• KSBB Journal
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• 제13권2호
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• pp.187-194
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• 1998

For mass production of polyhydroxyalkanoates (PHA), high cell density cultures of Alcaligenes eutrophus by fed-batch culture under phosphate-limitation condition has been investigated. PHA accumulation by the regulation by the regulation of initial phosphate concentration could be automatically induced, and high density cell culture above 200 g/L also could be successfully produced. The production of Poly-$\beta$-hydroxybutyrate (PHB) and dry cell weight increased with increasing the initial phosphate concentration. When the initial concentrations of phosphate were in the ranges of 1.5~4.5 g-PO$_4$/L, PHB and dry cell weight obtained were 83~266 g/L and 61~216 g/L, respectively, and PHB productivity was in the ranges of 1.35~3.10 g/L.h. When a mixture of glucose and propionic acid is used as carbon sources, poly(3-hydroxybutyrate-co-poly-3-hydroxyvalerate), P(3HB-co-3HV), could be also successfully produced under phosphate limitation condition. When the mole ratio of propionic acid to glucose in the feeding solution is 0.22, a final dry cell weight of 150 g/L and a P(3-HB-co-3HV) of 90 g/L were produced. Morphological changes and size distribution of PHB granules synthesized in A. eutrophus under phosphate-limitation condition are determined by TEM during the course of fed-batch. Mean granule diameters of PHB produced are in the range of 0.36~0.39 $\mu$m, and mean cell size was elongated from 0.54~0.59 $\mu$m$\times$ 1.3~1.5 $\mu$m to 0.83~0.89 $\mu$m $\times$2.0~2.3 $\mu$m. Phosphate concentration in media did not affect size distribution of PHB granule and cell.

• Animal cells and systems
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• 제12권4호
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• pp.211-217
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• 2008

Bax, a pro-apoptotic member of Bcl-2 family proteins, plays a central role in the mitochondria-dependent apoptosis. Apoptotic signals induce the translocation of Bax from cytosol into the mitochondria, which triggers the release of apoptogenic molecules such as cytochrome C and apoptosis-inducing factor, AIF. Bax-inhibiting peptide(BIP) is a cell permeable peptide comprised of five amino acids designed from the Bax-interaction domain of Ku70. Because BIP inhibits Bax translocation and Bax-mediated release of cytochrome C, BIP suppresses Bax-dependent apoptosis. In this study, we observed that BIP inhibited staurosporine-induced neuronal death in cultured cerebral cortex and cerebellar granule cells, but BIP failed to rescue granule cells from trophic signal deprivation-induced neuronal death, although both staurosporine-induced and trophic signal deprivation-induced neuronal death are dependent on Bax. These findings suggest that the mechanisms of the Bax activation may differ depending on the type of cell death induction, and thus BIP exhibits selective suppression of a subtype of Bax-dependent neuronal death.

• Applied Microscopy
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• 제26권4호
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• pp.411-420
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• 1996

A zinc-specific method (selenium method) has been employed to identify the zinc-containing cells in the cerebellum of the rats. When rats were allowed to survive 24 hours after the sodium selenite administration, zinc selenide reaction products formed in zinc-containing cellular boutons are retrogradely transported to the somata of those boutons. And the zinc selenide products accumulated in somata of the cells can be rendered visible by silver amplification of developer. Zinc-containing cells identified by the method were Bergmann glial and granule cells. Labeled zinc-containing cells were absent in molecular layer and white matter of the cerebellum. In ultrastructural level, the zinc selenide products were located in lysosomes of somata of the zinc-containing cells.

• Applied Microscopy
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• 제11권1호
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• pp.39-50
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• 1981

