The glomerulus – a view from the outside – the podocyte

In the past decade, podocyte research has been greatly aided by the development of powerful new molecular, cellular and animal tools, leading to elucidation of an increasing number of proteins involved in podocyte function and identification of mutated genes in hereditary glomerulopathies. Accumulating evidence indicates that podocyte disorders may not only underlie these hereditary glomerulopathies but also play crucial role in a broad spectrum of acquired glomerular diseases. Genetic susceptibility, environmental influence and systemic responses are all involved in the mediation of the pathogenesis of podocytopathies. Injured podocytes may predisopose to further injury of other podocytes and other adjacent/distant renal cells in a vicious cycle, leading to inexorable progression of glomerular injury. The classic view is that podocytes have a limited ability to proliferate in the normal mature kidney. However, recent research in rodents has provided suggestive evidence for podocyte regeneration resulting from differentiation of progenitor cells within Bowman's capsule.     

Aquatic protostelids – a study from northeastern Germany

A survey of protostelids in ponds of northeastern Germany showed a high degree of similarity between the species assemblages from submerged aquatic and terrestrial litter. Twelve species were recovered from 115 samples. A statistical analysis of species accumulation curves indicated that 90 % of the total diversity was recovered for both aquatic and terrestrial litter. All of the more common species were observed in both aquatic and terrestrial samples. However, 24 % of all cultures from terrestrial samples were positive for protostelids, compared with only 12 % for aquatic samples. An additional 20 samples collected from the water column did not yield any protostelids. The study indicates that vegetative stages of most protostelids seem to be able to survive and probably multiply on litter submerged in fresh water, but do not live as plankton. Most probably, submerged substrata are sinks for protostelid populations.     

Health migration from Norway to Spain – ambiguous belonging

Abstract

In line with Gustafson (2008), most studies of transnationalism have investigated migration from south to north. This article examines health-, welfare- and lifestyle-related migration from Norway to Spain. The phenomenon is increasing, with consequences for national and municipal policies. The focus is on how Norwegian health migrants cope. Based on anthropological fieldwork and life story interviews we ask: Who are these migrants? How did the migration step come into being? How do they cope when the decision is effectuated? What kind of identity-related challenges do they face? The article also discusses implications for future comparative research on the phenomenon.     

Hydromorphology – major results and conclusions from the STAR project

The major results and conclusions of the two papers in the hydromorphology section of the Hydrobiologia special issue on the EU STAR project are summarised. Several key findings have emerged from this research. Firstly, the hydromorphological characteristics of rivers between different geographical regions of Europe were found to vary considerably with rivers in each region possessing distinctive hydromorphological characteristics. Secondly, the hydromorphological attributes that most strongly influence two existing hydromorphological indices (the Habitat Quality Assessment and the Habitat Modification Score) were identified and attention was drawn to the accurate definition and recording of these attributes in field surveys and training courses. Thirdly, links between hydromorphological characteristics and macroinvertebrate quality indices were investigated. Two types of bank modification (resectioning and reinforcement) were significantly correlated with two biotic indices (EPT taxa and MTS), while channel modifications were negatively correlated with ASPT. While biotic indices were often strongly correlated with Habitat Quality Assessment they were less strongly related to Habitat Modification Score suggesting that physical habitat diversity may be more important in determining macroinvertebrate community structure than morphological alteration. The papers in this section provide important underpinning research for the implementation of the European Water Framework Directive. In both papers suggestions are made for further research on the hydromorphology of European rivers.     

