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931.
Bacterial lipopolysaccharide (LPS) is a potent stimulator of bone resorption in periodontitis. Co-culture systems of mouse calvaria-derived osteoblasts and bone marrow-derived preosteoclasts were used as an in vitro osteoclast differentiation. This study revealed that co-cultures using ddY or ICR mouse strain responded differently to LPS while responded equally to 1alpha,25(OH)2D3. Thus, the different response to LPS indicates dissimilarity of two mouse stains in their capacity for generating osteoclasts while the two mouse strains share the similarity in response to 1alpha,25(OH)2D3. To identify which cells between osteoblasts and preosteoclasts in the co-culture are responsible for the dissimilarity, the reciprocal co-cultures were performed between ddY and ICR mouse strains. The treatment of 1,25(OH)2D3 to ddY/ICR (osteoblasts from ddY/preosteoclasts from ICR) and ICR/ddY reciprocal co-cultures also showed the similarity. In case of LPS treatment, the results of ddY/ICR were similar to ddY/ddY and the results of the other reciprocal co-culture, ICR/ddY combination, were consistent with those of ICR/ICR. It suggests that the dissimilarity between the two mouse strains may resident in osteoblasts but not in preosteoclasts. Therefore, the osteoblast is responsible for mouse strain-dependent osteoclastogenesis in response to LPS. Although mouse models will continue to provide insights into molecular mechanisms of osteoclastogenesis, caution should be exercised when using different mouse strains, especially ddY and ICR strains as models for osteoclast differentiation. 相似文献
932.
Longan Shang Dai Di Fan Moon Il Kim Jin-dal-rae Choi Ho Nam Chang 《Biotechnology and Bioprocess Engineering》2007,12(4):417-423
High cell density culturing has been conducted for the production of poly(3-hydroxybutyrate) fed-batch cultures ofRalstonia eutropha with phosphate limitation. It was found that a high glucose concentration inhibited the synthesis of P(3HB) in the high cell
density culture ofR. eutropha. Although a low glucose concentration can trigger the synthesis of P(3HB) in a manner similar to that of phosphate limitation,
it also limited both the P(3HB) synthesis and the cell growth, and led to a low P(3HB) productivity because glucose is the
sole carbon source in this reaction. An unstructured model was proposed for predicting the cell growth and P(3HB) synthesis
in high cell density cultures ofR. eutropha, where the phosphate concentration played a key role in the accumulation of P(3HB) and in cell growth. Good agreements were
found between the experimental data and model predictions. The results of simulation showed that the final P(3HB) concentration
would decrease more than 25% when the glucose was concentration increased to 40 g/L, and indicated that the optimal glucose
concentration for P(3HB) production by high cell density cultures ofR. eutropha was around 9 g/L. 相似文献
933.
Yeon Sook Choi Doo Young Lee Ick Young Kim Hong Jin Kim Hong Woo Park Tae Boo Choe Ik-Hwan Kim 《Biotechnology and Bioprocess Engineering》2007,12(1):60-72
The stabilization of optimum pH for cells can cause a higher erythropoietin (EPO) production rate and a good growth rate with
the prolonged culture span in recombinant Chinese hamster ovary (r-CHO) cells. Our strategy for stabilizing the optimum pH
in this study is to reduce the lactate production by adding sodium lactate to a culture medium. When 40 mM sodium lactate
was added, a specific growth rate was decreased by approximately 22% as compared with the control culture. However the culture
longevity was extended to 187 h, and more than a 2.7-fold increase in a final accumulated EPO concentration was obtained at
40 mM of sodium lactate. On the condition that caused the high production of EPO, a specific glucose consumption rate and
lactate production rate decreased by 23.3 and 52%, respectively. Activity of lactate dehydrogenase (LDH) in r-CHO cells increased
and catalyzed the oxidation of lactate to pyruvate, together with the reverse reaction, at the addition of 40 mM sodium lactate.
The addition of 40 mM sodium lactate caused the positive effects on a cell growth and an EPO production in the absence of
carbon dioxide gas as well as in the presence of carbon dioxide gas by reducing the accumulation of lactate. 相似文献
934.
935.
Lee JH Rhee JE Park U Ju HM Lee BC Kim TS Jeong HS Choi SH 《Journal of microbiology and biotechnology》2007,17(2):325-334
Recently, quorum sensing has been implicated as an important global regulator controlling the production of numerous virulence factors such as capsular polysaccharides in bacterial pathogens. The nucleotide and deduced amino acid sequences of smcR, a homolog of V. harveyi luxR identified from V. vulnificus ATCC29307, were analyzed. The amino acid sequence of SmcR from V. vulnificus was 72 to 92% similar to those of LuxR homologs from Vibrio spp. Functions of SmcR were assessed by the construction of an isogenic mutant, whose smcR gene was inactivated by allelic exchanges, and by evaluating its phenotype changes in vitro and in mice. The disruption of smcR resulted in a significant alteration in biofilm formation, in type of colony morphology, and in motility. When compared with the wild-type, the smcR mutant exhibited reduced survival under adverse conditions, such as acidic pH and hyperosmotic stress. The smcR mutant exhibited decreased cytotoxic activity toward INT 407 cells in vitro. Furthermore, the intraperitoneal LD50 of the smcR mutant was approximately 10(2) times higher than that of parental wild-type. Therefore, it appears that SmcR is a novel global regulator, controlling numerous genes contributing to the pathogenesis as well as survival of V. vulnificus. 相似文献
936.
