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641.
Yon JM Baek IJ Lee SR Jin Y Kim MR Nahm SS Kim JS Ahn B Lee BJ Yun YW Nam SY 《Journal of molecular histology》2008,39(1):95-103
The cytoplasmic Cu/Zn-superoxide dismutase (SOD1) represents along with catalase and glutathione peroxidase at the first defense
line against reactive oxygen species in all aerobic organisms, but little is known about its distribution in developing embryos.
In this study, the expression patterns of SOD1 mRNA in mouse embryos were investigated using real-time RT-PCR and in situ
hybridization analyses. Expression of SOD1 mRNA was detected in all embryos with embryonic days (EDs) 7.5–18.5. The signal
showed the weakest level at ED 12.5, but the highest level at ED 15.5. SOD1 mRNA was expressed in chorion, allantois, amnion,
and neural folds at ED 7.5 and in neural folds, notochord, neuromeres, gut, and primitive streak at ED 8.5. In central nervous
system, SOD1 mRNA was expressed greatly in embryos of EDs 9.5–11.5, but weakly in embryos of ED 12.5. At EDs 9.5–12.5, the
expression of SOD1 mRNA was high in sensory organs such as tongue, olfactory organ (nasal prominence) and eye (optic vesicle),
while it was decreased in ear (otic vesicle) after ED 10.5. In developing limbs, SOD1 mRNA was greatly expressed in forelimbs
at EDs 9.5–11.5 and in hindlimbs at EDs 10.5–11.5. The signal increased in liver, heart and genital tubercle after ED 11.5.
In the sections of embryos after ED 13.5, SOD1 mRNA was expressed in various tissues and especially high in mucosa and metabolically
active sites such as lung, kidney, stomach, and intestines and epithelial cells of skin, whisker follicles, and ear and nasal
cavities. These results suggest that SOD1 may be related to organogenesis of embryos as an antioxidant enzyme. 相似文献
642.
Jae Sung Park Gi Hwan Yi Min Hee Nam Sun Ho Park 《Biotechnology and Bioprocess Engineering》2001,6(1):51-55
This study was conducted to establish a plant cell culture system for the production of medically important secondary metabolites
fromXanthium strumarium. The effects of plant growth regulators including NAA, 2,4-D, kinetin, and ABA were examined in terms of callus induction,
maintenance of callus and suspension cultures. It was shown that callus was induced upon treatment with NAA while embryo was
induced after treatment with 2,4-D. Callus formation was further improved by treatment with ABA and NAA. The level of callusing
increased by 17–29% for the seed case, cotyledon, leaf, and hypocotyl and by 96% in the case of the root. Suspension cell
lines were established using calli produced from cotyledon, hypocotyl and root and cultured at 25°C under light conditions.
The cells grew up to 15 g/L with NAA 2 ppm, BA 2 ppm, and ABA 1 ppm treatment. Supernatants of suspension cultures of cell
lines derived from coyledon and hypocotyl produced some distinctive secondary metabolites, one of which was identified as
8-epi-tomentosin, which belongs to the xanthanolides. The amounts of 8-epi-tomentosin produced by the cotyledon-and hypocotylderived cell lines were 13.4 mg/L and 11.0 mg/L, respectively. 相似文献
643.
644.
Rapid identification of bacterial pathogens is important for patient management and initiation of appropriate antibiotic therapy in the early stages of infection. Among the several techniques, capillary electrophoresis single-strand conformation polymorphism (CE-SSCP) analysis combined with small subunit rRNA gene-specific polymerase chain reaction (PCR) has come into the spotlight owing to its sensitivity, resolution, and reproducibility. Despite the advantages of the method, the design of PCR primers and optimization of multiplex PCR conditions remain to be studied so that as many pathogens as possible can be analyzed in a single run. Here we describe a novel two-step technique involving multiplex PCR pathogen detection by CE-SSCP analysis followed by singleplex PCR pathogen quantification by CE-SSCP. Specific PCR primers were designed for optimal separation of their products by CE-SSCP based on molecular weight. PCR conditions were then optimized for multiplex analysis of the targets. Subsequently, detected pathogens were quantified by PCR with specific primers. Eight clinically important strains were simultaneously identified under the optimized conditions. Each individual pathogen was then quantified at a level of sensitivity of tens of cells per milliliter. In conclusion, the two-step pathogen detection method based on CE-SSCP described here allows for sensitive detection of pathogens by multiplex PCR (first step) and quantification by specific PCR (second step). The results illustrate the potential of the method in clinical applications. 相似文献
645.
