• Proceedings of the Korea Society of Poultry Science Conference
• /
• 2002.11a
• /
• pp.46-58
• /
• 2002

포도당 대사에서 중심적인 역할을 담당하고 있는 호르몬인 인슐린의 작용기전은 이전에 알려진 것보다 매우 다양하고 복잡한 세포내 신호전달 체계에 의해서 수행된다. 지난 10여년간 이러한 세포 신호전달 흐름내 중간물질인 여러 가지 단백질의 역할에 대해서 많은 연구가 진행되어 적지 않은 성과를 거두고 있다. 근래에는 해당 유전자에 대해 분자생물학적인 조작을 가하여 실험동물 체내에서 이러한 중간 단백질이 발현되지 못하도록 한 후, 각 조직에서의 인슐린 신호전달 체계를 더욱 심도 있게 연구하고 있다. 여러 연구방법 가운데서, 특히 조직 특이적으로 특정 유전자를 제거하여 태어난 개체를 이용하고, 또한 이들을 서로 교배시켜 나타나는 현상을 연구하여 비정상적인 포도당대사를 이해하는데 많은 도움을 받고 있다. 동물종에 따른 대사상의 차이점 등으로 인해 적지 않은 한계를 갖고 있지만, 동물 질환모델은 포도당 대사와 같은 생체 내에서 중요한 작용을 깊게 이해하고 더 나아가서는 비정상적인 대사를 밝히는데 핵심적인 역할을 수행하고 있다. 기초분야의 성과를 활용하는 응용학문인 축산분야에서도 이러한 접근방법과 연구 결과는 시사하는 바가 있을 것이다.

• Progress in Superconductivity
• /
• v.12 no.2
• /
• pp.124-128
• /
• 2011

We have developed a high-$T_C$ SQUID magnetometer system to measure magnetocardiograms of laboratory rats. White noise of the measurement system was about 50 fT/$Hz^{1/2}$ when measured in a magnetically shielded box. We optimized the measurement position to obtain clear MCG wave from rat's small heart by using grid measurements. With the optimization, the MCG signal was successfully detected with the peak amplitude of about 50 pT. We could observe well defined P-, QRS-, and T-wave from the rat MCG. The results suggest that the developed system has a strong potential to monitor the progress of heart disease model using laboratory rat.

• Progress in Superconductivity
• /
• v.11 no.2
• /
• pp.147-151
• /
• 2010

We have developed a high-$T_c$ SQUID magnetocardiogram (MCG) system for small laboratory animals. White noise of the measurement system was about 30 fT/$Hz^{1/2}$ when measured in a magnetically shielded room. We optimized the measurement position to obtain clear MCG wave from rat's small heart by using grid measurements. With the optimization, the MCG signal was successfully detected with the peak amplitude of about 30 pT. We could observe well defined P-, QRS-, and T-waves from the rat MCG. The results suggest that the developed system has a strong potential to monitor the progress of the heart disease model by using a laboratory rat.

• Biomolecules & Therapeutics
• /
• v.14 no.2
• /
• pp.96-101
• /
• 2006

Amyloid$\beta(A{\beta})$ has been reported have an effect on the induction of oxidative stress that involves the functional and structural abnormalities in Alzheimer's disease. As a role of a radical scavenger, a green tea treatment was found have some inhibitory effect on the neurodegenerative process. The aim of this study was to determine if green tea catechin (GTC) reduces in transgenic model. To test this, transgenic mice carrying neuronspecific enolase (NSE) controlled C-terminus (105) of APP (APP-C105) were created and treated them with a low ana high dose of GTC for 6 months. Herein, we conclude that transgenic mice expressing NSE/APP-C105 were successfully created and the GTC-treated group exhibited significant reduction in body weight. Thus, GTC might be a good prevention of obesity or good treatment for AD patient.

• Archives of Pharmacal Research
• /
• v.22 no.6
• /
• pp.554-558
• /
• 1999

The effects of ethanolic extract (EEP) of propolis on chronic inflammation were evaluated using rat adjuvant arthritis. In the chronic inflammatory animal model, the arthritis index was suppressed by EEP treatments (50 mg/kg/day and 100 gm/kg/day, p.o.). Moreover, physical weakness, induced by the chronic disease state, was dose-dependently improved in the EEP-treated groups. It s analgesic effect, assessed using the tail-flick test, was comparable to prednisolone (2.5 mg/kg/day, p.o.) and acetyl salicylic acid (100 mg/kg/day, p.o.). In carrageenan rat hind paw edema, which was conducted to test the effects of subfractions of EEP, the petroleum ether sub-fraction (100 mg/kg, p.o.) showed an inhibitor effect on the paw edema whereas EEP (200 mg/kg, p.o.) showed a significant anti-inflammatory effect at 3 and 4 hrs after carrageenan injection. From these results, we conclude that the ethanolic extract of propolis had a profound anti-inflammatory effects on both chronic and acute inflammations.

