Evolutionary and functional epitopes of the Spätzle protein: new insights into activation of the Toll receptor

Spätzle, a dimeric ligand, binds to the Drosophila Toll receptor and activates the signal pathway functioning in both embryonic patterning and innate immunity. Here, we used the evolutionary trace approach based on phylogenetic information to predict the evolutionary epitope of Spätzle and found that it mainly clusters in several adjacent loops of Spätzle far from the cystine-knot structural domain. We designed six mutants of Spätzle based on the evolutionary epitope and transfected them into a stable cell line expressing the luciferase reporter gene under the control of the drosomycin promoter. Luciferase assays showed that these mutants cannot significantly activate the drosomycin promoter, suggesting the involvement of these sites in binding of Spätzle to the Toll receptor. These data highlight the importance of the Trp-loop of the mushroom-shaped Spätzle dimer in Toll receptor activation and demonstrate that evolution-guided site-specific mutagenesis represents a useful and promising strategy for understanding the ligand-receptor interaction.

Identification of key astrophysical resonances relevant for the 26g Al(p,gamma)27Si reaction in Wolf-Rayet stars, AGB stars, and classical novae

A gamma-ray spectroscopy study of ;{26g}Al+p resonant states in 27Si is presented. Excitation energies were measured with improved precision and first spin-parity assignments made for excited states in 27Si above the proton threshold. The results indicate the presence of low-lying resonances with l_{p}=0 and l_{p}=2 captures that could strongly influence the ;{26g}Al(p,gamma)27Si reaction rate at low stellar temperatures, found in low-mass asymptotic giant branch (AGB), intermediate-mass AGB, super AGB, and Wolf-Rayet stars.

Structure of 240Pu: evidence for octupole phonon condensation?

The expanded level structure of 240Pu available from the present study highlights the role of strong octupole correlations in this nucleus. In addition to a delayed alignment in the yrast band, the observations include the presence of both I(+)-->(I-1)(-) and I(-)-->(I-1)(+)E1 transitions linking states of the yrast and negative-parity bands at high spin and the presence of an additional even-spin, positive-parity band deexciting exclusively to the negative-parity sequence. The observations appear to be consistent with expectations based on the recently proposed concept of octupole phonon condensation.

The tensor distribution function

Diffusion weighted magnetic resonance imaging is a powerful tool that can be employed to study white matter microstructure by examining the 3D displacement profile of water molecules in brain tissue. By applying diffusion-sensitized gradients along a minimum of six directions, second-order tensors (represented by three-by-three positive definite matrices) can be computed to model dominant diffusion processes. However, conventional DTI is not sufficient to resolve more complicated white matter configurations, e.g., crossing fiber tracts. Recently, a number of high-angular resolution schemes with more than six gradient directions have been employed to address this issue. In this article, we introduce the tensor distribution function (TDF), a probability function defined on the space of symmetric positive definite matrices. Using the calculus of variations, we solve the TDF that optimally describes the observed data. Here, fiber crossing is modeled as an ensemble of Gaussian diffusion processes with weights specified by the TDF. Once this optimal TDF is determined, the orientation distribution function (ODF) can easily be computed by analytic integration of the resulting displacement probability function. Moreover, a tensor orientation distribution function (TOD) may also be derived from the TDF, allowing for the estimation of principal fiber directions and their corresponding eigenvalues.

Influence of aspirin and cigarette smoke extract on the expression of cyclin D1 and effects of cell cycle in esophageal squamous cell carcinoma cell line

The relationship between smoking and esophageal squamous cell carcinoma (ESCC) has been confirmed by epidemiology. Cyclin D(1) plays a critical role in regulating the cell cycle; it is an important regulator of cell cycle and can function as a transcriptional co-regulator. The importance of cyclin D(1) makes it an attractive target for anticancer therapy. Human ESCC cell line EC109 was cultured with aspirin and cigarette smoke extract (CSE) at different concentrations for 48 h. Cell growth was tested with 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide reduction assay; cyclin D(1) mRNA level was detected by reverse transcription-polymerase chain reaction assays; protein level of cyclin D(1) was detected by Western blot; the cell cycle change was monitored by flow cytometry detection assays. CSE stimulated cell proliferation, increased the protein level of cyclin D(1) in a dose-dependent manner (P < 0.01), and decreased the proportion of G(0)/G(1) phase cell of cell cycle. However, aspirin can inhibit the cell growth and suppress the protein level of cyclin D(1) after CSE affected the EC109 cell line in a dose-dependent manner (P < 0.01). Meanwhile, aspirin increased the proportion of G(0)/G(1) phase cell, while that of S and G(2)/M phases decreased. Aspirin can inhibit the cell growth and suppress the protein level of cyclin D(1) after CSE affected EC109 cell line. The probable mechanism is through decreasing the expression of cyclin D(1), thus stopping the transition of cell cycle from G(0)/G(1) to S phase.

