water in ambient condition, to say nothing of liquid water enviroment.
The ubiquitous nanoconfined water naturally plays an important role for various mechanisms such as biological processes, swelling clays, colloidal interaction, and friction.
In the 21st Century, the study of the nanoconfined water has begun in earnest due to the development of techniques to control stable nanoconfined space in ambient or liquid condition.
Meanwhile reported properties of nanoconfiend water are summarized as follows. (i) enhanced viscosity 10^2~10^7 times larger compared with bulk water, (ii) sluggish relaxation time (10^-2 ~ 10^-9 s), (iii) nonlinear viscoelasticity, and (iv) violence of classic interfacial force.
Although the various properties have been phenomenologically known, however, (1) the fundamental understanding of characteristics or the understanding of the relation between properties are still insufficient. And, (2) until now, the slow velocity (<~10^-6 m/s) experiments are performed only even though more fast-velocity friction frequently occurs in nature.
In this study, (1) the unified stress tensor of nanoconfined hydration water layer (HWL), which shows the relation between characteristics of HWL and leads the other physical quantities by relation between tapping and shear properties, is introduced and demonstrated using quartz tuning fork based atomic force microscopy (QTF-AFM). And, (2) through fast velocity ( ~1 mm/s) experiments, the nanoscale elastic turbulence, which is marvelous phenomenon since it is impossible in Newtonian flow, is observed. Moreover the autoregulation in capillary, which is phenomenon that blood flow velocity is maintained automatically despite of a blood pressure change, may be understood through the nanoscale elastic turbulence between red blood cell and capillary wall.
The study about unified stress tensor would contribute not alone nanoconfined water but methodology of various viscoelastic material studies. And elastic turbulence in nanoconfined water would be considered in various fields where nanoconfiend water exists. In particular, the physical understainding of autoregulation in capillary is anticipated to expand understanding of brain science such as cerebral infarction
or Alzheimer's disease.Contents
Abstract i
List of Figures v
Chapter 1 Introduction 1
Chapter 2 QTF-AFM 9
2.1 Quartz tunning fork (QTF) . . . . . . . . . . . . . . . . . . . . 9
2.2 QTF based Amplitude Modulation Atomic Force Microscopy (AM-AFM)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Chapter 3 Mechanical Characteristics of Confined Hydration Water Layer 20
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3.2 Development of Hydration Stress Tensor . . . . . . . . . . . . . 24
3.3 Validity of Hydration Stress Tensor using QTF-AFM . . . . . . 30
3.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
iii
Chapter 4 Nanoscale Turbulence in Confined HWL 39
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4.2 Nonlinear Dynamics of HWL . . . . . . . . . . . . . . . . . . . . 42
4.3 Reynolds and Weissenberg number . . . . . . . . . . . . . . . . 47
4.4 Viscoelastic Model . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.4.1 Linear Maxwell model . . . . . . . . . . . . . . . . . . . . 49
4.4.2 Nonlinear Maxwell model . . . . . . . . . . . . . . . . . . 50
4.5 Elastic Turbulence in Nonlinear Maxwell Model . . . . . . . . . 54
4.5.1 Additive Stress via Correlation between Fluctuations . . 54
4.5.2 Scaling of Additive Stress . . . . . . . . . . . . . . . . . 55
4.6 Fluidity of Confined HWL . . . . . . . . . . . . . . . . . . . . . 58
4.7 Understanding of Autoregulation in capillary via ET . . . . . . 60
4.8 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Chapter 5 Conclusions 67
] 70Docto
Regional Connectivity Changes According to Seizure Outcome of Temporal Epilepsy Surgery- A Magnetoencephalography Study
Objective: Temporal lobectomy is often successful in treatment of patients with medically intractable temporal lobe epilepsy (TLE), but prediction of its long-term outcome is of great interest. Here, we investigated usefulness of comparison analysis of pre- and post-surgical magnetoencephalopgrahy data in predicting prognosis of temporal lobectomy.
Methods: The authors retrospectively analyzed pre-and post-operative MEG and presence of any seizures after temporal lobectomy in 8 patients with TLE. Spectral powers averaged from spike-free epochs in each condition (pre- and post-operation) were compared between 4 patients free from seizures and the other 4 with recurrent seizures. We also performed connectivity analysis based on phase locking values (PLVs) around resection margins of possible epileptogenic focus as regions of interest.
