Early production of IL-22 but not IL-17 by peripheral blood mononuclear cells exposed to live Borrelia burgdorferi: the role of monocytes and interleukin-1

If insufficiently treated, Lyme borreliosis can evolve into an inflammatory disorder affecting skin, joints, and the CNS. Early innate immunity may determine host responses targeting infection. Thus, we sought to characterize the immediate cytokine storm associated with exposure of PBMC to moderate levels of live Borrelia burgdorferi. Since Th17 cytokines are connected to host defense against extracellular bacteria, we focused on interleukin (IL)-17 and IL-22. Here, we report that, despite induction of inflammatory cytokines including IL-23, IL-17 remained barely detectable in response to B. burgdorferi. In contrast, T cell-dependent expression of IL-22 became evident within 10 h of exposure to the spirochetes. This dichotomy was unrelated to interferon-γ but to a large part dependent on caspase-1 and IL-1 bioactivity derived from monocytes. In fact, IL-1β as a single stimulus induced IL-22 but not IL-17. Neutrophils display antibacterial activity against B. burgdorferi, particularly when opsonized by antibodies. Since neutrophilic inflammation, indicative of IL-17 bioactivity, is scarcely observed in Erythema migrans, a manifestation of skin inflammation after infection, protective and antibacterial properties of IL-22 may close this gap and serve essential functions in the initial phase of spirochete infection.     

Factors influencing α-tocopherol synthesis in pepper fruits

Determination of vitamin E in the fruit pericarp of green, yellow and red varieties of Capsicum annuum L. from the local market points to a parallel accumulation in pepper fruits of α-tocopherol with secondary carotenoids and triacylglycerols enriched in unsaturated fatty acids. Highest α-tocopherol concentrations of about 400 nmol per g of dry weight have been found in red fruits. Ripe yellow and red pepper fruits grown under greenhouse conditions were smaller and contained lower α-tocopherol contents than corresponding ones from the local market. An approximation to the α-tocopherol levels in market fruits has been observed, however, if the green plants had been treated with the bleaching herbicide norflurazone before fruit ripening, affecting the carotenoid pathway. Optimum herbicide efficiency has been obtained via watering of the green plants. In ripe fruits of the yellow and red varieties α-tocopherol contents were paralleled by increasing γ-tocopherol methyltransferase activities. In chromoplast preparations from pepper, methylation capacities have been found for γ- and δ-tocopherol as well as for the structurally related tocotrienols, the diterpene side chain of which consists of a geranylgeranyl- instead of the reduced phytyl residue found in tocopherols. β-Tocopherol was not methylated, which supports the position-specific methylation of prenylquinones at the 5 position of the tocopherol aromatic headgroup.     

Spinicaudata (“Conchostraca,” Crustacea) from the Middle Keuper (Upper Triassic) of the southern Germanic Basin,with a review of Carnian–Norian taxa and suggested biozones

The Coburg Sandstone member of the Hassberge Formation, Middle Keuper, Carnian, Upper Triassic, in the Germanic Basin of Central Europe contains spinicaudatan branchiopods which considerably broaden the known spectrum and provide important data on the phylogenetic history and intercontinental correlation of this systematic group. The spinicaudatan fauna for this lithostratigraphic unit is described in detail and includes Euestheria kozuri sp. nov., E.? sp. nov. A, Gregoriusella striatula sp. nov., Laxitextella freybergi Kelber and Kozur in Kozur and Weems, 2007, L. dorsorecta (Reible, 1962), and Laxitextella? sp. A. Additional discussions deal with Euestheria multicostata (Geyer, 1987), E. winterpockensis (Bock, 1953a), Laxitextella laxitexta (Sandberger in Jones, 1890), Laxitextella multireticulata (Reible, 1962), and “Laxitextella? hausmanni (Schmidt, 1938),” as well as problems with (sub)global zonations that are based on spinicaudatans and suggested to be of Carnian and Norian age.     

Metal Ion Concentrations in Body Fluids after Implantation of Hip Replacements with Metal-on-Metal Bearing – Systematic Review of Clinical and Epidemiological Studies

Introduction

The use of metal-on-metal (MoM) total hip arthroplasty (THA) increased in the last decades. A release of metal products (i.e. particles, ions, metallo-organic compounds) in these implants may cause local and/or systemic adverse reactions. Metal ion concentrations in body fluids are surrogate measures of metal exposure.

Objective

To systematically summarize and critically appraise published studies concerning metal ion concentrations after MoM THA.

Methods

Systematic review of clinical trials (RCTs) and epidemiological studies with assessment of metal ion levels (cobalt, chromium, titanium, nickel, molybdenum) in body fluids after implantation of metalliferous hip replacements. Systematic search in PubMed and Embase in January 2012 supplemented by hand search. Standardized abstraction of pre- and postoperative metal ion concentrations stratified by type of bearing (primary explanatory factor), patient characteristics as well as study quality characteristics (secondary explanatory factors).