Collective oblate rotation at high spins in neutron-rich 180Hf

We report on experimental evidence for collective oblate rotation becoming favored at high spins in a rigid, well-deformed, axially symmetric nucleus. Excited states established up to spin 20variant Planck's over 2pi in 180Hf are consistent with predictions that nucleon alignments would favor oblate over prolate shapes at high spins in neutron-rich Hf isotopes. The results highlight the influence of valence orbitals on the interplay between nucleon alignments and nuclear shapes and provide a rare example of independent particle dynamics in competing potential wells.

A systematic review of the clinical effectiveness and cost-effectiveness and economic modelling of minimal incision total hip replacement approaches in the management of arthritic disease of the hip

OBJECTIVES

To assess the clinical effectiveness and cost-effectiveness of minimal incision approaches to total hip replacement (THR) for arthritis of the hip.

DATA SOURCES

Major electronic databases were searched from 1966 to 2007. Relevant websites were also examined and experts in the field were consulted.

REVIEW METHODS

Studies of minimal (one or two) incision THR compared with standard THR were assessed for inclusion in the review of clinical effectiveness. A systematic review of economic evaluations comparing a minimal incision approach to standard THR was also performed and the estimates from the systematic review of clinical effectiveness were incorporated into an economic model. Utilities data were sourced to estimate quality-adjusted life-years (QALYs). Due to lack of data, no economic analysis was conducted for the two mini-incision surgical method.

RESULTS

Nine randomised controlled trials (RCTs), 17 non-randomised comparative studies, six case series and one registry were found to be useful for the comparison of single mini-incision THR with standard THR. One RCT compared two mini-incision THR with standard THR, and two RCTs, five non-randomised comparative studies and two case series compared two mini-incision with single mini-incision THR. The RCTs were of moderate quality. Most had fewer than 200 patients and had a follow-up period of less than 1 year. The single mini-incision THR may have some perioperative advantages, e.g. blood loss [weighted mean difference (WMD) -57.71 ml, p<0.01] and shorter operative time, of uncertain practical significance. It may also offer a shorter recovery period and greater patient satisfaction. Evidence on long-term outcomes (especially revision) is too limited to be useful. Lack of data prevented subgroup analysis. With respect to the two-incision approach, data were suggestive of shorter recovery compared with single-incision THR, but conclusions must be treated with caution. The costs to the health service, per patient, of single mini-incision THR depend upon assumptions made, but are similar at one year (7060 pounds sterling vs 7350 pounds sterling for standard THR). For a 40-year time horizon the costs were 11,618 pounds sterling for mini-incision and 11,899 pounds sterling for standard THR. Two existing economic evaluations were identified, but they added little, if any, value to the current evidence base owing to their limited quality. In the economic model, mini-incision THR was less costly and provided slightly more QALYs in both the 1- and 40-year analyses. The mean QALYs at 1 year were 0.677 for standard THR and 0.695 for mini-incision THR. At 40 years, the mean QALYs were 8.463 for standard THR and 8.480 for mini-incision. At 1 year the probabilistic sensitivity analyses indicate that mini-incision THR has a 95% probability of being cost-effective if society's willingness to pay for a QALY were up to 50,000 pounds sterling. This is reduced to approximately 55% for the 40-year analysis. The results were driven by the assumption of a 1-month earlier return to usual activities and a decreased hospital length of stay and operation duration following mini-incision THR. If mini-incision THR actually required more intensive use of resources it would become approximately 200 pounds sterling more expensive and would only be cost-effective (cost per QALY>30,000 pounds sterling) if recovery was 1.5 weeks faster. A threshold analysis around risk of revision showed, using the same cost per QALY threshold, mini-incision THR would have to have no more than a 7.5% increase in revisions compared with standard THR for it to be no longer considered cost-effective (one more revision for every 200 procedures performed). Further sensitivity analysis involved relaxing assumptions of equal long-term outcomes where possible. and broadly similar results to the base-case analysis were found in this and further sensitivity analyses.

