139 research outputs found

    Effect of transgenic tobacco plant, Nicotiana tabacum expressing ribosome inactivating gene isolated from the bulbs of Dutch iris, Iris hollandica on biological parameters of Myzus nicotianae (Hem.: Aphididea) and Spodoptera exigua (Lep.: Noctuidae)

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    The use of modified crop plants through gene transfer between different plant species plays an important role in pest control programs. We have investigated the insecticidal properties of two lines of tobacco transgenic plant consisting of IRIP (expressed with type 1 ribosome inactivating gene) and IRA (expressed with type 2 ribosome inactivating gene) against beet armyworm, Spodoptera exigua Hübner (Lepidoptera: Noctuidae) and tobacco aphid, Myzus nicotianane Blackman (Hemiptera: Aphididae). The transgenic tobacco plants expressing IRA increased mortality and decreased reproduction rate of tobacco aphid. The reproductive period of tobacco aphid fed on transgenic tobacco plant expressing IRA reduced in comparison with the control and IRIP. We did not observed any impact on reproduction parameters of the aphids treated with IRIP plant in comparison with control. Feeding second instar larvae of S. exigua on transgenic tobacco plant expressing IRA led to about 33.3% mortality. Weight of larvae and pupae as well as the rate of the emergence of adult S. exigua were significantly decreased in larvae fed on IRA in comparison with control. These results suggest that type-2 ribosome inactivating proteins serve as significant insecticidal factors on both insect pest and can be used in integrated pest control programs

    Effect of malathion insecticide on liver tissue and enzymes of Rutilus rutilus caspicus of the Caspian Sea

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    Malathion is an organophosphate insecticide which uses to destroy insects and pests of fruit trees, ornamental plants and agricultural corps. In the present study, effect of Malathion on liver and selected enzymes (SGOT, SGPT and ALP) was studied in Caspian Roach (Rutilus rutilus caspicus). Four treatments with three replications were designed to carry out the survey. Four groups of experimental fish (containing 30 fish in each group) were exposed to different concentrations of Malathion. e. 0, 0.01, 0.05 and 0.1 ppm respectively for 23 days. Blood collection was done in 3rd, 13th and 23th after exposure to Malathion and also 30 days after recovery in clean water and enzymes were measured using standard kits. Also liver tissues were isolated to histological examination. Results showed that tissues of control group (0ppm) were normal and there were no damages, yet there were hepatocytes degeneration, picnotic in nuclear, hepatocytes vacuolization, vascular congestion and sinusoid congestion in liver of other groups. Tissue damages were increased in higher malathion concentration and over time. Results related to enzymes showed that there were no significant differences in SGOT of fish treated with low concentrations of malathion (0.01 and 0.05 ppm) and control group but it was increased in highest concentration (p<0.05). Yet, SGPT increased significantly after passing 23 days in all fish exposed to malathion But ALP changes trend was decreasing

    Effect of plant ethanolic extracts of Rosmarinus officinalis L. and Nerium oleander L. on mortality, biological parameters and reproduction of Aphis gossypii (Hom.: Aphididae)

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    Aphis gossypii Glover (Hom.: Aphididae( is one of the most important pests in greenhouse and field. Considering the importance of human health and the environmental protection, reduction in pesticide application has to be considered as an essential issue in the pest control program. In the present study, effects of ethanolic extracts of Rosmarinus officinalis L. and Nerium oleander and an insecticide, imidacloprid were evaluated against Aphis gossypii. Leaf dipping method was used in the laboratory conditions (temperature of 25 ± 1 °C, 65 ± 5% relative humidity and 16 h light: 8 h dark). After 72-h, LC50 values of imidacloprid, plant extracts from rosemary and oleander were estimated 0.004, 24.69 and 45.26 mg/ml, respectively. In this study, the effects of sublethal concentration (LC30) of each treatment was evaluated against A. gossypii. Longevity and the number of offspring were estimated per female per day. In this experiment, significant effects were observed on the life table parameters such as survival, intrinsic rate of increase, net reproductive rate, finite rate of population increase and mean generation time, for aphids fed on the leaves treated with ethanolic plant extracts and imidacloprid as compared to the related controls. This information provides further support for plant extracts of R. officinalis and N. oleander having a good potential to control the A. gossypii. However before claiming firm conclusions, trials under glasshouse and field related conditions are needed to verify the applicability of these two plant extracts in control of A. gossypii

    The inhibitory effect of an RGD-human chitin-binding domain fusion protein on the adhesion of fibroblasts to reacetylated chitosan films

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    Biomaterials used for tissue engineering applications must provide a structural support for the tissue development and also actively interact with cells, promoting adhesion, proliferation, and differentiation. To achieve this goal, adhesion molecules may be used, such as the tripeptide Arg-Gly-Asp (RGD). A method based on the use of a carbohydrate-binding module, with affinity for chitin, was tested as an alternative approach to the chemical grafting of bioactive peptides. This approach would simultaneously allow the production of recombinant peptides (alternatively to peptide synthesis) and provide a simple way for the specific and strong adsorption of the peptides to the biomaterial. A fusion recombinant protein, containing the RGD sequence fused to a human chitin-binding module (ChBM), was expressed in E. coli. The adhesion of fibroblasts to reacetylated chitosan (RC) films was the model system selected to analyze the properties of the obtained proteins. Thus, the evaluation of cell attachment and proliferation on polystyrene surfaces and reacetylated chitosan films, coated with the recombinant proteins, was performed using mouse embryo fibroblasts 3T3. The results show that the recombinant proteins affect negatively fibroblasts anchorage to the materials surface, inhibiting its adhesion and proliferation. We also conclude that this negative effect is fundamentally due to the human chitin-binding domain.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/27359/2006, POCTI/BIO/45356/200