Shim JH Sung KJ Cho MC Choi WA Yang Y Lim JS Yoon DY 《Journal of microbiology and biotechnology》2007,17(9):1513-1520
Beta-1,3-glucans enhance immune reactions such as antitumor, antibacterial, antiviral, anticoagulatory, and wound healing activities. beta-1,3-Glucans have various functions depending on the molecular weight, degree of branching, conformation, water solubility, and intermolecular association. The molecular weight of the soluble glucan was about 15,000 as determined by a high-performance size exclusion chromatography. From the infrared (IR) and 13C NMR analytical data, the purified soluble glucan was found to exclusively consist of beta-D-glucopyranose with 1,3 linkage. We tested the immunestimulating activities of the soluble beta-1,3-glucan extracted from Agrobacterium sp. R259 KCTC 1019 and confirmed the following activities. IFN-gamma and each cytokines were induced in the spleens and thymus of mice treated with soluble beta-1,3-glucan. Adjuvant effect was observed on antibody production. Nitric oxide was synthesized in monocytic cell lines treated with beta-1,3-glucan. The cytotoxic and antitumor effects were observed on various cancer cell lines and ICR mice. These results strongly suggested that this soluble beta-1,3-glucan could be a good candidate for an immune-modulating agent. 相似文献
937.
Woo HJ Lee YS Park SJ Lim JT Jang KH Choi EH Choi YG Hwang UW 《Molecules and cells》2007,23(2):182-191
The complete mitochondrial genome of a troglobite millipede Antrokoreana gracilipes (Verhoeff, 1938) (Dipolopoda, Juliformia, Julida) was sequenced and characterized. The genome (14,747 bp) contains 37 genes (2 ribosomal RNA genes, 22 transfer RNA genes and 13 protein-encoding genes) and two large non-coding regions (225 bp and 31 bp), as previously reported for two diplopods, Narceus annularus (order Spirobolida) and Thyropygus sp. (order Spirostreptida). The A + T content of the genome is 62.1% and four tRNAs (tRNA(Ser(AGN)), tRNA(Cys), tRNA(Ile) and tRNA(Met)) have unusual and unstable secondary structures. Whereas Narceus and Thyropygus have identical gene arrangements, the tRNA(Thr) and tRNA(Trp) of Antrokoreana differ from them in their orientations and/or positions. This suggests that the Spirobolida and Spirostreptida are more closely related to each other than to the Dipolopoda. Three scenarios are proposed to account for the unique gene arrangement of Antrokoreana. The data also imply that the Duplication and Nonrandom Loss (DNL) model is applicable to the order Julida. Bayesian inference (BI) and maximum likelihood (ML) analyses using amino acid sequences deduced from the 12 mitochondrial protein-encoding genes (excluding ATP8) support the view that the three juliformian members are monophyletic (BI 100%; ML 100%), that Thyropygus (Spirostreptida) and Narceus (Spirobolida) are clustered together (BI 100%; ML 83%), and that Antrokoreana (Julida) is a sister of the two. However, due to conflict with previous reports using cladistic approaches based on morphological characteristics, further studies are needed to confirm the close relationship between Spirostreptida and Spirobolida. 相似文献
938.
This study was conducted to find the optimum extraction condition of Gold-Thread for antibacterial activity against Streptococcus mutans using The evolutionary operation-factorial design technique. Higher antibacterial activity was achieved in a higher extraction temperature (R2 = -0.79) and in a longer extraction time (R2 = -0.71). Antibacterial activity was not affected by differentiation of the ethanol concentration in the extraction solvent (R2 = -0.12). The maximum antibacterial activity of clove against S. mutans determined by the EVOP-factorial technique was obtained at 80 degrees C extraction temperature, 26 h extraction time, and 50% ethanol concentration. The population of S. mutans decreased from 6.110 logCFU/ml in the initial set to 4.125 logCFU/ml in the third set. 相似文献
939.
Lee JO Park MH Choi YH Ha YL Ryu CH 《Journal of microbiology and biotechnology》2007,17(11):1904-1907
The aim of this study was to develop a new fermentation method in order to improve the digestion of soybean protein, and to promote normal fermentation of soybean. A proximate composition, such as moisture, pH, and reducing sugar, of fermented soybeans by the new fermentation was similar to those of controls. Neutral protease activity, the most important factor for fermented soybean products, was the highest, having about 636 U/g at 54 h fermentation. The content of total free amino acid was almost 3-18 times higher than controls. The three-step fermented soybeans can be used as a functional food ingredient for human consumption, with higher protein digestibility. 相似文献
940.
Kim SK Kim SR Choi MS Park CE Kim YC Kim KY Whang KS Oh KT Kim IS 《Journal of microbiology and biotechnology》2007,17(10):1700-1703
Microorganisms capable of degrading crude oil were isolated and grown in soybean oil as a sole carbon source. The microbial cultures were used to control green peach aphids in vitro. Approximately 60% mortality of aphids was observed when the cultures were applied alone onto aphids. To examine the cultures as a pesticide formulation mixture, the cultures were combined with a low dose of the insecticide imidacloprid (one-fourth dose of recommended field-application rate) and applied onto aphids. The cultures enhanced significantly the insecticidal effectiveness of imidacloprid, which was higher than imidacloprid alone applied at the low dose. The isolated microorganisms exhibited high emulsifying index values and decreased surface tension values after being grown in soybean oil media. GC/MS analyses showed that microorganisms degraded soybean oil to fatty acids. The cultures were suggested to play the roles of wetting, spreading, and sticking agents to improve the effectiveness of imidacloprid. This is the first report on the control of aphids by using oil-degrading microbial cultures. 相似文献