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Summary: All plant populations fluctuate in time. Apart from the dynamics imposed by external forces such as climate, these fluctuations can be driven by endogenous processes taking place within the community. In this study, we aimed to identify potential role of soil‐borne microbial communities in driving endogenous fluctuations of plant populations.We combined a unique, 35‐yr long abundance data of 11 common plant species from a species‐rich mountain meadow with development of their soil microbiome (pathogenic fungi, arbuscular mycorrhizal fungi and oomycetes) observed during 4 yr of experimental cultivation in monocultures.Plant species which abundance fluctuated highly in the field (particularly legumes) accumulated plant pathogens in their soil mycobiome. We also identified increasing proportion of mycoparasitic fungi under highly fluctuating legume species, which may indicate an adaptation of these species to mitigate the detrimental effects of pathogens.Our study documented that long‐term fluctuations in the abundance of plant species in grassland communities can be explained by the accumulation of plant pathogens in plant–soil microbiome. By contrast, we found little evidence of the role of mutualists in plant population fluctuations. These findings offer new insights for understanding mechanisms driving both long‐term vegetation dynamics and patterns of species coexistence and richness. [ABSTRACT FROM AUTHOR]

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The resistance of the emerging human pathogen Stenotrophomonas maltophilia to tetracycline antibiotics mainly depends on multidrug efflux pumps and ribosomal protection enzymes. However, the genomes of several strains of this Gram‐negative bacterium code for a FAD‐dependent monooxygenase (SmTetX) homologous to tetracycline destructases. This protein was recombinantly produced and its structure and function were investigated. Activity assays using SmTetX showed its ability to modify oxytetracycline with a catalytic rate comparable to those of other destructases. SmTetX shares its fold with the tetracycline destructase TetX from Bacteroides thetaiotaomicron; however, its active site possesses an aromatic region that is unique in this enzyme family. A docking study confirmed tetracycline and its analogues to be the preferred binders amongst various classes of antibiotics. [ABSTRACT FROM AUTHOR]

Root densities in the field vary at the centimetre scale, but we have no information on whether this variation is linked to the variation in nutrient concentrations and availability. Roots of many species are able to proliferate in nutrient‐rich patches in controlled conditions in culture, but because data on nutrient concentrations and, in particular, on their temporal stability in the field are scarce, we do not know to what extent root distribution in the soil bears traces of such a response.Here, we linked centimetre‐scale measurements of soil nutrient concentrations over 6 weeks with estimation of root biomass and its species composition at the same points to determine whether there is any association between the two. In addition to phosphorus, nitrate and ammonium, we determined the concentrations of metal cations (magnesium, calcium and potassium). We used qPCR to determine the quantities of individual species in the root biomass samples.We found that calcium and magnesium (and to a lesser degree phosphorus and potassium) showed fine‐scale patchiness that was stable throughout the study (6 weeks) and was consistent over all these elements. Nutrient patches were associated with high root biomass and the occurrence of roots of several species. Such patches are formed primarily by elements with known low mobility in soil (cations, phosphorus). In contrast, nitrogen ions showed overwhelmingly high temporal variation with no relationship between root density and nitrogen concentration.Soil nutrient concentrations, thus, constitute a multidimensional signal. Some elements strongly vary in time, while some are much more stable and, thus, form stable patches that permit root response over periods of weeks or months. Among them, calcium and magnesium play an important role in forming soil heterogeneity at a scale comparable with the scale at which fine root densities also vary. As these cations affect a number of plant functions, their association with higher root densities confirms their role in the growth dynamics of terrestrial ecosystems. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

S1 nuclease from Aspergillus oryzae is a single‐strand‐specific nuclease from the S1/P1 family that is utilized in biochemistry and biotechnology. S1 nuclease is active on both RNA and DNA but with differing catalytic efficiencies. This study clarifies its catalytic properties using a thorough comparison of differences in the binding of RNA and DNA in the active site of S1 nuclease based on X‐ray structures, including two newly solved complexes of S1 nuclease with the products of RNA cleavage at atomic resolution. Conclusions derived from this comparison are valid for the whole S1/P1 nuclease family. For proper model building and refinement, multiple lattice‐translocation defects present in the measured diffraction data needed to be solved. Two different approaches were tested and compared. Correction of the measured intensities proved to be superior to the use of the dislocation model of asymmetric units with partial occupancy of individual chains. As the crystals suffered from multiple lattice translocations, equations for their correction were derived de novo. The presented approach to the correction of multiple lattice‐translocation defects may help to solve similar problems in the field of protein X‐ray crystallography. [ABSTRACT FROM AUTHOR]

Summary: The efficient uptake of nutrients depends on the ability of roots to respond to gradients of these resources. Although pot experiments have shown that species differ in their ability to proliferate their roots in nutrient‐rich patches, the role of such differences in determining root shapes in the field is unclear.We used fine‐scale quantitative (q)PCR‐based species‐specific mapping of roots in a grassland community to reconstruct species‐specific root system shapes. We linked them with data from pot experiments on the ability of these species to proliferate in nutrient‐rich patches and their rooting depth.We found remarkable diversity in root system shapes, from cylindrical to conical. Interspecific differences in rooting depths in pots were the main determinant of rooting depths in the field, whereas differences in foraging ability played only a minor role. Although some species with strong foraging ability did place their roots into nutrient‐rich soil layers, it was not a universal pattern.The results imply that although the vertical differentiation of grassland species is pronounced, it is primarily not driven by the differential plastic response of species to soil nutrient gradients. This may constrain the coexistence of species with similar rooting depths and may instead favour coexistence of species differing in their architectural blueprints. See also the Commentary on this article by McNickle, 235: 2143–2145. [ABSTRACT FROM AUTHOR]

Aims: Dynamics of plant communities are an outcome of species' responses to the external environment influenced by species' life history, growth patterns and their mutual interactions. We aimed to disentangle the long‐term directional trends, likely associated with decadal change in environmental conditions, from short‐term species fluctuations. Location: Krkonoše Mountains, North Bohemia, Czech Republic. Method: To disentangle these processes, we used data from four plots in a temperate mountain grassland recorded yearly from 1985 to 2019. Results: We identified distinct types of temporal dynamics of individual species (using Fourier analysis) as well as directional shifts in abundance of individual species. Species fluctuations were best predicted by species' traits (namely taller species and those with a larger bud bank being less likely to fluctuate), likely due to demographic processes specific for individual species within the community. In contrast, directional trends were better predicted by species' environmental preferences expressed by Ellenberg indicator values. We found consistent shifts in vegetation composition towards that with higher Ellenberg indicator values for soil reaction and light and lower indicator value for moisture, which can be explained both by the global change and local factors. Conclusion: Our results thus show that short‐term dynamics of individual species is determined by their traits, while long‐term trends of a grassland community are determined by the environmental change. [ABSTRACT FROM AUTHOR]