Gião MS Azevedo NF Wilks SA Vieira MJ Keevil CW 《Applied and environmental microbiology》2008,74(19):5898-5904
Although the route of transmission of Helicobacter pylori remains unknown, drinking water has been considered a possible transmission vector. It has been shown previously that, in water, biofilms are a protective niche for several pathogens, protecting them from stressful conditions, such as low carbon concentration, shear stress, and less-than-optimal temperatures. In this work, the influence of these three parameters on the persistence and cultivability of H. pylori in drinking-water biofilms was studied. Autochthonous biofilm consortia were formed in a two-stage chemostat system and then inoculated with the pathogen. Total numbers of H. pylori cells were determined by microscopy using a specific H. pylori 16S rRNA peptide nucleic acid probe, whereas cultivable cells were assessed by standard plating onto selective H. pylori medium. Cultivable H. pylori could not be detected at any time point, but the ability of H. pylori cells to incorporate, undergo morphological transformations, persist, and even agglomerate in biofilms for at least 31 days without a noticeable decrease in the total cell number (on average, the concentration was between 1.54 x 10(6) and 2.25 x 10(6) cells cm(-2)) or in the intracellular rRNA content may indicate that the loss of cultivability was due to entry into a viable but noncultivable state. Unlike previous results obtained for pure-culture H. pylori biofilms, shear stress did not negatively influence the numbers of H. pylori cells attached, suggesting that the autochthonous aquatic bacteria have an important role in retaining this pathogen in the sessile state, possibly by providing suitable microaerophilic environments or linking biomolecules to which the pathogen adheres. Therefore, biofilms appear to provide not only a safe haven for H. pylori but also a concentration mechanism so that subsequent sloughing releases a concentrated bolus of cells that might be infectious and that could escape routine grab sample microbiological analyses and be a cause of concern for public health. 相似文献
646.
Kwon NR Chae JC Choi KY Yoo M Zylstra GJ Kim YM Kang BS Kim E 《Applied microbiology and biotechnology》2008,79(3):417-422
A novel indigo-producing oxygenase gene, designated ipoA (1,197 bp) was characterized from Rhodococcus sp. strain T104. Three indigo-negative mutations (A58V, P59L, and G251D) were obtained through random mutagenesis using an E. coli mutator strain. Subsequent saturation mutagenesis resulted in the identification of nine and three amino acid substitutions that restore activity in the A58V and P59L mutants, respectively. Activity was not restored in the G251D mutation by any other amino acids. Interestingly, activity in the A58V mutant, where a methyl group is only replaced by an isopropyl side chain, is restored by a variety of amino acids, including polar ones. A molecular modeling study suggests that the residues at positions 58, 59, and 251 of the T104 IpoA enzyme are far from the active site, indicating that the mutations must alter the overall structure of the enzyme. 相似文献
647.
Beom Soo Kim 《Biotechnology letters》2002,24(2):125-130
Pseudomonas oleovorans was cultivated to produce medium chain length polyhydroxyalkanoates (MCL-PHAs) from octanoic acid and ammonium nitrate as carbon and nitrogen source, respectively, by a pH-stat fed-batch culture technique. The octanoate in the culture broth was maintained below 4 g l–1 by feeding the mixture of octanoic acid and ammonium nitrate when the culture pH rose above 7.1. The final cell concentrations of 63, 55 and 9.5 g l–1, PHA contents of 62, 75 and 67% of dry cell wt, and productivities of 1, 0.63 and 0.16 g l–1 h–1 were obtained when the C/N ratios in the feed were 10, 20 and 100 g octanoic acid g–1 ammonium nitrate, respectively. 相似文献
648.
Rohini Dwivedi Priyanka Samanta Poonam Sharma Fuming Zhang Sushil K. Mishra Pavel Kucheryavy Seon Beom Kim AyoOluwa O. Aderibigbe Robert J. Linhardt Ritesh Tandon Robert J. Doerksen Vitor H. Pomin 《The Journal of biological chemistry》2021,297(4)
Certain sulfated glycans, including those from marine sources, can show potential effects against SARS-CoV-2. Here, a new fucosylated chondroitin sulfate (FucCS) from the sea cucumber Pentacta pygmaea (PpFucCS) (MW ∼10–60 kDa) was isolated and structurally characterized by NMR. PpFucCS is composed of {→3)-β-GalNAcX-(1→4)-β-GlcA-[(3→1)Y]-(1→}, where X = 4S (80%), 6S (10%) or nonsulfated (10%), Y = α-Fuc2,4S (40%), α-Fuc2,4S-(1→4)-α-Fuc (30%), or α-Fuc4S (30%), and S = SO3−. The anti-SARS-CoV-2 activity of PpFucCS and those of the FucCS and sulfated fucan isolated from Isostichopus badionotus (IbFucCS and IbSF) were compared with that of heparin. IC50 values demonstrated the activity of the three holothurian sulfated glycans to be ∼12 times more efficient than heparin, with no cytotoxic effects. The dissociation constant (KD) values obtained by surface plasmon resonance of the wildtype SARS-CoV-2 spike (S)-protein receptor-binding domain (RBD) and N501Y mutant RBD in interactions with the heparin-immobilized sensor chip were 94 and 1.8 × 103 nM, respectively. Competitive surface plasmon resonance inhibition analysis of PpFucCS, IbFucCS, and IbSF against heparin binding to wildtype S-protein showed IC50 values (in the nanomolar range) 6, 25, and 6 times more efficient than heparin, respectively. Data from computational simulations suggest an influence of the sulfation patterns of the Fuc units on hydrogen bonding with GlcA and that conformational change of some of the oligosaccharide structures occurs upon S-protein RBD binding. Compared with heparin, negligible anticoagulant action was observed for IbSF. Our results suggest that IbSF may represent a promising molecule for future investigations against SARS-CoV-2. 相似文献
649.
650.
Platycodin D Inhibits Osteoclastogenesis by Repressing the NFATc1 and MAPK Signaling Pathway
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