73 research outputs found

    Expression of a Hyperthermophilic Cellobiohydrolase in Transgenic Nicotiana tabacum by Protein Storage Vacuole Targeting

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    Abstract Plant expression of microbial Cell Wall Degrading Enzymes (CWDEs) is a valuable strategy to produce industrial enzymes at affordable cost. Unfortunately, the constitutive expression of CWDEs may affect plant fitness to variable extents, including developmental alterations, sterility and even lethality. In order to explore novel strategies for expressing CWDEs in crops, the cellobiohydrolase CBM3GH5, from the hyperthermophilic bacterium Caldicellulosiruptor saccharolyticus, was constitutively expressed in N. tabacum by targeting the enzyme both to the apoplast and to the protein storage vacuole. The apoplast targeting failed to isolate plants expressing the recombinant enzyme despite a large number of transformants being screened. On the opposite side, the targeting of the cellobiohydrolase to the protein storage vacuole led to several transgenic lines expressing CBM3GH5, with an enzyme yield of up to 0.08 mg g DW 121 (1.67 Units g DW 121) in the mature leaf tissue. The analysis of CBM3GH5 activity revealed that the enzyme accumulated in different plant organs in a developmental-dependent manner, with the highest abundance in mature leaves and roots, followed by seeds, stems and leaf ribs. Notably, both leaves and stems from transgenic plants were characterized by an improved temperature-dependent saccharification profile. View Full-Tex

    Cell Synchronization Enhances Nuclear Transformation and Genome Editing via Cas9 Enabling Homologous Recombination in Chlamydomonas reinhardtii

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    In Chlamydomonas reinhardtii, the model organism for eukaryotic green algae and plants, the processes of nuclear transformation and genome editing in particular are still marked by a low level of efficiency, and so intensive work is required in order to create and identify mutants for the investigation of basic physiological processes, as well as the implementation of biotechnological applications. In this work, we show that cell synchronization during the stages of the cell cycle, obtained from long-term cultivation under specific growth conditions, greatly enhances the efficiency of transformation and allows the identification of DNA repair mechanisms that occur preferentially at different stages of the cell cycle. We demonstrate that the transformation of synchronized cells at different times was differentially associated with nonhomologous end joining (NHEJ) and/or homologous recombination (FIR), and makes it possible to knock-in specific foreign DNA at the genomic nuclear location desired by exploiting HR This optimization greatly reduces the overall complexity of the genome editing procedure and creates new opportunities for altering genes and their products

    Comparison of on-site field measured inorganic arsenic in rice with laboratory measurements using a field deployable method : Method validation

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    The authors express profound gratitude to the support of Commonwealth Scholarship funded by the UK government to Angstone Thembachako Mlangeni (MWCS-2015-334). The authors also acknowledges financial support from the Lilongwe University of Agriculture and Natural Resources (Malawi) for the field work. ATM acknowledges help and instrumentation technical support of Dr Edi Bralatei and Dr Magali Perez. ATM also acknowledges help and support of staff and farmers of Lifuwu, Bwanje, Domasi, Khanda, Baka, Nkondezi (Limphasa), Hara, Lufiriya, Kasinthuala, Nazolo and Nkhate research stations and rice schemes.Peer reviewedPostprin

    Metabolic regulation of the HBV-specific T cell function.

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    Chronically HBV infected subjects are more than 260 million worldwide; cirrhosis and liver cancer represent possible outcomes which affect around 700,000 patients per year. Both innate and adaptive immune responses are necessary for viral control and both have been shown to be defective in chronic patients. Metabolic remodeling is an essential process in T cell biology, particularly for T cell activation, differentiation and survival. Cellular metabolism relies on the conversion of nutrients into energy to support intracellular processes, and to generate fundamental intermediate components for cell proliferation and growth. Adaptive immune responses are the central mechanisms for the resolution of primary human infections leading to the activation of pathogen-specific B and T cell functions. In chronic HBV infection the anti-viral immune response fails to contain the virus and leads to persistent hepatic tissue damage which may finally result in liver cirrhosis and cancer. This T cell failure is associated with metabolic alterations suggesting that control of nutrient uptake and intracellular utilization as well as correct regulation of intracellular metabolic pathways are strategic for T cell differentiation during persistent chronic infections. This review will discuss some of the main features of the T cell metabolic processes which are relevant to the generation of an efficient antiviral response, with specific focus on their clinical relevance in chronic HBV infection in the perspective of possible strategies to correct deregulated metabolic pathways underlying T cell dysfunction of chronic HBV patients

    Malignidades primárias sincrônicas de pulmão e reto: relato de caso e revisão da literatura

