Genes of the GadX-GadW Regulon in Escherichia coli

Acid in the stomach is thought to be a barrier to bacterial colonization of the intestine. Escherichia coli, however, has three systems for acid resistance, which overcome this barrier. The most effective of these systems is dependent on transport and decarboxylation of glutamate. GadX regulates two genes that encode isoforms of glutamate decarboxylase critical to this system, but additional genes associated with the glutamate-dependent acid resistance system remained to be identified. The gadX gene and a second downstream araC-like transcription factor gene, gadW, were mutated separately and in combination, and the gene expression profiles of the mutants were compared to those of the wild-type strain grown in neutral and acidified media under conditions favoring induction of glutamate-dependent acid resistance. Cluster and principal-component analyses identified 15 GadX-regulated, acid-inducible genes. Reverse transcriptase mapping demonstrated that these genes are organized in 10 operons. Analysis of the strain lacking GadX but possessing GadW confirmed that GadX is a transcriptional activator under acidic growth conditions. Analysis of the strain lacking GadW but possessing GadX indicated that GadW exerts negative control over three GadX target genes. The strain lacking both GadX and GadW was defective in acid induction of most but not all GadX target genes, consistent with the roles of GadW as an inhibitor of GadX-dependent activation of some genes and an activator of other genes. Resistance to acid was decreased under certain conditions in a gadX mutant and even more so by combined mutation of gadX and gadW. However, there was no defect in colonization of the streptomycin-treated mouse model by the gadX mutant in competition with the wild type, and the gadX gadW mutant was a better colonizer than the wild type. Thus, E. coli colonization of the mouse does not appear to require glutamate-dependent acid resistance

Glycolytic and Gluconeogenic Growth of \u3cem\u3eEscherichia coli\u3c/em\u3e O157:H7 (EDL933) and \u3cem\u3eE. coli\u3c/em\u3e K-12 (MG1655) in the Mouse Intestine

Escherichia coli EDL933, an O157:H7 strain, is known to colonize the streptomycin-treated CD-1 mouse intestine by growing in intestinal mucus (E. A. Wadolkowski, J. A. Burris, and A. D. O\u27Brien, Infect. Immun. 58:2438-2445, 1990), but what nutrients and metabolic pathways are employed during colonization has not been determined. In this study, when the wild-type EDL933 strain was fed to mice along with an EDL933 ΔppsA ΔpckA mutant, which is unable to utilize tricarboxylic acid cycle intermediates and gluconeogenic substrates for growth, both strains colonized the mouse intestine equally well. Therefore, EDL933 utilizes a glycolytic substrate(s) for both initial growth and maintenance when it is the only E. coli strain fed to the mice. However, in the presence of large numbers of MG1655, a K-12 strain, it is shown that EDL933 utilizes a glycolytic substrate(s) for initial growth in the mouse intestine but appears to utilize both glycolytic and gluconeogenic substrates in an attempt to maintain colonization. It is further shown that MG1655 predominantly utilizes glycolytic substrates for growth in the mouse intestine whether growing in the presence or absence of large numbers of EDL933. Data are presented showing that although small numbers of EDL933 grow to large numbers in the intestine in the presence of large numbers of MG1655 when both strains are fed to mice simultaneously, precolonization with MG1655 affords protection against subsequent colonization by EDL933. Moreover, in mice that are precolonized with EDL933, small numbers of MG1655 are able to grow rapidly in the intestine and EDL933 is eliminated. In situ hybridization experiments using E. coli-specific rRNA probes showed that while MG1655 is found only in mucus, EDL933 is found both in mucus and closely associated with intestinal epithelial cells. The data are discussed with respect to competition for nutrients and to the protection that some intestinal commensal E. coli strains might afford against infection by O157:H7 strains

Biocomposite macrospheres based on strontium-bioactive glass for application as bone fillers