Antimony-Oxidizing Bacteria Isolated from Antimony-Contaminated Sediment – A Phylogenetic Study

Twelve antimony-resistant bacteria were isolated from sediment collected in the vicinity of an antimony oxide-producing factory in Korea. Eight of these strains were heterotrophic Sb(III)-oxidizing bacteria. Phylogenetic study showed that the Sb(III)-oxidizing bacteria fell within two subdivisions of Proteobacteria. Cupriavidus sp. NL4 and Comamonas sp. NL11 belong to the subdivision β-Proteobacteria. Acinetobacter sp. NL1, Acinetobacter sp. NL12, Pseudomonas sp. NL2, Pseudomonas sp. NL5, Pseudomonas sp. NL6, and Pseudomonas sp. NL10 are the members of the γ-subdivision of the Proteobacteria. Among them, Cupriavidus sp. NL4 completely oxidized 100 μmoles of Sb(III) per liter of medium in 500 h, while the other strains were not able to oxidize all of the Sb(III) in the medium, even with longer incubation. The results imply that diverse bacterial lineages are able to detoxify sites polluted with Sb(III) by oxidizing it to Sb(V), and to contribute to antimony cycling in natural environments.     

MARMoSET – Extracting Publication-ready Mass Spectrometry Metadata from RAW Files

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Highlights

• •Automated metadata extraction from potentially large sets of mass spectrometric raw data.
• •Reduction of extracted metadata into groups of shared parameter sets.
• •Tabular representation for quality control, reporting and publication.

     

Neuronal Avalanches Differ from Wakefulness to Deep Sleep – Evidence from Intracranial Depth Recordings in Humans

Neuronal activity differs between wakefulness and sleep states. In contrast, an attractor state, called self-organized critical (SOC), was proposed to govern brain dynamics because it allows for optimal information coding. But is the human brain SOC for each vigilance state despite the variations in neuronal dynamics? We characterized neuronal avalanches – spatiotemporal waves of enhanced activity - from dense intracranial depth recordings in humans. We showed that avalanche distributions closely follow a power law – the hallmark feature of SOC - for each vigilance state. However, avalanches clearly differ with vigilance states: slow wave sleep (SWS) shows large avalanches, wakefulness intermediate, and rapid eye movement (REM) sleep small ones. Our SOC model, together with the data, suggested first that the differences are mediated by global but tiny changes in synaptic strength, and second, that the changes with vigilance states reflect small deviations from criticality to the subcritical regime, implying that the human brain does not operate at criticality proper but close to SOC. Independent of criticality, the analysis confirms that SWS shows increased correlations between cortical areas, and reveals that REM sleep shows more fragmented cortical dynamics.     

Bioenergy from permanent grassland – A review: 1. Biogas

Grassland biomass is suitable in numerous ways for producing energy. It is well established as feedstock for biogas production. The aim of this review is to summarize current knowledge on suitability and sustainability of grassland biomass for anaerobic digestion. In the first section grassland management for biogas feedstock as well as specifics of harvest, postharvest and digestion technology are described. Methane yields from grass are influenced by many factors. While the effects of some parameters such as grass species, cutting period and management intensity can be regarded as well known, other parameters such as preservation and processing still need investigation. In the second section economic aspects and environmental impacts are discussed. Profitability can be achieved depending on grass silage supply costs and the concept of anaerobic digestion and energy use. Grassland biomass for biogas production competes with other feedstock and other forms of grassland use, in particular animal husbandry. In developed countries a growing production of milk and meat is achieved with decreasing ruminant numbers, resulting in an increasing amount of surplus grassland with a remarkable bioenergy potential. In emerging and developing countries a rapidly rising demand for and production of milk and meat induce growing pressure on grasslands, so that their use for animal feed presumably will take priority over use for bioenergy. Grasslands provide a variety of essential environmental benefits such as carbon storage, habitat function, preservation of ground and surface water quality. When producing biogas from grassland these benefits will remain or even grow, providing appropriate grassland management is implemented. In particular, greenhouse gas emissions can be considerably reduced.     

Microbial hydantoinases – industrial enzymes from the origin of life?