Pleomorphic adenoma (PA) is the most common salivary gland neoplasm, and its diagnosis is straightforward in the majority of cases. However, not infrequently, PA shows unusual and uncommon histological features that can be confused with those of malignancy. The difficulties in diagnosing PA arise from its ability to mimic invasion, show atypical or metaplastic cytomorphology, and show morphological features that overlap with those of established salivary gland carcinomas. In addition, recognising early malignant transformation to carcinoma ex‐pleomorphic adenoma continues to be a frequent challenge. This review describes the diagnostic pitfalls of PA, and offers a systematic approach to avoid them by combining classic histopathology with novel immunohistochemical and molecular tests. [ABSTRACT FROM AUTHOR]

The FAD‐dependent oxidoreductase from Chaetomium thermophilum (CtFDO) is a novel thermostable glycoprotein from the glucose–methanol–choline (GMC) oxidoreductase superfamily. However, CtFDO shows no activity toward the typical substrates of the family and high‐throughput screening with around 1000 compounds did not yield any strongly reacting substrate. Therefore, protein crystallography, including crystallographic fragment screening, with 42 fragments and 37 other compounds was used to describe the ligand‐binding sites of CtFDO and to characterize the nature of its substrate. The structure of CtFDO reveals an unusually wide‐open solvent‐accessible active‐site pocket with a unique His–Ser amino‐acid pair putatively involved in enzyme catalysis. A series of six crystal structures of CtFDO complexes revealed five different subsites for the binding of aryl moieties inside the active‐site pocket and conformational flexibility of the interacting amino acids when adapting to a particular ligand. The protein is capable of binding complex polyaromatic substrates of molecular weight greater than 500 Da. [ABSTRACT FROM AUTHOR]

Aim: The outcome of interaction between plant individuals is often expected to be determined by differences in their sizes with other traits playing minor roles. However, such findings typically come from manipulative experiments in experimental gardens. Consequently, little is known about the relative roles of size vs other traits in the field, particularly in communities other than forests. Here we aimed; (a) to determine the relative role of size‐related traits in pairwise interactions between common species in a species‐rich grassland community; and (b) to determine which other traits predict outcomes of such interactions in the field, and which traits predict mean competitive effects and responses of individual species. Location: The Krkonoše Mts., Czech Republic. Methods: We fitted dynamic models with explicit terms for pairwise interactions on a 31‐year long data series of spatially explicit ramet counts of 19 coexisting species in a mountain meadow. We compared these fits with those having total neighbour biomass as the only competition term to determine whether accounting for pairwise interactions increases model fit. Further we linked estimates of the parameters of pairwise interactions with species traits, including size‐related traits. Results: Comparison of models with and without pairwise predictors showed that pairwise interactions provided better fits only in less than half of the cases. The main determinant of competitive interactions was leaf area and, to a lesser extent, mean ramet biomass; there was an additional signal of difference in rooting depth. Conclusion: Plant size and overall biomass have overwhelming effects on species‐to‐species interactions even in unproductive grassland communities, despite low differentiation of plant species along the size axis there. However, the weak albeit detectable signal of predictors not related to size of pairwise interactions points to possible mechanisms of within‐community niche differentiation, which can be captured by inter‐specific difference in functional traits and tested experimentally. [ABSTRACT FROM AUTHOR]

Roots are capable of strong plastic responses to environmental signals, but the extent of such responses in the field is essentially unknown. Here, we aimed to identify interspecific root aggregations and segregations as indicators of plastic responses to the presence of other species. Furthermore, we asked whether aggregations change with heterogeneity in overall root density along soil depth and whether root communities show any relationship to species' functional traits.We used quantitative real‐Time PCR to estimate root quantities of nine grassland species in soil blocks at a centimetre scale. We combined these estimates with fine‐scale recording of species' positions above‐ground. We used deviations between measured root density and that expected from the relationship to above‐ground species abundance to correct for different chances of individual species to meet due to the non‐random distribution of their individuals. This approach allows us to identify whether species associations below‐ground are due to plastic response of their roots.We showed that while there were signals of both interspecific aggregation and segregation, prevalence of aggregation over segregation strongly increased with increasing soil depth. In shallow layers, where root density is high and its heterogeneity low, roots are likely to respond to a number of signals which produce both interspecific aggregation and segregation. In contrast, in deeper layers, where root density is low and its heterogeneity high, root distribution is likely to be driven primarily by foraging for resources, producing aggregations. Species composition of the root community did not show any relationship to functional traits (SLA, shoot life span, spreading distance and rooting depth) of the examined species.Synthesis. The results imply that processes that determine interspecific root associations change at a scale of centimetres which is close to the scale of individual fine roots. They also imply that while root foraging might explain root co‐occurrence under low root density, very different processes determine it when root density is high. Our findings also support the notion that roots, while extremely plastic, may not receive sufficient signals to elicit a response in the field if overall root density is high and homogeneous. [ABSTRACT FROM AUTHOR]

Summary: Impatiens glandulifera is a globally successful invader that primarily spreads along riparian habitats; however, during the last ~20 years, it has started to colonise forests, but little has been published on impacts of this recent spread. Several factors may have contributed to this phenomenon: (i) high propagule pressure from large and widespread riparian populations, (ii) extensive anthropogenic and natural disturbances in the forest ecosystems, (iii) increased use of forest machinery efficiently spreading the seeds together with (iv) a wide environmental tolerance of the species. The impacts of I. glandulifera on native communities in forests are manifold. Contrasting effects are reported on native plant species diversity, richness and growth of saplings of co‐occurring species, as well as negative effects on soil mycorrhizal fungi. We suggest that the eradication of I. glandulifera populations in forests is more feasible than along watercourses because the recolonisation in forests is limited and, in some cases, populations are outcompeted by woody species during succession. [ABSTRACT FROM AUTHOR]

Among the traits whose relevance for plant invasions has recently been suggested are genome size (the amount of nuclear DNA) and ploidy level. So far, research on the role of genome size in invasiveness has been mostly based on indirect evidence by comparing species with different genome sizes, but how karyological traits influence competition at the intraspecific level remains unknown. We addressed these questions in a common‐garden experiment evaluating the outcome of direct intraspecific competition among 20 populations of Phragmites australis, represented by clones collected in North America and Europe, and differing in their status (native and invasive), genome size (small and large), and ploidy levels (tetraploid, hexaploid, or octoploid). Each clone was planted in competition with one of the others in all possible combinations with three replicates in 45‐L pots. Upon harvest, the identity of 21 shoots sampled per pot was revealed by flow cytometry and DNA analysis. Differences in performance were examined using relative proportions of shoots of each clone, ratios of their aboveground biomass, and relative yield total (RYT). The performance of the clones in competition primarily depended on the clone status (native vs. invasive). Measured in terms of shoot number or aboveground biomass, the strongest signal observed was that North American native clones always lost in competition to the other two groups. In addition, North American native clones were suppressed by European natives to a similar degree as by North American invasives. North American invasive clones had the largest average shoot biomass, but only by a limited, nonsignificant difference due to genome size. There was no effect of ploidy on competition. Since the North American invaders of European origin are able to outcompete the native North American clones, we suggest that their high competitiveness acts as an important driver in the early stages of their invasion. [ABSTRACT FROM AUTHOR]