CONCLUSIONS

Compared with standard THR, minimal incision THR has small perioperative advantages in terms of blood loss and operation time. It may offer a shorter hospital stay and quicker recovery. It appears to have a similar procedure cost to standard THR, but evidence on its longer term performance is very limited. Further long-term follow-up data on costs and outcomes including analysis of subgroups of interest to the NHS would strengthen the current economic evaluation.

Secretion expression of recombinant glucagon inEscherichia coli

A novel approach for the preparation of recombinant human glucagon was described. An expression vector pAGluT, containing phoA promoter, phoA signal peptide and glucagon gene, was constructed by means of genetic engineering.Escherichia coli strain YK537 was transformed with pAGluT. High-level secretory expression of recombinant human glucagon was achieved. The expression yield of recombinant human glucagon was found to be 80 mg/L, approximately 30% of the total proteins in supernatant. The biological activities and the physicochemical properties of the purified recombinant human glucagon were found to be the same as that of native glucagon. In addition, our results suggested that phoA expression system may be suitable for the expression of other small peptides.

Seed yield of near-isogenic soybean lines with introgressed quantitative trait loci conditioning resistance to corn earworm (Lepidoptera: Noctuidae) and soybean looper (Lepidoptera: Noctuidae) from PI 229358

The development of superior soybean, Glycine max (L.) Merr., cultivars exhibiting resistance to insects has been hindered due to linkage drag, a common phenomenon when introgressing alleles from exotic germplasm. Simple-sequence repeat (SSR) markers were used previously to map soybean insect resistance (SIR) quantitative trait loci (QTLs) in a'Cobb' X PI 229358 population, and subsequently used to create near-isogenic lines (NILs) with SIR QTL i n a 'Benning' genetic background. SIR QTLs were mapped on linkage groups (LGs) M (SIRQTL-M), G (SIRQTL-G), and H (SIRQTL-H). The objectives of this study were to 1) evaluate linkage drag for seed yield by using Benning-derived NILs selected for SIRQTL-M, SIRQTL-H, and SIRQTL-G; 2) assess the amount of PI 229358 genome surrounding the SIR QTL in each Benning NIL; and 3) evaluate the individual effects these three QTLs on antibiosis and antixenosis to corn earworm, Helicoverpa zea (Boddie), and soybean looper, Pseudoplusia includens (Walker). Yield data collected in five environments indicated that a significant yield reduction is associated with SIRQTL-G compared with NILs without SIR QTL. Overall, there was no yield reduction associated with SIRQTL-M or SIRQTL-H. A significant antixenosis and antibiosis effect was detected for SIRQTL-M in insect feeding assays, with no effect detected in antixenosis or antibiosis assays for SIRQTL-G or SIRQTL-H without the presence of PI 229358 alleles at SIRQTL-M. These results support recent findings concerning these loci.

C/EBPbeta represses p53 to promote cell survival downstream of DNA damage independent of oncogenic Ras and p19(Arf)

