Diagnosis of invasive fungal disease in hospitalized patients with chronic obstructive pulmonary disease

Background

The role of culture-independent techniques (galactomannan, (1-3)-β-d-glucan) in the early diagnosis of invasive fungal diseases (IFD) is well assessed in hematological patients, but there are no clear conclusions in patients with chronic obstructive pulmonary disease (COPD).

Evaluating the predicted extinction risk of living amphibian species with the fossil record

Bridging the gap between the fossil record and conservation biology has recently become of great interest. The enormous number of documented extinctions across different taxa can provide insights into the extinction risk of living species. However, few studies have explored this connection. We used generalised boosted modelling to analyse the impact of several traits that are assumed to influence extinction risk on the stratigraphic duration of amphibian species in the fossil record. We used this fossil‐calibrated model to predict the extinction risk for living species. We observed a high consensus between our predicted species durations and the current IUCN Red List status of living amphibian species. We also found that today's Data Deficient species are mainly predicted to experience short durations, hinting at their likely high threat status. Our study suggests that the fossil record can be a suitable tool for the evaluation of current taxa‐specific Red Listing status.     

In Vivo Analysis of Centromeric Proteins Reveals a Stem Cell-Specific Asymmetry and an Essential Role in Differentiated,Non-proliferating Cells

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Distinct Mechanisms of Nuclease-Directed DNA-Structure-Induced Genetic Instability in Cancer Genomes

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Inactivation of bacterial quorum sensing signals N-acyl homoserine lactones is widespread in yeasts

The inactivation of quorum sensing signals, a phenomenon known as quorum quenching, has been described in diverse microorganisms, though it remains almost unexplored in yeasts. Beyond the well-known properties of these microorganisms for the industry or as eukaryotic models, the role of yeasts in soil or in the inner tissues of a plant is largely unknown. In this report, the wider survey of quorum quenching activities in yeasts isolated from Antarctic soil and the inner tissues of sugarcane, a tropical crop, is presented. Results show that, independently of their niche, quorum quenching activities are broadly present in unicellular fungi. Although yeasts showing a broad range of quorum quenching activity are present in the two niches, at the same time specific AHL inactivation profiles can also be found. Furthermore, yeasts from both sampling sites show quorum quenching activities compatible with lactonase-like and acylase-like inactivations of AHLs. Interestingly, the characterization of Rhodotorula mucilaginosa 7Apo1 showed that the presence of a particular AHL does not interfere with the quenching of a second molecule. Evidence suggests that yeasts could play a role in the modulation of the quorum sensing activity of bacteria. The relationship among phylogeny, sampling sites and yeast quorum quenching activities of the isolates is analyzed.     

Salt tolerance of two perennial grass <Emphasis Type="Italic">Brachypodium sylvaticum</Emphasis> accessions

Key message

We studied the salt stress tolerance of two accessions isolated from different areas of the world (Norway and Tunisia) and characterized the mechanism(s) regulating salt stress in Brachypodium sylvaticum Osl1 and Ain1.

Abstract

Perennial grasses are widely grown in different parts of the world as an important feedstock for renewable energy. Their perennial nature that reduces management practices and use of energy and agrochemicals give these biomass crops advantages when dealing with modern agriculture challenges such as soil erosion, increase in salinized marginal lands and the runoff of nutrients. Brachypodium sylvaticum is a perennial grass that was recently suggested as a suitable model for the study of biomass plant production and renewable energy. However, its plasticity to abiotic stress is not yet clear. We studied the salt stress tolerance of two accessions isolated from different areas of the world and characterized the mechanism(s) regulating salt stress in B. sylvaticum Osl1, originated from Oslo, Norway and Ain1, originated from Ain-Durham, Tunisia. Osl1 limited sodium transport from root to shoot, maintaining a better K/Na homeostasis and preventing toxicity damage in the shoot. This was accompanied by higher expression of HKT8 and SOS1 transporters in Osl1 as compared to Ain1. In addition, Osl1 salt tolerance was accompanied by higher abundance of the vacuolar proton pump pyrophosphatase and Na⁺/H⁺ antiporters (NHXs) leading to a better vacuolar pH homeostasis, efficient compartmentation of Na⁺ in the root vacuoles and salt tolerance. Although preliminary, our results further support previous results highlighting the role of Na⁺ transport systems in plant salt tolerance. The identification of salt tolerant and sensitive B. sylvaticum accessions can provide an experimental system for the study of the mechanisms and regulatory networks associated with stress tolerance in perennials grass.

