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81.
Woo-Jong Yim Selvaraj Poonguzhali Munusamy Madhaiyan Pitchai Palaniappan M. A. Siddikee Tongmin Sa 《Journal of microbiology (Seoul, Korea)》2009,47(2):147-155
Diazotrophic bacteria isolated from the rhizosphere of Chinese cabbage were assessed for other plant growth promoting characteristics
viz., production of IAA, ethylene, ACC deaminase, phosphate solubilization, and gnotobiotic root elongation. Their effect on inoculation
to Chinese cabbage was also observed under growth chamber conditions. A total of 19 strains that showed higher nitrogenase
activity identified by 16S rRNA gene sequence analysis were found to be the members of the genera Pseudomonas and Agrobacterium belonging to α- and γ-Proteobacteria groups. These strains were also efficient in producing IAA and ACC deaminase though they produced low levels of ethylene
and no phosphate solubilization. In addition, inoculation of selected diazotrophic bacterial strains significantly increased
seedling length, dry weight, and total nitrogen when compared to uninoculated control. The colonization of crop plants by
diazotrophic bacteria can be affected by many biotic and abiotic factors, and further studies are oriented towards investigating
the factors that could influence the establishment of a selected bacterial community. 相似文献
82.
Jessica R. Sheldon Mi-Sung Yim Jessica H. Saliba Wai-Hong Chung Kwok-Yin Wong Kam Tin Leung 《Applied and environmental microbiology》2012,78(23):8331-8339
The protein RpoS is responsible for mediating cell survival during the stationary phase by conferring cell resistance to various stressors and has been linked to biofilm formation. In this study, the role of the rpoS gene in Escherichia coli O157:H7 biofilm formation and survival in water was investigated. Confocal scanning laser microscopy of biofilms established on coverslips revealed a nutrient-dependent role of rpoS in biofilm formation, where the biofilm biomass volume of the rpoS mutant was 2.4- to 7.5-fold the size of its rpoS+ wild-type counterpart in minimal growth medium. The enhanced biofilm formation of the rpoS mutant did not, however, translate to increased survival in sterile double-distilled water (ddH2O), filter-sterilized lake water, or unfiltered lake water. The rpoS mutant had an overall reduction of 3.10 and 5.30 log10 in sterile ddH2O and filter-sterilized lake water, respectively, while only minor reductions of 0.53 and 0.61 log10 in viable counts were observed for the wild-type form in the two media over a 13-day period, respectively. However, the survival rates of the detached biofilm-derived rpoS+ and rpoS mutant cells were comparable. Under the competitive stress conditions of unfiltered lake water, the advantage conferred by the presence of rpoS was lost, and both the wild-type and knockout forms displayed similar declines in viable counts. These results suggest that rpoS does have an influence on both biofilm formation and survival of E. coli O157:H7 and that the advantage conferred by rpoS is contingent on the environmental conditions. 相似文献
83.
The role of the peroxisome proliferator-activated receptor-gamma (PPARgamma) in cell differentiation, cell-cycle arrest, and apoptosis has attracted increasing attention. We have recently demonstrated that PPARgamma ligands-troglitazone (TGZ) induced apoptosis in lung cancer cells. In this report, we further studied the role of ERK1/2 in lung cancer cells treated by TGZ. The result demonstrated that TGZ induced PPARgamma and ERK1/2 accumulation in the nucleus, in which the co-localization of both proteins was found. The activation of ERK1/2 resulted in apoptosis via a mitochondrial pathway. Both PPARgamma siRNA and U0126, a specific inhibitor of ERK1/2, were able to block these effects of TGZ, suggesting that apoptosis induced by TGZ was PPARgamma and ERK1/2 dependent. Inhibition of ERK1/2 by U0126 also led to a significant decrease in the level of PPARgamma, indicating a positive cross-talk between PPARgamma and ERK1/2 or an auto-regulatory feedback mechanism to amplify the effect of ERK1/2 on cell growth arrest and apoptosis. In addition to ERK1/2, TGZ also activated Akt. Interestingly, inhibition of ERK1/2 prevented the activation of Akt whereas the suppression of Akt had no effect on ERK1/2, suggesting that Akt was not necessary for TGZ-PPARgamma-ERK pathway. However, the inhibition of Akt promoted the release of cytochrome c, suggesting the activation of Akt may have a negative effect on apoptosis induced by TGZ. In conclusion, our study has demonstrated that TGZ, a synthetic PPARgamma ligand, induced apoptosis in NCI-H23 lung cancer cells via a mitochondrial pathway and this pathway was PPARgamma and ERK1/2 dependent. 相似文献
84.