The flavor aspect of pharmaceutical formulations is very important in terms of their acceptability for the patient. This work is aimed at using of a novel promising type of electronic tongue (ET), consisting of a potentiometric sensor array, for the discrimination and assessment the taste of commercial pharmaceuticals based on ibuprofen (Ibuflam 4 %). The sensor array was formed by six ion‐selective membranes (ISMs) based on both specific and non‐specific active components. Analysis of potentiometric signal outputs including statistical data processing utilizing the principal component analysis (PCA) method allowed evaluating the role of individual active components of the ISMs in the sense of taste control of the pharmaceutical preparation Ibuflam 4 % before and after flavoring. The sensing array can be used to identify differences in flavor within individual batches from the same producer, since ISMs provide a different response to all components present in the analyzed pharmaceutical. The ET contains ISMs which are able to recognize the bitter taste in the framework of the batches of ibuprofen based pharmaceuticals. To recognize bitter taste, it was essential to include ISMs, providing a response to a particular type of taste, namely, specific and non‐specific ISMs. The experimental findings show that taste‐sensing potentiometric sensor system can be a good alternative to the human panel and is able to detect the slight changes in taste. [ABSTRACT FROM AUTHOR]

There is remarkable variation in life histories of coexisting plant species. These "alternative designs" for the given set of environmental conditions are likely to play a role in species niche differences and thus may underlie species coexistence, although there is no clear demonstration of it. Currently available data on within‐community differentiation concern primarily easy and measurable traits that are not fully informative of life history variation. Their relevance for functional differentiation of species and species coexistence is far from clear.Here, we examined differentiation of coexisting species in demographic parameters and how it determines species' response to neighbours. We determined these parameters for a set of 21 co‐occurring species by fitting a process‐based model to a long‐term (30 years) data series of shoot counts. We examined the functional relevance of these parameters using species responses in a field removal experiment. We further asked with which functional traits they are correlated.Species were differentiated along two largely independent axes: (a) slow vs. fast, separating species according to instantaneous growth rate, competitive response and intraspecific density dependence; and (b) dispersal vs. local dynamics, which separated species with strong dispersal (by seeds or vegetative) from species that tended to stay in the occupied spot. While the slow‐fast axis was associated with commonly used leaf and seed traits, the dispersal axis was best predicted by lateral spreading distance.Each of these two axes predicted different components of species' responses to neighbour competition: the slow‐fast axis was a good predictor of the short‐term response, whereas dispersal axis was a good predictor of the long‐term response.Synthesis. Demographic differentiation of coexisting species resembles to an important degree demographic differentiation known from large‐scale comparisons. This differentiation is functionally meaningful also at the fine scale; its role in species' responses to competition implies it is involved in species niche differentiation and coexistence. While seed and leaf traits are important correlates of demographic differentiation, a hitherto underappreciated trait, viz. lateral spreading distance, is an important predictor of the dispersal axis at the fine scale and should be more widely used. A plain language summary is available for this article. [ABSTRACT FROM AUTHOR]

Secretory carcinoma (SC) of salivary glands is a newly described low‐grade malignancy characterized by the presence of ETV6 rearrangement. Only a few cases and very small series with cytomorphology were reported so far. Six cases of fine‐needle aspirations (FNAs) from afterward histologically, immunohistochemically and genetically confirmed SCs were retrieved from the archives of the authors. Ancillary immunocytochemistry (ICC) and translocation detection were performed on cell blocks (CBs). All aspirates were sufficiently cellular and cells were arranged in more or less cohesive groups with only mild nuclear polymorphism. The cytoplasm was eosinophilic, granulated and vacuolated, especially in CBs. Secretory material within the microcystic spaces was periodic acid‐Schiff (PAS) positive. Triple positivity of immunomarkers S‐100 protein, mammaglobin and vimentin was present. The proliferation index was low. Ancillary techniques suggested the possibility of SC in a few cytology cases; nevertheless, the final diagnosis was based on histomorphology, immunohistochemistry and genetics. The SC of salivary glands is detectable pre‐operatively using ICC and genetics. The presence of the diagnostic ETV6 rearrangement increases the accuracy of FNA to the maximum. According to the Milan system, cases genetically not confirmed should be categorized as Suspicious for Malignancy or Salivary Gland Neoplasm of Uncertain Malignant Potential (SUMP), both requiring surgery. [ABSTRACT FROM AUTHOR]

Background: Our aim was to identify the number of cases of secretory carcinoma (SC) of the major salivary gland in a population‐based cohort and review its clinical behavior with long‐term follow‐up. Methods: All malignant salivary gland tumors (MSGTs) diagnosed between 1980 and 2014 were assessed for histological features compatible with SC and 140 were selected for further analysis. Results: Twenty two new cases of SC were identified, 19 of which were originally classified as acinic cell carcinoma, and 3 as adenocarcinoma, not otherwise specified (NOS). Lymph node involvement was less common in SC tumors (5%) than in the control group (11%). Disease recurrence was seen less frequently in SC (9%) than the control group (20%). Mean disease‐free survival was 192 months for SC compared with 162 months for controls (P = 0.15). Conclusion: The clinical course of SC is typically indolent with a low risk of relapse not significantly different from other low‐grade MSGT. [ABSTRACT FROM AUTHOR]

The HelD is a helicase‐like protein binding to Bacillus subtilis RNA polymerase (RNAP), stimulating transcription in an ATP‐dependent manner. Here, our small angle X‐ray scattering data bring the first insights into the HelD structure: HelD is compact in shape and undergoes a conformational change upon substrate analog binding. Furthermore, the HelD domain structure is delineated, and a partial model of HelD is presented. In addition, the unique N‐terminal domain of HelD is characterized as essential for its transcription‐related function but not for ATPase activity, DNA binding, or binding to RNAP. The study provides a topological basis for further studies of the role of HelD in transcription. [ABSTRACT FROM AUTHOR]

Abstract: Flubendazole (FLU), a benzimidazole anthelmintic drug widely used in veterinary medicine, has been approved for the treatment of gut‐residing nematodes in humans. In addition, FLU is now considered a promising anti‐cancer agent. Despite this, information about biotransformation of this compound in human is lacking. Moreover, there is no information regarding whether cancer cells are able to metabolize FLU in order to deactivate it. For these reasons, the present study was designed to identify all metabolites of Phase I and Phase II of FLU in human liver and in various cancer cells using ultra high‐performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) analysis. Precision‐cut human liver slices and 9 cell lines of different origin (breast, colon, oral cavity) were used as in vitro model systems. Our study showed that FLU with a reduced carbonyl group (FLUR) is the only FLU metabolite formed in the human liver. All human cancer cell lines were able to form FLUR. In addition, methylated FLUR was detected in breast cells MCF7 and intestinal SW480 cells. The accumulation of FLU and its reduction to FLUR markedly differed among cells. The extent of FLU reduction was in a good correlation with the detected expression level of carbonyl reductase 1. In most cases, FLU entered in a higher amount and was reduced to a lesser extent in proliferating (metastatic) cells than in differentiated (non‐cancerous, non‐metastatic) ones. These results support the promising potential of FLU in anti‐cancer therapy. [ABSTRACT FROM AUTHOR]