     

Telomere length alterations in microsatellite stable colorectal cancer and association with the immune response

Telomeres are repetitive sequences (TTAGGG) located at the end of chromosomes. Telomeres progressively shorten with each cell replication cycle, ultimately leading to chromosomal instability and loss of cell viability. Telomere length anomaly appears to be one of the earliest and most prevalent genetic alterations in malignant transformation. Here we aim to estimate telomere length from whole-exome sequencing data in colon tumors and normal colonic mucosa, and to analyze the potential association of telomere length with clinical factors and gene expression in colon cancer.Reads containing at least five repetitions of the telomere sequence (TTAGGG) were extracted from the raw sequences of 42 adjacent normal-tumor paired samples. The number of reads from the tumor sample was normalized to build the Tumor Telomere Length Ratio (TTLR), considered an estimation of telomere length change in the tumor compared to the paired normal tissue. We evaluated the associations between TTLR and clinical factors, gene expression and copy number (CN) aberrations measured in the same tumor samples.Colon tumors showed significantly shorter telomeres than their paired normal samples. No significant association was observed between TTLR and gender, age, tumor location, prognosis, stromal infiltration or molecular subtypes. The functional gene set enrichment analysis showed pathways related to immune response significantly associated with TLLR.By extracting a relative measure of telomere length from whole-exome sequencing data, we have assessed that colon tumor cells predominantly shorten telomeres, and this alteration is associated with expression changes in genes related to immune response and inflammation in tumor cells.     

Carotenoids in roots indicated the level of stress induced by mannitol and sodium azide treatment during the early stages of maize germination

Chemical mutagens, such as sodium azide, have attracted the interest of plant breeders. Azide creates DNA point mutations and affects plant growth and development, disturbs metabolic activity and inhibits protein and DNA replication, whereas mannitol is used to simulate drought stresses in tissue culture. To identify biochemical markers for stress tolerance, maize seeds were germinated under mannitol and sodium azide induced stress in controlled conditions for 7 days. Then levels of chlorophyll, carotenoids, phenolics and aldehydes produced were subsequently determined. Germination percentage was not affected by either mannitol or sodium azide and was always above 85%. However, total fresh weight decreased by 50% with the application of 153.4 mM mannitol and 0.26 mM azide in combination. This treatment significantly reduced plantlet growth from 0.94 g in the control to 0.53 g in the treated materials. Root weight reduced by 68.1%, cotyledons by 14.3%, stems by 65.0% and leaves by 70.0% in treated samples. The level of carotenoids in roots was the clearest biochemical indicator of stress produced by the mannitol and sodium azide treatment. Carotenoids increased from 0.01 µg g^??1 fresh weight in the control to 9.03 µg g^??1 fresh weight in the treated materials. A large-scale seed treatment with mannitol and sodium azide was carried out. 2296 seeds were placed in magenta containers with 153.4 mM mannitol and 0.26 mM NaN₃. At 7 days of germination, the heaviest seedlings (450) (450/2296?=?20%) were transferred to soil environment. Forty-two plants (42/450?=?9.3%) were off-type phenotypes at 45 days. Genetic variants may have been obtained following the novel procedure described here which combines chronic treatment with sodium azide and selection pressure with mannitol to simulate drought conditions.     

Predator-induced Swarms in the Tadpoles of an African Savanna Frog,Phrynomantis microps

Aggregations in tadpoles of the West African savanna frog Phrynomantis microps were often observed in their breeding ponds in our study area, situated in Comoé National Park, Ivory Coast. Experiments under seminatural conditions demonstrated that this behaviour was only shown while predators were present. The tadpoles reacted differently to different predators. Factors inducing swarm behaviour were optical (the predator) and/or chemical (liquid from injured tadpoles). Alarm substances are not species-specific. Kinship seems not to play a role in swarm formation.     

Improvement of culture conditions to overproduce β-galactosidase from Escherichia coli in Bacillus subtilis

The effect of some culture variables in the production of β-galactosidase from Escherichia coli in Bacillus subtilis was evaluated. The lacZ gene was expressed in B. subtilis using the regulatory region of the subtilisin gene aprE. The host contained also the hpr2 and degU32 mutations, which are known to overexpress the aprE gene. We found that, when this overproducing B. subtilis strain was grown in mineral medium supplemented with glucose (MMG), β-galactosidase production was partially growth-associated, as 40%–60% of the maximum enzyme activity was produced before the onset of the stationary phase. In contrast, when a complex medium was used, β-galactosidase was produced only at low levels during vegetative growth, whereas it accumulated to high levels during early stationary phase. Compared with the results obtained in complex media, a 20% increase in specific β-galactosidase activity in MMG supplemented with 11.6 g/l glucose was obtained. On the 1-l fermenter scale, a threefold increase in volumetric β-galactosidase activity was obtained when the glucose concentration was varied from 11 g/l to 26 g/l. In addition, glucose feeding during the stationary phase resulted in a twofold increase in volumetric enzyme activity as cellular lysis was prevented. Finally, we showed that oxygen uptake and carbon dioxide evolution rates can be used for on-line determination of the onset of stationary phase, glucose depletion and biomass concentration. Received: 18 April 1996 / Received revision: 27 August 1996 / Accepted: 6 September 1996