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41.
Martins-de-Souza D Martins D Astua-Monge G Coletta-Filho HD Winck FV Baldasso PA de Oliveira BM Marangoni S Machado MA Novello JC Smolka MB 《Current microbiology》2007,54(2):119-123
The fastidious bacterium Xylella fastidiosa is associated with important crop diseases worldwide. We have recently shown that X. fastidiosa is a peculiar organism having unusually low values of gene codon bias throughout its genome and, unexpectedly, in the group of the most abundant proteins. Here, we hypothesized that the lack of codon usage optimization in X. fastidiosa would incapacitate this organism to undergo quick and massive changes in protein expression as occurs in a classical stress response. Proteomic analysis of the response to heat stress in X. fastidiosa revealed that no changes in protein expression can be detected. Moreover, stress-inducible proteins identified in the closely related citrus pathogen Xanthomonas axonopodis pv citri were found to be constitutively expressed in X. fastidiosa. These proteins have extremely high codon bias values in the X. citri and other well-studied organisms, but low values in X. fastidiosa. Because biased codon usage is well known to correlate to the rate of protein synthesis, we speculate that the peculiar codon bias distribution in X. fastidiosa is related to the absence of a classical stress response, and, probably, alternative strategies for survival of X. fastidiosa under stressfull conditions. 相似文献
42.
Jaqueline Inês Alves de Andrade Eduardo Akifumi Ono Glauber Cruz de Menezes Elenice Martins Brasil Rodrigo Roubach Elisabeth Criscuolo Urbinati Marcos Tavares-Dias Jaydione Luiz Marcon Elizabeth Gusmo Affonso 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2007,146(4):576
This study evaluated the influence of diets supplemented with 500, 800, 1200 mg kg− 1 of vitamin C (ascorbic acid or AA) and vitamin E (α-tocopherol or α-T) on the physiological responses of pirarucu fed for 2 months. Weight and mortality were not affected by dietary vitamin type or their concentrations. Significant increase (p < 0.05) on the red blood cells count was obtained on treatments with 800 and 1200 mg AA kg− 1 and on the hemoglobin concentration on treatment with 500 mg α-T kg− 1 relatively to control. Mean corpuscular volume presented a significant decrease (p < 0.05) on treatment with 800 and 1200 mg AA kg−1 when compared to control. Mean corpuscular hemoglobin concentration was significantly high (p < 0.05) on treatment with 500 mg α-T kg− 1. Only in vitamin C treatments, we noticed a significant increase (p < 0.05) in the number of leucocytes relative to control. All fish in the vitamin-supplemented treatments, except 500 mg AA kg− 1, had high total protein values compared to control. Fish treated with 800 or 1200 mg α-T kg− 1 also showed increases in plasma glucose concentrations. Our results suggest that 800 and 1200 mg AA kg− 1 are probably the most suitable concentrations for pirarucu diets, although high vitamin E diets are not necessary for quantitative leucocyte increases for this species. 相似文献
43.
Daniel Martins Bruno Menezes de Oliveira Alessandro dos Santos Farias Ricardo Shiniti Oka Horiuchi Cleyton Crepaldi Domingues Eneida de Paula Sérgio Marangoni Wagner Farid Gattaz Emmanuel Dias-Neto José Camillo Novello 《Briefings in Functional Genomics and Prot》2007,6(1):70-75
Protein extraction is the most important step to reveal a proteome by Two-Dimensional Gel Electrophoresis. Usually, the urea/thiourea based standard protein extraction buffer (SB) is combined with detergents with the aim of achieving better resolution and solubilization of different classes of proteins. In order to produce better gels and achieve the greatest spot resolution of Human Brain Proteins, comparisons using 2-DE of extracted proteins from Human Brain Frontal Cortex with SB constituents (7M Urea, 2M Thiourea and 100mM DTT) were made, using different detergent compositions in the buffer. SB preparations in combination with CHAPS and ASB-14 as well as with ASB-16 (reported for the first time in 2-DE experiments) have been tested. Our results confirm that the most efficient solubilizing solution for 2-DE analysis of cytosolic and membrane Human Brain Proteins is SB combined with 4% CHAPS and 2% ASB-14. 相似文献
44.
