Cellular recognition of trimyristoylated peptide or enterobacterial lipopolysaccharide via both TLR2 and TLR4

Evidence for specific and direct bacterial product recognition through toll-like receptors (TLRs) has been emphasized recently. We analyzed lipopeptide analogues and enterobacterial lipopolysaccharide (eLPS) for their potential to activate cells through TLR2 and TLR4. Whereas bacterial protein palmitoylated at its N-terminal cysteine and N-terminal peptides derived thereof are known to induce TLR2-mediated cell activation, a synthetic acylhexapeptide mimicking a bacterial lipoprotein subpopulation for which N-terminal trimyristoylation is characteristic (Myr(3)CSK(4)) activated cells not only through TLR2 but also through TLR4. Conversely, highly purified eLPS triggered cell activation through overexpressed TLR2 in the absence of TLR4 expression if CD14 was coexpressed. Accordingly, TLR2(-/-) macrophages prepared upon gene targeting responded to Myr(3)CSK(4) challenge, whereas TLR2(-/-)/TLR4(d/d) cells were unresponsive. Through interferon-gamma (IFNgamma) priming, macrophages lacking expression of functional TLR4 and/or MD-2 acquired sensitivity to eLPS, whereas TLR2/TLR4 double deficient cells did not. Not only TLR2(-/-) mice but also TLR4(-/-) mice were resistant to Myr(3)CSK(4) challenge-induced fatal shock. d-Galactosamine-sensitized mice expressing defective TLR4 or lacking TLR4 expression acquired susceptibility to eLPS-driven toxemia upon IFNgamma priming, whereas double deficient mice did not. Immunization toward ovalbumin using Myr(3)CSK(4) as adjuvant was ineffective in TLR2(-/-)/TLR4(-/-) mice yet effective in wild-type, TLR2(-/-), or TLR4(-/-) mice as shown by analysis of ovalbumin-specific serum Ig concentration. A compound such as Myr(3)CSK(4) whose stimulatory activity is mediated by both TLR2 and TLR4 might constitute a preferable adjuvant. On the other hand, simultaneous blockage of both of the two TLRs might effectively inhibit infection-induced pathology.     

Gruppen-Gründung und Reproduktion bei Nacktmullen (Heterocephalus glaber) im Zoo Dresden

When establishing a new breeding group of Naked mole-rats three significant hurdles are to overcome: 1. Determination of sex. 2. Get over the group specific smell (between individuals of different groups). 3. Get over the reproductive blockade. This report describes experiences achieving these goals as well as establishes requirements for a successful breeding. The sex determination of nonreproductive Naked mole rats is tainted with great uncertainty, because the anogenital region of both sexes appears quite similar. For a lack of births and a failure of rearing offspring the following reasons seem to be responsible: 1. Incorrect sex determination at the time of group founding. 2. The reproductive blockade could not be overcome because of disadvantageous hierarchical relations within the group. 3. Pregnancy is interrupted due to disturbances from outside the enclosure or social stress within the group. 4. Due to these disturbances the alpha-female is not often enough willing to suckle her youngsters.     

Pluralizing the Costeños—Reflections on Michael Schroeder’s cultural geographies of grievance and war: Nicaragua’s Atlantic Coast region in the first Sandinista revolution, 1927–1934

In this response article to Michael Schroeder's contribution "Cultural Geographies of Grievance and War: Nicaragua's Atlantic Coast Region in the First Sandinista Revolution, 1927–1934", the author argues that Sandino's limited success in the region was not mainly the result of an erroneous view of the local situation. His main difficulty was the absence of a coherent Atlantic Coast society and culture. In view of the mosaic of heterogeneous groups involved in long-standing rivalries or recent conflicts immersed in the racist environment of the enclave economy, a political project that could have integrated all major population groups was impossible. Sandinista propaganda did not merely consist of lofty nationalist and spiritualist jargon. There were also efforts to address the concrete problems of the people on the Atlantic Coast, such as economic depression and unemployment, and the Moravian missionaries’ attempt to enforce strict sexual morals in indigenous and Creole settlements.     