Traditional bioactive glass powders are typically composed of irregular particles that can be packed into dense configurations presenting low interconnectivity, which can limit bone ingrowth. The use of novel biocomposite sphere formulations comprising bioactive factors as bone fillers are most advantageous, as it simultaneously allows for packing the particles in a 3-dimensional manner to achieve an adequate interconnected porosity, enhanced biological performance, and ultimately a superior new bone formation. In this work, we develop and characterize novel biocomposite macrospheres of Sr-bioactive glass using sodium alginate, polylactic acid (PLA), and chitosan (CH) as encapsulating materials for finding applications as bone fillers. The biocomposite macrospheres that were obtained using PLA have a larger size distribution and higher porosity and an interconnectivity of 99.7%. Loose apatite particles were observed on the surface of macrospheres prepared with alginate and CH by means of soaking into a simulated body fluid (SBF) for 7 days. A dense apatite layer was formed on the biocomposite macrospheresâ surface produced with PLA, which served to protect PLA from degradation. In vitro investigations demonstrated that biocomposite macrospheres had minimal cytotoxic effects on a human osteosarcoma cell line (SaOS-2 cells). However, the accelerated degradation of PLA due to the degradation of bioactive glass may account for the observed decrease in SaOS-2 cells viability. Among the biocomposite macrospheres, those composed of PLA exhibited the most promising characteristics for their potential use as fillers in bone tissue repair applications.This work was funded by grant #2019/15960-6, São Paulo Research Foundation in Brazil (FAPESP) and the Portuguese Foundation for Science and Technology (FCT), Reference UID/CTM/50025/2019 and FCT/Minister of Science, Technology and Higher Education in Portugal (MCTES) and by European Regional Development Fund (FEDER) funds through the COMPETE 2020 Program in the framework of ORAiDEA project (ref n° 39985 - AAC 31/SI/2017). The authors would also like to acknowledge Materials Research Center (CENIMAT) of the Associated Laboratory Institute of Nanostructures, Nanomodeling and Nanofabrication (i3N), NOVA University of LisbonCENIMAT|i3N and National Council for Scientific and Technological Development in Brazil CNPq (303149/2018-3). Ibrahim Fatih Cengiz acknowledges the FCT distinction attributed to him under the “Estímulo ao Emprego Científico” program (2021.01969.CEECIND). The authors thank the financial support provided under the projects: “HEALTH-UNORTE: Setting-up biobanks and regenerative medicine strategies to boost research in cardiovascular, musculoskeletal, neurological, oncological, immunological, and infectious diseases”, reference NORTE-01-0145-FEDER-000039, funded by the Norte Portugal Regional Coordination and Development Commission (CCDR-N), under the NORTE2020 Program; Projects LA/P/0037/2020, UIDP/50025/2020, and UIDB/50025/ 2020 of the Associate Laboratory i3N financed by national funds from FCT

Does resistance training improve body image satisfaction among the elderly? A cross-sectional study

OBJECTIVE: This study aims to evaluate whether body image satisfaction improves with practice in resistance training in elderly women. METHODS: Forty women were selected and randomly divided into an untrained group (UN) group and a group trained in resistance exercises (RT). To evaluate body image satisfaction, the silhouette matching task was used. RESULTS: No differences were found between current (5.45±0.24) and ideal (4.7±0.12) silhouettes in the RT group. However, the UN group showed a significant difference (po0.01) between current (10.4±0.43) and ideal (5.6±0.26) silhouettes. The current silhouette was significantly different between the UN and RT groups (po0.002). However, the ideal silhouette value did not differ between them. Body satisfaction was present in 90% of the participants in the RT group, and the difference was 15% less than that in the UN group (x2 test, po0.001). CONCLUSION: Resistance training in elderly women can promote satisfaction with their body image

Avaliação funcional pré e pós-programa de exercício físico de pacientes em hemodiálise

