1,406 research outputs found
Differential Kinetics of Aspergillus nidulans and Aspergillus fumigatus Phagocytosis
Acknowledgements: The authors would like to acknowledge Fraser P. Coxon and Ian Ganley for providing LC3-GFP-mCherry BMDMs. M.S.G. was supported by an FEMS research grant and F.L.v.d.V. was supported by ZonMW under the name EURO-CMC frame of E-Rare-2, the ERA-Net for Research on Rare Diseases.Peer reviewedPublisher PD
A Search for Trypanosoma brucei rhodesiense Diagnostic Antigens by Proteomic Screening and Targeted Cloning
Background: The only available diagnostic method for East African trypanosomiasis is light microscopy of blood samples. A simple immunodiagnostic would greatly aid trypanosomiasis control. Methodology and Principal Findings: To find trypanosome proteins that are specifically recognised by sera from human sleeping sickness patients, we have screened the Trypanosoma brucei brucei proteome by Western blotting. Using cytosolic, cytoskeletal and glycosomal fractions, we found that the vast majority of abundant trypanosome proteins is not specifically recognised by patient sera. We identified phosphoglycerate kinase (PGKC), heat shock protein (HSP70), and histones H2B and H3 as possible candidate diagnostic antigens. These proteins, plus paraflagellar rod protein 1, rhodesain (a cysteine protease), and an extracellular fragment of the Trypanosoma brucei nucleoside transporter TbNT10, were expressed in E. coli and tested for reactivity with patient and control sera. Only TbHSP70 was preferentially recognized by patient sera, but the sensitivity and specificity were insufficient for use of TbHSP70 alone as a diagnostic. Immunoprecipitation using a native protein extract revealed no specifically reacting proteins. Conclusions: No abundant T. brucei soluble, glycosomal or cytoskeletal protein is likely to be useful in diagnosis. To find useful diagnostic antigens it will therefore be necessary to use more sophisticated proteomic methods, or to test a ver
Trypanocidal activity of tioamide-sustituted imidazoisoquinolinones: Electrochemical properties and biological effects
Three thioamide-substituted imidazoisoquinolinones, which possess an heterocyclic center similar to tryptanthrin and are named C1, C2 and C3, were studied regarding: a) its in vitro anti-Trypanosoma cruzi activity, b) its cytotoxicity and electrochemical behaviour and c) its effect on cell viability, redox state and mitochondrial function . The assayed compounds showed a significant activity against the proliferative forms, but only C1 showed activity on the trypomastigote form (for C1, IC50 epi = 1.49 µM; IC50 amas = 1.74 µM and IC50 try = 34.89 µM). The presence of an antioxidant compound such as ascorbic acid or dithiotreitol induced a three-fold increase in the antiparasitic activity, whereas glutathione had a dual effect depending on its concentration. Our results indicate that these compounds, which exhibited low toxicity to the host cells, can be reduced inside the parasite by means of the pool of low molecular weight thiols, causing oxidative stress and parasite death by apoptosis. The antiparasitic activity of the compounds studied could be explained by a loss of the capacity of the antioxidant defense system of the parasite to keep its intracellular redox state. C1 could be considered a good candidate for in vivo evaluation .Fil: Frank, Fernanda Maria. Consejo Nacional de Investigaciones CientiÂficas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral "Profesor R. A. Margni"; ArgentinaFil: Ciccarelli, Allejandra Beatriz. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Centro de Investigacion Sobre Porfirinas y Porfirias; ArgentinaFil: Bollini, Mariela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; ArgentinaFil: Bruno, Ana M.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; ArgentinaFil: Batlle, Alcira Maria del C.. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Centro de Investigacion Sobre Porfirinas y Porfirias; ArgentinaFil: Lombardo, Maria Elisa. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Centro de Investigacion Sobre Porfirinas y Porfirias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; Argentin
Feeding live Black Soldier Fly larvae (Hermetia illucens) to laying hens: effects on feed consumption, hen health, hen behaviour and egg quality
The use of insects in animal feed has the potential to reduce the demand for soybean production and reduce the deforestation and loss of natural resources. In particular, the black soldier fly (BSF, Hermetia illucens) larvae have received attention due to their ability to convert organic waste into high-value biomass. Several studies have investigated the effects of providing BSF larvae to both broilers and laying hens. However, knowledge gaps regarding hens’ voluntary intake of live larvae and the effects of larvae consumption on egg production still remain. Therefore, the aim of the present study was to determine the effects of the consumption of 4 different amounts of live BSF larvae on laying hen feed consumption, hen health and fearfulness, and egg production and quality. To this end, 40 Bovans White laying hens were housed individually and provided with 0, 10, 20% or ad libitum daily portions of live larvae from 18 to 30 wk of age. The larvae consumption and concentrate consumption, hen weight, egg production, and egg quality were monitored. Overall, differences were found between the hens given ad libitum access to larvae compared to the other treatments. Ad libitum hens, consumed 163 ± 41 g larvae/hen/day, consumed less concentrate (P = 0.03) and gained more weight (P = 0.0002) than all other treatments. They also had an overall higher consumption of protein, fat and energy (P 0.05). There was also no effect on hen behavior toward a novel object or in an open field test. This study is the first to provide different amounts of live BSF larvae, including an ad libitum portion to laying hens. The 20% diet could promote sustainability in the egg industry and be economically advantageous if BSF larvae can be bought in bulk for less than 40% of the cost of the concentrate
