A novel ligand of the formyl peptide receptor: annexin I regulates neutrophil extravasation by interacting with the FPR

The glucocorticoid-regulated protein annexin I (lipocortin I) has been shown to mediate antiinflammatory activities of glucocorticoids, but the molecular basis of its action has remained elusive. Here we show that annexin I acts through the formyl peptide receptor (FPR) on human neutrophils. Peptides derived from the unique N-terminal domain of annexin I serve as FPR ligands and trigger different signaling pathways in a dose-dependent manner. Lower peptide concentrations possibly found in inflammatory situations elicit Ca2+ transients without fully activating the MAP kinase pathway. This causes a specific inhibition of the transendothelial migration of neutrophils and a desensitization of neutrophils toward a chemoattractant challenge. These findings identify annexin I peptides as novel, endogenous FPR ligands and establish a mechanistic basis of annexin I-mediated antiinflammatory effects.

Association between chromosomal instability and prognosis in colorectal cancer: a meta-analysis

BACKGROUND

Several studies have suggested that microsatellite instability (MSI) resulting from defective DNA mismatch repair confers a better prognosis in colorectal cancer (CRC). Recently, however, data have suggested this is secondary to the effects of ploidy/chromosomal instability (CIN). To estimate the prognostic significance of CIN for survival, data from published studies have been reviewed and pooled.

METHODS

Studies stratifying survival in CRC by CIN status were identified by searching PubMed and hand-searching bibliographies of identified studies. Two reviewers confirmed study eligibility and extracted data independently, and data were pooled using a fixed-effects model. The principal outcome measure was the HR for death.

RESULTS

63 eligible studies reported outcome in 10 126 patients, 60.0% of whom had CIN+ (aneuploid/polyploid) tumours. The overall HR associated with CIN was 1.45 (95% CI 1.35 to 1.55, p<0.001). In patients with stage II-III CRCs, the HR was 1.45 (95% CI 1.27 to 1.65, p<0.001). The effect was similar for progression-free survival (HR = 1.71, 95% CI 1.51 to 1.94, p<0.001). There was no evidence of significant interstudy heterogeneity.

CONCLUSION

CIN is associated with a worse prognosis in CRC, and should be evaluated as a prognostic marker, together with MSI status, in all clinical trials, particularly those involving adjuvant therapies.

Molecular diversity at 18 loci in 321 wild and 92 domesticate lines reveal no reduction of nucleotide diversity during Triticum monococcum (Einkorn) domestication: implications for the origin of agriculture

The diploid wheat Triticum monococcum L. (einkorn) was among the first crops domesticated by humans in the Fertile Crescent 10,000 years ago. During the last 5,000 years, it was replaced by tetraploid and hexaploid wheats and largely forgotten by modern breeders. Einkorn germplasm is thus devoid of breeding bottlenecks and has therefore preserved in unfiltered form the full spectrum of genetic variation that was present during its domestication. We investigated haplotype variation among >12 million nucleotides sequenced at 18 loci across 321 wild and 92 domesticate T. monococcum lines. In contrast to previous studies of cereal domestication, we sampled hundreds of wild lines, rather than a few dozen. Unexpectedly, our broad sample of wild lines reveals that wild einkorn underwent a process of natural genetic differentiation, most likely an incipient speciation, prior to domestication. That natural differentiation was previously overlooked within wild einkorn, but it bears heavily upon inferences concerning the domestication process because it brought forth 3 genetically, and to some extent morphologically, distinct wild einkorn races that we designate here as alpha, beta, and gamma. Only one of those natural races, beta, was exploited by humans for domestication. Nucleotide diversity and haplotype diversity in domesticate einkorn is higher than in its wild sister group, the einkorn beta race, indicating that einkorn underwent no reduction of diversity during domestication. This is in contrast to findings from previous studies of domestication history among more intensely bred crop species. Taken together with archaeological findings from the Fertile Crescent, the data indicate that a specific wild einkorn race that arose without human intervention was subjected to multiple independent domestication events.

