929 research outputs found

    Biocidal activity in soils by biochar from pyrolysis biorefinery process

    Get PDF
    Useful soil applications of biochar, the biocarbon solid coproduct of biomass pyrolysis, will likely improve the economics of pyrolysis biorefineries. Adding biochar to soils to achieve any number of goals should also consider unintended effects upon soil biology. Herein, we explored two biocidal activities of fluidized-bed fast pyrolysis biochars (FPBC) created over a temperature range of 450-700 oC on the survival of pathogenic E. coli O157:H7 and beneficial arbuscular mycorrhizas (AM) symbioses in soils. For pathogen decontamination, FPBC created at \u3c 500°C proved microbiologically inert, while that created at 600°C proved biocidal over 7 weeks of sampling (P \u3c 0.05) with populations significantly reduced at 3% and 3.5% concentration (5.34 and 5.84 log CFU/g, respectively) compared with concentrations of 0.0-2.0%. Ageing of FPBC created under similar conditions for 2 years resulted in loss of efficacy. FPBC greatly reduced colonization of roots by the AM fungus when we examined the interaction of biochar addition and arbuscular mycorrhizal (AM) fungus inoculation upon growth and phosphorus (P) uptake by Allium porrum L. These responses could be related to physicochemical properties of the biochars as higher surface areas were accompanied by higher AM fungus colonization. The findings are pertinent to selecting pyrolysis biorefinery biochars for application to agricultural soils for purposes such as inactivation of pathogenic bacteria while being mindful of potential impacts upon the AM symbiosis if applied. Biochar II: Production, Characterization and Applications. Cetraro (Calabrial) Italy, September 15-20, 2019

    The disappearance of the "revolving door" patient in Scottish general practice: successful policies

    Get PDF
    <b>Background</b> We describe the health of "revolving door" patients in general practice in Scotland, estimate changes in their number over the timescale of the study, and explore reasons for changes, particularly related to NHS and government policy.<p></p> <b>Methods</b> A mixed methods predominantly qualitative study, using a grounded theory approach, set in Scottish general practice. Semi-structured interviews were conducted with professional key informants, 6 Practitioner Services staff who administer the GP registration system and 6 GPs with managerial or clinical experience of working with "revolving door" patients. Descriptive statistical analysis and qualitative analysis of patient removal episodes linked with routine hospital admissions, outpatient appointments, drug misuse treatment episodes and deaths were carried out with cohorts of "revolving door" patients identified from 1999 to 2005 in Scotland.<p></p> <b>Results</b> A "revolving door" patient is removed 4 or more times from GP lists in 7 years. Patients had complex health issues including substance misuse, psychiatric and physical health problems and were at high risk of dying. There was a dramatic reduction in the number of "revolving door" patients during the course of the study.<p></p> <b>Conclusions</b> "Revolving door" patients in general practice had significant health problems. Their numbers have reduced dramatically since 2004 and this probably resulted from improved drug treatment services, pressure from professional bodies to reduce patient removals and the positive ethical regulatory and financial climate of the 2004 GMS GP contract. This is a positive development for the NHS

    3-D Ultrastructure of O. tauri: Electron Cryotomography of an Entire Eukaryotic Cell

    Get PDF
    The hallmark of eukaryotic cells is their segregation of key biological functions into discrete, membrane-bound organelles. Creating accurate models of their ultrastructural complexity has been difficult in part because of the limited resolution of light microscopy and the artifact-prone nature of conventional electron microscopy. Here we explored the potential of the emerging technology electron cryotomography to produce three-dimensional images of an entire eukaryotic cell in a near-native state. Ostreococcus tauri was chosen as the specimen because as a unicellular picoplankton with just one copy of each organelle, it is the smallest known eukaryote and was therefore likely to yield the highest resolution images. Whole cells were imaged at various stages of the cell cycle, yielding 3-D reconstructions of complete chloroplasts, mitochondria, endoplasmic reticula, Golgi bodies, peroxisomes, microtubules, and putative ribosome distributions in-situ. Surprisingly, the nucleus was seen to open long before mitosis, and while one microtubule (or two in some predivisional cells) was consistently present, no mitotic spindle was ever observed, prompting speculation that a single microtubule might be sufficient to segregate multiple chromosomes