Results: Spectral analysis on peri-lesional areas demonstrated relative increase of delta power in the patients without seizure freedom. On connectivity analysis, decrease of PLVs between other areas and temporal lobe focus after surgery were noted in patients with good surgical outcome while persistence or increase were found in patients with recurred seizures.
Conclusion: This pilot study on comparison of power spectrum and connectivity metrics between pre- and post-op MEG exhibits a potential for predicting seizure outcome after TLE surgery.ope
Non-invasively enhanced intracranial transplantation of mesenchymal stem cells using focused ultrasound mediated by overexpression of cell-adhesion molecules
Although there have been reports of promising results regarding the transplantation of mesenchymal stem cells (MSCs) for neurodegenerative diseases through the use of neuronal differentiation or control of the microenvironment, traditional surgical transplantation methods like parenchymal or intravenous injection have limitations such as secondary injuries in the brain, infection, and low survival rate of stem cells in the target site. Focused ultrasound (FUS) treatment is an emerging modality for the treatment of brain diseases, including neurodegenerative disorders. The various biological effects of FUS treatment have been investigated; therefore, the goal is now to improve the delivery efficiency and function of MSCs by capitalizing on the advantages of FUS. In this study, we demonstrated that FUS increases MSC transplantation into brain tissue by >2-fold, and that this finding might be related to the activation of intercellular adhesion molecule-1 in endothelial and subendothelial cells and vascular adhesion molecule-1 in endothelial cells.ope
Analytical Tools and Databases for Metagenomics in the Next-Generation Sequencing Era
Metagenomics has become one of the indispensable tools in microbial ecology for the last few decades, and a new revolution in metagenomic studies is now about to begin, with the help of recent advances of sequencing techniques. The massive data production and substantial cost reduction in next-generation sequencing have led to the rapid growth of metagenomic research both quantitatively and qualitatively. It is evident that metagenomics will be a standard tool for studying the diversity and function of microbes in the near future, as fingerprinting methods did previously. As the speed of data accumulation is accelerating, bioinformatic tools and associated databases for handling those datasets have become more urgent and necessary. To facilitate the bioinformatics analysis of metagenomic data, we review some recent tools and databases that are used widely in this field and give insights into the current challenges and future of metagenomics from a bioinformatics perspective.
Development of Time Varying Kalman Smoother for Extracting Fetal ECG using Independent Component Analysis : Preliminary Study
Fetal heart rate monitoring is important information to assess fetal well-being. Non-invasive fetal ECG (electrocardiography) can be derived from maternal abdominal signal. And various promising signal processing methods have been introduced to extract fetal ECG from mother’s composite abdominal signal. However, non-invasive fetal ECG monitoring still has not been widely used in clinical practice due to insufficient reliable measurement and difficulty of signal processing. In application of signal processing method to extract fetal ECG, it might be lower signal to noise ratio due to time varying white Gaussian noise. In this paper, time varying Kalman smoother is proposed to remove white noise in fetal ECG and its feasibility is confirmed. Wiener process was set as Kalman system model and covariance matrix was modified according to white Gaussian noise level. Modified error covariance matrix changed Kalman gain and degree of smoothness. Optimal covariance matrix according to various amplitude in Gaussian white noise was extracted by 5 channel fetal ECG model, and feasibility of proposed method could be confirmed.ope
Molecular ecology of prokaryotic community in Korean tidal flat
Thesis(doctor`s)--서울대학교 대학원 :생명과학부,2007.Docto
Toward Perfect Light Trapping in Thin-Film Photovoltaic Cells: Full Utilization of the Dual Characteristics of Light
A novel light trapping configuration called a compound parabolic trapper (CPT) is proposed. A CPT integrated with a V-groove textured surface increases the power conversion efficiency of polymer solar cells from 9.38% to 10.4%. A multiscale system applying the integrated schemes to a nanopatterned plasmonic PV improves it further to 10.8%, achieving almost black absorption of 94.1%. © 2015 WILEY-VCH Verlag GmbH &amp;amp; Co. KGaA, Weinheim
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