Model Study: An experimental study Introduction: Chronic Kidney Disease (CKD) refers to a syndromic diagnosis which leads to a progressive and irreversible loss of renal function. A hemodialysis patient may have limitations in functional capacity, pulmonary function and respiratory musclular strength impacting in quality of life. Objective: To evaluate the effects of an exercise program on pulmonary function, functional capacity, quality of life and pain in patients undergoing hemodialysis. Methodology: The study included 28 patients of both genders, women and men aged between 40 and 60 years undergoing dialysis at the Kidney Institute, Santa Casa de Misericordia in Presidente Prudente-SP. Primary outcomes included respiratory muscular strength measurements assessed by manovacuometry. The functional capacity was evaluated by a six minute walking test. A life quality questionnaire was applied to evaluate quality of life (SF36-KDQOL). Lung function was evaluated by spirometry. Pain was assessed by a visual analogue scale. The exercise program consisted of training 3 times a week for 40 minutes on hemodialysis during eight weeks. At the end of the program all patients were reassessed. Results:There was no significant difference in the values of FVC and FEV1 before and after the exercise program as well as the index Tiffenau. The value of post MIP was significantly higher than the value obtained in the pre program. For variable MEP no significant difference was found. Functional capacity evaluations showed that there were no significant differences (p> 0.05). The evaluation of quality of life, about the domains of specific areas of CKD showed statistical significance when comparing the list of symptoms and problems with overloading of renal disease and professional role. Indicators related to pain were significantly reduced after the program (P <0.05). Discussion: A chronic kidney patient faces complex situations of physical, social and financial aspects. Although no statistically significant results were found in all variables, the study corroborates to others found in the literature, which suggests that an exercise program can be positive for this population. Conclusion: Although lung capacity and functional capacity did not submit changes to the end of the study, reduced levels of pain, fatigue and dyspnea suggest improvement in functional performance after exercise programs.Modelo do estudo: Estudo experimental. Introdução: A Doença Renal Crônica (DRC) refere-se a um diagnóstico sindrômico de perda progressiva e irreversível da função renal. O paciente submetido à hemodiálise pode apresentar limitações na capacidade funcional, função pulmonar e força muscular respiratória, com consequentes prejuízos na qualidade de vida. Objetivo: Avaliar os efeitos de um programa de exercício físico sobre a função pulmonar, capacidade funcional, qualidade de vida e dor, em pacientes que realizam hemodiálise. Metodologia: Participaram do estudo 28 pacientes de ambos os sexos, com idade entre 40 e 60 anos, em programa de hemodiálise no Instituto do Rim da Santa Casa de Misericórdia de Presidente Prudente-SP. A força muscular respiratória foi avaliada pela manovacuometria, a capacidade funcional, pelo TC6', a qualidade de vida, pelo questionário KDQOLSF, a função pulmonar, pela espirometria e a dor, pela EVA. Após as avaliações, os pacientes iniciaram o programa de exercícios, que foi desenvolvido três vezes por semana, durante 40 minutos em hemodiálise, por oito semanas. Ao final do programa, os pacientes foram reavaliados. Resultados: Não houve diferença significativa dos valores da CVF e VEF1 pré e pós-programa de exercícios, assim como do Índice de Tiffenau. O valor da PImax pós-programa foi significativamente maior que o obtido na avaliação pré-programa. Para a variável PEmax, não foi encontrada diferença significativa. As avaliações da capacidade funcional inicial e final não apresentaram diferenças significativas (p>0,05). A avaliação da qualidade de vida, quanto aos domínios das áreas específicas da DRC, mostrou que houve significância estatística, ao comparar a lista de sintomas e problemas com a sobrecarga da DRC e papel profissional. Os indicadores relativos à dor foram reduzidos, após o programa (p<0,05). Discussão: O DRC enfrenta situações complexas de dependência física, social e financeira. Apesar de não apresentar resultados estatisticamente significativos em todas as variáveis avaliadas, este estudo, corroborando outros encontrados na literatura, sugere um programa de exercício físico, com aspectos positivos para essa população. Conclusão: Embora a capacidade pulmonar e a capacidade funcional (TC6') não tenham apresentado alterações ao final do experimento, os níveis reduzidos de dor, cansaço e dispneia sugerem melhora do desempenho funcional, após programas de exercício físico para DRC

Produção orgânica de rabanete em plantio direto sobre cobertura morta e viva.