Abstract: Vertical differentiation in root placement is one of the potential mechanisms of plant niche differentiation. It can be due to the remarkable plasticity of roots in response to nutrients and neighbours, but most data on it come from pot or garden experiments. The roles of vertical differentiation and of plasticity in it in the field are thus not well known. We examined species‐specific root vertical distribution in a montane grassland using quantitative real‐time PCR. We asked whether individual species differ in their rooting depths, whether such differences are associated with above‐ground functional traits (such as height or specific leaf area), and whether they respond to the presence of a competitor. This response was assessed by comparison of species‐specific vertical profiles between control plots and plots where the dominant species, Festuca rubra, had been removed. Vertical profiles of individual species varied considerably, from species with most root biomass concentrated in the uppermost (<2 cm) soil layer, through species with uniform vertical distribution, to a species with roots predominantly below 8 cm (Nardus stricta). Species at the fast end of the plant economy spectrum were more likely to place their roots in the uppermost layers. Grassland species, thus, exploit different parts of the below‐ground resources in spite of their short stature, minor differences in height above‐ground and shallow soil. While below‐ground and above‐ground biomasses of most species were higher in the removal plots, species rooting patterns did not change in response to the removal. The interspecific differences in vertical profiles were thus due to species' innate differences, not to plastic responses to the presence of the dominant species. Synthesis. The findings imply that vertical root differentiation in the field is strong and can contribute to niche differentiation. However, the role of root plasticity in natural systems may be considerably weaker than in artificial systems with few species and strong nutrient gradients. This absence of the plastic response in the field is likely to be due to a fairly homogeneous distribution of nutrients in the soil and to the predominantly symmetric nature of below‐ground competition. [ABSTRACT FROM AUTHOR]

The literature suggests that small genomes promote invasion in plants, but little is known about the interaction of genome size with other traits or about the role of genome size during different phases of the invasion process. By intercontinental comparison of native and invasive populations of the common reed Phragmites australis, we revealed a distinct relationship between genome size and invasiveness at the intraspecific level. Monoploid genome size was the only significant variable that clearly separated the North American native plants from those of European origin. The mean Cx value (the amount of DNA in one chromosome set) for source European native populations was 0.490 ± 0.007 (mean ± SD), for North American invasive 0.506 ± 0.020, and for North American native 0.543 ± 0.021. Relative to native populations, the European populations that successfully invaded North America had a smaller genome that was associated with plant traits favoring invasiveness (long rhizomes, early emerging abundant shoots, resistance to aphid attack, and low C:N ratio). The knowledge that invasive populations within species can be identified based on genome size can be applied to screen potentially invasive populations of Phragmites in other parts of the world where they could grow in mixed stands with native plants, as well as to other plant species with intraspecific variation in invasion potential. Moreover, as small genomes are better equipped to respond to extreme environmental conditions such as drought, the mechanism reported here may represent an emerging driver for future invasions and range expansions. [ABSTRACT FROM AUTHOR]

Understanding species' abilities to cope with changing climate is a key prerequisite for predicting the future fates of species and ecosystems. Despite considerable research on species responses to changing climate, we still lack understanding of the role of specific climatic factors, and their interactions, for species responses. We also lack understanding of the relative importance of plasticity vs. adaptation in determining the observed responses., As a model, we use a dominant clonal grass, Festuca rubra, originating from a natural climatic grid of 12 localities in western Norway that allows factorial combinations of temperature (mean growing season temperatures ranging from 6·5 to 10·5 °C) and precipitation (annual precipitation ranging from 600 to 2700 mm). We grew clones from all populations in four growth chambers representing the four climatic extremes in the climate grid (warm/cold × wet/dry)., Genetic differentiation and direction and magnitude of plastic responses vary systematically among populations throughout the climatic grid. Growth-related plant traits are highly plastic and their degree of plasticity depends on their origin. In contrast, the traits reflecting species' foraging strategy are not plastic but vary with the climate of origin. Levels of plasticity of growth-related traits and genetically differentiated foraging traits thus might constrain local populations' ability to cope with novel climates., Synthesis. Shifts in temperature and precipitation, at the scale and direction expected for the region in the next century, are likely to dramatically affect plant performance. This study illustrates how the interplay between genetic differentiation and plasticity in response to both temperature and precipitation will affect the specific responses of species to climate change. Such complex responses will affect how climate-change impacts scale up to the community and ecosystem levels. Future studies thus need to specifically consider regionally relevant climate-change projections, and also explore the role of genetic differentiation and plasticity and how this varies within local floras. Our study also demonstrates that even widespread species with seemingly broad climatic niches may strongly differ in their population performance and plasticity. Climate-change studies should therefore not be limited to rare and restricted species. [ABSTRACT FROM AUTHOR]

This account presents comprehensive information on the biology of Phragmites australis (Cav.) Trin. ex Steud. ( P. communis Trin.; common reed) that is relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors and to the abiotic environment, plant structure and physiology, phenology, floral and seed characters, herbivores and diseases, as well as history including invasive spread in other regions, and conservation., Phragmites australis is a cosmopolitan species native to the British flora and widespread in lowland habitats throughout, from the Shetland archipelago to southern England. It is widespread throughout Ireland and is native in the Channel Islands. Native populations occur naturally in temperate zones and on every continent except Antarctica. Some populations in Australia and North America have been introduced from elsewhere and have become naturalized, and in North America, some of these are known to be invasive where they compete with native local populations of P. australis. Typical habitats in Britain range from shallow still water along waterbody edges to marshlands, saltmarshes and drier habitat on slopes up to 470 m above sea level. Additional habitats outside Britain are springs in arid areas, riverine lowlands (−5 m above sea level) and groundwater seepage points up to 3600 m above sea level. Although it occurs on a wide range of substrates and can tolerate pH from 2·5 to 9·8, in Britain it prefers pH >4·5 and elsewhere it thrives in mildly acidic to mildly basic conditions ( pH 5·5-7·5). The species plays a pivotal role in the successional transition from open water to woodland., Phragmites australis is a tall, helophytic, wind-pollinated grass with annual shoots up to 5 m above-ground level from an extensive system of rhizomes and stolons. A single silky inflorescence develops at the end of each fertile stem and produces 500-2000 seeds. The plant is highly variable genetically and morphologically., Expansion of established populations is mainly through clonal growth of the horizontal rhizome system and ground-surface stolons, while new populations can establish from rhizomes, stem fragments and seeds. Shoots generally emerge in spring, with timing determined primarily by physiology that is mediated by external conditions (e.g. local climate including frost)., Many populations in the British Isles have experienced some decline over the past two decades and there is concern that there might be further losses along the east coast as sea level rises. There have recently also been localized expansions, especially in highly modified habitats, where P. australis reedbeds have been planted as wildlife habitat, rehabilitated mineral and gravel beds, and bioremediation filter beds for industrial and transport infrastructure. Native populations outside Britain also demonstrate both types of trend: they are declining in many parts of Western Europe and North America, yet also colonize many disturbed, ruderal habitats (e.g. the edges of agricultural fields and motorways) throughout its native and non-native range and can form 'weedy' monodominant populations (e.g. in Australia and China). [ABSTRACT FROM AUTHOR]

