• Plant Biotechnology Reports
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• v.2 no.1
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• pp.87-92
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• 2008

An improved protocol for high frequency plant regeneration via somatic embryogenesis from zygotic embryo-derived cell suspension cultures of watershield (Brasenia schreberi) was developed. Zygotic embryos formed pale-yellow globular structures and white friable callus at a frequency of 80% when cultured on halfstrength MS medium supplemented with $0.3mg\;l^{-1}$ 2,4-D. However, the frequency of formation of pale-yellow globular structures and white friable callus decreased slightly with increasing concentrations of 2,4-D up to $3mg\;l^{-1}$, where the frequency reached ~50% of the control. Cell suspension cultures from zygotic embryoderived white friable callus were established using half-strength MS medium supplemented with $0.3mg\;l^{-1}$ 2,4-D. Upon plating of cell aggregates on half-strength MS basal medium, approximately 8.3% gave rise to somatic embryos and developed into plantlets. However, the frequency of plantlet development from cell aggregates was sharply increased (by up to 55%) when activated charcoal and zeatin were applied. Regenerated plantlets were successfully transplanted to potting soil and grown to normal plants in a growth chamber. The distinctive feature of this study is the establishment of a high frequency plant regeneration system via somatic embryogenesis from zygotic embryo-derived cell suspension cultures of water-shield, which has not been previously reported. The protocol for plant regeneration of watershield through somatic embryogenesis could be useful for the mass propagation and transformation of selected elite lines.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2003.04a
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• pp.114-114
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• 2003

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.1
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• pp.42-50
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• 2001

The activity of immobilized cell-support particle aggregates is influenced by physical and biochemical elements, mass transfer, and physiology. Accordingly, the mathematical model discussed in this study is capable of predicting the steady state and transient concentration profiles of the cell mass and substrate, plus the effects of the substrate and product inhibition in an immobilized cell-support aggregate. The overall mathematical model is comprised of material balance equations for the cell mass, major carbon source, dissolved oxygen, and non-biomass products in a bulk suspension along with a single particle model. A smaller bead size and higher substrate concentration at the surface of the particle, resulted in a higher supply of the substrate into the aggregate and consequently a higher biocatalyst activity.

• Applied Microscopy
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• v.24 no.3
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• pp.46-54
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• 1994

In ultrathin section of the tissue of odontoglossum ringspot virus (ORSV)-infected Cymbidium goeringii Reichenbach, ORSV particles appeared as bundles of irregular aggregates of various length which were called stacked plates or rounded plates. Virus particles were found in the cytoplasm in electron clear zones and they also found between cell wall and plasma membrane. They mainly clustered in parallel aggregates and sometimes oriented randomly. The X-bodies and paramural bodies were observed near the cell membrane and these contained vacuole-like cavities. The cell wall of infected tissue expanded largely. Some chloroplast in ORSV infected cell was irregular. No virus particle was present in mitochondria, nuclei, vacuoles, vesicles or other organelles. The plasmodesmata slightly enlarged, and virus-associated granules were present around it.

• 전기의세계
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• v.28 no.8
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• pp.66-71
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• 1979

This paper describes electrical analysis of the information processing of the nervous system. A general-purpose electrical neuronal model for simulating the electrical activity in a single nerve cell and in small groups of nerve cell has constructed. This model consists of two basic electronic modules to represent respectively a "cell body" and an "axon (with synapses)", together with various related appurtenances. The primary advantages of this method are; holistic view, actual physical representation of various electrical activities in a single nerve cell, display of the activity of all nerve cells flexibility with respect to network parameters. Moreover, this model can effectively help push forward our general ability to explore and conceptualize the electrical activity of interconnected networks of nerve cell behaving in concert. Also, this electronic module technique is the best of various means for this task of realistic representation of aggregates of neurons.gregates of neurons.

• Molecules and Cells
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• v.27 no.6
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• pp.621-627
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• 2009

Spinocerebellar ataxia type 1 (SCA1) is an autosomal-dominant neurodegenerative disorder characterized by ataxia and progressive motor deterioration. SCA1 is associated with an elongated polyglutamine tract in ataxin-1, the SCA1 gene product. As summarized in this review, recent studies have clarified the molecular mechanisms of SCA1 pathogenesis and provided direction for future therapeutic approaches. The nucleus is the subcellular site where misfolded mutant ataxin-1 acts to cause SCA1 disease in the cerebellum. The role of these nuclear aggregates is the subject of intensive study. Additional proteins have been identified, whose conformational alterations occurring through interactions with the polyglutamine tract itself or non-polyglutamine regions in ataxin-1 are the cause of SCA-1 cytotoxicity. Therapeutic hope comes from the observations concerning the reduction of nuclear aggregation and alleviation of the pathogenic phenotype by the application of potent inhibitors and RNA interference.

