• The Journal of the Korean bone and joint tumor society
• /
• v.5 no.3
• /
• pp.178-182
• /
• 1999

We report a case of bizarre parosteal osteochondromatous proliferation of the right femur in an 18-year-old man. Roentgenograms showed a calcific mass attached to the underlying cortex with a broad base. Histologically, the lesion showed hypercellular cartilaginous tissue with maturation into trabecular bone, which contained spindle cells and lymphocytes in the intertrabecular spaces. Bizarre parosteal osteochondromatous proliferations are a form of heterotopic ossification and should not be mistaken for osteosarcoma or chondrosarcoma.

• Applied Microscopy
• /
• v.38 no.2
• /
• pp.97-105
• /
• 2008

The fine structural modification of the granulocytes between the molt and intermolt period were investigated by the transmission electron microscopy. The granular hemocytes of the spider Araneus ventricosus were composed of three subtypes: eosinophilic granulocytes (EGs), basophilic granulocytes (BGs) and cyanocytes. Both of the EGs and BGs have electron dense granules within their cytoplasms, however the granules of BGs are larger than those of EGs. During the molt period, some of the EGs have fine structural modification in their cell organelles including formation of phagosomes as a result of active phagocytosis. However, the BGs have no phagosomes, but electron densities of the granules are changed to lower states than the intermolt period. The cyanocyte is the biggest hemocyte among the granulocytes. They contain numerous hemocyanin crystals in the cytoplasm with some electron-lucent vacuoles. During the molt period, some of the cyanocytes are changed to irregular shapes. High magnification electron micrographs reveal that the lattice sub-structure of the hemocyanin crystals are very similar to those of microtubules, and each tubule is composed of approximately 20 filaments with fine fibrillar structure.

• Elastomers and Composites
• /
• v.44 no.2
• /
• pp.98-105
• /
• 2009

The cochlea of the inner ear has two core components, basilar membrane and hair cells. The basilar membrane disperses incoming sound waves by their frequencies. The hair cells are on the basilar membrane, and they are the sensory receptors generating bioelectric signals. In this paper, a biomimetic technology using ZnO piezoelectric nano-pillar was studied as the part of developing process for artificial cochlea and novel artificial mechanosensory system mimicking human auditory senses. In particular, ZnO piezoelectric nano-pillar was fabricated by both low and high temperature growth methods. ZnO piezoelectric nano-pillars were grown on solid (high temperature growth) and flexible (low temperature growth) substrates. The substrates were patterned prior to ZnO nano-pillar growth so that we can selectively grow ZnO nano-pillar on the substrates. A multi-physical simulation was also conducted to understand the behavior of ZnO nano-pillar. The simulation results show electric potential, von Mises stress, and deformation in the ZnO nano-pillar. Both the experimental and computational works help characterize and optimize ZnO nano-pillar.

• Journal of Life Science
• /
• v.23 no.11
• /
• pp.1311-1316
• /
• 2013

Heterogeneous nuclear ribonucleoprotein L (hnRNP L) is a major pre-mRNA binding protein and it is an abundant nuclear protein that shuttles between the nucleus and the cytoplasm. hnRNP L is known to be related to many cellular processes, including chromatin modification, pre-mRNA splicing, mRNA export of intronless genes, internal ribosomal entry site (IRES)-mediated translation, mRNA stability, and spermatogenesis. In order to identify the cellular proteins interacting with hnRNP L, this study performed a yeast two-hybrid screening, using a human liver cDNA library. The study identified insulin-like growth factor binding protein-4 (IGFBP-4) as a novel interaction partner of hnRNP L in the human liver. It then discovered, for the first time, that hnRNP L interacts specifically with IGFBP-4 in a yeast two-hybrid system. The authenticity of this two-hybrid interaction of hnRNP L and IGFBP-4 was confirmed by an in vitro pull-down assay.