Effect of prophylactic treatment on suicide risk in patients with major affective disorders. Data from a randomized prospective trial

Recent findings have indicated that lithium treatment markedly reduces suicide risk in major affective disorders. To compare the effect of lithium with carbamazepine and amitriptyline, suicidal behavior was analyzed during the randomized prospective long-term MAP study (N = 378; duration 2.5 years). Of the nine suicides and five attempted suicides, none took place during lithium treatment. The findings support the view that lithium has a specific antisuicidal effect over and above its prophylactic benefit.

Temporal control of i-motif switch lifetimes for autonomous operation of transient DNA nanostructures

System integration of the DNA i-motif switch with a tunable pH environment allows programmable lifetimes of DNA duplex hybridization and higher level self-assemblies in closed and autonomous systems.

Functional DNA nanotechnology creates increasingly complex behaviors useful for sensing, actuation or computation, as enabled via the integration of dynamic and responsive structural DNA motifs. However, temporally controlled and dynamic DNA structures with programmable lifetimes, that are able to operate autonomously and self-revert to the starting state are challenging to achieve due to tedious and very system-specific sequence design. Here, we present a straightforward concept to program transient lifetimes into DNA duplexes based on the pH-sensitive DNA i-motif switch. We integrate the i-motif switch with an internal, non-linear pH-resetting function using a rationally designed chemical reaction framework, by which the switch autonomously undergoes a complete “off–on–off”-cycle without the use of additional external triggers. The lifetime of the activated “on”-state (i.e. the hybridized state) can be systematically programmed over several hours. The system can be readily implemented into hybrid DNA structures on larger length scales. Focusing on autonomous materials, we demonstrate temporal control of transient fluorescence signals and temporary aggregation of gold nanoparticles.

Polarized hyphal growth in Candida albicans requires the Wiskott-Aldrich Syndrome protein homolog Wal1p

The yeast-to-hypha transition is a key feature in the cell biology of the dimorphic human fungal pathogen Candida albicans. Reorganization of the actin cytoskeleton is required for this dimorphic switch in Candida. We show that C. albicans WAL1 mutants with both copies of the Wiskott-Aldrich syndrome protein (WASP) homolog deleted do not form hyphae under all inducing conditions tested. Growth of the wild-type and wal1 mutant strains was monitored by in vivo time-lapse microscopy both during yeast-like growth and under hypha-inducing conditions. Isotropic bud growth produced round wal1 cells and unusual mother cell growth. Defects in the organization of the actin cytoskeleton resulted in the random localization of actin patches. Furthermore, wal1 cells exhibited defects in the endocytosis of the lipophilic dye FM4-64, contained increased numbers of vacuoles compared to the wild type, and showed defects in bud site selection. Under hypha-inducing conditions wal1 cells were able to initiate polarized morphogenesis, which, however, resulted in the formation of pseudohyphal cells. Green fluorescent protein (GFP)-tagged Wal1p showed patch-like localization in emerging daughter cells during the yeast growth phase and at the hyphal tips under hypha-inducing conditions. Wal1p-GFP localization largely overlapped with that of actin. Our results demonstrate that Wal1p is required for the organization of the actin cytoskeleton and hyphal morphogenesis in C. albicans as well as for endocytosis and vacuole morphology.

Leukocyte-independent plasma extravasation during endotoxemia

OBJECTIVES

To determine the meaning of leukocyte-endothelial interactions for the development of endotoxin-induced vascular leakage.

DESIGN

Randomized, blinded, controlled trial.

SETTING

Experimental laboratory.

SUBJECTS

Twenty-four male Wistar rats.

INTERVENTIONS

After application of fucoidin to prevent leukocyte rolling and adherence (25 mg/kg; n = 8; fucoidin/LPS group) or saline 0.9% (n = 8; LPS group), animals were given an intravenous infusion of endotoxin (Escherichia coli lipopolysaccharide 026:B6; 2 mg/kg/hr) over 120 mins. Animals in the control group (n = 8) received an equivalent volume of saline 0.9%.