Hydantoinases are valuable enzymes for the production of optically pure d- and l-amino acids. They catalyse the reversible hydrolytic ring cleavage of hydantoin or 5′-monosubstituted hydantoins and are therefore classified in the EC nomenclature as cyclic amidases (EC 3.5.2.). In the EC nomenclature, four different hydantoin-cleaving enzymes are described: dihydropyrimidinase (3.5.2.2), allantoinase (EC 3.5.2.5), carboxymethylhydantoinase (EC 3.5.2.4), and N-methylhydantoinase (EC 3.5.2.14). Beside these, other hydantoinases with known metabolic functions, such as imidase and carboxyethylhydantoinase and enzymes with unknown metabolic function, are described in the literature and have not yet been classified. An important question is whether the distinct hydantoinases, which are frequently classified as l-, d-, and non-selective hydantoinases depending on their substrate specificity and stereoselectivity, are related to each other. In order to investigate the evolutionary relationship, amino acid sequence data can be used for a phylogenetic analysis. Although most of these enzymes only share limited sequence homology (identity<15%) and therefore are only distantly related, it can be shown (i) that most of them are members of a broad set of amidases with similarities to ureases and build a protein superfamily, whereas ATP-dependent hydantoinases are not related, (ii) that the urease-related amidases have evolved divergently from a common ancestor and (iii) that they share a metal-binding motif consisting of conserved histidine residues. The difference in enantioselectivity used for the classification of hydantoinases on the basis of their biotechnological value does not reflect their evolutionary relationship, which is to a more diverse group of enzymes than was assumed earlier. This protein superfamily probably has its origin in the prebiotic conditions of the primitive earth. Received: 24 August 1998 / Received revision: 9 November 1998 / Accepted: 21 November 1998     

Young ISHAM – Uniting Young Scientists from all over the World

The Young section of the International Society of Human and Animal Mycology (= Young ISHAM), was established for connecting young scientists and representing their needs within the society. Discussing practical issues and providing support helps especially PhD student dealing with ups and downs in science. We are developing resources related to scientific publishing and reviewing, publishing ethics, funding and grant application skills, career building, and presentation techniques. Young ISHAM will help younger scientists in all aspects of their scientific career, to ensure that a new generation of medical mycologists is prepared to engage with the challenges within our field.     

The polyphyly of Neotragus – Results from genetic and morphometric analyses

Dwarf antelope species were commonly united in the tribe “Neotragini” (Bovidae, Mammalia) due to their general morphological appearance. However, phylogenetic analyses have shown that not all dwarf antelopes are closely related, so it was suggested to restrict the name Neotragini to the type genus Neotragus. In our study we use mitochondrial cytochrome b sequences and linear skull measurements to further investigate the similarity of all three Neotragus species. Our analyses support the close relationship of N. moschatus and N. batesi. However, N. pygmaeus – the type species, which was never before included in phylogenetic analyses – is not closely related. It might share a most recent common ancestor with another “dwarf antelope”, the Klipspringer Oreotragus oreotragus, and the duikers in the taxon Cephalophini. Hence, we suggest resurrecting the genus Nesotragus von Dueben, 1846 for Nesotragus moschatus and N. batesi.     

Angioleiomyosarcoma – a very rare malignant tumour from the soft tissue

In the article we describe a case of a 12-year old boy with the tumour in the small pelvis. The only one abnormality in laboratory tests was a 3-numeral ESR and a big solid tumour probably extended from the urine bowel, found on radiological examination. On surgery the tumour was found to extend from the ascendent colon. On pathological examination, it was described as angioleiomyosarcoma with metastases in the lymph nodes. The boy was treated with IX courses consisting of ifosfamide, vepeside or ifosfamide, adriamycine and vincristine. At present, the child is in the first complete remission, 7 months after completion chemotherapy.     

Metal mobilization from soils by phytosiderophores – experiment and equilibrium modeling

Aims

To test if multi–surface models can provide a soil-specific prediction of metal mobilization by phytosiderophores (PS) based on the characteristics of individual soils.

Methods

Mechanistic multi-surface chemical equilibrium modeling was applied for obtaining soil-specific predictions of metal and PS speciation upon interaction of the PS 2’-deoxymugineic acid (DMA) with 6 soils differing in availability of Fe and other metals. Results from multi-surface modeling were compared with empirical data from soil interaction experiments.