Several dynamic models have shown that dynamics of legumes and grasses can result in periodic behaviour. These oscillations arise due to delays in nitrogen flows coupled with differences in ability to compete for light. However, long-term time series on legume dynamics that could be used to test predictions of these models are almost non-existent., We examine legume oscillations in a semi-natural mountain grassland using a long-term (Tilde; 30 years) data series on aboveground biomass of individual species and on nitrogen and phosphorus content over time., Using autocorrelation analysis, we show that there is a strong periodicity (with period of 8-9 years) of legume and grass biomass and nitrogen content in the grass biomass. These three variables are in fairly stable phase shifts relative to each other, with a grass peak followed by a peak in C : N ratio in grasses which is followed by a legume peak. Phosphorus content in either legume or grass biomass does not show synchronous cycling with legume or grass biomass or nitrogen content in grass., Fitting a dynamic linear model to the data showed that legumes affect nitrogen content in grasses, and grass biomass both affects and is affected by nitrogen content. In contrast, there is no negative effect of grasses on legumes, indicating some other process must be responsible for the legume decline. Manuring, which was occasionally applied to the plots, also does not seem to affect the cycling. Second-order term for legumes showed some evidence of self-inhibitory effects in legumes, but phosphorus content in legumes shows no support for phosphorus limitation. The most likely explanation of the legume decline should be sought elsewhere (pathogens, soil biota etc.)., Synthesis. Long-term data support the existing the claim that legume dynamics are the key driver of nitrogen dynamics in nutrient-poor semi-natural grasslands. Grasses benefit from the nutrient enrichment due to legume cycling, but are a passive element and do not play a role in legume limitation. Apart from the role of nutrient cycling, these legume-driven nutrient dynamics also constitutes processes by which long-term richness of meadows is maintained. [ABSTRACT FROM AUTHOR]

Aim Riparian habitats are amongst the most invaded ecosystems world-wide. The great abundance of invasive species in river corridors is attributed to the efficient transport of alien species' propagules and reduced competition from native plants due to regular flooding. Once an invasive species has become established, river corridors can serve as stepping stones for spread into other habitats. We have chosen the Himalayan balsam Impatiens glandulifera Royle, highly invasive annual in riparian areas, as a model for spread of invasive species from linear river corridors. Location Central Europe. Methods We mapped its distribution and recorded its abundance in over 1200 patches along four rivers in central Europe, differing in the time of balsam's introduction (1900-1995). The patches were characterized in terms of the distance from the riverbank, height above the river surface, degree of soil disturbance and flooding regime. Results The patches at sites subject to flooding had twice as many individuals as those that were not subject to flooding, regardless of their distance from the riverbank and height above the river surface. There was a strong effect of the river identity, with river invaded 20 years ago being less infested than those invaded earlier. The distance from the riverbank at which the populations occurred differed and did not depend on river identity/residence time. The patches in tributaries were on average two times further from the bank of the main river than those located elsewhere. Main conclusions Flooding is an important factor affecting the abundance of I. glandulifera, and accounts for its spread and dominance along river corridors probably due to spreading the seeds, increasing nutrient availability and disturbing native vegetation. It is likely that the number of I. glandulifera populations will increase in the future, especially along small water courses. [ABSTRACT FROM AUTHOR]

Inherited neuromuscular disorder ( NMD) is a wide term covering different genetic disorders affecting muscles, nerves, and neuromuscular junctions. Genetic and clinical heterogeneity is the main drawback in a routine gene-by-gene diagnostics. We present Czech NMD patients with a genetic cause identified using targeted next-generation sequencing ( NGS) and the spectrum of these causes. Overall 167 unrelated patients presenting NMD falling into categories of muscular dystrophies, congenital muscular dystrophies, congenital myopathies, distal myopathies, and other myopathies were tested by targeted NGS of 42 known NMD-related genes. Pathogenic or probably pathogenic sequence changes were identified in 79 patients (47.3%). In total, 37 novel and 51 known disease-causing variants were detected in 23 genes. In addition, variants of uncertain significance were suspected in 7 cases (4.2%), and in 81 cases (48.5%) sequence changes associated with NMD were not found. Our results strongly indicate that for molecular diagnostics of heterogeneous disorders such as NMDs, targeted panel testing has a high-clinical yield and should therefore be the preferred first-tier approach. Further, we show that in the genetic diagnostic practice of NMDs, it is necessary to take into account different types of inheritance including the occurrence of an autosomal recessive disorder in two generations of one family. [ABSTRACT FROM AUTHOR]

Glandular odontogenic cyst (sialo-odontogenic cyst) ( GOC) is an uncommon developmental odontogenic cyst. Its clinical significance lies in its tendency to recur, and histopathological features which mimic those of mucoepidermoid carcinoma ( MC). Molecular methods such as fluorescence in situ hybridisation ( FISH) have the potential to identify genetic abnormalities that are specific to MC and thus avoid this diagnostic pitfall. This report describes three cystic lesions of the jaws with a differential diagnosis of GOC and MC. One occurred in the mandibular premolar area of a 49-year-old woman and was diagnosed as GOC. The second developed in the maxilla of a man aged 39 in association with an impacted second premolar tooth. This was initially diagnosed as dentigerous cyst, but after recurrence 6 years later, the diagnosis was revised to GOC. The third occurred in the left retromolar area of a 30-year-old woman 5 years after the extraction of the left mandibular third molar; a diagnosis of GOC was favoured after two incisional biopsies, but a third showed unequivocal, invasive MC which had infiltrated nerves and bone. Morphologically, the only distinguishing feature was the so-called epithelial sphere, whorl or plaque-like thickening, which was identified in both GOC but not in the MC. FISH confirmed the above diagnoses by demonstrating a MAML2 rearrangement in the MC, but in neither of the GOC. While histopathology may reliably distinguish between GOC and MC, the presence of the specific MAML2 rearrangement in the latter clinches the diagnosis. [ABSTRACT FROM AUTHOR]

