• Proceedings of the Botanical Society of Korea Conference
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• 1998.07a
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• pp.10-18
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• 1998

For improvement of plants in disease resistance, it is most important to elucidate the mechanism to perceive and respond to the signal molecules of invaders. A model system with pea and its pathogen, Mycosphaerella pinodes, showed that the fungal elicitor induced defense responses in all plant species tested but that the suppressor of the fungus blocked or delayed the expression of defense responses and induced accessibility only in the host plant. In the world, many researchers believe that the pathogens` signals are recognized only on the receptors in the plasma membranes. Though we found that the ATPase and polyphosphoinositide metabolism in isolated plasma membranes responded to these fungal signals, we failed to detect specific actions of the suppressor in vitro on these plasma membrane functions. Recently, we found that ATPase (NTPases) and superoxide generating system in isolated cell wall were regulated by these fungal signals even in vitro, especially, by the suppressor in a strictly species-specific manner and also that the cell wall alone prepared an original defense system. The effects of both fungal signals on the isolated cell wall functions in vitro coincide perfectly with those on defense responses in vivo. In this treatise, we discuss the key role of the cell wall, which is plant-specific and the most exterior organelle, in determining host-parasite specificity and molecular target for improvement of plants.

• Journal of Plant Biology
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• v.31 no.2
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• pp.91-100
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• 1988

The effect of Ca2+ and polyamines on the activity $\beta$-glucan synthetase II(GSII) related to cell wall synthesis was studied in carrot suspension cultured cells. The activity of GS II is four times higher than that of $\beta$-glucan synthetase I in carrot suspension cultured cells and in vitro expreiment, the activity of GSII was increased in response to increase in concentration of Ca2+ and polyamines. When carrot suspension cultured cells were incubated together with Ca2+ and polyamines, the GSII activity was high at 0.1mM of Ca2+ and 1mM of putrescine. Also, polycationic poly-L-lysine and poly-L-ornithine increased about 50% the GSII activity than that of the control, respectively. These results may imply that Ca2+ and polyamines were related to the enzyme activity as a polycationic nature. In addition, verapamil as the calcium channel blocker and flunarizine as an antagonist of calcium mechanism in cytoplasm decreased GSII activity ramarkably, Ca2+ and calmodulin stimulated GSII activity as Ca2+ of free ion rather than Ca2+ calmodulin complex. The effect of 2,4-D on the GSII activity in culture medium is shown to be low at 0.1mg per liter and GSII activity increased about 30% more than that of the 0.1mg/l at the range of 0.3-1.0mg per litere. Cummulative results suggest that Ca2+ and polyfamines stimulate the cell wall synthesis by means of the enhancement of GSII activity responsible for synthesizing the cell wall components.

• Journal of Microbiology and Biotechnology
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• v.16 no.5
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• pp.786-790
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• 2006

Cellular components of Lactococcus lactis ssp. lactis (heat-killed whole cells, cytoplasm, and cell walls) were tested for their in vivo immunopotentiating activity. Peritoneal macrophages from mice orally administered with heat-killed whole cells exhibited significantly greater phagocytic activity than the groups administered with cell-wall fraction or cytoplasm fraction. The cytotoxicity of natural-killer cells was the highest in the group administered with whole cells, and the production of cytokines ($IFN-\gamma$, IL-2, and IL-12) in spleen cells was significantly higher, when cellular components were injected, and it tended to be higher in the cell-wall and cytoplasm groups than in the whole-cell group. Interestingly, the cytokine production of Peyer's patch cells was high, when cytoplasm fractions were administered. These results demonstrate that whole cells and cytoplasm and cell-wall fractions of L. lactis ssp. lactis have immunopotentiating activities, which are related to the stimulation of Peyer's patches.

• Food Science and Biotechnology
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• v.14 no.3
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• pp.405-409
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• 2005

Cellular components of Lactococcus lactis ssp. lactis (heat-killed whole cells, cytoplasm, and cell walls) were tested for their in vivo immunopotentiating activities. Peritoneal macrophages from mice injected intraperitoneally with cell-wall fractions exhibited significantly greater phagocytic activity than groups injected with whole cells or cytoplasm fraction. Cytotoxicity of natural-killer cells was highest in cytoplasm fractions. Production of cytokines (IFN-${\gamma}$, IL-2, IL-6, and IL-12) in spleen cells was significantly higher when cellular components were injected intraperitoneally, and tended to be higher in whole-cell and cytoplasm groups than in cell-wall group. These results demonstrate lactic acid bacteria whole cells and their cytoplasm and cell-wall tractions have immunopotentiating activities.