    Galanin-immunoreactivity identifies a distinct population of inhibitory interneurons in laminae I-III of the rat spinal cord

    Get PDF
    Background: Inhibitory interneurons constitute 30-40% of neurons in laminae I-III and have an important anti-nociceptive role. However, because of the difficulty in classifying them we know little about their organisation. Previous studies have identified 3 non-overlapping groups of inhibitory interneuron, which contain neuropeptide Y (NPY), neuronal nitric oxide synthase (nNOS) or parvalbumin, and have shown that these differ in postsynaptic targets. Some inhibitory interneurons contain galanin and the first aim of this study was to determine whether these form a different population from those containing NPY, nNOS or parvalbumin. We also estimated the proportion of neurons and GABAergic axons that contain galanin in laminae I-III. Results: Galanin cells were concentrated in laminae I-IIo, with few in laminae IIi-III. Galanin showed minimal co-localisation with NPY, nNOS or parvalbumin in laminae I-II, but most galanin-containing cells in lamina III were nNOS-positive. Galanin cells constituted similar to 7%, 3% and 2% of all neurons in laminae I, II and III, and we estimate that this corresponds to 26%, 10% and 5% of the GABAergic neurons in these laminae. However, galanin was only found in similar to 6% of GABAergic boutons in laminae I-IIo, and similar to 1% of those in laminae IIi-III. Conclusions: These results show that galanin, NPY, nNOS and parvalbumin can be used to define four distinct neurochemical populations of inhibitory interneurons. Together with results of a recent study, they suggest that the galanin and NPY populations account for around half of the inhibitory interneurons in lamina I and a quarter of those in lamina I

    Human cultured dendritic cells show differential sensitivity to chemotherapy agents as assessed by the MTS assay

    Get PDF
    Assessment of the chemosensitivity of dendritic cells (DC) may allow more rational development of combined chemotherapy and immunotherapy protocols. Human monocyte-derived DC generated reproducible results in the MTS (Owen’s reagent) assay, which was then used to study DC survival after treatment with four different chemotherapy agents. DC preparations from three different donors were used per drug. DC were sensitive to doxorubicin (concentration range 0.1–50 μM) with variation in sensitivity between donors (IC50 244–1100 nM). The most extreme variation was seen for vinblastine (concentration range 250–0.025 μM with IC50 0.15–17.25 μM). In contrast, there was relative resistance to etoposide (concentration range 0.2–200 μM) and 5-fluorouracil (concentration range 0.7–7700 μM) with no toxicity seen until 50 μM and 770 μM respectively. The function of DC in allogeneic mixed leucocyte reactions closely paralleled results from the MTS assays. The differential sensitivity to chemotherapy agents did not appear to be due to expression of P-glycoprotein. These results suggest that etoposide or 5-fluorouracil is less likely to reduce the immunotherapeutic potential of DC and may be valuable in the design of prodrug activation therapy. © 1999 Cancer Research Campaig

    Adenovirus-mediated hypoxia-targeting cytosine deaminase gene therapy enhances radiotherapy in tumour xenografts

    Get PDF
    Hypoxia is closely associated with the radioresistance of tumours; therefore, targeting hypoxic areas is very important for cancer therapy. The aim of this study is to establish such a targeting strategy by applying a bacterial cytosine deaminase (BCD)/5-fluorocytosine (5-FC) gene therapy system and to examine whether the strategy enhances the efficacy of radiotherapy in a tumour xenograft. The hypoxia-responsive promoter 5HREp, in which five copies of the hypoxia-response element (HRE) enhance transcription from a cytomegalovirus minimal promoter, was employed to induce the expression of BCD under hypoxic conditions. The adenoviral vector Ad/5HREp-BCD, encoding the gene 5HREp-BCD, robustly induced BCD expression under hypoxic conditions and this led to significant cytotoxicity in combination with 5-FC in vitro. Intratumoral Ad/5HREp-BCD administration resulted in the expression of BCD at the border between normoxic and necrotic regions. The BCD/5-FC gene therapy enhanced the therapeutic effects of both single (12.5 Gy) and fractionated (3 Gy × 5 days) radiotherapy with few side effects and significantly increased tumour growth doubling time by up to 2.4-fold (P<0.01) and 2.5-fold (P<0.05), respectively. All of these results suggest that the present BCD/5-FC gene therapy has the ability to specifically target hypoxic tumour cells and significantly improves the control of tumour growth after radiotherapy