Aims Polymorphous low-grade adenocarcinoma ( PLGA) is the second most common intra-oral salivary gland malignancy. The vast majority of PLGAs harbour a PRKD1 E710D hot-spot somatic mutation or somatic rearrangements of PRKD1, PRKD2 or PRKD3. Given the kinase domain homology among PRKD1, PRKD2 and PRKD3, we sought to define whether PLGAs lacking PRKD1 somatic mutations or PRKD gene family rearrangements would be driven by somatic mutations affecting the kinase domains of PRKD2 or PRKD3. Methods and results DNA was extracted from eight microdissected PLGAs lacking PRKD1 somatic mutations or PRKD gene family rearrangements. Samples were thoroughly centrally reviewed, microdissected and subjected to Sanger sequencing of the kinase domains of the PRKD2 and PRKD3 genes. None of the PLGAs lacking PRKD1 somatic mutations or PRKD gene family rearrangements harboured somatic mutations in the kinase domains of the PRKD2 or PRKD3 genes. Conclusion PLGAs lacking PRKD1 somatic mutations or PRKD gene family rearrangements are unlikely to harbour somatic mutations in the kinase domains of PRKD2 or PRKD3. Further studies are warranted to define the driver genetic events in this subgroup of PLGAs. [ABSTRACT FROM AUTHOR]

The present in vitro study was designed to test and compare anthelmintic activity, hepatotoxicity, and biotransformation of four selected aminoacetonitrile derivatives (AADs): monepantel (MOP, anthelmintic approved for the treatment), AAD-970, AAD-1154, and AAD-1336. Micro-agar larval development test, MTT test of cytotoxicity, and biotransformation study coupled with Ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) technique were used for this purpose. Larvae of two Haemonchus contortus strains (drug susceptible and multi-drug resistant) and primary cultures of rat and ovine hepatocytes served as model systems. All AADs (including MOP) exhibited significant larvicidal effect in H. contortus susceptible as well as multi-resistant strains, much higher than those of reference anthelmintics thiabendazole and flubendazole. AAD-1154 provides the best results for most tested parameters among all AADs in this study. The cytotoxicity test showed that all AADs can be considered as nontoxic for hepatocytes. In the biotransformation study, Phase I and Phase II metabolites of AADs were identified and schemes of possible metabolic pathways in ovine hepatocytes were proposed. Biotransformation of MOP was much more extensive than biotransformation of other AADs. Based on obtained results, AAD-1154 and AAD-1336 can be considered as promising candidates for further in vivo testing. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Tomato multifunctional nuclease TBN1 belongs to the type I nuclease family, which plays an important role in apoptotic processes and cell senescence in plants. The newly solved structure of the N211D mutant is reported. Although the main crystal-packing motif (the formation of superhelices) is conserved, the details differ among the known structures. A phosphate ion was localized in the active site of the enzyme. The binding of the surface loop to the active centre is stabilized by the phosphate ion, which correlates with the observed aggregation of TBN1 in phosphate buffer. The conserved binding of the surface loop to the active centre suggests biological relevance of the contact in a regulatory function or in the formation of oligomers. [ABSTRACT FROM AUTHOR]

Human LLT1 is a C-type lectin-like ligand of NKR-P1 (CD161, gene KLRB1), a C-type lectin-like receptor of natural killer cells. Using X-ray diffraction, the first experimental structures of human LLT1 were determined. Four structures of LLT1 under various conditions were determined: monomeric, dimeric deglycosylated after the first N-acetylglucosamine unit in two forms and hexameric with homogeneous GlcNAc2Man5 glycosylation. The dimeric form follows the classical dimerization mode of human CD69. The monomeric form keeps the same fold with the exception of the position of an outer part of the long loop region. The hexamer of glycosylated LLT1 consists of three classical dimers. The hexameric packing may indicate a possible mode of interaction of C-type lectin-like proteins in the glycosylated form. [ABSTRACT FROM AUTHOR]

Questions Wildfire is a natural disturbance that shapes vegetation characteristics worldwide, while prescribed fire is increasingly used to modify vegetation composition and structure. Due to invasion of many ecosystems by exotic species, a concern of land managers is whether wildfire and prescribed fire alter plant communities in favour of exotics. We assessed the global literature describing community-level responses of native and exotic species groups to wildfire and prescribed fire and characterized the geographic and temporal scope of the data to inform research needs. Location Predominantly the United States of America and Australia. Methods We used meta-analysis to (1) test whether native and exotic species composition (richness or diversity) and performance (cover, density and biomass) differ in response to wildfire and prescribed fire, and (2) assess how the composition and performance of these species groups vary with time elapsed since fire and habitat types. Results Most community-level research on how native and exotic species respond to fire has been conducted in the US and Australia, typically over short time scales, and with a focus on temperate forest and grassland ecosystems. Prescribed fire benefited native composition over short time scales (<1 yr) but, on average, had no effect on native performance, nor on exotic composition or performance. In contrast, wildfire consistently enhanced exotic composition and performance over all time scales, while having no effect on native species composition and significantly reducing native performance. Additionally, responses varied by habitat: native species groups responded positively to prescribed fire in heathlands and to a lesser extent in temperate grasslands, while responding negatively to wildfire in arid shrublands and heathlands, and to a more modest degree in tropical savannas. Exotic species groups responded positively to wildfire in arid shrublands, temperate forests and heathlands. Conclusions This quantitative assessment of the literature revealed strong evidence for a positive response of exotics to wildfire, coupled with a striking near-absence of negative responses. The assessment additionally suggests that while prescribed fire does benefit native composition, on average, it does not appear to greatly facilitate native performance; however site-specific variation in how communities responded to fire was pronounced, underscoring the importance of local assessments in determining mechanistic drivers and management policy. [ABSTRACT FROM AUTHOR]

We present a case of epidermoid carcinoma arising in Warthin's tumour of parotid gland in an 80-year-old woman. Light microscopy revealed small foci typical of benign Warthin's tumour with transition to epidermoid carcinoma. Immunohisto-chemical and ultrastructural observations confirmed the epidermoid features of the malignant cells. The differential diagnosis of a metastasis from an epidermoid carcinoma to the stroma of Warthin's tumour and also of the so-called metaplastic variant of Warthin's tumour is discussed. [ABSTRACT FROM AUTHOR]

