Pathology of Anopheles stephensi after infection with Plasmodium berghei berghei. II. Changes in amino acid contents.

Infection with Plasmodium berghei results in the disease of a relatively high percentage of mosquitoes depending on the experimental conditions. The damage caused by the parasites may be so severe that the host dies. It can also become manifest for instance in a change in the amino acid content of the mosquito homogenate. The amino acid content of mosquitoes fed on a glucose solution, normal mouse blood, or the blood of infected mice was analysed qualitatively and quantitatively over a period of 14 days. The amino acids lysine, phenylalanine, proline, threonine, and tyrosine are always found in higher concentrations in infected mosquitoes. The content of leucine (and/or isoleucine) increased from the 6th day and glutamic acid from the 9th day compared to the controls. Lower concentrations were found for alanine, aspartic acid, glycine, and serine as compared to uninfected mosquitoes. Further investigations on this subject might help to find the causes for the susceptibility or resistance of individual mosquitoes to plasmodia.     

Transfer of Natural Micro Structures to Bionic Lightweight Design Proposals

The abstraction of complex biological lightweight structure features into a producible technical component is a funda- mental step within the transfer of design principles from nature to technical lightweight solutions. A major obstacle for the transfer of natural lightweight structures to technical solutions is their peculiar geometry. Since natural lightweight structures possess irregularities and often have extremely complex forms due to elaborate growth processes, it is usually necessary to simplify their design principles. This step of simplification/abstraction has been used in different biomimetic methods, but so far, it has an arbitrary component, i.e. it crucially depends on the competence of the person who executes the abstraction. This paper describes a new method for abstraction and specialization of natural micro structures for technical lightweight compo- nents. The new method generates stable lightweight design principles by using topology optimization within a design space of preselected biological archetypes such as diatoms or radiolarian. The resulting solutions are adapted to the technical load cases and production processes, can be created in a large variety, and may be further optimized e.g. by using parametric optimization.     

Prey Selection by the Water Bug Aphelocheirus aestivalis Fabr. (Heteroptera: Aphelocheiridae)

Feeding experiments were conducted in situ in flow through boxes to determine the vulnerability of different prey types (the mayfly larvae Baetis, Ephemerella and Ecdyonurus spp., the caddisfly larva Hydropsyche spp. and the crustacean Gammarus spp.) to the predaceous water bug Aphelocheirus aestivalis and to estimate the predation impact of Aphelocheirus on prey populations. Experiments with equal densities of mixed prey and experiments where each prey was tested individually revealed that Baetis and Ephemerella were most vulnerable to Aphelocheirus predation: Hydropsyche, Ecdyonurus and Gammarus were little/not preyed upon. The present results suggest that vulnerability of prey depends mainly upon prey mobility and microhabitat overlap between predator and prey and that feeding behaviour of Aphelocheirus resembles more that of megalopterans than of stoneflies. Experiments with different prey densities (120–720 prey m⁻²) showed that the predation rate of Aphelocheirus increased with increasing prey density. Experiments with different substrates documented that mortality rates of prey decreased with increasing substrate complexity. When substrate conditions were complex mortality rates in the control and in the experimental boxes were the same which suggest little importance of Aphelocheirus predation on mayflies in the study site.     

Applicability of various brands of mixed-phase extraction columns for opiate extraction from blood and serum

Four commercially available types of mixed-phase solid-phase extraction (SPE) columns (Bond Elut Certify, Isolute Confirm HCX, Chromabond Drug and Bakerbond Narc-2) were examined in order to compare the extraction efficiencies and chromatographic purity of extracts. The absolute recovery of morphine, 6-monoacetylmorphine and codeine was examined in blood and serum (ten samples each at two concentration levels), using SPE columns of the same batch. GC-MS (ion trap) and HPLC with amperometric detection were used for quantitation. A distinct variability in extraction recovery was observed among the same batches of all brands of SPE columns. All extracts were chromatographically pure and no interfering peaks were observed, neither in GC-MS nor in HPLC examinations, but in some extracts large peaks of plasticizers were identified. The measurements of flow velocities of the same samples of blood or serum through the SPE columns of the same batch showed very large variability of random charactere. The morphometric analysis of particles was performed for two batches of each sort of SPE columns by means of an image analysing system. Symmetrical distribution of particle size was observed only in Chromabond MN Drug packing, while in other cartridges large fractions of fine particles and nonhomogenous distribution were found. Only in one case the morphometric findings were pretty concordant with the data available from the manufacturer; in two cases, observed data varied considerably from the expected, and in one case no information was available at all. The study showed generally that there was room for improvement in the quality of mixed-phase SPE columns.     