CCAAT/enhancer-binding protein-beta (C/EBPbeta) is a mediator of cell survival and tumorigenesis. When C/EBPbeta(-/-) mice are treated with carcinogens that produce oncogenic Ras mutations in keratinocytes, they respond with abnormally elevated keratinocyte apoptosis and a block in skin tumorigenesis. Although this aberrant carcinogen-induced apoptosis results from abnormal upregulation of p53, it is not known whether upregulated p53 results from oncogenic Ras and its ability to induce p19(Arf) and/or activate DNA-damage response pathways or from direct carcinogen-induced DNA damage. We report that p19(Arf) is dramatically elevated in C/EBPbeta(-/-) epidermis and that C/EBPbeta represses a p19(Arf) promoter reporter. To determine whether p19(Arf) is responsible for the proapoptotic phenotype in C/EBPbeta(-/-) mice, C/EBPbeta(-/-);p19(Arf-/-) mice were generated. C/EBPbeta(-/-);p19(Arf-/-) mice responded to carcinogen treatment with increased p53 and apoptosis, indicating p19(Arf) is not essential. To ascertain whether oncogenic Ras activation induces aberrant p53 and apoptosis in C/EBPbeta(-/-) epidermis, we generated K14-ER:Ras;C/EBPbeta(-/-) mice. Oncogenic Ras activation induced by 4-hydroxytamoxifen did not produce increased p53 or apoptosis. Finally, when C/EBPbeta(-/-) mice were treated with differing types of DNA-damaging agents, including alkylating chemotherapeutic agents, they displayed aberrant levels of p53 and apoptosis. These results indicate that C/EBPbeta represses p53 to promote cell survival downstream of DNA damage and suggest that inhibition of C/EBPbeta may be a target for cancer cotherapy to increase the efficacy of alkylating chemotherapeutic agents.

Biomechanical Properties of the Condyle Created by Osteodistraction

A new condyle can be reconstructed by osteodistraction, but the biomechanical properties of the neocondyle remain unknown. This study examined the hypothesis that the biomechanical properties of neocondylar cancellous bone could reach control levels 24 weeks after its creation by osteodistraction. The right mandibular condyles were removed and reconstructed by osteo-distraction in 16 adult goats. Their contralateral condyles served as controls. Microstructural and mechanical properties were examined by microcomputed tomography and mechanical testing. At 24 weeks after distraction, the neocondyle grew larger in size, but the shape and histological features were similar to those of the controls. The cancellous bone of the neocondyle even appeared to be more dense and stiffer in comparison with the control condyle. The results of this study suggest that the neocondyle created by osteodistraction develops nearly normal biomechanical properties for functional loading by 24 weeks after creation.

Positive selection targeting the cathelin-like domain of the antimicrobial cathelicidin family

The cathelin-like domain (CLD) of cathelicidins is grouped in the same superfamily with cystatins, natural cysteine protease inhibitors, due to their structural similarity. Intriguingly, human hCAP-18/LL37 and pig protegrin-3 (PG3) CLDs exhibit opposite effects against cathepsin L. Here, I evaluated the functional importance of the CLD through identifying whether positive selection has driven adaptive evolution of this domain. As a result, four positively selected sites were detected and three of them are located on a loop region previously recognized as a key determinant of the activating effect of the PG3 CLD. Analysis of amino acid variability of the CLD led to the discovery of a conserved region and three highly variable regions, in which two are subjected to positive selection. Positive selection targeting the variable regions provides a starting point for experimentally establishing a direct link between the observed amino acid changes and functional divergence of the CLD family.

Effects of defoliating insect resistance QTLs and a cry1Ac transgene in soybean near-isogenic lines

The crystal proteins coded by transgenes from Bacillus thuringiensis (Bt) have shown considerable value in providing effective insect resistance in a number of crop species, including soybean, Glycine max (L.) Merr. Additional sources of soybean insect resistance would be desirable to manage the development of tolerance/resistance to crystal proteins by defoliating insects and to sustain the deployment of Bt crops. The objective of this study was to evaluate the effects and interactions of three insect resistance quantitative trait loci (QTLs; QTL-M, QTL-H, and QTL-G) originating from Japanese soybean PI 229358 and a cry1Ac gene in a "Benning" genetic background. A set of 16 BC(6)F(2)-derived near isogenic lines (NILs) was developed using marker-assisted backcrosses and evaluated for resistance to soybean looper [SBL, Pseudoplusia includens (Walker)] and corn earworm [CEW, Helicoverpa zea (Boddie)] in field cage, greenhouse, and detached leaf assays. Both Bt and QTL-M had significantly reduced defoliation by both SBL and CEW and reduced larval weight of CEW. The antibiosis QTL-G had a significant effect on reducing CEW larval weight and also a significant effect on reducing defoliation by SBL and CEW in some assays. The antixenosis QTL-H had no main effect, but it appeared to function through interaction with QTL-M and QTL-G. Adding QTL-H and QTL-G further enhanced the resistance of the Bt and QTL-M combination to CEW in the field cage assay. These results should help guide the development of strategies for effective management of insect pests and for sustainable deployment of Bt genes.