• Journal of the Korean Wood Science and Technology
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• v.15 no.3
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• pp.14-23
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• 1987

This study was carried out to investigate the anatomical characteristics, the radial and axial variation of the cell dimension and bulk density for four bamboo species used as the major material of bamboo products in Korea; Phyllostachys(P.bambusoides, P.edulis, P.nigra var.henonis, and Pnigra). The results obtained were summarized as follows; 1) In the outer part of culm, the mophological difference of cell diameter and distribution were not acknowledged. However, gum-like substance was occurred In the epidermis, hypodermis, cortex and metaxylem vessel of P.nigra, while it was occured only in the metaxylem vessel of P.edulis. 2) The protoxylem vessel in the central zone of culm-wall could be in the two types; the first type consisted of 4-5 small cell pieces occurred in P.edulis and P.nigra var. henonis, the second type of 1-2 large cell pieces in P.bambusoides and P.nigra. And transition of cell diameter from the vascular bundle sheath to the ground tissue was gradually enlarged in P.nigra and P.edulis but abruptly in P.bambusoides and P.nigra var. henonis. 3) Thin-wall tyloses were well developed in the outer and central zone of culm-wall in four species. 4) Compared with the central part of culm-wall, the number of parenchyma cells and the amount of the vascular bundle sheaths per unit area were a few in the inner part. The inner part nearest to the pith cavity was consisted of thick-well parenchyma cell. 5) The dimensional variations of metaxylem vessel and parenchyma cell in the radial direction were decreased from the inner part to the epidermis in all species observed. 6) The fiber length was the maximum in the central zone and its diameter was increased from the inner part to the outer part. In the axial variation. fiber length was slightly increased from the base and then decresed slowly toward the top, and its diameter was reverse. 7) The axial variation of the bulk density was continuously increased from the base toward the top and its radial variation was rapidly increased from the inner part to the epidermis.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.11
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• pp.1659-1676
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• 2002

Ruminant animals develop a diverse and sophisticated microbial ecosystem for digesting fibrous feedstuffs. Plant cell walls are complex and their structures are not fully understood, but it is generally believed that the chemical properties of some plant cell wall compounds and the cross-linked three-dimensional matrix of polysaccharides, lignin and phenolic compounds limit digestion of cell wall polysaccharides by ruminal microbes. Three adaptive strategies have been identified in the ruminal ecosystem for degrading plant cell walls: production of the full slate of enzymes required to cleave the numerous bonds within cell walls; attachment and colonization of feed particles; and synergetic interactions among ruminal species. Nonetheless, digestion of fibrous feeds remains incomplete, and numerous research attempts have been made to increase this extent of digestion. Exogenous fibrolytic enzymes (EFE) have been used successfully in monogastric animal production for some time. The possibility of adapting EFE as feed additives for ruminants is under intensive study. To date, animal responses to EFE supplements have varied greatly due to differences in enzyme source, application method, and types of diets and livestock. Currently available information suggests delivery of EFE by applying them to feed offers the best chance to increase ruminal digestion. The general tendency of EFE to increase rate, but not extent, of fibre digestion indicates that the products currently on the market for ruminants may not be introducing novel enzyme activities into the rumen. Recent research suggests that cleavage of esterified linkages (e.g., acetylesterase, ferulic acid esterase) within the plant cell wall matrix may be the key to increasing the extent of cell wall digestion in the rumen. Thus, a crucial ingredient in an effective enzyme additive for ruminants may be an as yet undetermined esterase that may not be included, quantified or listed in the majority of available enzyme preparations. Identifying these pivotal enzyme(s) and using biotechnology to enhance their production is necessary for long term improvements in feed digestion using EFE. Pretreating fibrous feeds with alkali in addition to EFE also shows promise for improving the efficacy of enzyme supplements.

• Journal of Plant Biology
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• v.32 no.3
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• pp.151-162
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• 1989

Secretory ducts in the stem of Panax ginseng seedlings are observed with light and electron microscopes to clarify development of the epithelial cells of secretory ducts. Secretory duct initial cell is developed from procambial cell which originated from initial cell is differentiated into ipithelial cell ofsecretory ducts. Intercellular space between the epithelial cells are gradually expanded and differentiated into duct lumen. Disintegrations of epithelial cells occur throughout all the stages of development. The cytoplasm of epithelial cells darken and the epithelial cell wall are lysed, preceding their disintegraton. In the epithelial cell organelles are scattered in the cytoplasm. Development of vcuoles are sparse at the early stage. Starch grains decreased gradually, while lipid droplets increased. Free ribosomes are distributed throughout the cytoplasm and secretory vesicles which originated from rough endoplasmic reticulum and Golgi complex are fused with the plasmalemma. These suggest that the cellular metabolism is active. Microtubules and plasmodesmata are typically observed in the thickened epithelial cell wall. Secretions are accumulated in duct lumen.