Enhanced initial growth of atomic-layer-deposited metal oxides on hydrogen-terminated silicon
A route is presented for activation of hydrogen-terminated Si(100) prior to atomic layer deposition. It is based on our discovery from in situ infrared spectroscopy that organometallic precursors can effectively initiate oxide growth. Narrow nuclear resonance profiling and Rutherford backscattering spectrometry show that surface functionalization by pre-exposure to 108 Langmuir trimethylaluminum at 300 °C leads to enhanced nucleation and to nearly linear growth kinetics of the high-permittivity gate dielectrics aluminum oxide and hafnium oxide
South American medicinal flora: a promising source of novel compounds with antiprotozoal activity
Native populations of South America have employed herb-based preparations for the treatment
of parasite diseases. In this review, some examples of South American medicinal plants from which
bioactive molecules have been isolated are presented. Results of our research related to the study of novel
compounds with antiprotozoal activity are also presented herein. Peruvin and psilostachyin, two sesquiterpene
lactones isolated from the Argentine medicinal species Ambrosia tenuifolia, presented significative in
vitro activity on Trypanosoma cruzi epimastigotes and trypomastigotes. Psilostachyin also presented in vivo
activity in T. cruzi infected mice. Both compounds were also active on Leishmania spp. The results obtained
suggest that psilostachyin could be considered a potential lead molecule in the development of novel
trypanocidal agents.Colegio de Farmacéuticos de la Provincia de Buenos Aire
The ACER pollen and charcoal database: a global resource to document vegetation and fire response to abrupt climate changes during the last glacial period
Quaternary records provide an opportunity to examine the nature of the
vegetation and fire responses to rapid past climate changes comparable in
velocity and magnitude to those expected in the 21st-century. The best
documented examples of rapid climate change in the past are the warming events
associated with the Dansgaard–Oeschger (D–O) cycles during the last glacial
period, which were sufficiently large to have had a potential feedback through
changes in albedo and greenhouse gas emissions on climate. Previous
reconstructions of vegetation and fire changes during the D–O cycles used
independently constructed age models, making it difficult to compare the
changes between different sites and regions. Here, we present the ACER (Abrupt
Climate Changes and Environmental Responses) global database, which includes
93 pollen records from the last glacial period (73–15 ka) with a temporal
resolution better than 1000 years, 32 of which also provide charcoal records.
A harmonized and consistent chronology based on radiometric dating (14C,
234U∕230Th, optically stimulated luminescence (OSL), 40Ar∕39Ar-dated tephra
layers) has been constructed for 86 of these records, although in some cases
additional information was derived using common control points based on event
stratigraphy. The ACER database compiles metadata including geospatial and
dating information, pollen and charcoal counts, and pollen percentages of the
characteristic biomes and is archived in Microsoft AccessTM at
https://doi.org/10.1594/PANGAEA.870867
How much is too much? Feeding live black soldier fly larvae to laying hens
The use of insects in animal feed has the potential to reduce the demand for soybean productionand reduce the deforestation and loss of natural resources. In particular, black soldier fl y (BSF,Hermetia illucens) larvae have received attention due to their ability to convert organic wasteinto high-value biomass. Several studies have investigated the effects of providing BSF larvaeto both broilers and laying hens. However, knowledge gaps regarding hens’ voluntary intakeof live larvae and the effects of larvae consumption on egg production still remain. Therefore,the aim of the present study was to determine the effects of the provision of four differentamounts of live BSF larvae on laying hen feed consumption, hen health and fearfulness, andegg production and quality. To this end, 40 Bovans White laying hens were housed individuallyand provided with 0%, 10%, 20% or ad libitum daily portions of live larvae (relative toexpected dry matter intake) plus a complementary concentrated pelleted feed from 18 to 30weeks of age. Larvae consumption and concentrate consumption, hen weight, egg productionand egg quality were monitored. Overall, differences were found between the hens given adlibitum access to larvae compared to the other treatments. Ad libitum hens, consumed 163± 41 g larvae/hen/day, consumed less concentrates (P = 0.03) and gained more weight (P =0.0002) than all other treatments. They also had an overall higher consumption of protein,fat and energy (P 0.05). Furthermore, therewas no effect on hen behaviour towards a novel object or in an open fi eld test. This studyshows that ad libitum feeding of live BSF larvae had no strong effects on egg production oregg quality, but did reduce feed consumption and increased hen weight, which can have healthconsequences in the long term. Nevertheless, including BSF larvae in the diet of hens couldbe an interesting option for the future
The genomes of two key bumblebee species with primitive eusocial organization
Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation
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