Results

Overall, 104 studies (11 RCTs, 93 epidemiological studies) totaling 9.957 patients with measurement of metal ions in body fluids were identified and analyzed. Consistently, median metal ion concentrations were persistently elevated after implantation of MoM-bearings in all investigated mediums (whole blood, serum, plasma, erythrocytes, urine) irrespective of patient characteristics and study characteristics. In several studies very high serum cobalt concentrations above 50 µg/L were measured (detection limit typically 0.3 µg/L). Highest metal ion concentrations were observed after treatment with stemmed large-head MoM-implants and hip resurfacing arthroplasty.

Discussion

Due to the risk of local and systemic accumulation of metallic products after treatment with MoM-bearing, risk and benefits should be carefully balanced preoperatively. The authors support a proposed „time out“ for stemmed large-head MoM-THA and recommend a restricted indication for hip resurfacing arthroplasty. Patients with implanted MoM-bearing should receive regular and standardized monitoring of metal ion concentrations. Further research is indicated especially with regard to potential systemic reactions due to accumulation of metal products.     

Structural response of Photosystem 2 to iron deficiency: characterization of a new photosystem 2-IdiA complex from the cyanobacterium Thermosynechococcus elongatus BP-1

Iron deficiency triggers various processes in cyanobacterial cells of which the synthesis of an additional antenna system (IsiA) around photosystem (PS) 1 is well documented [T.S. Bibby, J. Nield, J. Barber, Iron deficiency induces the formation of an antenna ring around trimeric photosystem I in cyanobacteria, Nature 412 (2001) 743-745, E.J. Boekema, A. Hifney, A.E. Yakushevska, M. Piotrowski, W. Keegstra, S. Berry, K.P. Michel, E.K. Pistorius, J. Kruip, A giant chlorophyll-protein complex induced by iron deficiency in cyanobacteria, Nature 412 (2001) 745-748]. Here we show that PS2 also undergoes prominent structural changes upon iron deficiency: Prerequisite is the isolation and purification of a PS2-IdiA complex which is exclusively synthesized under these conditions. Immunoblotting in combination with size exclusion chromatography shows that IdiA is only bound to dimeric PS2. Using single particle analysis of negatively stained specimens, IdiA can be localized in averaged electron micrographs on top of the CP43 subunit facing the cytoplasmic side in a model derived from the known 3D structure of PS2 [B. Loll, J. Kern, W. Saenger, A. Zouni, J. Biesiadka, Towards complete cofactor arrangement in the 3.0 A resolution structure of photosystem II, Nature 438 (2005) 1040-4]. The presence of IdiA as integral part of PS2 is the first example of a new PS2 protein being expressed under stress conditions, which is missing in highly purified PS2 complexes isolated from iron-sufficient cells.     

Protein folding and the robustness of cells

The intricate intracellular infrastructure of all known life forms is based on proteins. The folded shape of a protein determines both the protein's function and the set of molecules it will bind to. This tight coupling between a protein's function and its interconnections in the molecular interaction network has consequences for the molecular course of evolution. It is also counter to human engineering approaches. Here we report on a simulation study investigating the impact of random errors in an abstract metabolic network of 500 enzymes. Tight coupling between function and interconnectivity of nodes is compared to the case where these two properties are independent. Our results show that the model system under consideration is more robust if function and interconnection are intertwined. These findings are discussed in the context of nanosystems engineering.     

A <Emphasis Type="Italic">Synechococcus elongatus</Emphasis> PCC 7942 mutant with a higher tolerance toward the herbicide bentazone also confers resistance to sodium chloride stress

Following a N-methyl-N'-nitro-N-nitrosoguanidine-based mutagenesis of Synechococcus elongatus PCC 7942 wild type, we were able to select several mutants with an enhanced tolerance toward the herbicide bentazone (3-isopropyl-1H-2,1,3-benzothiadiazine-4(3H)-one 2,2-dioxide). Mutant Mu1 has in part been previously characterized. In the present paper we report on another mutant, called Mu2, which also has a higher tolerance toward bentazone. Since Mu2 showed a better growth than WT when cultivated with elevated NaCl concentrations in the growth medium and since S. elongatus WT has previously been classified to be low salt tolerant, we were especially interested in the identification of the modifications conferring this higher salt tolerance to mutant Mu2. Immunoblot analyses provided evidence that Mu2 had a constitutively higher expression of PsbO and of IsiA. In addition, in Mu2 a significantly higher concentration of IdiA was detected under salt stress as compared to WT. These three proteins most likely contribute to a better protection and/or stabilization of photosystem II. Moreover, Mu2 had a higher amount of the photosystem I reaction center proteins PsaAB under salt stress than WT. In addition, the amount of the ferredoxin:NADP+ oxidoreductase and also of the ATP synthase was constitutively higher in Mu2 than in WT. In contrast to WT the latter two proteins did not decrease under salt stress in Mu2. Therefore, it can be assumed that Mu2 could maintain a high cyclic electron transport activity around photosystem I under salt stress. It can be assumed that the combination of these modifications of the electron transport chain cause a better protection of photosystem II against oxidative damage and cause an increase of cyclic electron transport activity around photosystem I with ATP synthesis. Thus, the overall cellular energization in Mu2 relative to WT is improved. Together with putative other not yet identified modifications this seems to enable Mu2 to energize its cytoplasmic membrane-localized ion pumps more effectively than WT and, as a consequence, to keep the intracellular NaCl concentration low.     