MEASUREMENTS AND MAIN RESULTS

Leukocyte rolling and leukocyte adherence, red cell velocity, vessel diameters, venular wall shear rate, volumetric blood flow, and macromolecular leakage were determined in mesenteric postcapillary venules using in vivo videomicroscopy at baseline, 60 mins, and 120 mins after start of a continuous endotoxin infusion. Fucoidin prevented leukocyte rolling (baseline, 3+/-2 rollers; 120 mins, 3+/-1 rollers; not significant vs. baseline; p < .01 vs. LPS group) and reduced the adherence of leukocytes at baseline and during endotoxemia and showed only a slight increase in adherent leukocytes (baseline, 100+/-38 cells/mm2; 120 mins, 244+/-68 cells/mm2; p < .05 vs. baseline; p < .01 vs. LPS group). In the LPS group, endotoxin exposure induced a marked increase in adherent leukocytes (baseline, 248+/-24 cells/mm2; 120 mins, 560+/-57 cells/mm2; p < .01). Leukocyte adherence in control animals (control group) did not increase significantly. Macromolecular leakage, expressed as the ratio of perivenular to intravenular fluorescence intensity after injection of fluorescence-labeled albumin, increased from 0.16+/-0.03 to 0.49+/-0.04 (p < .01 vs. baseline; p < .05 vs. control) during the infusion of endotoxin in the LPS group. Fucoidin application did not diminish the extravasation of albumin (baseline, 0.09+/-0.03; 120 mins, 0.61+/-0.10; p < .01 vs. baseline; p < .01 vs. control).

CONCLUSIONS

These results demonstrate that despite a significant reduction of adherent leukocytes to the endothelium by fucoidin, there is no reduction in macromolecular leakage, indicating that leukocyte-endothelial interactions only play a minor role for the development of macromolecular leakage and microvascular damage in the early phase of endotoxemia.

Controlling fast transport of cold trapped ions

We realize fast transport of ions in a segmented microstructured Paul trap. The ion is shuttled over a distance of more than 10(4) times its ground state wave function size during only five motional cycles of the trap (280 μm in 3.6 μs). Starting from a ground-state-cooled ion, we find an optimized transport such that the energy increase is as low as 0.10±0.01 motional quanta. In addition, we demonstrate that quantum information stored in a spin-motion entangled state is preserved throughout the transport. Shuttling operations are concatenated, as a proof-of-principle for the shuttling-based architecture to scalable ion trap quantum computing.

Effects of dobutamine and dopexamine on hepatic micro- and macrocirculation during experimental endotoxemia: an intravital microscopic study in the rat

OBJECTIVE

To test the effects of dobutamine and dopexamine on hepatic portal and sinusoidal blood flow in a model of normodynamic endotoxemia.

DESIGN

Randomized, controlled trial.

SETTING

Experimental laboratory.

SUBJECTS

Male Wistar rats (250-350 g).

INTERVENTIONS

A total of 40 male Wistar rats were randomized into four groups: a control group, which only received Ringer's solution; an endotoxin group, which received a continuous infusion of 2 mg/kg body weight (bw)/hr of endotoxin; a dobutamine group, which received endotoxin and a continuous infusion of dobutamine (3 microg/kg bw/min); and a dopexamine group, which received endotoxin and dopexamine (2 microg/kg bw/min). The experimental period was 120 min.

MEASUREMENTS AND MAIN RESULTS

Mean arterial blood pressure (MAP), heart rate (HR), and cardiac output (CO) were detected. Portal blood flow was measured using an ultrasonic flow probe positioned around the portal vein, and sinusoidal blood flow was detected in the left liver lobe using intravital microscopy. All detected variables remained stable in the control group. In the endotoxin group, HR increased significantly and MAP decreased significantly from 111 +/- 10 mm Hg to 95 +/- 8 mm Hg at 120 mins, whereas CO remained unchanged. Both in the dobutamine and the dopexamine group HR increased and MAP decreased more than in the endotoxin group. CO increased in both groups significantly. Portal blood flow (23 +/- 4 mL/min to 16 +/- 3 mL/min) and sinusoidal blood flow (38.6 +/- 2.5 to 22.8 +/- 1.2 10(3) microm(3)/sec) decreased significantly in the endotoxin group. In the dobutamine and the dopexamine group portal and sinusoidal blood flow remained at baseline values.

CONCLUSIONS

In our model of endotoxemia, dobutamine and dopexamine preserved systemic and hepatic blood flow. These preservations of hepatic blood flow during endotoxemia could portend beneficial effects but need to be studied further.