Monepantel (MOP) is a new anthelmintic drug intended for the treatment and control of gastrointestinal roundworms (nematodes) infection and associated disease in sheep. The aim of our study was to find out metabolic pathways of MOP in sheep in vivo and in its parasite Haemonchus contortus ex vivo. MOP biotransformation in two H. contortus strains with different sensitivity to anthelmintics was also compared. Ultra high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) technique is used for the identification of MOP metabolites in ovine urine, faeces, and nematodes. MOP biotransformation study in sheep in vivo led to the identification of 13 MOP metabolites; 7 of them have not been described previously in in vitro study. The study of MOP biotransformation in H. contorus ex vivo reveals four MOP metabolites. The nitrile hydrolysis as a new biotransformation pathway in helminths ex vivo is reported here for the first time. Unlike sheep, H. contorus nematodes are not able to metabolize MOP via phase II biotransformation. Nematodes of resistant White river (WR) strain form more types of MOP metabolites than nematodes of sensitive inbred susceptible Edinburgh (ISE) strain. Based on obtained results, schemes of metabolic pathways of MOP in sheep and nematodes are proposed. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Flavonoids, plant secondary metabolites present in fruits and vegetables, show antioxidant and anti-tumorigenic effects in vitro, but their poor absorption from gastrointestinal tract limits their systemic efficacy in humans. On the other hand, flavonoids could protect intestinal cells against carcinogens by their potential to inhibit the enzymes metabolizing pre-carcinogenic compounds (e.g. CYP1A) to reactive ones. This work was designed to test the effect of quercetin (the most abundant flavonoid) and rutin (the most abundant glycosidic form) on the activity, expression and inducibility of CYP1A in intestinal HCT-8 cells. CYP1A enzymatic activity was measured by ethoxyresorufin-O-deethylase (EROD) activity, CYP1A protein expression was detected by western blotting. The effect of flavonoids on viability of cells was examined by neutral red uptake test. No cytotoxic effect of flavonoids up to 50 μM concentration was observed. Quercetin significantly inhibited EROD activity in the cells, where CYP1A had been preinduced by β-naphthoflavone and methylcholanthrene, and it also significantly reduced the CYP1A induction mediated by these model inducers. The effect of rutin was substantially weaker and mostly insignificant in all conducted experiments. The results suggest that quercetin may have a potential to limit the CYP1A-mediated activation of pre-carcinogens in intestinal cells. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The bacterial enzyme organophosphorus acid anhydrolase (OPAA) is able to catalyze the hydrolysis of both proline dipeptides (Xaa-Pro) and several types of organophosphate (OP) compounds. The full three-dimensional structure of the manganese-dependent OPAA enzyme is presented for the first time. This enzyme, which was originally isolated from the marine bacterium Alteromonas macleodii, was prepared recombinantly in Escherichia coli. The crystal structure was determined at 1.8 Å resolution in space group C2, with unit-cell parameters a = 133.8, b = 49.2, c = 97.3 Å, β = 125.0°. The enzyme forms dimers and their existence in solution was confirmed by dynamic light scattering and size-exclusion chromatography. The enzyme shares the pita-bread fold of its C-terminal domain with related prolidases. The binuclear manganese centre is located in the active site within the pita-bread domain. Moreover, an Ni2+ ion from purification was localized according to anomalous signal. This study presents the full structure of this enzyme with complete surroundings of the active site and provides a critical analysis of its relationship to prolidases. [ABSTRACT FROM AUTHOR]

Type I plant nucleases play an important role in apoptotic processes and cell senescence. Recently, they have also been indicated to be potent anticancer agents in in vivo studies. The first structure of tomato nuclease I (TBN1) has been determined, its oligomerization and activity profiles have been analyzed and its unexpected activity towards phospholipids has been discovered, and conclusions are drawn regarding its catalytic mechanism. The structure-solution process required X-ray diffraction data from two crystal forms. The first form was used for phase determination; the second form was used for model building and refinement. TBN1 is mainly α-helical and is stabilized by four disulfide bridges. Three observed oligosaccharides are crucial for its stability and solubility. The active site is localized at the bottom of the positively charged groove and contains a zinc cluster that is essential for enzymatic activity. An equilibrium between monomers, dimers and higher oligomers of TBN1 was observed in solution. Principles of the reaction mechanism of the phosphodiesterase activity are suggested, with central roles for the zinc cluster, the nucleobase-binding pocket (Phe-site) and Asp70, Arg73 and Asn167. Based on the distribution of surface residues, possible binding sites for dsDNA and other nucleic acids with secondary structure were identified. The phospholipase activity of TBN1, which is reported for the first time for a nuclease, significantly broadens the substrate promiscuity of the enzyme, and the resulting release of diacylglycerol, which is an important second messenger, can be related to the role of TBN1 in apoptosis. [ABSTRACT FROM AUTHOR]

Many plant communities show strong fine-scale spatiotemporal dynamics due to frequent natality and mortality events. This process is often non-random, implying that the community can be broken into groups within which species mutually replace each other in time and are distinct from the other such groups. We examined whether such groups fill separate niches and are functionally complementary in a species-rich mountain grassland. We used cluster analysis of fine-scale spatial data time series to discern which species were more likely to replace each other in space. Next, a four-year removal experiment (removing one group in each experimental treatment, or similar amount of biomass across all groups) was used to determine whether simultaneous occurrence of all these groups would maintain a greater total biomass than if an entire group were eliminated. The results do not support the hypothesis that the simultaneous presence of groups of species that replace each other in space is necessary for the community to attain its maximum biomass. However, the experiment showed strong differences among the replacement groups in their capacity for opportunistic behaviour: some groups responded quickly to space made available by removal while others did not. Furthermore, there were strong differences between groups composed primarily of grasses and groups composed primarily of dicots. In spite of the large differences among these groups, they are not functionally complementary. We therefore conclude that replacement processes in this grassland community more closely resemble a neutral process with sets of species differing in the speed at which they fill empty spaces. [ABSTRACT FROM AUTHOR]

Process of aging is accompanied by changes in the biotransformation of xenobiotics and impairment of normal cellular functions by free radicals. Therefore, this study was designed to determine age-related differences in the activities and/or expressions of selected drug-metabolizing and antioxidant enzymes in young and old rats. Specific activities of 8 drug-metabolizing enzymes and 4 antioxidant enzymes were assessed in hepatic subcellular fractions of 6-week-old and 21-month-old male Wistar rats. Protein expressions of carbonyl reductase 1 (CBR1) and glutathione S-transferase (GST) were determined using immunoblotting. Remarkable age-related decrease in specific activities of CYP2B, CYP3A, and UDP-glucuronosyl transferase was observed, whereas no changes in activities of CYP1A2, flavine monooxygenase, aldo-keto reductase 1C, and antioxidant enzymes with advancing age were found. On the other hand, specific activity of CBR1 and GST was 2.4 folds and 5.6 folds higher in the senescent rats compared with the young ones, respectively. Interindividual variability in CBR1 activity increased significantly with rising age. We suppose that elevated activities of GST and CBR1 may protect senescent rats against xenobiotic as well as eobiotic electrophiles and reactive carbonyls, but they may alter metabolism of drugs, which are CBR1 and especially GSTs substrates. [ABSTRACT FROM AUTHOR]

