A tandem repeats database for bacterial genomes: application to the genotyping of Yersinia pestis and Bacillus anthracis

Background  

Some pathogenic bacteria are genetically very homogeneous, making strain discrimination difficult. In the last few years, tandem repeats have been increasingly recognized as markers of choice for genotyping a number of pathogens. The rapid evolution of these structures appears to contribute to the phenotypic flexibility of pathogens. The availability of whole-genome sequences has opened the way to the systematic evaluation of tandem repeats diversity and application to epidemiological studies.     

Antioxidant enzymes, free-radical damage, and response to paraquat in liver and kidney of long-living growth hormone receptor/binding protein gene-disrupted mice.

Numerous studies have shown that the lifespan can be extended by caloric restriction or by altering the growth hormone (GH)-insulin-like growth factor 1 signaling pathway. Both of these manipulations produce physiological alterations, such as increased insulin sensitivity, and reduced glucose levels and body size. However, it is difficult to evaluate whether these are merely correlates of delayed aging or whether they have a direct causal effect on lifespan. One parameter that has been demonstrated to have causal, positive effects on longevity in invertebrates is improved antioxidant defenses. We measured activities of antioxidant enzymes Cu/Zn superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) and quantified free-radical damage by lipid peroxidation (LP) and protein oxidation (PO) measurements in liver and kidney tissues, and evaluated the response to paraquat-induced oxygen toxicity in the long-living GH receptor/binding protein gene knockout (GHR-KO) mouse. We found that in the kidney, SOD was lower and GPx was higher in GHR-KO mice, and LP was higher in female GHR-KO mice only. In the liver, female GHR-KO mice had lower GPx, while male GHR-KO mice had lower CAT and higher LP. GHR-KO males were also more susceptible to paraquat toxicity compared to females or normal males. We conclude that in long-living GHR-KO mice, GH-resistance does not confer longevity by improved free-radical scavenging in the liver and kidney, suggesting that greater free-radical defenses in other tissues, or altered glucose metabolism may have a more central role in extending the lifespan of these animals.     

Verzeichniss der im Golfe von Triest gesammelten Meeralgen

Ohne Zusammenfassung     

Carbon monoxide uptake and the resulting carboxyhemoglobin in man

In order to calculate the carboxyhemoglobin concentration in human blood under various circumstances and for particular groups or individuals, the model proposed originally by Coburn and coworkers in a slightly revised form was tested. The relevant breathing parameters were measured as minute averages and used for computation of COHb time course. At the same time blood samples were taken and analysed for carboxyhemoglobin. For four different subjects, various breathing conditions and work rates the average deviation of experimental data from theoretical predictions is 7.4%. Some data are presented graphically. Excellent conformity of all the results indicate, that the model is suitable to show the influence of most physiological and breathing parameters on the dynamics of carbon monoxide uptake.     

Rhizophydium Dicksonii Wright

Ohne Zusammenfassung     

Correction to: In vitro cellular and proteome assays identify Wnt pathway and CDKN2A-regulated senescence affected in mesenchymal stem cells from mice after a chronic LD gamma irradiation in utero

Radiation and Environmental Biophysics -     

Cross‐talk between monocyte invasion and astrocyte proliferation regulates scarring in brain injury

Scar formation after brain injury is still poorly understood. To further elucidate such processes, here, we examine the interplay between astrocyte proliferation taking place predominantly at the vascular interface and monocyte invasion. Using genetic mouse models that decrease or increase reactive astrocyte proliferation, we demonstrate inverse effects on monocyte numbers in the injury site. Conversely, reducing monocyte invasion using CCR2^?/? mice causes a strong increase in astrocyte proliferation, demonstrating an intriguing negative cross‐regulation between these cell types at the vascular interface. CCR2^?/? mice show reduced scar formation with less extracellular matrix deposition, smaller lesion site and increased neuronal coverage. Surprisingly, the GFAP⁺ scar area in these mice is also significantly decreased despite increased astrocyte proliferation. Proteomic analysis at the peak of increased astrocyte proliferation reveals a decrease in extracellular matrix synthesizing enzymes in the injury sites of CCR2^?/? mice, highlighting how early key aspects of scar formation are initiated. Taken together, we provide novel insights into the cross‐regulation of juxtavascular proliferating astrocytes and invading monocytes as a crucial mechanism of scar formation upon brain injury.     

