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41.
Use of response surface methodology to examine chitinase regulation in the basidiomycete Moniliophthora perniciosa 总被引:1,自引:0,他引:1
Maíza Alves Lopes Dayane Santos Gomes Maria Gabriela Bello Koblitz Carlos Priminho Pirovani Júlio Czar de Mattos Cascardo Aristteles Ges-Neto Fabienne Micheli 《Mycological Research》2008,112(3):399-406
We report here the first analysis of chitinase regulation in Moniliophthora perniciosa, the causal agent of the witches' broom disease of cacao. A multivariate statistical approach was employed to evaluate the effect of several variables, including carbon and nitrogen sources and cultivation time, on M. perniciosa non-secreted (detected in mycelium, i.e. in symplasm and cell wall) and secreted (detected in the culture medium) chitinase activities. Non-secreted chitinase activity was enhanced by peptone and chitin and repressed by glucose. Chitinase secretion was increased by yeast extract alone or in combination with other nitrogen sources, and by N-acetylglucosamine, and repressed in presence of chitin. The best cultivation times for non-secreted and secreted chitinase activities were 30 and 20 d, respectively. However, chitinase activity was always higher in the mycelium than in the culture medium, suggesting a relatively poor chitinase secretion activity. Conversely, higher mycelial growth was observed when the activity of the non-secreted chitinase was at its lowest, i.e. when the fungus was grown on glucose and yeast extract as sources of carbon and nitrogen, respectively. Conversely, the induction of non-secreted chitinase activity by chitin decreased the mycelium growth. These results suggest that the culture medium, by the induction or repression of chitinases, affected the hyphal growth. Thus, as an essential component of M. perniciosa growth, chitinases may be a potential target for strategies to control disease. 相似文献
42.
Hematopoietic chimerism monitoring based on STRs: quantitative platform performance on sequential samples. 总被引:3,自引:0,他引:3
Don Kristt Moshe Israeli Ronit Narinski Hagit Or I Yaniv Jerry Stein Tirza Klein 《Journal of biomolecular techniques》2005,16(4):380-391
Hematopoietic stem cell transplantation (HSCT) creates a donor-recipient cellular chimerism in the patient, which is quantitatively assayed from peripheral blood based on STR-DNA. Since chimerism values often vary across a patient's samples, it is important to determine to what extent this variability reflects technical aspects of platform performance. This issue is systematically assessed in the current study for the first time. Using the SGM Plus multiplex PCR kit and ABI platform, the longitudinal performance of STR markers was quantitatively evaluated in two chimeric models with true values, and in patient samples (n >500 marker loci). Computation of percent chimerism for each marker, and mean (sample) percent chimerism, standard deviation, and coefficient of variance was performed by our ChimerTrack utility. In chimeric models with known values, individual markers exhibited an accuracy (observed/true) of 88-98%; replication precision was 92-100% true, with a mean error of 2%. Fragment size calling was greater than 99% accurate and precise. Patient results were comparable for markers, relaive to sample means. One source of technical variability in chimerism estimation was allelic differential amplification efficiency. The latter was influenced by signal amplitude, dye label, marker size, and allelic size interval. It can be concluded that long-term chimeric tracking is routinely feasible using this platform in conjunction with ChimerTrack software. Importantly, mean percent chimerism, for any sample, should closely approximate the true chimeric status, with a technical accuracy of 98%. Guidelines are presented for selecting an optimized marker profile. 相似文献
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44.
Carolina David Wiener Karen Jansen Gabriele Ghisleni Manuella Pinto Kaster Luciano Dias de Mattos Souza Diogo Rizzato Lara Luiz Valmor Portela Ricardo Azevedo da Silva Jean Pierre Oses 《Neurochemical research》2013,38(7):1394-1398
Several biological factors have been recently related with major depression and bipolar disorder. The aim of our paper was to investigate the peripheral levels of the protein neuronal specific enolase (NSE), a putative marker of neuronal damage, comparing patients with major depressive disorder and bipolar disorder to control subjects. This is a case–control study nested in a cross-sectional population-based survey. Psychopathology screen was performed using the Mini-International Neuropsychiatric Interview 5.0 and blood samples were collected from 108 young adults. Three groups were selected, 36 healthy controls, 36 subjects with major depression disorder and 36 subjects with bipolar disorder. Serum levels of NSE significantly decreased (p = 0.002) in major depression disorder (2.19 ± 1.78 ng/mL) and bipolar disorder subjects (2.53 ± 2.61 ng/mL) compared to the control group (3.55 ± 2.19 ng/mL). In conclusion, peripheral neuronal specific enolase may be a useful marker drug-naïve major depression disorder and bipolar disorder, but its pathophysiological significance and response to treatment should be further investigated. 相似文献
45.