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    Case report of a 62 years old man diagnosed by anatomopathology with primary lung and rectal cancer. The patient had a long-term exposition to polycyclic aromatic hydrocarbons (coke fuel). It was concluded, after literature review, that multiple primary malignancies are not as unusual as imagined, and that secondary lesions in cancer patients should only be labelled as a metastasis only after detailed evaluation.Relato de caso de um homem de sessenta e dois anos, diagnosticado por estudo anatomopatológico com neoplasias primárias de reto e pulmão. O paciente referia exposição de longa data a hidrocarbonetos policíclicos aromáticos (carvão-coque). Concluiu-se, após revisão da literatura médica, que tal multiplicidade de malignidades não é tão incomum como se imagina e que lesões secundárias em pacientes com câncer só devem ser rotuladas como metástase após avaliação adequada

    Does direction of results of abstracts submitted to scientific conferences on drug addiction predict full publication?

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    <p>Abstract</p> <p>Background</p> <p>Data from scientific literature show that about 63% of abstracts presented at biomedical conferences will be published in full. Some studies have indicated that full publication is associated with the direction of results (publication bias). No study has looked into the occurrence of publication bias in the field of addiction.</p> <p>Objectives</p> <p>To investigate whether the significance or direction of results of abstracts presented at the major international scientific conference on addiction is associated with full publication</p> <p>Methods</p> <p>The conference proceedings of the US Annual Meeting of the College on Problems of Drug Dependence (CPDD), were handsearched for abstracts of randomized controlled trials and controlled clinical trials that evaluated interventions for prevention, rehabilitation and treatment of drug addiction in humans (years searched 1993–2002). Data regarding the study designs and outcomes reported were extracted. Subsequent publication in peer reviewed journals was searched in MEDLINE and EMBASE databases, as of March 2006.</p> <p>Results</p> <p>Out of 5919 abstracts presented, 581 met the inclusion criteria; 359 (62%) conference abstracts had been published in a broad variety of peer reviewed journals (average time of publication 2.6 years, SD +/- 1.78). The proportion of published studies was almost the same for randomized controlled trials (62.4%) and controlled clinical trials (59.5%) while studies that reported positive results were significantly more likely to be published (74.5%) than those that did not report statistical results (60.9%.), negative or null results (47.1%) and no results (38.6%), Abstracts reporting positive results had a significantly higher probability of being published in full, while abstracts reporting null or negative results were half as likely to be published compared with positive ones (HR = 0.48; 95%CI 0.30–0.74)</p> <p>Conclusion</p> <p>Clinical trials were the minority of abstracts presented at the CPDD; we found evidence of possible publication bias in the field of addiction, with negative or null results having half the likelihood of being published than positive ones.</p

    Functional reconstitution of HBV-specific CD8 T cells by in vitro polyphenol treatment in chronic hepatitis B.

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    Background & aims In chronic HBV infection, mitochondrial functions and proteostasis are dysregulated in exhausted HBV-specific CD8 T cells. To better characterise the potential involvement of deregulated protein degradation mechanisms in T cell exhaustion, we analysed lysosome-mediated autophagy in HBV-specific CD8 T cells. Bioactive compounds able to simultaneously target both mitochondrial functions and proteostasis were tested to identify optimal combination strategies to reconstitute efficient antiviral CD8 T cell responses in patients with chronic HBV infection. Methods Lysosome-mediated degradation pathways were analysed by flow cytometry in virus-specific CD8 T cells from patients with chronic HBV infection. Mitochondrial function, intracellular proteostasis, and cytokine production were evaluated in HBV-peptide-stimulated T cell cultures, in the presence or absence of the polyphenols resveratrol (RSV) and oleuropein (OLE) and their metabolites, either alone or in combination with other bioactive compounds. Results HBV-specific CD8 T cells from patients with CHB showed impaired autophagic flux. RSV and OLE elicited a significant improvement in mitochondrial, proteostasis and antiviral functions in CD8 T cells. Cytokine production was also enhanced by synthetic metabolites, which correspond to those generated by RSV and OLE metabolism in vivo, suggesting that these polyphenols may also display an effect after transformation in vivo. Moreover, polyphenolic compounds improved the T cell revitalising effect of mitochondria-targeted antioxidants and of programmed cell death protein 1/programmed cell death ligand 1 blockade. Conclusions Simultaneously targeting multiple altered intracellular pathways with the combination of mitochondria-targeted antioxidants and natural polyphenols may represent a promising immune reconstitution strategy for the treatment of chronic HBV infection. Lay summary In chronic hepatitis B, antiviral T lymphocytes are deeply impaired, with many altered intracellular functions. In vitro exposure to polyphenols, such as resveratrol and oleuropein, can correct some of the deregulated intracellular pathways and improve antiviral T cell function. This effect can be further strengthened by the association of polyphenols with antioxidant compounds in a significant proportion of patients. Thus, the combination of antioxidants and natural polyphenols represents a promising strategy for chronic hepatitis B therapy