Results

For soils in which equilibrium was reached during the interaction experiment, multi-surface models could well predict PS equilibrium speciation. However, in uncontaminated calcareous soils, equilibrium was not reached within a week, and experimental and modeled DMA speciation differed considerably. In soils with circum-neutral pH, on which Fe deficiency is likely to occur, no substantial Fe mobilization by DMA was predicted. However, in all but the contaminated soils, Fe mobilization by DMA was observed experimentally. Cu and Ni were the quantitatively most important metals competing with Fe for complexation and mobilization by DMA.

Conclusion

Thermodynamics are unable to explain the role of PS as Fe carrier in calcareous soils, and the kinetic aspects of metal mobilization by PS need to be closer examined in order to understand the mechanisms underlying strategy II Fe acquisition.     

‘Heparin’ – from anticoagulant drug into the new biology

This overview attempts to cover, from a personal viewpoint, the development of the heparin field during the last four decades. In particular, it emphasizes the metamorphosis of heparan sulfate (HS), from a disturbing contaminant in heparin production to the present-day key player in cell and developmental biology. Our understanding of the structural properties of the polysaccharides has been greatly promoted by studies of their biosynthesis. We now have a fairly detailed view of the various enzymatic reactions, that convert the initial [4GlcA1-4GlcNAc1-]_n polymer into sulfated products with highly variable proportions of GlcA/IdoA and of N-acetyl, N-sulfate and O-sulfate substituents. It is also recognized that the variously substituted domains of the polysaccharide serve to interact, in more or less specific fashion, with a multitude of proteins, and that these interactions are essential to the biological functions of the proteins. Molecular genetics has unravelled the gene structures for almost all of the enzymes required to synthesize a heparin or HS chain, and has shown that several of these proteins exhibit genetic polymorphism. While differences in substrate specificity between enzyme isoforms may help to explain the structural variability of, in particular, HS chains, we still only partly understand the key features of heparin/HS biosynthesis and its regulation.     

Characterization of haemoglobin from Actinorhizal plants – An in silico approach

Plant haemoglobins (Hbs), found in both symbiotic and non-symbiotic plants, are heme proteins and members of the globin superfamily. Hb genes of actinorhizal Fagales mostly belong to the non-symbiotic type of haemoglobin; however, along with the non-symbiotic Hb, Casuarina sp. posses a symbiotic one (symCgHb), which is expressed specifically in infected cells of nodules. A thorough sequence analysis of 26 plant Hb proteins, currently available in public domain, revealed a consensus motif of 29 amino acids. This motif is present in all the members of symbiotic class II Hbs including symCgHb and non-symbiotic Class II Hbs, but is totally absent in Class I symbiotic and non-symbiotic Hbs. Further, we constructed 3D structures of Hb proteins from Alnus and Casuarina through homology modelling and peeped into their structural properties. Structure-based studies revealed that the Casuarina symbiotic haemoglobin protein shows distinct stereochemical properties from that of the other Casuarina and Alnus Hb proteins. It also showed considerable structural similarities with leghemoglobin structure from yellow lupin (pdb id 1GDI). Therefore, sequence and structure analyses point to the fact that symCgHb protein shows significant resemblance to symbiotic haemoglobin found in legumes and may thus eventually play a similar role in shielding the nitrogenase from oxygen as seen in the case of leghemoglobin.     

Druggable protein–protein interactions – from hot spots to hot segments

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Macrophytes and diatoms – major results and conclusions from the STAR project

The interactions between sensitivity and variability of macrophyte and diatom communities were evaluated as a research support of methodologies required by the Water Framework Directive. Slope and shading were identified as additional typological parameters improving links between unimpacted macrophyte communities and running water types. Two other studies demonstrated indication value of macrophytes for assessment of nutrient enrichment and hydromorphological degradation. The special exercises were realized within the STAR project to evaluate sources of variability/uncertainty in assessment methods based on macrophytes and diatoms. Sampling period and shading of the site were found as major factors affecting variability in macrophyte assessment results. Uncertainty of diatom assessment is predominantly associated with selection of site, substrate type and taxonomic identification. Further extension of indication systems and definition of macrophyte/diatom-specific typology of running waters are considered as the main aims of subsequent investigations.