• Tuberculosis and Respiratory Diseases
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• v.46 no.2
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• pp.273-280
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• 1999

This is a report of gastric metastases secondary from a primary small cell carcinoma of the lung in two men. Blood-borne metastatic involvement of the stomach by cancer is a rare entity. According to the reports in the literature the prevalence of metastasis to the stomach occurs in 0.4% and the most common cell type of the primary lung carcinoma is large cell type(3.7%) followed by adenocarcinoma(2.4%), small cell carcinoma(1.7%) and squamous cell carcinoma(0.7%). The most common tumors that spread to the stomach through the blood stream are malignant melanoma, breast carcinoma and lung carcinoma. Most of the gastrointestinal tract metastases had no specific symptoms because of its submucosal involvement. The prognosis was poor and the mean survival period from the onset of symptoms was 49 days. The first patient was a 56-year-old man who had primary lung carcinoma with brain metastasis. Gastroscopic findings showed two elevated mass lesions in the anterior wall of the mid body with central ulcer and the posterior wall of the fundus with intact surface mucosa. Pathologic examination of stomach tissue revealed small cell type tumor cells infiltrate in the stomach wall segmentally without destruction of the glands. The second patient was a 67-year-old man who had no other evidence of the distant metastasis. Gastroscopic findings showed a huge, oval shaped, ulcerofungating mass with deep penetrating central ulcer coated with dirty exudate in the anterior wall from mid to upper body of the stomach, and thickened elevated rugal folds in the posterior wall of the fundus. Pathologic examination of stomach tissues revealed the small cell type tumor cells showing small smudged nucleus infiltrate into the mucosa of the stomach and the architecture of mucosa intact. We report the two cases of metastatic gastric cancer from the primary small cell lung carcinoma with the literature review.

• Journal of Powder Materials
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• v.27 no.2
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• pp.119-125
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• 2020

One of the promising candidates for accident-tolerant fuel (ATF), a ceramic microcell fuel, which can be distinguished by an unusual cell-like microstructure (UO₂ grain cell surrounded by a doped oxide cell wall), is being developed. This study deals with the microstructural observation of the constituent phases and the wetting behaviors of the cell wall materials in three kinds of ceramic microcell UO₂ pellets: Si-Ti-O (STO), Si-Cr-O (SCO), and Al-Si-Ti-O (ASTO). The chemical and physical states of the cell wall materials are estimated by HSC Chemistry and confirmed by experiment to be mixtures of Si-O and Ti-O for the STO; Si-O and Cr-O for SCO; and Si-O, Ti-O, and Al-Si-O for the ASTO. From their morphology at triple junctions, UO₂ grains appear to be wet by the Si-O or Al-Si-O rather than other oxides, providing a benefit on the capture-ability of the ceramic microcell cell wall. The wetting behavior can be explained by the relationships between the interface energy and the contact angle.

• Journal of Bio-Environment Control
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• v.15 no.1
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• pp.91-99
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• 2006

This study was conducted to determine the influence of postharvest dipping treatment with aminoethoxyvinylglycine (AVG) on ethylene production and composition of non-cellulosic neutral sugars in cell walls of 'Tsugaru' apple fruits during storage. Fruits were harvested on August 20, soaked in AVG 50 and 75 $mg L^{-1}$ solution for 5 minutes, and stored in cold storage chamber at $0{\pm}1^{\circ}C$ for 60 days. Fruit quality factor, ethylene productions, and cell wall component changes were investigated at 20 days interval. As a result, the fruit firmness and acid content were much higher in AVG treated fruits than those of untreated one during 60 days of cold storage. Ethylene production of AVG treated fruits was reduced to the level of 1/10 compared with untreated one. As to the change of non-cellulosic neutral sugars in the cell walls of 'Tsu- garu' fruits, the major sugar was arabinose and galactose in water, CDTA and $Na_2CO_3$ soluble fractions. The content of arabinose and galactose in untreated fruits increased as the softening of fruits was in progress, but the fruits treated with AVG showed a little change during storage, so it is predicted that these two cell wall compositional sugars were not solubilized by the treatment of AVG. Accordingly, the marketability of 'Tsu- garu' fruits could remarkably increase when soaking the fruits in AVG solution after harvest.