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101.
102.
Background
Metabolically versatile soil bacteria Burkholderia cepacia complex (Bcc) have emerged as opportunistic pathogens, especially of cystic fibrosis (CF). Previously, we initiated the characterization of the phenylacetic acid (PA) degradation pathway in B. cenocepacia, a member of the Bcc, and demonstrated the necessity of a functional PA catabolic pathway for full virulence in Caenorhabditis elegans. In this study, we aimed to characterize regulatory elements and nutritional requirements that control the PA catabolic genes in B. cenocepacia K56-2. 相似文献103.
Hussien M Alwadie & Zakaria AM Baka 《Archives Of Phytopathology And Plant Protection》2013,46(3-4):195-209
A 12 month period survey of the fungi associated with Euphorbia inarticulata was evaluated. Sampling was concentrated mainly in Aseer region (South-West Saudi Arabia) and seven fungal species were identified as pathogens of this plant. Melampsora euphorbiae and Alternaria euphorbiicola were the most common species on this plant. Bipolaris euphorbiae, Botrytis ricini, Colletotrichum gloeosporioides, Oidium sp., Sphaceloma poinsettiase and Uromyces euphorbiae were less frequent species. These fungal pathogens were recorded for the first time on Euphorbia inarticulata in Saudi Arabia. Scanning and transmission electron microscopy revealed the colonization of M. euphorbiae, as an example, in leaf tissues of E. inarticulata. Remarkable ultrastructural changes in chloroplasts and nuclei of infected cells of E. inarticulata as a result of infection by M. euphorbiae were observed. 相似文献
104.
Afiniki B Zarafi AM Emechebe AD Akpa O Alabi 《Archives Of Phytopathology And Plant Protection》2013,46(1):11-17
The effect of various levels of nitrogen (0.0, 30.0, 60.0, 120.0) and phosphorus (0.0, 6.5, 13.0, 36.0) on the incidence and severity of downy mildew of pearl millet and yield of two pearl millet varieties (Zango and GB8375) were studied under field conditions in 2000 and 2001 respectively. Both nitrogen and phosphorus significantly increased incidence and severity of the disease in the two varieties. Grain yield and 1000 grain weight of the varieties also increased with nitrogen and phosphorus levels. 相似文献
105.
Andreea Dudu Sergiu Emil Georgescu Patrick Berrebi Marieta Costache 《Genetics and molecular biology》2012,35(4):886-891
Sturgeons are fish species with a complex biology. They are also characterized by complex aspects including polyploidization and easiness of hybridization. As with most of the Ponto-Caspian sturgeons, the populations of Acipenser ruthenus from the Danube have declined drastically during the last decades. This is the first report on mitochondrial point heteroplasmy in the cytochrome b gene of this species. The 1141 bp sequence of the cytb gene in wild sterlet sturgeon individuals from the Lower Danube was determined, and site heteroplasmy evidenced in three of the 30 specimens collected. Two nucleotide sequences were identified in these heteroplasmic individuals. The majority of the heteroplasmic sites are synonymous and do not modify the sequence of amino acids in cytochrome B protein. To date, several cases of point heteroplasmy have been reported in animals, mostly due to paternal leakage of mtDNA. The presence of specific point heteroplasmic sites might be interesting for a possible correlation with genetically distinct groups in the Danube River. 相似文献
106.
R Gassner M J Buckley H Georgescu R Studer M Stefanovich-Racic N P Piesco C H Evans S Agarwal 《Journal of immunology (Baltimore, Md. : 1950)》1999,163(4):2187-2192
Continuous passive motion manifests therapeutic effects on inflamed articular joints by an as-yet-unknown mechanism. Here, we show that application of cyclic tensile stress (CTS) in vitro abrogates the catabolic effects of IL-1beta on chondrocytes. The effects of CTS are mediated by down-regulation of IL-1beta-dependent inducible NO production, and are directly attributed to the inhibition of inducible NO synthase (iNOS) mRNA expression and protein synthesis. The inhibition of iNOS induction by CTS is paralleled by abrogation of IL-1beta-induced down-regulation of proteoglycan synthesis. Furthermore, CTS inhibits iNOS expression and up-regulates proteoglycan synthesis at concentrations of IL-1beta frequently observed in inflamed arthritic joints, suggesting that the actions of CTS may be clinically relevant in suppressing the sustained effects of pathological levels of IL-1beta in vivo. These results are the first to demonstrate that mechanisms of the intracellular actions of CTS in IL-1beta-activated chondrocytes are mediated through inhibition of a key molecule in the signal transduction pathway that leads to iNOS expression. 相似文献
107.