Jacky L. Snoep Mark R. de Graef Adrie H. Westphal Arie de Kok M. Joost Teixeira de Mattos Oense M. Neijssel 《FEMS microbiology letters》1993,114(3):279-283
Abstract The effect of NADH on the activity of the purified pyruvate dehydrogenase complexes (PDHc) of Enterococcus (Ec.) faecalis, Lactococcus lactis, Azotobacter vinelandii and Escherichia coli was determined in vitro. It was found that the PDHc of E. coli and L. lactis was active only at relatively low NADH/NAD ratios, whereas the PDHc of Ec. faecalis was inhibited only at high NADH/NAD ratios. The PDHc of Azotobacter vinelandii showed an intermediate sensitivity. The organisms were grown in chemostat culture under conditions that led to different intracellular NADH/NAD ratios and the PDHc activities in vivo could be calculated from the specific rates of product formation. Under anaerobic growth conditions, only Ec. faecelis expressed PDHc activity in vivo. The activities in vivo of the complexes of the different organisms were in good agreement with their properties determined in vitro. The physiological consequences of these results are discussed. 相似文献
46.
Roy Moezelaar M. Joost Teixeira de Mattos Lucas J. Stal 《FEMS microbiology letters》1995,127(1-2):47-50
Abstract The cyanobacterium Microcystis PCC7806 was found to possess an NAD-dependent lactate dehydrogenase (EC 1.1.1.27) which catalyzes the reduction of pyruvate to l-lactate. The enzyme required fructose 1,6-bisphosphate for activity and displayed positive cooperativity towards pyruvate. Lactate was not formed during fermentation by cell suspensions, possibly due to low intracellular concentrations of fructose 1,6-bisphosphate and/or pyruvate. 相似文献
47.
Our aim was to investigate the population fluctuation and the damage caused by the phytophagous mites Calacarus heveae Feres, Tenuipalpus heveae Baker, and Eutetranychus banksi (McGregor) on clones FX 2784, FX 3864, and MDF 180 in rubber tree crops from southeastern Bahia, Brazil. Moreover, we tested for the influence of climatic variables on occurrence patterns of these species throughout weekly samples performed from October to April. The infestation peaks was between mid-January and late February. The clones FX 2784 and FX 3864 had the highest infestations and more severe damage possibly caused by C. heveae, which was the most frequent and abundant species in all clones. We found that sunlight duration and rainfall were the most important factors for C. heveae while T. heveae was affected by rainfall and temperature. Eutetranychus banksi was only affected by sunlight duration. However, the best models had low goodness of fit. We concluded that the clones FX 2784 and FX 3864 had a higher susceptibility to mite attack, and the association between climatic variables and favorable physiological conditions were determinant for the population increase of the species from January to April. 相似文献
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49.
Ruben Girsowicz Oksana Koryachenko Chen Sherman Einav Mayzlish-Gati Tirza Doniger 《Soil & Sediment Contamination》2018,27(3):175-185
The present study evaluated the effect of crude oil contamination on a microbial community in hyper-arid soils. The Evrona Nature Reserve of Israel, situated in the Arava, was exposed twice in the last 40 years to petroleum-hydrocarbon-spill pollution. The first pollution event took place 40 years ago and was never treated, presenting a unique future time-point perspective to the second (2014) contamination event. Soil samples were collected after the second spill, and abiotic properties and bacterial diversity in the sampled soil were analyzed. The results showed that there is a significant decrease over time in the number of observed bacterial species in the contaminated samples, coupled together with bacterial species replacement toward species capable of using source oil as the sole carbon and energy source. The presence of petroleum in soil significantly changed the composition and functional diversity of a microbial community, and the Evrona Nature Reserve is still in the middle of a bioremediation process even 40 years after the crude oil contamination. 相似文献
50.
Robson Campos Silva Daniella Maria Coelho Britto Wagner de Fátima Pereira Gustavo Eustáquio Alvin Brito-Melo Cristiane Tolentino Machado Marcelo Mattos Pedreira 《Reproductive biology》2018,18(2):169-176
Doxorubicin (DXR) is a widely used chemotherapeutic anticancer agent that has potent activity against several solid and non-solid human malignant tumors, including childhood malignancies. However, DXR has serious toxic effects on tissues with rapid cell cycles, such as myeloid and lymphatic tissues, intestinal mucosa, testes and ovaries. In the present study, the short- and medium-term toxic effects of DXR on the reproductive system of male Wistar rats were evaluated using morphometric and stereological tools to quantify damage to the seminiferous epithelium. Adult male Wistar rats were treated with dose of 7.5?mg/kg of DXR and were sacrificed at seven, 14, 21 and 28?days after treatment. The testes were fixed in glutaraldehyde solution, routinely processed and embedded in plastic for evaluation under a light microscope. A significant reduction in testis weight was found as a result of massive germ cell apoptosis. Differences in comparison to the control group were found in the relative frequency of all stages of the seminiferous epithelium cycle, with significant differences for stages VIII–XI. Apoptosis significantly decreased the number of pachytene spermatocytes in the stages evaluated (I, II–III and VIII) at seven and 14?days. At 21 and 28?days after treatment, the testes exhibited the massive loss of germ cells that resulted in a missing cell layer. Moreover, reductions in the height of seminiferous tubules, tubular diameter and tubular compartment as well as an increase in the intertubular compartment were found in the period studied. 相似文献