• Applied Microscopy
• /
• v.12 no.2
• /
• pp.11-22
• /
• 1982

The morphological development of Mycoplasma pneumoniae attached to solid surfaces was examined by light and electron microscopies. Critical point drying and carbon replication techniques revealed that during the growth cycle of developing microcolonies, the morphological form coincided with the pH of the culture. M. pneumoniae appeared to have a well defined morphology associated with age of the culture. The organisms were dimorphic, with round cells capable of reproduction and segments consisting of a spindle shaped body with one pointed and one knob-like end. Starting with single cells, there were the following stages in the development of a culture: replication stage through binary fission and segmentation, stage of confluency, and a degeneration stage into rough spherical forms. The round cells appearrd to replicate by binary fission during the lag and early log phases of growth, while spindle segments replicated by segmentation during most of the logarithmic growth. The growth of the filaments and replication of the segments occured at the knob-like ends, showing a type of polarity, and formed a meshwork across the surface. This development could be cycled under favorable growth conditions, but the culture aged and when the conditions became adverse(e.g. pH 6.8 or lower), filamentous cells converted to spherical forms, losing their reproductive capability.

• Journal of Life Science
• /
• v.28 no.5
• /
• pp.597-604
• /
• 2018

Although the core mechanisms of Attention Deficit/Hyperactivity Disorder (ADHD) are unknown, several ADHD-associated proteins have been studied. G-protein - coupled receptor kinase interacting protein-1 (GIT1) is a multifunctional adapter protein that affects neuron growth and dendrite formation. GIT1-deficient mice have shown ADHD-like behavior and also recovered through amphetamine treatment. In this study, gliotransmitters were investigated in both intracellular and extracellular space from GIT1-deficient mice. To measure the amount of gliotransmitters, primary astrocyte cultures were taken from the cerebral and cerebellar cortices of wild (WT), hetero (HE), and knock-out (KO) mice. Major gliotransmitters were analyzed using high-performance liquid chromatography. It was observed that the amount of excitatory and inhibitory gliotransmitters were dependent on genotype and showed a change in excitation/inhibition ratios. Interestingly, the major excitatory gliotransmitter, glutamate, existed at the lowest level in WT mice, but the amount of inhibitory gliotransmitters, gamma-aminobutyric acid (GABA) and glycine, varied depending on brain region. Remarkably, an increased amount of GABA was measured at the intracellular cerebrum in WT mice compared with KO mice. It was presumed that KO mice would secrete more inhibitory gliotransmitters to compensate for GIT1 depletion or else acquire a defect to reuptake-secreted GABA. This may be a possible mechanism for ADHD pathology.

• Clinical and Experimental Reproductive Medicine
• /
• v.30 no.4
• /
• pp.293-298
• /
• 2003

목 적: 인간의 배아줄기세포는 전분화능과 영속성을 가지고 있어 발생 및 분화에 관련된 기초 연구 뿐 만 아니라 재생의학, 약물검색 등에서도 매우 유용한 재료로 이용될 수 있다.본 연구에서는 유전체의 변형이 배아줄기세포주의 확립 효율에 미치는 영향을 살펴보고자 비정상적인 포배기 배아에서 내세포괴를 분리하여 배양하였다. 연구 방법: 인간의 체외수정 및 배아이식술에서 공여 받은1개 또는3개의 전핵이 관찰되는 비정상 수정란 (n=20)과 착상전 유전진단에서 이수성이 확인된 배아 (n=27)를 대상으로 하였다. 일반적인 immunosurgery 방법으로 영양배엽세포들을 제거하고 내세포괴를 분리한 후 PMEF 혹은 STO feeder 세포위에서 배양하였다. 배아줄기세포의 배양시스템을 검증하기 위해서 이미 확립된 Miz-hES1 cell line을 동시에 같은 조건 하에서 계대배양하였다. 결 과: 비정상 수정란에서 발생된 포배기 배아에서 분리한 1개의 내세포괴가 배아줄기세포와 유사한 colony를 형성하였으나, 계대배양에는 실패하였다. 이수성 배아에서 발생된 포배기 배아의 내세포괴 배양에서는 두개의 colony가 계대배양 중에 영양배엽세포의 형태로 분화되어 미분화 상태를 유지하지 못하였다. 동일한 시기와 조건 하에서 계대배양된 Miz-hES1 cell line이 미분화상태로 유지됨을 karyotyping (46, XY)과 immunophenotyping (positive in SSEA-3 and -4)으로 확인하였다. 결 론: 본 연구의 결과에서 비정상 수정란과 이수성 배아에서 발생된 포배기 배아에서 유래한 내세포괴는 배아줄기세포주 확립 및 미분화 상태 유지 능력이 매우 저조한 것으로 여겨진다. 따라서, 인간의 배아줄기세포주를 확립하는데 있어 배아의 정상여부가 중요한 요소로 작용할 것으로 생각된다.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.2 no.2
• /
• pp.185-193
• /
• 1999