High diversity of poliovirus strains isolated from the central nervous system from patients with vaccine-associated paralytic poliomyelitis. 总被引:6,自引:6,他引:6 下载免费PDF全文
M M Georgescu F Delpeyroux M Tardy-Panit J Balanant M Combiescu A A Combiescu S Guillot R Crainic 《Journal of virology》1994,68(12):8089-8101
To establish the etiology of vaccine-associated paralytic poliomyelitis (VAPP), isolates from the central nervous system (CNS) from eight patients with VAPP were compared with stool isolates from the same patients. The vaccine (Sabin) origin was checked for all of the available isolates. Unique and similar strains were recovered from paired stool and CNS samples for five of the eight VAPP cases and the three wild-type cases included in the study. In the remaining three VAPP cases, the stool samples and, in one case, the CNS samples contained mixtures of strains. In two of these cases an equivalent of the CNS isolate was found among the strains separated by plaque purification from stool mixtures, and in one case different strains were isolated from CNS and stool. This shows that the stool isolate in VAPP might not be always representative of the etiologic agent of the neurological disease. A wide variety of poliovirus vaccine genomic structures appeared to be implicated in the etiology of VAPP. Of nine CNS vaccine-derived strains, four were nonrecombinant and five were recombinant (vaccine/vaccine or even vaccine/nonvaccine). The neuropathogenic potential of the isolates was evaluated in transgenic mice sensitive to poliovirus. All of the CNS-isolated strains lost the attenuated phenotype of the Sabin strains. However, for half of them, the neurovirulence was lower than expected, suggesting that the degree of neurovirulence for transgenic mice is not necessarily correlated with the neuropathogenicity in humans. 相似文献
108.
Molecular evidence for the rapid propagation of mouse t haplotypes from a single, recent, ancestral chromosome 总被引:11,自引:0,他引:11
Silver LM; Hammer M; Fox H; Garrels J; Bucan M; Herrmann B; Frischauf AM; Lehrach H; Winking H; Figueroa F 《Molecular biology and evolution》1987,4(5):473-482
Mouse t haplotypes are variant forms of chromosome 17 that exist at high
frequencies in worldwide populations of two species of commensal mice. To
determine both the relationship of t haplotypes to each other and the
species within which they exist, 35 representative t haplotypes were
analyzed by means of 10 independent molecular probes, including five DNA
clones and five polypeptide spots identified by means of two- dimensional
gel electrophoresis. All of the tested haplotypes were found to share
restriction fragments and polypeptide spots that are absent in mice
carrying wild-type forms of chromosome 17. This observation provides the
first direct evidence that all of the known t haplotypes are descendents of
a single ancestral chromosome. The absence of variation among t haplotypes
could mean that this ancestral chromosome existed relatively recently, in
which case it would be necessary to postulate introgressions of t
haplotypes across species lines to explain their presence in both Mus
domesticus and M. musculus. Alternatively, it is possible that the
ancestral chromosome existed prior to the split between M. domesticus and
M. musculus and that, by chance, our probes fail to detect polymorphisms
that exist among the t haplotypes. A further result of our analysis is the
characterization of a partial t haplotype in a wild population of Israeli
mice.
相似文献
109.
Valentin Flaudias Marie Christine Picot Jorge Lopez-Castroman Pierre-Michel Llorca Audrey Schmitt Jean Perriot Vera Georgescu Philippe Courtet Xavier Quantin Sébastien Guillaume 《PloS one》2016,11(3)
Background
Executive functions are linked to tobacco dependence and craving. In this cross-sectional study, we assessed the impact of three executive functions: updating, inhibition and shifting processes on tobacco craving and dependence.Method
134 tobacco consumers were included in this study: 81 moderately (Fagerström score <7) and 53 heavily dependent (Fagerström score >7). Dependence was assessed with the Fagerström test and craving with the tobacco craving questionnaire (TCQ 12). We used the Stroop test and the Hayling test to measure inhibition, the Trail Making Test to measure shifting processes and the n-back test to measure updating processes. A multivariate logistic model was used to assess which variables explained best the level of nicotine dependence.Results
Inhibition (p = 0.002) and updating (p = 0.014) processes, but not shifting processes, were associated with higher tobacco dependence. Inhibition capacity had a significant effect on the nicotine dependence level independently of age, education, time since last cigarette, intellectual quotient, craving, updating and shifting process.Conclusions
Nicotine dependence level seems better explained by inhibition capacities than by craving and updating effects. The capacity to inhibit our behaviours is a good predictor of the severity of tobacco dependence. Our results suggest a prefrontal cortex dysfunction affecting the inhibitory capacities of heavy tobacco dependent smokers. Further studies are needed to investigate the application of these findings in the treatment of tobacco dependence. 相似文献110.
Laurent AF Frantz Joshua G Schraiber Ole Madsen Hendrik-Jan Megens Mirte Bosse Yogesh Paudel Gono Semiadi Erik Meijaard Ning Li Richard PMA Crooijmans Alan L Archibald Montgomery Slatkin Lawrence B Schook Greger Larson Martien AM Groenen 《Genome biology》2013,14(9):R107