43 research outputs found

    A facile quantitative assay for viral particle genesis reveals cooperativity in virion assembly and saturation of an antiviral protein

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    Conventional assays of viral particle assembly and release are time consuming and laborious. We have developed an enzymatic virus-like particle (VLP) genesis assay that rapid and quantitative and is also versatile and applicable to diverse viruses including HIV-1 and Ebola virus. Using this assay, which has a dynamic range of several orders of magnitude, we show that the efficiency of VLP assembly and release, i.e., the fraction of the expressed protein that is assembled into extracellular particles, is dependent on the absolute level of expression of either HIV-1 Gag or Ebola virus VP40. We also demonstrate that the activity of the antiviral factor tetherin is dependent on the level of HIV-1 Gag expression and the numbers of VLPs generated, and appears to become saturated as these parameters are increased

    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)

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    What information and the extent of information research participants need in informed consent forms: a multi-country survey

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    Background: The use of lengthy, detailed, and complex informed consent forms (ICFs) is of paramount concern in biomedical research as it may not truly promote the rights and interests of research participants. The extent of information in ICFs has been the subject of debates for decades; however, no clear guidance is given. Thus, the objective of this study was to determine the perspectives of research participants about the type and extent of information they need when they are invited to participate in biomedical research. Methods: This multi-center, cross-sectional, descriptive survey was conducted at 54 study sites in seven Asia-Pacific countries. A modified Likert-scale questionnaire was used to determine the importance of each element in the ICF among research participants of a biomedical study, with an anchored rating scale from 1 (not important) to 5 (very important). Results: Of the 2484 questionnaires distributed, 2113 (85.1%) were returned. The majority of respondents considered most elements required in the ICF to be \u27moderately important\u27 to \u27very important\u27 for their decision making (mean score, ranging from 3.58 to 4.47). Major foreseeable risk, direct benefit, and common adverse effects of the intervention were considered to be of most concerned elements in the ICF (mean score = 4.47, 4.47, and 4.45, respectively). Conclusions: Research participants would like to be informed of the ICF elements required by ethical guidelines and regulations; however, the importance of each element varied, e.g., risk and benefit associated with research participants were considered to be more important than the general nature or technical details of research. Using a participant-oriented approach by providing more details of the participant-interested elements while avoiding unnecessarily lengthy details of other less important elements would enhance the quality of the ICF

    31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

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    Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

    Menstrual Distress and Psychological Well-being

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    The term menstrual distress is used to mention the all-negative symptoms like pain and discomfort, pathological behaviours, impairments in performance, amenorrhea, negative affect and irregularity which are related to menstrual cycle. The menstruation is the natural phenomenon in women. Most of the females feel extreme level of pain, mood swing, depression, anxiety, stress during menstruation and they do not have much awareness regarding menstruation and hygiene practices. Menstruation not only affects the physical health but its psychological effects are louder and distressing. But the topic is treated with silence and rarely talked about. So, there is need to bring into light the how menstrual distress has impact on routine life of females. The purpose of the present review is to explore that how menstrual distress affects the psychological well-being of the females

    PRACTITIONERS SECTION - INTERNET RESOURCES FOR DIABETES

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    Internet is transforming lives of many people in the world. Nowadays Internet has become one of the most common media to extract information of interest to researchers. The Internet is composed of a large number of smaller interconnected networks called Intranets. These Intranets connect thousands computers enabling them to share information with each other and to share various resources such as powerful super computers, software and databases of information. It has made it possible for people all over the world to effectively and inexpensively communicate with each other. The Internet has become world's biggest library where retrieval of scientific resources is only a mouse click away. The geometric growth in Internet usage is mainly due to the great success of "World Wide Web". Various useful databases on diabetes are already on 'the Net' and many more being added regularly. The present article is an attempt to provide a review of several sites that may be of great significance to the diabetes researchers before execution for new assignment/project

    Incidence of adverse drug reaction and its outcome among patients in tertiary care hospital, Uttar Pradesh

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    Introduction: World Health Organization defines adverse drug reactions (ADRs) as any noxious, unintended, and undesired effect of a drug, which occurs at doses used in humans for prophylaxis, diagnosis, or therapy. For evaluating the incidence and outcome of adverse drug reactions (ADRs) to assist in minimizing the deleterious effects, the present study was planned to find the incidence of ADR, its severity, and outcomes among patients. Material and Methods: The spontaneous ADR reporting technique and the Suspected Adverse Drug Reaction Reporting Form were used for the data collection and reporting. All patients who developed an ADR during the study period has included. By using Expanded Rawlins and Thompson’s classification, all patients were categorized into types A to F and classified according to the severity levels (mild, moderate, severe) by applying the Modified Hartwig severity scale. The classification of outcomes of the ADRs was done as per WHO criteria as fatal, continuing, recovering, recovered, unknown, or any other. Results: Type B (Bizarre) ADRs were found to be the most frequently occurring ADRs (51%) followed by type A (Augmented) 29%. Maximum ADR cases were found in the 12-45 years age group (58%).&nbsp

    Enhanced proteolysis leads to pre-mature cell death under the influence of elicitor like mycelial components from Karnal bunt (<i>Tilletia indica</i>)<i> </i>pathogen in wheat callus cultures

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    746-750Calli raised from mature embryos of susceptible wheat cultivar WH 542 were used in the present study as in vitro bioassay system to study the influence of disease determinant(s) of Karnal bunt (Tilletia &nbsp;indica), a semi-biotrophic fungal pathogen of wheat. Influence of elicitor and conditioned medium (CM) prepared from fungal cultures of T. indica was investigated on induction of programmed cell death (PCD). Induction of PCD was observed as hypersensitive response (HR) in terms of browning at localized regions of call us cultures and induction of proteolytic enzyme(s). Elicitor treated calli showed higher induction of protease activity than untreated and CM-treated cultures, which showed not much change in the activity. It was further substantiated by gel protease assay and activation of caspase-3 like protein(s) in call us cultures that clearly suggested the presence of signaling molecule(s) in the fungal elicitor preparation rather than in conditioned medium. This study further demonstrated that only elicitor preparation possesses such molecule(s), which might be cell wall bound components, rather than secretory in nature as CM was unable to induce PCD in wheat callus cultivars
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