77 research outputs found

    Viral discovery and diversity in trypanosomatid protozoa with a focus on relatives of the human parasite <i>Leishmania</i>.

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    Knowledge of viral diversity is expanding greatly, but many lineages remain underexplored. We surveyed RNA viruses in 52 cultured monoxenous relatives of the human parasite &lt;i&gt;Leishmania&lt;/i&gt; ( &lt;i&gt;Crithidia&lt;/i&gt; and &lt;i&gt;Leptomonas&lt;/i&gt; ), as well as plant-infecting &lt;i&gt;Phytomonas&lt;/i&gt; &lt;i&gt;Leptomonas pyrrhocoris&lt;/i&gt; was a hotbed for viral discovery, carrying a virus (Leptomonas pyrrhocoris ostravirus 1) with a highly divergent RNA-dependent RNA polymerase missed by conventional BLAST searches, an emergent clade of tombus-like viruses, and an example of viral endogenization. A deep-branching clade of trypanosomatid narnaviruses was found, notable as &lt;i&gt;Leptomonas seymouri&lt;/i&gt; bearing Narna-like virus 1 (LepseyNLV1) have been reported in cultures recovered from patients with visceral leishmaniasis. A deep-branching trypanosomatid viral lineage showing strong affinities to bunyaviruses was termed " &lt;i&gt;Leishbunyavirus&lt;/i&gt; " (LBV) and judged sufficiently distinct to warrant assignment within a proposed family termed " &lt;i&gt;Leishbunyaviridae&lt;/i&gt; " Numerous relatives of trypanosomatid viruses were found in insect metatranscriptomic surveys, which likely arise from trypanosomatid microbiota. Despite extensive sampling we found no relatives of the totivirus &lt;i&gt;Leishmaniavirus&lt;/i&gt; (LRV1/2), implying that it was acquired at about the same time the &lt;i&gt;Leishmania&lt;/i&gt; became able to parasitize vertebrates. As viruses were found in over a quarter of isolates tested, many more are likely to be found in the &gt;600 unsurveyed trypanosomatid species. Viral loss was occasionally observed in culture, providing potentially isogenic virus-free lines enabling studies probing the biological role of trypanosomatid viruses. These data shed important insights on the emergence of viruses within an important trypanosomatid clade relevant to human disease

    Modulation of metabolic activity of phagocytes by antihistamines

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    The purpose of the study was to investigate the effects of H1-antihistamines of the 1st generation (antazoline, bromadryl, brompheniramine, dithiaden, cyclizine, chlorcyclizine, chlorpheniramine, clemastine) and the 2nd generation (acrivastine, ketotifen, and loratadine) on the respiratory burst of phagocytes. Reactive oxygen species generation in neutrophils isolated from rat blood was measured using luminol-enhanced chemiluminescence. Changes in nitrite formation and iNOS protein expression by RAW 264.7 macrophages were analysed using Griess reaction and Western blotting. The antioxidative properties of drugs in cell-free systems were detected spectrophotometrically, luminometrically, fluorimetrically, and amperometrically. The majority of the H1-antihistamines tested (bromadryl, brompheniramine, chlorcyclizine, chlorpheniramine, clemastine, dithiaden, and ketotifen) exhibited a significant inhibitory effect on the chemiluminescence activity of phagocytes. H1-antihistamines did not show significant scavenging properties against superoxide anion and hydroxyl radical, thus this could not contribute to the inhibition of chemiluminescence. H1-antihistamines had a different ability to modulate nitric oxide production by LPS-stimulated macrophages. Bromadryl, clemastine, and dithiaden were the most effective since they inhibited iNOS expression, which was followed by a significant reduction in nitrite levels. H1-antihistamines had no scavenging activity against nitric oxide. It can be concluded that the effects observed in the H1-antihistamines tested are not mediated exclusively via H1-receptor pathway or by direct antioxidative properties. Based on our results, antihistamines not interfering with the microbicidal mechanisms of leukocytes (antazoline, acrivastine and cyclizine) could be used preferentially in infections. Other antihistamines should be used, under pathological conditions accompanied by the overproduction of reactive oxygen species

    Alien Plants Introduced by Different Pathways Differ in Invasion Success: Unintentional Introductions as a Threat to Natural Areas