The effects of acute corticosterone on lithium chloride-induced conditioned place aversion and locomotor activity in rats

Acute administration of corticosterone (CORT) facilitates learning in a number of associative paradigms including lithium chloride (LiCl)-induced conditioned taste aversion learning. The present study examined the effects of acute CORT on LiCl-induced conditioned place aversions in male rats. Automated open-fields were partitioned into two chambers distinct in tactile and visual cues. Animals received either LiCl (64 mg/kg, 0.15 M) or saline (NaCl, 0.15 M) followed 10 min later by either CORT (5 mg/kg) or beta-cyclodextrin vehicle (45%) prior to placement in one of the chambers. Control rats received NaCl-Vehicle paired with both chambers. Three experimental groups received either NaCl-CORT, LiCl-Vehicle or LiCl-CORT paired with the preferred chamber and NaCl-Vehicle (control) paired with the non-preferred chamber. During extinction trials, animals were allowed to choose between the two chambers. Locomotor activity and its distribution within the chambers were assessed during both conditioning and extinction trials. CORT administration produced significant increases in a variety of measures of locomotor activity during conditioning trials. During extinction trials both LiCl groups displayed a conditioned place aversion while the NaCl-CORT group did not. In addition, significant increases in vertical activity were recorded in both LiCl groups in the LiCl-paired chamber. Moreover, CORT administration had no effect on LiCl-induced conditioned place aversion as time spent in the LiCl-paired chamber did not significantly differ between LiCl-Vehicle and LiCl-CORT groups. Significant increases in a number of measures of horizontal activity were also observed in both CORT groups. The present study shows that acute CORT administration does not significantly influence LiCl-induced conditioned place aversions and suggests that the facilitatory effects of acute CORT administration on learning are highly context-dependent.     

Magnetic field perception in the Rainbow Trout, <Emphasis Type="Italic">Oncorhynchus</Emphasis> <Emphasis Type="Italic">mykiss</Emphasis>

In this study, we present evidence for the perception of different magnetic field parameters in a facultative anadromous fish species of the family Salmonidae. Magnetic field perception of the rainbow trout, Oncorhynchus mykiss, was demonstrated with a heartbeat conditioning test. The electrocardiogram was measured with subcutaneously inserted silver wire electrodes in freely swimming fish. We demonstrate a conditioned response (i.e. a significant longer interval between two heartbeats) to an intensity/inclination shift for three adult and two juvenile rainbow trouts. Moreover, a conditioned response to a 90° direction shift was demonstrated for three adult and two juvenile trouts. These findings support the hypothesis that the rainbow trout is able to perceive different magnetic field parameters. Furthermore, the study demonstrates magnetosensation in different developmental stages in the rainbow trout, i.e. juvenile and adult fish.     

Formation and degradation of lipid bodies found in the riboflavin-producing fungus Ashbya gossypii

Microdroplets in the hyphae of Ashbya gossypii were found to become stained by Nile red. Purification of the stainable substance showed that the yellow fluorescent bodies consisted of triacylglycerol. During growth on glucose as the carbon source 8%–12% of the mycelial dry weight was found to be neutral lipid. When glucose declined in the medium, the content decreased to 3%–4% and the respiration quotient shifted to 0.6 indicating a reserve function of the fat. The fatty acid composition of the storage lipid was found to be strongly influenced by the carbon source. Mycelia cultivated on glucose contained 5% linoleic acid and 20% palmitoleic acid in their neutral fat while linoleic acid made up 54% and palmitoleic acid was not detectable (< 0.1%) in soybean-oil-grown mycelia. When plant oil was given as the sole carbon source, the fatty acid composition of the storage lipid showed a high similarity to the fed fat. ¹⁴C-labelled free oleic acid added to a culture growing on soybean oil was immediately incorporated into the fungal lipid. A pulse of 0.9 g/l free palmitoleic acid, fed during growth on olive oil, increased the content of this particular fatty acid in the fungal triacylglycerol from 0.8% to 9.6%. In addition, a liberation of free fatty acid and diacylglyceride was found in the culture supernatant when pure triolein was given as the sole carbon source. Obviously, the fungus cleaved the lipid serving as the carbon source extracellularly and used the liberated fatty acids for its storage lipid formation.This paper is dedicated to Prof. Dr. F. Wagner on the occasion of his 65th birthday