    Treatment Outcomes of Multidrug-Resistant Tuberculosis: A Systematic Review and Meta-Analysis

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    BACKGROUND:Treatment outcomes for multidrug-resistant Mycobacterium Tuberculosis (MDRTB) are generally poor compared to drug sensitive disease. We sought to estimate treatment outcomes and identify risk factors associated with poor outcomes in patients with MDRTB. METHODOLOGY/PRINCIPAL FINDINGS:We performed a systematic search (to December 2008) to identify trials describing outcomes of patients treated for MDRTB. We pooled appropriate data to estimate WHO-defined outcomes at the end of treatment and follow-up. Where appropriate, pooled covariates were analyzed to identify factors associated with worse outcomes. Among articles identified, 36 met our inclusion criteria, representing 31 treatment programmes from 21 countries. In a pooled analysis, 62% [95% CI 57-67] of patients had successful outcomes, while 13% [9]-[17] defaulted, 11% [9]-[13] died, and 2% [1]-[4] were transferred out. Factors associated with worse outcome included male gender 0.61 (OR for successful outcome) [0.46-0.82], alcohol abuse 0.49 [0.39-0.63], low BMI 0.41[0.23-0.72], smear positivity at diagnosis 0.53 [0.31-0.91], fluoroquinolone resistance 0.45 [0.22-0.91] and the presence of an XDR resistance pattern 0.57 [0.41-0.80]. Factors associated with successful outcome were surgical intervention 1.91 [1.44-2.53], no previous treatment 1.42 [1.05-1.94], and fluoroquinolone use 2.20 [1.19-4.09]. CONCLUSIONS/SIGNIFICANCE:We have identified several factors associated with poor outcomes where interventions may be targeted. In addition, we have identified high rates of default, which likely contributes to the development and spread of MDRTB

    Adhesion Failures Determine the Pattern of Choroidal Neovascularization in the Eye: A Computer Simulation Study

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    Choroidal neovascularization (CNV) of the macular area of the retina is the major cause of severe vision loss in adults. In CNV, after choriocapillaries initially penetrate Bruch's membrane (BrM), invading vessels may regress or expand (CNV initiation). Next, during Early and Late CNV, the expanding vasculature usually spreads in one of three distinct patterns: in a layer between BrM and the retinal pigment epithelium (sub-RPE or Type 1 CNV), in a layer between the RPE and the photoreceptors (sub-retinal or Type 2 CNV) or in both loci simultaneously (combined pattern or Type 3 CNV). While most studies hypothesize that CNV primarily results from growth-factor effects or holes in BrM, our three-dimensional simulations of multi-cell model of the normal and pathological maculae recapitulate the three growth patterns, under the hypothesis that CNV results from combinations of impairment of: 1) RPE-RPE epithelial junctional adhesion, 2) Adhesion of the RPE basement membrane complex to BrM (RPE-BrM adhesion), and 3) Adhesion of the RPE to the photoreceptor outer segments (RPE-POS adhesion). Our key findings are that when an endothelial tip cell penetrates BrM: 1) RPE with normal epithelial junctions, basal attachment to BrM and apical attachment to POS resists CNV. 2) Small holes in BrM do not, by themselves, initiate CNV. 3) RPE with normal epithelial junctions and normal apical RPE-POS adhesion, but weak adhesion to BrM (e.g. due to lipid accumulation in BrM) results in Early sub-RPE CNV. 4) Normal adhesion of RBaM to BrM, but reduced apical RPE-POS or epithelial RPE-RPE adhesion (e.g. due to inflammation) results in Early sub-retinal CNV. 5) Simultaneous reduction in RPE-RPE epithelial binding and RPE-BrM adhesion results in either sub-RPE or sub-retinal CNV which often progresses to combined pattern CNV. These findings suggest that defects in adhesion dominate CNV initiation and progression

    MALDI imaging mass spectrometry for direct tissue analysis: a new frontier for molecular histology

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    Matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) is a powerful tool for investigating the distribution of proteins and small molecules within biological systems through the in situ analysis of tissue sections. MALDI-IMS can determine the distribution of hundreds of unknown compounds in a single measurement and enables the acquisition of cellular expression profiles while maintaining the cellular and molecular integrity. In recent years, a great many advances in the practice of imaging mass spectrometry have taken place, making the technique more sensitive, robust, and ultimately useful. In this review, we focus on the current state of the art of MALDI-IMS, describe basic technological developments for MALDI-IMS of animal and human tissues, and discuss some recent applications in basic research and in clinical settings

    Plant lectins: the ties that bind in root symbiosis and plant defense

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    Lectins are a diverse group of carbohydrate-binding proteins that are found within and associated with organisms from all kingdoms of life. Several different classes of plant lectins serve a diverse array of functions. The most prominent of these include participation in plant defense against predators and pathogens and involvement in symbiotic interactions between host plants and symbiotic microbes, including mycorrhizal fungi and nitrogen-fixing rhizobia. Extensive biological, biochemical, and molecular studies have shed light on the functions of plant lectins, and a plethora of uncharacterized lectin genes are being revealed at the genomic scale, suggesting unexplored and novel diversity in plant lectin structure and function. Integration of the results from these different types of research is beginning to yield a more detailed understanding of the function of lectins in symbiosis, defense, and plant biology in general

    Approaches in biotechnological applications of natural polymers

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    Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)
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