성숙하고 정상인 포유류 6종의 동물들을 이용하여 위에 분포하는 비만세포의 형태와, 세포내 과립의 구조적 형태의 종간차이를 비교하고자 전자현미경으로 관찰을 하였다. 저자는 특히 관찰된 세포질내 과립을 편의상 다음과 같이 분류하였다. 1) 동질성 과립 (homogeneous granule, GR1) 2) 미세 입자과립 (particulate granule, GR2) a. 고전자밀도 미세 입자과립 (dark dense particulate granule, GR2-1) b. 중전자밀도 미세 입자과립 (less dense particulate graunle, GR2-2) 3) 망상구조과립 (reticular granule, GR5) a, 고전자말도 망상구조과립(dark dense reticular granule, GR5-1) b. 저전자밀도 망상구조과립(light dense reticular granule, GR5-2) 포유류인 염소, 개, 고양이, 햄스터에서는 대부분 세포질내 소기관중 골지체 및 사립체가 나타났으며 세포질내 과립의 대부분이 전자밀도가 높은 동질성인 것 (GR1)과 미세입자형으로 된 것 (GR2)이 나타났다. 그러나 Guinea pig에서는 망상구조형의 과립들 (GR5-1, GR5-2)이 나타났다. 또한 개와 Guinea pig 에서 과립의 한쪽이 함몰되었거나 반월형인 것이 나타났다. 위 결과로 보아 표유류 각 종 간의 비만세포, 세포내 과립은 형태학적으로 차이가 있음을 알 수 있으며, 이러한 차이는 아마도 종 간의 기능에 따른 과립의 구조적 차이와 구성성분 및 성숙도등과 상관관계가 있는 것으로 추측된다.

• Applied Microscopy
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• 제17권1호
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• pp.98-114
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• 1987

Degranulation of the rat peritoneal mast cell induced by intraperitoneal injection of horseradish peroxidase(HRP) was studied using light and electron microscopes. 1. Rat peritoneal mast cells in the Tyrode's buffered salt solution injected control group did not show any particular morphological changes following the specified time course. 2. Under the light microscope, the majority of mast cells observed 10 minutes after HRP injection were nearly the same as those of the control group. However, after 30 minutes, granule densities or staining properties of certain cells began to decrease and these appearances increased gradually until 12 hours after injection, at which time small groups of granules being stained pale-red or pink with toluidine blue were easily identified in the cytoplasm of many cells, and numerous extruded granuleg were scattered around these cells. 3. In the mast cells representing the early stage of degranulation induced by HRP, the electron densities of certain granules decreased as the size enlarged, and perigranular cavities were formed by perigranular membrane expansion. As a result, a thin cytoplasmic septum was formed between the expanded perigranular membrane and the cytoplasmic membrane in the cell periphery, and fusion of the adjacent perigranular membranes was observed in the inner side of the cell. 4. In some mast cells, one or two changes in the peripheral cytoplasmic septum could be seen. One was a focal rupture of the peripheral septum and the other was the formation of a saccule containing one or more vesicles. This saccule was thought to be used for granule-extrusion site and/or material absorptive apparatus judging from the morphological characteristics. 5. As the degranulation proceeded, the granule was extruded from the cell after partial rupture of the peripheral cytoplasmic septum. This phenomenon proceeded to-ward the inner side of the cell through the fused perigranular cavities, and consequently several distinct cavities containing a few unextruded membrane-free granules were formed throughout the cytoplasm after 12 hours. As a rule, the granule-extrusion sites were relatively fewer while the cytoplasmic cavities resulting from degranulation were more numerously observed. Thus, it was thought that the granule-extrusion sites tended to be restricted in the HRP-induced degranulation.

• Toxicological Research
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• 제12권1호
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• pp.69-79
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• 1996

Primary culture of cerebellar neuronal cells derived from 8-day old Long-Evans rats was used. Pure granule cells, astrocytes or mixed cells culture systems were prepared. These cells were differentiated and developed synaptic connections. And the astrocytes were identified by immunostaining with glial fibrillary acidic protein (GFAP). Methamphetamine (MAP), which acts on dopaminergic system and cadmium (Cd), a toxic heavy metal, were applied and biochemical assays and electrophysiological studies were performed. $LC_50$ values estimated by MTT assay of MAP and Cd were 3 mM and 2$\mu M$ respectively. Cells were treated with 1 mM or 2 mM MAP and 1$\mu M$ $CdCl_2$ for 48 hour, and the incubation media were analyzed for the content of released LDH. MAP (2 mM) and Cd significantly increased the LDH release. Cell viability was decreased in both groups and some cytopathological changes like cell swelling or vacuolization were seen. The cerebellar granule cells were used for measuring membrane currents using whole-cell clamp technique. Sodium and potassium currents were not affected by MAP neither Cd, but calcium current was significantly reduced by Cd but not affected by MAP. Therefore, in vitro neurotoxicity test system using neuronaI cells and astrocytes cultures were established and can be used in screening of potential neurotoxic chemicals.