85.
Pandiyan Indiragandhi Rangasamy Anandham Kyounga Kim Woojong Yim Munusamy Madhaiyan Tongmin Sa 《World journal of microbiology & biotechnology》2008,24(7):1037-1045
This study aimed to examine the induction of defense responses in tomato elicited by Methylobacterium
oryzae CBMB20 as a consequence of reduced stress ethylene level possibly through its ACC deaminase activity. Significantly increased
activities of pathogenesis-related (PR) proteins and defense enzymes such as β-1,3-glucanase, phenylalanine ammonia-lyase,
peroxidase and polyphenol oxidase were noted in M. oryzae CBMB20 pretreated and challenged with Pseudomonas syringae pv. tomato (Pst) compared to either control or M. oryzae-treated tomato plants in both growth chamber and greenhouse conditions. Increased PR proteins and defense enzyme activities
were correlated with the reduction of stress ethylene level. M. oryzae CBMB20 reduced the stress ethylene level about 27% and 55% when challenged with Pst, in growth chamber and greenhouse on
day 7 respectively and the effect was comparable to that of the chemical ethylene biosynthesis inhibitor AVG, L-α-(2-aminoethoxyvinyl)-glycine
hydrochloride. As a consequence of reduced stress ethylene level and its effect on defense response in crop plants, the disease
severity was reduced 26% in M. oryzae CBMB20-treated plants challenged with pathogen. Therefore, inoculation of M. oryzae CBMB20 would induce the defense enzymes and contribute to the enhanced resistance of tomato plants against the pathogen Pst. 相似文献
86.
Parasitic worms survive within their immunocompetent hosts by modulating their immune system and by inhibiting inflammatory responses directed against the parasites. This immunomodulation has a spill over effect and also inhibits inflammatory responses originating from other causes. For this reason, persons who are infected with certain species of worms show a lower rate of allergic diseases as compared to persons who are free of parasites. In the same line, studies in mouse models revealed that many inflammatory diseases can be treated by worm infections. This effect is among others owing to specific proteins that are released by the worms. Such secreted immunomodulators, shaped by co‐evolution between parasites and their hosts, could become lead compounds for the development of new therapies against allergic and inflammatory diseases. 相似文献
87.
Kyungdo Han Yu-Mi Park Hyuk-Sang Kwon Seung-Hyun Ko Seung-Hwan Lee Hyeon Woo Yim Won-Chul Lee Yong Gyu Park Mee Kyoung Kim Yong-Moon Park 《PloS one》2014,9(1)
Background
Blood pressure (BP) is directly and causally associated with body size in the general population. Whether muscle mass is an important factor that determines BP remains unclear.Objective
To investigate whether sarcopenia is associated with hypertension in older Koreans.Participants
We surveyed 2,099 males and 2,747 females aged 60 years or older.Measurements
Sarcopenia was defined as an appendicular skeletal muscle mass divided by body weight (ASM/Wt) that was <1 SD below the gender-specific mean for young adults. Obesity was defined as a body mass index (BMI) ≥25 kg/m2. Subjects were divided into four groups based on presence or absence of obesity or sarcopenia. Hypertension was defined as a systolic BP (SBP) ≥140 mmHg, a diastolic BP (DBP) ≥90 mmHg, or a self-reported current use of antihypertensive medications.Results
The overall prevalence of hypertension in the four groups was as follows 49.7% for non-obese non-sarcopenia, 60.9% for non-obese sarcopenia, 66.2% for obese non-sarcopenia and 74.7% for obese sarcopenia. After adjustment for age, gender, regular activity, current smoking and alcohol use, the odds ratio (OR) for having hypertension was 1.5 (95% confidence interval (CI) = 1.23–1.84) in subjects in the non-obese sarcopenia group, 2.08 (95% CI = 1.68–2.57) in the obese non-sarcopenia group and 3.0 (95% CI = 2.48–3.63) in the obese sarcopenia group, compared with the non-obese non-sarcopenia group (p for trend <0.001). Controlling further for body weight and waist circumference did not change the association between hypertension and sarcopenia. The association between sarcopenia and hypertension was more robust in the subjects with diabetes mellitus.Conclusion
Body composition beyond BMI has a considerable impact on hypertension in elderly Koreans. Subjects with sarcopenic obesity appear to have a greater risk of hypertension than simply obese or sarcopenia subjects. 相似文献88.