• Biomolecules & Therapeutics
• /
• v.10 no.4
• /
• pp.218-223
• /
• 2002

This study compared the blood-brain barrier permeability of [$^3H$] taurine in senescence-accelerated mouse (SAM) and normal mouse with common carotid artery perfusion (CCAP) method and intravenous injection technique to establish a possible relation between aging and changes in tissue levels of taurine. The SAM strains show senescence acceleration and age-associated pathological phenotypes similar to geriatric disorders seen in humans. In the result of this experiments, the plasma clearance of [$^3H$]taurine in SAM was almost comparable with that of normal mice by intravenous injection technique, but the brain volume of distribution ($V_{D brain}$) of [$^3H$]taurine in SAM by CCAP method reduced by 85% compared with that in normal mice. These results suggest that aging may have an effect on the brain transport activity of taurine in disease state model animal.

• Molecules and Cells
• /
• v.44 no.6
• /
• pp.377-383
• /
• 2021

Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is a novel virus that causes coronavirus disease 2019 (COVID-19). To understand the identity, functional characteristics and therapeutic targets of the virus and the diseases, appropriate infection models that recapitulate the in vivo pathophysiology of the viral infection are necessary. This article reviews the various infection models, including Vero cells, human cell lines, organoids, and animal models, and discusses their advantages and disadvantages. This knowledge will be helpful for establishing an efficient system for defense against emerging infectious diseases.

• Biomedical Science Letters
• /
• v.28 no.2
• /
• pp.101-108
• /
• 2022

High-fat diet (HFD)-fed ovariectomized (OVX) female mice were used as an animal model of obese postmenopausal women. We investigated the effects of ascorbic acid on the histological changes induced in the liver. Plasma alanine aminotransferase levels and liver weights were higher in mice fed an HFD for 18 weeks than in mice fed a low-fat diet, effects that were inhibited by ascorbic acid. Similarly, mice fed an ascorbic acid-supplemented HFD had less hepatic lipid accumulation than did mice fed an HFD alone. Moreover, administration of ascorbic acid reduced inflammatory cells, including mast cells and CD68-positive cells, and inflammatory foci in the liver and inhibited hepatocyte ballooning. Hepatic collagen levels were lower in ascorbic acid-treated versus non-treated mice. These results suggest that ascorbic acid inhibits hepatic steatosis, inflammation, and fibrosis in obese OVX mice. Thus, ascorbic acid intake may be useful for postmenopausal women with nonalcoholic fatty liver disease.

• Electronics and Telecommunications Trends
• /
• v.38 no.1
• /
• pp.46-54
• /
• 2023

The announcement of the US Environmental Protection Agency that it will stop conducting or funding experimental studies on mammals by 2035 should prioritize ongoing efforts to develop and use alternative toxicity screening methods to animal testing. Toxicity screening is likely to be further developed considering the combination of human-induced pluripotent-stem-cell-derived organ-on-a-chip and multielectrode array (MEA) technologies. We briefly review the current status of MEA technology and MEA-based neuropharmacological drug screening using various cellular model systems. Highlighting the coronavirus disease pandemic, we shortly comment on the importance of early prediction of toxicity by applying artificial intelligence to the development of rapid screening methods.

• Laboraroty Animal Research
• /
• v.34 no.4
• /
• pp.166-175
• /
• 2018

Recombination activating gene-2 (RAG-2) plays a crucial role in the development of lymphocytes by mediating recombination of T cell receptors and immunoglobulins, and loss of RAG-2 causes severe combined immunodeficiency (SCID) in humans. Rag-2 knockout mice created using homologous recombination in ES cells have served as a valuable immunodeficient platform, but concerns have persisted on the specificity of Rag-2-related phenotypes in these animals due to the limitations associated with the genome engineering method used. To precisely investigate the function of Rag-2, we recently established a new Rag-2 knockout FVB mouse line ($Rag-2^{-/-}$) manifesting lymphopenia by employing a CRISPR/Cas9 system at Center for Mouse Models of Human Disease. In this study, we further characterized their phenotypes focusing on histopathological analysis of lymphoid organs. $Rag-2^{-/-}$ mice showed no abnormality in development compared to their WT littermates for 26 weeks. At necropsy, gross examination revealed significantly smaller spleens and thymuses in $Rag-2^{-/-}$ mice, while histopathological investigation revealed hypoplastic white pulps with intact red pulps in the spleen, severe atrophy of the thymic cortex and disappearance of follicles in lymph nodes. However, no perceivable change was observed in the bone marrow. Moreover, our analyses showed a specific reduction of lymphocytes with a complete loss of mature T cells and B cells in the lymphoid organs, while natural killer cells and splenic megakaryocytes were increased in $Rag-2^{-/-}$ mice. These findings indicate that our $Rag-2^{-/-}$ mice show systemic lymphopenia with the relevant histopathological changes in the lymphoid organs, suggesting them as an improved Rag-2-related immunodeficient model.