• BMB Reports
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• v.49 no.9
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• pp.459-473
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• 2016

Neurodegenerative diseases (NDs) often involve the formation of abnormal and toxic protein aggregates, which are thought to be the primary factor in ND occurrence and progression. Aged neurons exhibit marked increases in aggregated protein levels, which can lead to increased cell death in specific brain regions. As no specific drugs/therapies for treating the symptoms or/and progression of NDs are available, obtaining a complete understanding of the mechanism underlying the formation of protein aggregates is needed for designing a novel and efficient removal strategy. Intracellular proteolysis generally involves either the lysosomal or ubiquitin-proteasome system. In this review, we focus on the structure and assembly of the proteasome, proteasome-mediated protein degradation, and the multiple dynamic regulatory mechanisms governing proteasome activity. We also discuss the plausibility of the correlation between changes in proteasome activity and the occurrence of NDs.

• KSBB Journal
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• v.19 no.5
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• pp.374-380
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• 2004

Production of therapeutic proteins by transgenic plant cell suspension cultures is an attractive system alternative to the other expression system. However, plant cell cultures have shown low expression level of foreign proteins and decreased cell viability by the changes of culture conditions. Therefore, it is necessary to enhance cell viability during the culture period. In this study, a quantitative analysis technique was designed to measure relative cell viability for plant suspension cells which have cell wall and aggregates. It was found that the programmed cell death of plant cells by apoptosis was essentially linked with the apoptotic pathway of animal cells. Therefore, effects of nicotinamide, 3-aminobenzamide and antioxidants on cell viability and apoptosis were examined in transgenic Nicotiana tabacum cells producing hGM-CSF. With those additives, cell viability could be maintained and apoptosis could be redued. In the result, the extracellular production of hGM-CSF could be enhanced 2.5 fold. It was also found that the supplementation of glutathione and ascorbic acid suppressed both the cold stress-induced decrease in cell viability and the increase of total genomic DNA fragmentation.

• The Journal of the Korean Society for Microbiology
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• v.17 no.1
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• pp.75-85
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• 1982

In order to demonstrate the effect of specific serum IgG antibody on the adherence of Streptococcus mutans to smooth surface and the mechanism of effective adherence inhibition by IgG antibody, in the present study authors obtained purified IgG from different immunogen preparations of S. mutans NCTC 10449(serotype c) and observed the effect of each IgG preparation on the adherence of each S. mutans strain cultured in different conditions. In addition, the present study was undertaken to observe the cross-reactivity of IgG and the effect of sucrose concentration on the adherence of S. mutans in vitro non-growth condition. The adherence of S. mutans to glass surface was effectively inhibited by serum IgG antibody. At the same IgG concentrations, anti-2% fructose grown/1N NaCl washed S. mutans NCTC 10449 cell showed greater adherence inhibitory effect to S. mutans strains than anti-2% sucrose grown and anti-S. mutans NCTC 10449 cell wall, and the greater inhibitory effects of IgG preparations were observed in assay using 2% fructose grown S. mutans cell preparations than using 0.1% sucrose grown cell preparations. These results suggest that the more effective adherence inhibition by serum IgG antibody is due to the reaction with S. mutans cell surface antigens rather than glucan and cell-associated glucosyltransferase. The greatest adherence inhibitory effect of IgG to S. mutans strains was observed on homologous NCTC 10449 strain and the inhibition cross-reactivities were observed between serotype c, e, and f strains. More pronounced cross-reactivity of adherence inhibition of IgG to S. mutans was observed in assay using anti-2% fructose grown/1N NaCl washed cell than using other IgG preparations, and observed in assay using 2% fructose grown S. mutans cell preparations than 0.1% sucrose grown cell preparations. It was interested that low, but adequate concentration of reactive IgG antibody significantly increased the adherence ability of S. mutans. This result may be due to the formation of small cell aggregates resulted in a increase in the numbers of organisms which adhered to glass surface. The adherence of S. mutans to glass surface was possible in the absence of glucan-synthetic activity. Low level of sucrose significantly increased the adherence ability of S. mutans to glass surface, but excessive amount of sucrose induced large cell aggregates resulted in a decrease in the numbers of organism which adhered.

• Journal of Chest Surgery
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• v.13 no.4
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• pp.507-511
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• 1980

Most cases of plasma-cell granuloma occur in adult skeleton system. They usually present as a single lesion, but multiple lesions are not uncommon. Roentgenographically, the lesions are lytic, sclerotic or mixed, but in the majority there is some degree of sclerosis. No specific etiologic agent is known, but it is postulated that the reaction may be associated with a variety of organisms of low-grade virulence. Certain organisms have long been known to produce predominantly plasmacytic infiltrate, notably spirochetes, mycobacteria and some exotic viruses. It is most important, however, that this entity, plasma-cell granuloma, be distinguished from multiple myeloma so those potentially life-threatening chemotherapeutic agents are not prescribed. Histologically, aggregates of chronic inflammatory cells are intermingled with the meets of plasma cells, and note the markedly thickened bone trabeculae in surrounding bone. We experienced a case of plasma-cell granuloma of right 7th. rib, occurring in 32 year old male and reported it with review of literatures.