We present a modification of the weighted K-nearest neighbours imputation method (KNNimpute) for missing values (MVs) estimation in microarray data based on the reuse of estimated data. The method was called iterative KNN imputation (IKNNimpute) as the estimation is performed iteratively using the recently estimated values. The estimation efficiency of IKNNimpute was assessed under different conditions (data type, fraction and structure of missing data) by the normalized root mean squared error (NRMSE) and the correlation coefficients between estimated and true values, and compared with that of other cluster-based estimation methods (KNNimpute and sequential KNN). We further investigated the influence of imputation on the detection of differentially expressed genes using SAM by examining the differentially expressed genes that are lost after MV estimation. The performance measures give consistent results, indicating that the iterative procedure of IKNNimpute can enhance the prediction ability of cluster-based methods in the presence of high missing rates, in non-time series experiments and in data sets comprising both time series and non-time series data, because the information of the genes having MVs is used more efficiently and the iterative procedure allows refining the MV estimates. More importantly, IKNN has a smaller detrimental effect on the detection of differentially expressed genes. 相似文献
45.
A survey of epitheliocystis disease in farmed Nile tilapia (Oreochromis niloticus Linnaeus, 1758) in Brazil 下载免费PDF全文
46.
Reinaldo de Menezes Martins Cristina de Albuquerque Possas Akira Homma 《Memórias do Instituto Oswaldo Cruz》2015,110(1):114-124
This paper presents, from the perspective of technological development and
production, the results of an investigation examining 61 clinical studies with
vaccines conducted in Brazil between 1938-2013, with the participation of the Oswaldo
Cruz Institute (IOC) and the Oswaldo Cruz Foundation (Fiocruz). These studies have
been identified and reviewed according to criteria, such as the kind of vaccine
(viral, bacterial, parasitic), their rationale, design and methodological strategies.
The results indicate that IOC and Fiocruz have accumulated along this time
significant knowledge and experience for the performance of studies in all clinical
phases and are prepared for the development of new vaccines products and processes.
We recommend national policy strategies to overcome existing regulatory and financing
constraints. 相似文献
47.
48.
49.
Prema Menezes William C. Miller David A. Wohl Adaora A. Adimora Peter A. Leone William C. Miller Joseph J. Eron Jr. 《PloS one》2011,6(7)
Background
Patients who participate in clinical trials may experience better clinical outcomes than patients who initiate similar therapy within clinical care (trial effect), but no published studies have evaluated a trial effect in HIV clinical trials.Methods
To examine a trial effect we compared virologic suppression (VS) among patients who initiated HAART in a clinical trial versus in routine clinical care. VS was defined as a plasma HIV RNA ≤400 copies/ml at six months after HAART initiation and was assessed within strata of early (1996–99) or current (2000–06) HAART periods. Risk ratios (RR) were estimated using binomial models.Results
Of 738 persons initiating HAART, 30.6% were women, 61.7% were black, 30% initiated therapy in a clinical trial and 67% (n = 496) had an evaluable six month HIV RNA result. HAART regimens differed between the early and current periods (p<0.001); unboosted PI regimens (55.6%) were more common in the early and NNRTI regimens (46.4%) were more common in the current period. Overall, 78% (95%CI 74, 82%) of patients achieved VS and trial participants were 16% more likely to achieve VS (unadjusted RR 1.16, 95%CI 1.06, 1.27). Comparing trial to non-trial participants, VS differed by study period. In the early period, trial participants initiating HAART were significantly more likely to achieve VS than non-trial participants (adjusted RR 1.33; 95%CI 1.15, 1.54), but not in the current period (adjusted RR 0.98; 95%CI 0.87, 1.11).Conclusions
A clear clinical trial effect on suppression of HIV replication was observed in the early HAART period but not in the current period. 相似文献50.