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    BACKGROUND: Understanding the dimensions of pathways of introduction of alien plants is important for regulating species invasions, but how particular pathways differ in terms of post-invasion success of species they deliver has never been rigorously tested. We asked whether invasion status, distribution and habitat range of 1,007 alien plant species introduced after 1500 A.D. to the Czech Republic differ among four basic pathways of introduction recognized for plants. PRINCIPAL FINDINGS: Pathways introducing alien species deliberately as commodities (direct release into the wild; escape from cultivation) result in easier naturalization and invasion than pathways of unintentional introduction (contaminant of a commodity; stowaway arriving without association with it). The proportion of naturalized and invasive species among all introductions delivered by a particular pathway decreases with a decreasing level of direct assistance from humans associated with that pathway, from release and escape to contaminant and stowaway. However, those species that are introduced via unintentional pathways and become invasive are as widely distributed as deliberately introduced species, and those introduced as contaminants invade an even wider range of seminatural habitats. CONCLUSIONS: Pathways associated with deliberate species introductions with commodities and pathways whereby species are unintentionally introduced are contrasting modes of introductions in terms of invasion success. However, various measures of the outcome of the invasion process, in terms of species' invasion success, need to be considered to accurately evaluate the role of and threat imposed by individual pathways. By employing various measures we show that invasions by unintentionally introduced plant species need to be considered by management as seriously as those introduced by horticulture, because they invade a wide range of seminatural habitats, hence representing even a greater threat to natural areas

    TRY plant trait database – enhanced coverage and open access

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    Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits—almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    TRY plant trait database – enhanced coverage and open access

    Get PDF
    Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    Životní spokojenost přeživších holocaust

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    Objective: Find out the impact of the Holocaust trauma on life satisfaction of alive Czech survivors, and to compare it with a control group of respondents. Design: Prospective study Participants: The total number of respondents in the study was 130. The exposed group consisted of 65 Czech Holocaust survivors (average age 88.5 years), control group of 65 Czech seniors (average age 88 years). Methods: The article presents a quantitative research assessing the life satisfaction of survivors using the standardized Life Satisfaction Questionnaire by Fahrenberg et al. (1986) on a main group, and compares it with a control group. A non-parametric test for two selections (Mann - Whitney) at a significance level of 0.05 was used to test the hypotheses. Results: In spite of wide spectrum of the Holocaust effects, the exposed group shows higher or the same satisfactionin the most of the monitored areas compared to the control group (Health Me 4 vs. 3, p - 0.000; Workand employment Me 6 vs. 5, p - 0.000; Financial situation Me 6 vs. 4, p - 0.000; Leisure time Me 4 vs. 4, p - 0.002; Marriage and partnership Me 2 vs. 0, p - 0.284; Own self Me 4 vs. 3, p - 0.000; Sexuality Me 3 vs. 3, p - 0.879; Friends and acquaintances Me 5 vs. 4, p - 0.002; Housing Me 5 vs. 4, p - 0.000; Overall life satisfaction Me 5 vs. 4, p - 0.001). On the contrary, they are less satisfied in the area Children (Me 4 vs. 5, p - 0.016). Conclusions: The research displays integration of hardiness and vulnerability, lust for life and the ability of man to live and survive in extreme conditions and still feel a joy of life.íl: Zjistit dopad traumatu holocaustu na životní spokojenost žijících českých přeživších a porovnat jej s kontrolní skupinou respondentů. Design: Prospektivní studie Účastníci: Celkový počet respondentů ve studii byl 130. Exponovanou skupinu tvořilo 65 českých přeživších holocaustu (průměrný věk 88,5 let), kontrolní skupinu 65 českých seniorů (průměrný věk 88 let). Metody: Článek představuje kvantitativní výzkum hodnotící životní spokojenost přeživších pomocí standardizovaného dotazníku Life Satisfaction Questionnaire od Fahrenberga et al. (1986) na hlavní skupině a srovnává ji s kontrolní skupinou. K testování hypotéz byl použit neparametrický test pro dva výběry (Mann - Whitney) na hladině významnosti 0,05. Výsledky: I přes široké spektrum účinků holocaustu vykazuje exponovaná skupina ve většině sledovaných oblastí vyšší nebo stejnou spokojenost ve srovnání s kontrolní skupinou (Zdraví Me 4 vs. 3, p - 0,000; Práce a zaměstnání Me 6 vs. 5, p - 0,000; Finanční situace Já 6 vs. 4, p - 0,000; Volný čas Já 4 vs. 4, p - 0,002; Manželství a partnerství Já 2 vs. 0, p - 0,284; Vlastní já Já 4 vs. 3 , p - 0,000; Sexualita já 3 vs. 3, p - 0,879; přátelé a známí já 5 vs. 4, p - 0,002; Bydlení já 5 vs. 4, p - 0,000; Celková životní spokojenost já 5 vs. 4, p - 0,001). Naopak méně spokojeni jsou v oblasti Děti (Já 4 vs. 5, p - 0,016). Závěry: Výzkum ukazuje integraci odolnosti a zranitelnosti, chuti do života a schopnosti člověka žít a přežít v extrémních podmínkách a přitom pociťovat radost ze život
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