    An intestinal Th17 subset is associated with inflammation in crohn's disease and activated by adherent-invasive Escherichia coli (aiec)

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    IFNγ-producing ex-Th17-cells ("Th1/17") were shown to play a key pathogenic role in experimental colitis and are abundant in the intestine. Here, we identified and characterized a novel, potentially colitogenic subset of Th17-cells in the intestine of patients with Crohn's Disease (CD). Human Th17-cells expressing CCR5 ("pTh17") co-expressed T-bet and RORC/γt and produced very high levels of IL-17, together with IFN-γ. They had a gene signature of Th17 effector cells and were distinct from established Th1/17-cells. pTh17-cells, but not Th1/17-cells, were associated with intestinal inflammation in CD, and decreased upon successful anti-TNF therapy with infliximab. Conventional CCR5(-)Th17-cells differentiated to pTh17 cells with IL-23 in vitro. Moreover, anti-IL-23 therapy with risankizumab strongly reduced pTh17-cells in the intestine. Importantly, intestinal pTh17-cells were selectively activated by adherent-invasive Escherichia coli (AIEC), but not by a commensal/probiotic E. coli strain. AIEC induced high levels of IL-23 and RANTES from DC. Intestinal CCR5 +Th1/17-cells responded instead to Cytomegalovirus and were reduced in UC, suggesting an unexpected protective role. In conclusion, we identified an IL-23-inducible subset of human intestinal Th17-cells. pTh17 cells produced high levels of pro-inflammatory cytokines, were selectively associated with intestinal inflammation in CD, and responded to CD-associated AIEC, suggesting a key colitogenic role

    Sudden Unexpected Deaths and Vaccinations during the First Two Years of Life in Italy: A Case Series Study

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    Background The signal of an association between vaccination in the second year of life with a hexavalent vaccine and sudden unexpected deaths (SUD) in the two days following vaccination was reported in Germany in 2003. A study to establish whether the immunisation with hexavalent vaccines increased the short term risk of SUD in infants was conducted in Italy. Methodology/Principal Findings The reference population comprises around 3 million infants vaccinated in Italy in the study period 1999–2004 (1.5 million received hexavalent vaccines). Events of SUD in infants aged 1–23 months were identified through the death certificates. Vaccination history was retrieved from immunisation registries. Association between immunisation and death was assessed adopting a case series design focusing on the risk periods 0–1, 0–7, and 0–14 days after immunisation. Among the 604 infants who died of SUD, 244 (40%) had received at least one vaccination. Four deaths occurred within two days from vaccination with the hexavalent vaccines (RR = 1.5; 95% CI 0.6 to 4.2). The RRs for the risk periods 0–7 and 0–14 were 2.0 (95% CI 1.2 to 3.5) and 1.5 (95% CI 0.9 to 2.4). The increased risk was limited to the first dose (RR = 2.2; 95% CI 1.1 to 4.4), whereas no increase was observed for the second and third doses combined. Conclusions The RRs of SUD for any vaccines and any risk periods, even when greater than 1, were almost an order of magnitude lower than the estimates in Germany. The limited increase in RRs found in Italy appears confined to the first dose and may be partly explained by a residual uncontrolled confounding effect of age

    Potential and Challenges of Improving Photosynthesis in Algae

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    Sunlight energy largely exceeds the energy required by anthropic activities, and therefore its exploitation represents a major target in the field of renewable energies. The interest in the mass cultivation of green microalgae has grown in the last decades, as algal biomass could be employed to cover a significant portion of global energy demand. Advantages of microalgal vs. plant biomass production include higher light-use efficiency, efficient carbon capture and the valorization of marginal lands and wastewaters. Realization of this potential requires a decrease of the current production costs, which can be obtained by increasing the productivity of the most common industrial strains, by the identification of factors limiting biomass yield, and by removing bottlenecks, namely through domestication strategies aimed to fill the gap between the theoretical and real productivity of algal cultures. In particular, the light-to-biomass conversion efficiency represents one of the major constraints for achieving a significant improvement of algal cell lines. This review outlines the molecular events of photosynthesis, which regulate the conversion of light into biomass, and discusses how these can be targeted to enhance productivity through mutagenesis, strain selection or genetic engineering. This review highlights the most recent results in the manipulation of the fundamental mechanisms of algal photosynthesis, which revealed that a significant yield enhancement is feasible. Moreover, metabolic engineering of microalgae, focused upon the development of renewable fuel biorefineries, has also drawn attention and resulted in efforts for enhancing productivity of oil or isoprenoids
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