Hybrid maize breeding with doubled haploids: I. One-stage versus two-stage selection for testcross performance

Optimum allocation of resources is of fundamental importance for the efficiency of breeding programs. The objectives of our study were to (1) determine the optimum allocation for the number of lines and test locations in hybrid maize breeding with doubled haploids (DHs) regarding two optimization criteria, the selection gain ΔG _k and the probability P _k of identifying superior genotypes, (2) compare both optimization criteria including their standard deviations (SDs), and (3) investigate the influence of production costs of DHs on the optimum allocation. For different budgets, number of finally selected lines, ratios of variance components, and production costs of DHs, the optimum allocation of test resources under one- and two-stage selection for testcross performance with a given tester was determined by using Monte Carlo simulations. In one-stage selection, lines are tested in field trials in a single year. In two-stage selection, optimum allocation of resources involves evaluation of (1) a large number of lines in a small number of test locations in the first year and (2) a small number of the selected superior lines in a large number of test locations in the second year, thereby maximizing both optimization criteria. Furthermore, to have a realistic chance of identifying a superior genotype, the probability P _k of identifying superior genotypes should be greater than 75%. For budgets between 200 and 5,000 field plot equivalents, P _k > 75% was reached only for genotypes belonging to the best 5% of the population. As the optimum allocation for P _k (5%) was similar to that for ΔG _k , the choice of the optimization criterion was not crucial. The production costs of DHs had only a minor effect on the optimum number of locations and on values of the optimization criteria. C. Friedrich H. Longin and H. Friedrich Utz contributed equally to this work.     

High-throughput phenotypic assessment of cardiac physiology in four commonly used inbred mouse strains

Mice with genetic alterations are used in heart research as model systems of human diseases. In the last decade there was a marked increase in the recognition of genetic diversity within inbred mouse strains. Increasing numbers of inbred mouse strains and substrains and analytical variation of cardiac phenotyping methods require reproducible, high-throughput methods to standardize murine cardiovascular physiology. We describe methods for non-invasive, reliable, easy and fast to perform echocardiography and electrocardiography on awake mice. This method can be used for primary screening of the murine cardiovascular system in large-scale analysis. We provide insights into the physiological divergence of C57BL/6N, C57BL/6J, C3HeB/FeJ and 129P2/OlaHsd mouse hearts and define the expected normal values. Our report highlights that compared to the other three strains tested C57BL/6N hearts reveal features of heart failure such as hypertrophy and reduced contractile function. We found several features of the mouse ECG to be under genetic control and obtained several strain-specific differences in cardiac structure and function.     

Hydrolysis and transesterification reactions of candesartan cilexetil observed during the solid phase extraction procedure

Candesartan cilexetil is an angiotensin receptor antagonist widely used in the treatment of high blood pressure. This prodrug is metabolised into candesartan, which blocks the receptors AT1 for angiotensin II decreasing the blood pressure levels. During the development of a solid phase extraction procedure for the chromatographic determination of eight antihypertensive compounds, lack of linearity and reproducibility was observed only for candesartan cilexetil. Due to this fact, a stability study for this prodrug was performed. It showed that the lack of linearity and reproducibility was based on hydrolysis and transesterification processes which occurred during the drying step after elution with methanol into glass tubes. These phenomena could be reproduced artificially under basic conditions, which demonstrated the presence of basic residues in glass tubes. The study of this potential hydrolysis and transesterification reactions is very important to assure that labile drugs containing ester groups remain unaffected.     

Partial purification and characterization of a cellular protein that binds to the SV40 core origin of DNA replication

A monkey cell factor that interacts specifically with double- and single-stranded DNA sequences in the early domain of the simian virus 40 (SV40) core origin of replication was identified using gel-retention assays. The protein was enriched over 1200-fold using ion-exchange and affinity chromatography on single-strand DNA cellulose. Binding of protein to mutant origin DNA restriction fragments was correlated with replication activity of the mutant DNAs. Exonuclease footprint experiments on single-stranded DNA revealed prominent pause sites in the early domain of the core origin. The results suggest that this cellular protein may be involved in SV40 DNA replication.