Purpose: Proliferation of bile duct-like structures and fibrosis is a hepatic cellular reaction observed in most forms of human liver disease and in a variety of experimental conditions associated with liver injury. The aim of this study was to investigate the activation of Ito cells and bile duct proliferation in the rat after common bile duct ligation (CBDL). Methods: Hepatic morphological abnormalities were examined in rats whose bile ducts had been irreversibly ligated for 15, 21, 24 and 28 days. The liver was examined by immunohistochemical staining for ${\alpha}$-smooth muscle actin, the known marker of activated Ito cells, and light and electron microscopes. Results: After CBDL, the bile canalicular proliferation and interstitial fibrosis were gradually increased in the periportal areas extended to hepatic sinusoids. Ito cells positive for ${\alpha}$-smooth muscle actin were frequently observed in the periductular space and in perisinusoidal space of Disse. Ito cells and myofibroblasts were gradually increased in the interstitial fibrosis until the 28th day after CBDL. Ito cells and myofibroblasts had microfilaments with dense body at the periphery of the cell. Conclusions: Our results suggest that Ito cells may be fibroblastic or myogenic. It has also been postulated that during the development of hepatic fibrosis, Ito cells become myofibroblasts or fibroblast like cells.

• Journal of the Korean Applied Science and Technology
• /
• v.35 no.1
• /
• pp.194-204
• /
• 2018

This study was to investigate the effect of the extract(KP-HE) from Kalopanax pictus(KP) fermented with Hericium erinaceum(HE) mycelium on oxidative modification of neurofilament-L(NF-L) which is closely related to neurodegenerative disorders. The oxidative modification of NF-L was induced by AAPH producing peroxyl radicals in solution, and KP, HE, and KP-HE was investigated. KP and HE did not protect NF-L against peroxyl radical-mediated NF-L modification whereas KP-HE significantly prevented NF-L modification induced by peroxyl radical. KP-HE inhibited the formation of dityrosine in oxidative modification of NF-L and stimulated the peroxyl radical scavenging activity. The effects of KP, HE, and KP-HE on the modification of NF-L by tetrahydropapaveroline(THP), a neurotoxin found in patients with Parkinson's disease was investigated. KP-HE also prevented THP-mediated NF-L modification as compared to KP and HE. In addition, KP-HE significantly inhibited the formation of dityrosine in oxidative modified NF-L and enhanced the inhibition of reactive oxygen species(ROS) was generated by THP. The results suggested that KP-HE can contribute to protected cell from oxidative stress was induced by ROS and neurotoxin. Therefore, KP-HE could potentially be used as a valuable functional food ingredient to prevent neurodegenerative disorders.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.31 no.8
• /
• pp.855-861
• /
• 2007

Haptic rendering is a process providing force feedback during interactions between a user and a virtual object. This paper presents a real-time haptic rendering technique for deformable objects based on visual information of intervention between a tool and a real object in a remote place. A user can feel the artificial reaction force through a haptic device in real-time when a slave system exerts manipulation tasks on a deformable object. The models of the deformable object and the manipulator are created from the captured image obtained with a CCD camera and the recognition of objects is achieved using image processing techniques. The force at a rate of 1 kHz for stable haptic interaction is deduced using extrapolation of forces at a low update rate. The rendering algorithm developed was tested and validated on a test platform consisting of a one-dimensional indentation device and an off-the shelf force feedback device. This software system can be used in a cellular manipulation system providing artificial force feedback to enhance a success rate of operations.