• Applied Microscopy
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• 제20권1호
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• pp.1-16
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• 1990

The epidermal tissue of Korean planaria Phagocata vivida(Ijima et Kaburaki) is composed of the simple columnar epithelium. The ventral epidermis of this animals is thinner than the dorsal epidermis and has a furrow in the median line in which dark cell is observed. The clear cells which are electron-lucent are located either side of the dark cells. Those are compactly covered with long cilia. The free surface of the latero-ventral epidermis is tightly contacted with the earth and this epidermal free surface has a great number of short cilia, and a lot of C-type of basophilic granule cell are migrated into the cytoplasm of epithelium from mesenchyme passing through the basement membrane and then this granules are put out of latero-ventral free surface. Dorsal epidermis is thickest among the whole epidermis of these animals and the rhabdite granules are more distributed in dorsal epidermis than in ventral epidermis. According to the cytochemical and ultrastructural research, composed epidermis of this planaria are divided into nine type cells, that is, ciliated columnar epithelium, dark cell, mucous cell, rhabdite-forming cell, sunk round cell, A type, B type, C type and D type of basophilic granule cell.

• BMB Reports
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• 제49권2호
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• pp.93-98
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• 2016

Germline stem cells (GSCs) are the best understood adult stem cell types in the nematode Caenorhabditis elegans, and have provided an important model system for studying stem cells and their cell fate in vivo, in mammals. In this review, we propose a mechanism that controls GSCs and their cell fate through selective activation, repression and mobilization of the specific mRNAs. This mechanism is acutely controlled by known signal transduction pathways (e.g., Notch signaling and Ras-ERK MAPK signaling pathways) and P granule (analogous to mammalian germ granule)-associated mRNA regulators (FBF-1, FBF-2, GLD-1, GLD-2, GLD-3, RNP-8 and IFE-1). Importantly, all regulators are highly conserved in many multi-cellular animals. Therefore, GSCs from a simple animal may provide broad insight into vertebrate stem cells (e.g., hematopoietic stem cells) and their cell fate specification.

• 한국환경농학회지
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• 제15권3호
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• pp.306-315
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• 1996

납 내성균인 P. aeruginosa의 균체내 납 축적 특성, 축적형태 및 균체내에 축적된 납의 회수 방법을 조사한 결과는 다음과 같다. 납 농도가 100mg/l인 용액중에서 처리 48시간 후 납 내성균주의 납 처리율은 약 97% 이상이었다. 납이 축적된 균체를 전자현미경으로 관찰한 결과, 균체의 cell wall과 cell membrane에 많은 electron-dense granule들이 형성되어 있었으며, electron-dense granule들을 EDS로 분석한 결과, 이 granule들은 lead complex인 것으로 확인되었다. 공시균주의 균체내 축적된 납은 증류수에 의해서는 거의 탈착이 되지 않았으나 EDTA 처리에 의해서는 약 87% 이상 탈착되었다. 납이 축적된 균체를 $550^{\circ}C$에서 회화시켰을 때 건조균체량의 약 30%에 해당하는 작열잔류화합물들이 생성되었으며, 이 작열잔류화합물들을 EDS로 분석한 결과, 납이 약 86% 이상 함유되어 있는 비교적 순수한 납 화합물인 것으로 확인되었다.

• Journal of Photoscience
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• 제7권1호
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• pp.31-34
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• 2000

The heterotrichous ciliate Stentor coeruieus shows a step-up photophobic response to visible light In the previous paper, the existence of GTP-binding proteins was confirmed by using the antisera against the carboxy terminal decapeptide of transducin $\alpha$ subunit. The photoreceptor, stentorin, is localized in the pigment granule. If the immunoreactive G-protein directly interacts with the photoreceptor stentorin, the G-protein expected to be located in the pigment granule rather than plasma membrane. To elucidate the function of the immunoreactive G-protein, the localization of the G-protein in Stentor coeruleus was studied. The results suggest that this G-protein is located in the myoneme involved in the contraction and extension of the cell rather than in the pigment granule.