Change in the bryophyte diversity and species composition of Central European temperate broad-leaved forests since the late nineteenth century

The diversity and species composition of the bryophyte flora colonizing the forest floor, live trees and deadwood in semi-natural broad-leaved forests of northern Germany was compared between a recent survey in 2013 and historical records from around 1900. The survey was based on the comparison of presence/absence data and their interpretation with help of ecological indicator values. Total species richness has declined in bryophytes growing on the forest floor but not in the other guilds, whereas a dramatic species turnover was found for all three guilds. This turnover was apparently primarily driven by the increased atmospheric load of reactive nitrogen from anthropogenic emissions. Sensitive species were replaced by more eutrophication-tolerant bryophytes; liverworts are overrepresented among the sensitive and thus declining species. Promotion of the competitive strength of vascular plants due to increased nitrogen levels is the likely cause of the reduction of bryophyte species richness on the forest floor. Former acidification by high atmospheric sulfur dioxide loads has left an imprint in the bryophyte vegetation by having favored acidophytic species and discriminating against basiphytic species. An increase in the mean indicator value for temperature suggests a beginning effect of climate warming on the bryophyte vegetation. Change in forest structure had an apparently smaller imprint on the bryophyte diversity of the studied semi-natural forests than atmospheric chemistry and climate. In this respect, bryophytes differ from the ecologically similar lichens, where published studies from the same region showed a dramatic decline of species richness and a stronger susceptibility to forest management.     

Carbon pool densities and a first estimate of the total carbon pool in the Mongolian forest‐steppe

The boreal forest biome represents one of the most important terrestrial carbon stores, which gave reason to intensive research on carbon stock densities. However, such an analysis does not yet exist for the southernmost Eurosiberian boreal forests in Inner Asia. Most of these forests are located in the Mongolian forest‐steppe, which is largely dominated by Larix sibirica. We quantified the carbon stock density and total carbon pool of Mongolia's boreal forests and adjacent grasslands and draw conclusions on possible future change. Mean aboveground carbon stock density in the interior of L. sibirica forests was 66 Mg C ha^?1, which is in the upper range of values reported from boreal forests and probably due to the comparably long growing season. The density of soil organic carbon (SOC, 108 Mg C ha^?1) and total belowground carbon density (149 Mg C ha^?1) are at the lower end of the range known from boreal forests, which might be the result of higher soil temperatures and a thinner permafrost layer than in the central and northern boreal forest belt. Land use effects are especially relevant at forest edges, where mean carbon stock density was 188 Mg C ha^?1, compared with 215 Mg C ha^?1 in the forest interior. Carbon stock density in grasslands was 144 Mg C ha^?1. Analysis of satellite imagery of the highly fragmented forest area in the forest‐steppe zone showed that Mongolia's total boreal forest area is currently 73 818 km², and 22% of this area refers to forest edges (defined as the first 30 m from the edge). The total forest carbon pool of Mongolia was estimated at ~ 1.5?1.7 Pg C, a value which is likely to decrease in future with increasing deforestation and fire frequency, and global warming.     

Extraction, structural characterisation and evaluation of hydroxycinnamate esters of orchard grass (Dactylis glomerata) as substrates for polyphenol oxidase

Polyphenol oxidase (PPO) activity has been reported in orchard grass (Dactylis glomerata); however, to date, no endogenous substrates have been identified. In the present study, we report the isolation and structural elucidation of PPO substrates in this species. The free phenol fraction was extracted, separated by reverse-phase chromatography and six potential substrates, including two hydroxycinnamate esters, were identified by UV spectrometry, electrospray ionisation-tandem mass spectrometry (LC-ESI-MSⁿ) and 1D and 2D NMR analyses (¹H NMR, ¹³C NMR, DEPT, COSY, HMQC and HMBC). Furthermore, three caffeoylquinic acids (3-CQA, 4-CQA and 5-CQA) were identified by comparison of their spectral data (ESI-MS) with those of known compounds and literature data. Five of these compounds were demonstrated to be substrates for orchard grass PPO.