Mukherjee M Chow SY Yusoff P Seetharaman J Ng C Sinniah S Koh XW Asgar NF Li D Yim D Jackson RA Yew J Qian J Iyu A Lim YP Zhou X Sze SK Guy GR Sivaraman J 《The EMBO journal》2012,31(5):1308-1319
Phosphotyrosine-binding domains, typified by the SH2 (Src homology 2) and PTB domains, are critical upstream components of signal transduction pathways. The E3 ubiquitin ligase Hakai targets tyrosine-phosphorylated E-cadherin via an uncharacterized domain. In this study, the crystal structure of Hakai (amino acids 106-206) revealed that it forms an atypical, zinc-coordinated homodimer by utilizing residues from the phosphotyrosine-binding domain of two Hakai monomers. Hakai dimerization allows the formation of a phosphotyrosine-binding pocket that recognizes specific phosphorylated tyrosines and flanking acidic amino acids of Src substrates, such as E-cadherin, cortactin and DOK1. NMR and mutational analysis identified the Hakai residues required for target binding within the binding pocket, now named the HYB domain. ZNF645 also possesses a HYB domain but demonstrates different target specificities. The HYB domain is structurally different from other phosphotyrosine-binding domains and is a potential drug target due to its novel structural features. 相似文献
89.
W C Lineaweaver K Hui K Yim M Ruyle B Shuster J Eggleston S Grover 《Plastic and reconstructive surgery》1999,103(6):1553-1560
At our Medical Center, our reconstructive service has actively sought referrals of acute and chronic infections by declaring an interest in undertaking the integrated management and reconstruction of these cases. The practices of the two senior surgeons were reviewed for three academic years (1992 to 1995). Cases of surgical infection were analyzed as to site, ablative procedures, and reconstructive procedures. In total, 139 patients with 147 infections were identified. Sites of infection included head and neck (9.5 percent), trunk and pelvis (39.5 percent), upper extremity (22 percent), and lower extremity (29 percent). One-hundred thirty-one ablative procedures were done on this group, as were 126 reconstructive procedures, including 17 fasciocutaneous flaps, 26 pedicled muscle flaps, and 28 microsurgical flaps. With a mean follow-up of 14 months, 92 percent of these patients had resolution of infection. The 8 percent failure group included recurrences, amputation, and death. This series demonstrates that a plastic surgery service can attract a diverse population of surgical infections and manage them successfully with ablation and a wide variety of reconstructive procedures. The coordination of ablation and reconstruction may be optimally performed by the plastic surgeon. 相似文献
90.
Jung KH Kim MJ Ha E Kim HK Kim YO Kang SA Chung JH Yim SV 《Bioscience, biotechnology, and biochemistry》2007,71(5):1360-1364
Beta-glucan was recently shown to have the ability to enhance and stimulate the immune system in humans, but little is known about its the anti-inflammatory effects. We investigated the effect of beta-glucan on the production of tumor necrosis factor-alpha (TNF-alpha), a major pro-inflammatory mediator, in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. beta-Glucan decreased the production and expression of TNF-alpha. In addition, it blocked LPS-stimulated activation of nuclear factor kappa B (NF-kappaB). Hence beta-glucan might suppress LPS-stimulated TNF-alpha production by inhibiting NF-kappaB in BV2 microglial cells. 相似文献