O objetivo deste trabalho foi avaliar o uso de plantas espontâneas e cobertura viva de amendoim forrageiro(Arachis pintoi), associado à aplicação de composto orgânico na produção orgânica do rabanete em plantio direto. O experimento foi instalado na Universidade Federal do Acre, em Rio Branco-AC, de 15/06 a 14/07/2007. O delineamento experimental utilizado foi em blocos casualizados com parcelas subdivididas 4x3, em quatro repetições. As parcelas corresponderam ao sistema de plantio direto com cobertura viva de amendoim forrageiro, cobertura viva de planta espontânea, cobertura morta de planta espontânea e sistema de plantio em canteiro com solo descoberto. As subparcelas foram compostas pelas doses de composto orgânico de 5, 10 e 15 t ha-1 (base seca). O plantio direto na palha de plantas espontâneas teve desempenho semelhante ao preparo convencional do solo, ambos superiores ao plantio sobre as coberturas vivas. A produtividade do rabanete cv. Cometo, não foi afetada pelas doses crescentes de composto orgânico, podendo aplicar-se apenas 5 t ha-1, enquanto em preparo convencional do solo, o aumento da produtividade ultrapassa o plantio direto na palha apenas na dose maior de composto (15 t ha-1)

Haplotypes of the bovine IgG2 heavy gamma chain in tick-resistant and tick-susceptible breeds of cattle

Bovines present contrasting, heritable phenotypes of infestations with the cattle tick, Rhipicephalus (Boophilus) microplus. Tick salivary glands produce IgG-binding proteins (IGBPs) as a mechanism for escaping from host antibodies that these ectoparasites ingest during blood meals. Allotypes that occur in the constant region of IgG may differ in their capacity to bind with tick IGBPs; this may be reflected by the distribution of distinct allotypes according to phenotypes of tick infestations. In order to test this hypothesis, we investigated the frequency of haplotypes of bovine IgG2 among tick-resistant and tick-susceptible breeds of bovines. Sequencing of the gene coding for the heavy chain of IgG2 from 114 tick-resistant (Bos taurus indicus, Nelore breed) and tick-susceptible (B. t. taurus, Holstein breed) bovines revealed SNPs that generated 13 different haplotypes, of which 11 were novel and 5 were exclusive of Holstein and 3 of Nelore breeds. Alignment and modeling of coded haplotypes for hinge regions of the bovine IgG2 showed that they differ in the distribution of polar and hydrophobic amino acids and in shape according to the distribution of these amino acids. We also found that there was an association between genotypes of the constant region of the IgG2 heavy chain with phenotypes of tick infestations. These findings open the possibility of investigating if certain IgG allotypes hinder the function of tick IGBPs. If so, they may be markers for breeding for resistance against tick infestations

QAPgrid: A Two Level QAP-Based Approach for Large-Scale Data Analysis and Visualization

Background: The visualization of large volumes of data is a computationally challenging task that often promises rewarding new insights. There is great potential in the application of new algorithms and models from combinatorial optimisation. Datasets often contain “hidden regularities” and a combined identification and visualization method should reveal these structures and present them in a way that helps analysis. While several methodologies exist, including those that use non-linear optimization algorithms, severe limitations exist even when working with only a few hundred objects. Methodology/Principal Findings: We present a new data visualization approach (QAPgrid) that reveals patterns of similarities and differences in large datasets of objects for which a similarity measure can be computed. Objects are assigned to positions on an underlying square grid in a two-dimensional space. We use the Quadratic Assignment Problem (QAP) as a mathematical model to provide an objective function for assignment of objects to positions on the grid. We employ a Memetic Algorithm (a powerful metaheuristic) to tackle the large instances of this NP-hard combinatorial optimization problem, and we show its performance on the visualization of real data sets. Conclusions/Significance: Overall, the results show that QAPgrid algorithm is able to produce a layout that represents the relationships between objects in the data set. Furthermore, it also represents the relationships between clusters that are feed into the algorithm. We apply the QAPgrid on the 84 Indo-European languages instance, producing a near-optimal layout. Next, we produce a layout of 470 world universities with an observed high degree of correlation with the score used by the Academic Ranking of World Universities compiled in the The Shanghai Jiao Tong University Academic Ranking of World Universities without the need of an ad hoc weighting of attributes. Finally, our Gene Ontology-based study on Saccharomyces cerevisiae fully demonstrates the scalability and precision of our method as a novel alternative tool for functional genomics