The development of 2-benzimidazole substituted pyrimidine based inhibitors of lymphocyte specific kinase (Lck)

This communication details the synthesis, biological activity, and binding mode of a novel class of 2-benzimidazole substituted pyrimidines. The most potent analogs disclosed showed low nanomolar activity for the inhibition of Lck kinase and a representative analog was co-crystallized with Hck (a structurally related member of the Src family kinases).     

High dynamic range characterization of the trauma patient plasma proteome

Although human plasma represents an attractive sample for disease biomarker discovery, the extreme complexity and large dynamic range in protein concentrations present significant challenges for characterization, candidate biomarker discovery, and validation. Herein we describe a strategy that combines immunoaffinity subtraction and subsequent chemical fractionation based on cysteinyl peptide and N-glycopeptide captures with two-dimensional LC-MS/MS to increase the dynamic range of analysis for plasma. Application of this "divide-and-conquer" strategy to trauma patient plasma significantly improved the overall dynamic range of detection and resulted in confident identification of 22,267 unique peptides from four different peptide populations (cysteinyl peptides, non-cysteinyl peptides, N-glycopeptides, and non-glycopeptides) that covered 3,654 different proteins with 1,494 proteins identified by multiple peptides. Numerous low abundance proteins were identified, exemplified by 78 "classic" cytokines and cytokine receptors and by 136 human cell differentiation molecules. Additionally a total of 2,910 different N-glycopeptides that correspond to 662 N-glycoproteins and 1,553 N-glycosylation sites were identified. A panel of the proteins identified in this study is known to be involved in inflammation and immune responses. This study established an extensive reference protein database for trauma patients that provides a foundation for future high throughput quantitative plasma proteomic studies designed to elucidate the mechanisms that underlie systemic inflammatory responses.     

NKG2D-RAE-1 receptor-ligand variation does not account for the NK cell defect in nonobese diabetic mice

NK cells from NOD mice induced with poly(I:C) in vivo exhibit low cytotoxicity against a range of target cells, but the genetic mechanisms controlling this defect are yet to be elucidated. Defects in the expression of NKG2D and its ligands, the RAE-1 molecules, have been hypothesized to contribute to the reduced NK function present in NOD mice. In this study, we show that segregation of the NK-mediated killing phenotype did not correlate with the NOD Raet1 haplotype and that the large alterations in NKG2D expression previously reported on NK cells expanded in vitro were not observed in primary, poly(I:C)-elicited NK cells in vivo. Additional studies indicate a complex genetic control of defective NOD NK cells including genes linked to the MHC and possibly those that are associated with an altered cytokine response to the TLR3-agonist poly(I:C).     

Oxidative stress and lipid mediators induced in alveolar macrophages by ultrafine particles

In ambient aerosols, ultrafine particles (UFP) and their agglomerates are considered to be major factors contributing to adverse health effects. Reactivity of agglomerated UFP of elemental carbon (EC), Printex 90, Printex G, and diesel exhaust particles (DEP) was evaluated by the capacity of particles to oxidize methionine in a cell-free in vitro system for determination of their innate oxidative potential and by alveolar macrophages (AMs) to determine production of arachidonic acid (AA), including formation of prostaglandin E2 (PGE2), leukotriene B4 (LTB4), reactive oxygen species (ROS), and oxidative stress marker 8-isoprostane. EC exhibiting high oxidative potential induced generation of AA, PGE2, LTB4, and 8-isoprostane in canine and human AMs. Printex 90, Printex G, and DEP, showing low oxidative capacity, still induced formation of AA and PGE2, but not that of LTB4 or 8-isoprostane. Aging of EC lowered oxidative potential while still inducing production of AA and PGE2 but not that of LTB4 and 8-isoprostane. Cellular ROS production was stimulated by all particles independent of oxidative potential. Particle-induced formation of AA metabolites and ROS was dependent on mitogen-activated protein kinase kinase 1 activation of cytosolic phospholipase A2 (cPLA2) as shown by inhibitor studies. In conclusion, cPLA2, PGE2, and ROS formation was activated by all particle types, whereas LTB4 production and 8-isoprostane were strongly dependent on particles' oxidative potential. Physical and chemical parameters of particle surface correlated with oxidative potential and stimulation of AM PGE2 and 8-isoprostane production.