Deletion of the dynein heavy-chain gene DYN1 leads to aberrant nuclear positioning and defective hyphal development in Candida albicans

Cytoplasmic dynein is a microtubule-associated minus-end-directed motor protein. CaDYN1 encodes the single dynein heavy-chain gene of Candida albicans. The open reading frames of both alleles of CaDYN1 were completely deleted via a PCR-based approach. Cadyn1 mutants are viable but grow more slowly than the wild type. In vivo time-lapse microscopy was used to compare growth of wild-type (SC5314) and dyn1 mutant strains during yeast growth and after hyphal induction. During yeast-like growth, Cadyn1 strains formed chains of cells. Chromosomal TUB1-GFP and HHF1-GFP alleles were used both in wild-type and mutant strains to monitor the orientation of mitotic spindles and nuclear positioning in C. albicans. In vivo fluorescence time-lapse analyses with HHF1-GFP over several generations indicated defects in dyn1 cells in the realignment of spindles with the mother-daughter axis of yeast cells compared to that of the wild type. Mitosis in the dyn1 mutant, in contrast to that of wild-type yeast cells, was very frequently completed in the mother cells. Nevertheless, daughter nuclei were faithfully transported into the daughter cells, resulting in only a small number of multinucleate cells. Cadyn1 mutant strains responded to hypha-inducing media containing l-proline or serum with initial germ tube formation. Elongation of the hyphal tubes eventually came to a halt, and these tubes showed a defect in the tipward localization of nuclei. Using a heterozygous DYN1/dyn1 strain in which the remaining copy was controlled by the regulatable MAL2 promoter, we could switch between wild-type and mutant phenotypes depending on the carbon source, indicating that the observed mutant phenotypes were solely due to deletion of DYN1.

Role of platelet-activating factor in leukocyte-independent plasma extravasation and mast cell activation during endotoxemia

BACKGROUND

Independently from leukocyte adherence, endothelial factors and mast cell activation seems to promote microvascular permeability. Platelet-activating factor (PAF) has been shown to play a significant role in endotoxin-induced leukocyte adherence. The aim of our study was to investigate if there is also a role for PAF in mediating leukocyte-independent microvascular permeability changes and activation of mast cells during endotoxemia. Therefore, during endotoxemia microvascular permeability and mast cell activation were determined after inhibition of L-selectin-mediated leukocyte adherence by fucoidin and after inhibition of PAF effects by the PAF receptor antagonist BN52021.

MATERIALS AND METHODS

In male Wistar rats, red cell velocity (V(RBC)), venular wall shear rate, microvascular permeability, leukocyte adherence, and mast cell activation were determined in mesenteric postcapillary venules using intravital microscopy at baseline and 60 and 120 min after start of a continuous infusion of endotoxin (ETX; 2 mg/kg/h, Escherichia coli O26:B6) (ETX group). Animals in the FUCO/ETX group received fucoidin (25 mg/kg body wt) in addition to the procedure described above. Animals in the FUCO/ETX/PAF-ANT group received fucoidin and the PAF receptor antagonist BN52021 (5 mg/kg body wt) prior to the continuous endotoxin infusion. Control animals (control group) received only equivalent volumes of NaCl 0.9%.

RESULTS

There were no microhemodynamic and macrohemodynamic differences between groups. In all endotoxin-challenged groups macromolecular leakage and mast cell activity increased significantly, starting at 60 min. Both macromolecular leakage and mast cell activity were significantly higher in the FUCO/ETX group than in the FUCO/ETX/PAF-ANT group and control group. Differences in macromolecular leakage between groups were significant at 120 min. Differences in mast cell activity between groups were significant at 60 and 120 min.

CONCLUSIONS

The results of our study demonstrate a leukocyte-independent plasma extravasation that can be inhibited by the PAF receptor antagonist BN52021, indicating the involvement of PAF in the pathophysiology of leukocyte-independent microvascular damage during early endotoxemia. Mast cell activity seems to precede leukocyte-independent macromolecular leakage.

Acousto-optic modulator as an electronically selectable unidirectional device in a ring laser

An acousto-optic modulator causes unidirectional operation of dye and Ti:sapphire ring lasers. The modulator has a low insertion loss in the cavity and can be used to switch the direction of the beam electronically. The ring-laser performance is characterized, and experiments to probe the origin of the unidirectional operation are described.