Aims: The aim of this study was to devise a molecular classification for salivary duct carcinomas (SDCs) based on the similarities between SDCs and breast carcinomas and on characteristics of the microarray-based gene expression profiling-defined molecular subtypes of breast cancer. Methods and results: Forty-two pure salivary duct carcinomas, 35 of which contained an in-situ component as defined by histological review and/or immunohistochemical analysis, were stained with antibodies for oestrogen receptor (ER), progesterone receptor (PR), androgen receptor (AR), human epidermal growth factor receptor 2 (HER2), epidermal growth factor receptor (EGFR) and cytokeratin (CK) 5/6. Based on these markers, tumours were classified into HER2, luminal androgen receptor-positive, basal-like, luminal and indeterminate phenotype. Analysis revealed that 16.7%, 69%, 4.8%, 9.5% and 0% were of HER2, luminal androgen receptor-positive, basal-like, indeterminate and luminal phenotype, respectively. The in-situ and invasive components displayed the same molecular subtype in all but one case. Conclusions: Salivary duct carcinomas can be classified into molecular subgroups approximately equivalent to those in the breast. We also report on the existence of a subgroup of bona fide pure salivary duct carcinomas that have a 'basal-like' phenotype. Understanding the phenotypic complexity of SDCs may help to expedite the identification of novel therapeutic targets for these aggressive tumours. [ABSTRACT FROM AUTHOR]

Semi-natural temperate grasslands in Europe make an important contribution to biodiversity, but their existence has been endangered by both agricultural intensification and abandonment. In the Czech Republic, Arrhenatherion meadows are a typical example, with their conservation made difficult by the scarcity of research on effective management practices. We examined effects of two potentially useful approaches, application of 56 kg N ha−1 and earlier first mowing (i.e. in the middle of May, about 2 weeks earlier than usual), on species composition of an Arrhenatherion grassland in central Bohemia over a 7-year period (1998-2004). These treatments did not influence species richness, but resulted in small changes in canopy structure in terms of cover of individual species and particular plant functional groups. N application resulted in increases in nitrophilous species and tall graminoids, especially Alopecurus pratensis, Festuca pratensis, Heracleum sphondylium and Ranunculus acris, and in decreases in short graminoids. Earlier mowing decreased tall herbs, especially H. sphondylium, and might thus be useful in compensating for increases in some nitrophilous species owing to N application. However, earlier mowing had negative impacts on spring-flowering species in terms of reduced cover. [ABSTRACT FROM AUTHOR]

Four novel linear non-peptidic HIV-1 protease inhibitors derived from 2,5-diamino-1,6-diphenyl-3-hexanol were synthesized and characterized. All of them exhibit tight binding to HIV-1 protease, with inhibition constants Ki in the range 20 p m-5 n m. The investigated inhibitors were crystallized, and their crystal structures were determined by X-ray diffraction. In all cases, the conformations found in the crystalline state differ significantly from the conformations obtained by computational docking of the inhibitor in the binding cleft of native HIV-1 protease. Owing to the prevalence of hydrophobic substituents in all these inhibitors, the conformational mobility in water solution is restricted to their compact forms. The spectrum of low-energy conformations in solution dramatically changes during the formation of inhibitor crystals (phenyl ring stacking as a leading motif) or during the formation of a complex with HIV-1 protease (elongated conformation suitable to fit the enzyme pockets as a factor responsible for tight binding). High conformational flexibility and low conformational stress in the molecules of these inhibitors most likely increase their biological activity in comparison with more rigid compounds. [ABSTRACT FROM AUTHOR]

Kutílek Š, Skálová S, Vethamuthu J, Geier P, Feber J. Transient hyperphosphatasemia in pediatric renal transplant patients - Is there a need for concern and when? Pediatr Transplantation 2012: 16: E5-E9. © 2010 John Wiley & Sons A/S. Abstract: TH of infancy and early childhood is characterized by transiently increased S-ALP, predominantly its bone or liver isoforms. There are neither signs of metabolic bone disease or hepatopathy corresponding to the increased S-ALP, nor a common underlying/triggering disease. TH may also occur in children post-renal Tx, which may raise significant concerns and anxiety. We describe four patients aged 2.8-7 yr in whom the TH occurred at 11-34 (median = 28) months after Tx and lasted from 40 to 105 (median = 63) days. No obvious cause/trigger of TH could be found; the clinical status and bone turnover were not altered. In cases of TH post-Tx, we recommend the evaluation of basic biochemical indices and wrist X-ray. If these results are normal, TH is most likely the diagnosis and the S-ALP can be monitored over the next three months without further testing. In patients with persisting TH for more than three months and/or in children with pre-existing or suspected metabolic bone disease, further evaluation may be indicated. In conclusion, TH is a benign disorder in patients post-Tx. Detailed investigation including bone biopsy is only indicated in patients with persisting TH. [ABSTRACT FROM AUTHOR]

The paper reports the structure of the small laccase from Streptomyces coelicolor determined from a crystal soaked with potassium hexacyanoferrate [K4Fe(CN)6]. The decolorization of the natively blue crystal observed upon soaking indicates the reduction of the enzyme in the crystal. The ligand binds between laccase molecules and stabilizes the crystal. The increased diffraction limit of the diffraction data collected from this crystal enabled the refinement of the small laccase structure at 2.3 Å resolution, which is the highest resolution obtained to date. [ABSTRACT FROM AUTHOR]

The endonuclease TBN1 from Solanum lycopersicum (tomato) was expressed in Nicotiana benthamiana leaves and purified with suitable quality and in suitable quantities for crystallization experiments. Two crystal forms (orthorhombic and rhombohedral) were obtained and X-ray diffraction experiments were performed. The presence of natively bound Zn2+ ions was confirmed by X-ray fluorescence and by an absorption-edge scan. X-ray diffraction data were collected from the orthorhombic (resolution of 5.2 Å) and rhombohedral (best resolution of 3.2 Å) crystal forms. SAD, MAD and MR methods were applied for solution of the phase problem, with partial success. TBN1 contains three Zn2+ ions in a similar spatial arrangement to that observed in nuclease P1 from Penicillium citrinum. [ABSTRACT FROM AUTHOR]

Weinreb I, Simpson R H, Skálová A, Perez-Ordoñez B, Dardick I, Chetty R & Hunt J L (2010) Histopathology , 707-715 To describe a salivary adenoma composed largely of unilayered ducts resembling striated ducts, and to differentiate it from similar adenomas, including canalicular and intercalated duct adenoma. Six unilayered ductal adenomas were identified in parotid (four) and palate (two). They were encapsulated, ranged from 0.5 to 3.0 cm and composed of closely apposed ducts with virtually no stroma. The ducts varied in size and showed cysts up to 0.1 cm. The cells were eosinophilic and bland. Prominent cell membranes, reminiscent of 'striations' of normal striated ducts, were seen. The typical epithelial 'beading' pattern with abundant stroma of canalicular adenoma was absent. The tumours expressed keratins (six of six) and S100 (five of six). Smooth muscle actin (SMA) revealed no myoepithelial cells. Two tumours showed focal bilayered ducts with calponin or smooth muscle myosin heavy chain, but the tumours were largely unilayered. Only isolated cells in three tumours were positive with p63; a pattern identical to striated ducts. In contrast, the normal excretory and intercalated ducts all contained diffuse bilayering with basal or myoepithelial markers. Striated duct adenomas are unilayered ductal tumours that recapitulate normal striated ducts. [ABSTRACT FROM AUTHOR]