    Impact of a Plasmodium falciparum AMA1 Vaccine on Antibody Responses in Adult Malians

    Get PDF
    Apical Membrane Antigen 1 (AMA1) of Plasmodium falciparum merozoites is a leading blood-stage malaria vaccine candidate. Protection of Aotus monkeys after vaccination with AMA1 correlates with antibody responses.A randomized, controlled, double-blind phase 1 clinical trial was conducted in 54 healthy Malian adults living in an area of intense seasonal malaria transmission to assess the safety and immunogenicity of the AMA1-C1 malaria vaccine. AMA1-C1 contains an equal mixture of yeast-expressed recombinant proteins based on sequences from the FVO and 3D7 clones of P. falciparum, adsorbed on Alhydrogel. The control vaccine was the hepatitis B vaccine (Recombivax). Participants were enrolled into 1 of 3 dose cohorts (n = 18 per cohort) and randomized 2:1 to receive either AMA1-C1 or Recombivax. Participants in the first, second, and third cohorts randomized to receive AMA1-C1 were vaccinated with 5, 20 and 80 microg of AMA1-C1, respectively. Vaccinations were administered on days 0, 28, and 360, and participants were followed until 6 months after the final vaccination. AMA1-C1 was well tolerated; no vaccine-related severe or serious adverse events were observed. AMA1 antibody responses to the 80 microg dose increased rapidly from baseline levels by days 14 and 28 after the first vaccination and continued to increase after the second vaccination. After a peak 14 days following the second vaccination, antibody levels decreased to baseline levels one year later at the time of the third vaccination that induced little or no increase in antibody levels.Although the AMA1-C1 vaccine candidate was well-tolerated and induced antibody responses to both vaccine and non-vaccine alleles, the antibody response after a third dose given at one year was lower than the response to the initial vaccinations. Additionally, post-vaccination increases in anti-AMA1 antibody levels were not associated with significant changes in in vitro growth inhibition of P. falciparum.ClinicalTrials.gov NCT00343005

    Pesticide exposure in honey bees results in increased levels of the gut pathogen Nosema

    Get PDF
    Global pollinator declines have been attributed to habitat destruction, pesticide use, and climate change or some combination of these factors, and managed honey bees, Apis mellifera, are part of worldwide pollinator declines. Here we exposed honey bee colonies during three brood generations to sub-lethal doses of a widely used pesticide, imidacloprid, and then subsequently challenged newly emerged bees with the gut parasite, Nosema spp. The pesticide dosages used were below levels demonstrated to cause effects on longevity or foraging in adult honey bees. Nosema infections increased significantly in the bees from pesticide-treated hives when compared to bees from control hives demonstrating an indirect effect of pesticides on pathogen growth in honey bees. We clearly demonstrate an increase in pathogen growth within individual bees reared in colonies exposed to one of the most widely used pesticides worldwide, imidacloprid, at below levels considered harmful to bees. The finding that individual bees with undetectable levels of the target pesticide, after being reared in a sub-lethal pesticide environment within the colony, had higher Nosema is significant. Interactions between pesticides and pathogens could be a major contributor to increased mortality of honey bee colonies, including colony collapse disorder, and other pollinator declines worldwide

    11th German Conference on Chemoinformatics (GCC 2015) : Fulda, Germany. 8-10 November 2015.

    Get PDF
    corecore