A functionally atypical amidating enzyme from the human parasite Schistosoma mansoni

Many neuropeptide transmitters require the presence of a carboxy-terminal alpha-amide group for biological activity. Amidation requires conversion of a glycine-extended peptide intermediate into a C-terminally amidated product. This post-translational modification depends on the sequential action of two enzymes (peptidylglycine alpha-hydroxylating monooxygenase or PHM, and peptidyl-alpha-hydroxyglycine alpha-amidating lyase or PAL) that in most eukaryotes are expressed as separate domains of a single protein (peptidylglycine alpha-amidating monooxygenase or PAM). We identified a cDNA encoding PHM in the human parasite Schistosoma mansoni. Transient expression of schistosome PHM (smPHM) revealed functional properties that are different from other PHM proteins; smPHM displays a lower pH-optimum and, when expressed in mammalian cells, is heavily N-glycosylated. In adult worms, PHM is found in the trans-Golgi network and secretory vesicles of both central and peripheral nerves. The widespread occurrence of PHM in the nervous system confirms the important role of amidated neuropeptides in these parasitic flatworms. The differences between schistosome and mammalian PHM suggest that it could be a target for new chemotherapeutics.

Characterisation and glucoregulatory actions of a novel acylated form of the (Pro(3))GIP receptor antagonist in type 2 diabetes

In this study, we tested the biological activity of a novel acylated form of (Pro(3))glucose-dependent insulinotropic polypetide [(Pro3)GIP] prepared by conjugating palmitic acid to Lys(16) to enhance its efficacy in vivo by promoting binding to albumin and extending its biological actions. Like the parent molecule (Pro(3))GIP, (Pro(3))GIPLys(16)PAL was completely stable to the actions of DPP-IV and significantly (p <0.01 to p <0.001) inhibited GIP-stimulated cAMP production and cellular insulin secretion. Furthermore, acute administration of (Pro(3))GIPLys(16)PAL also significantly (p <0.05 to p <0.001) countered the glucose-lowering and insulin-releasing actions of GIP in ob/ob mice. Daily injection of (Pro(3))GIPLys(16)PAL (25 nmol/kg bw) in 14-18-week-old ob/ob mice over 14 days had no effect on body weight, food intake or non-fasting plasma glucose and insulin concentrations. (Pro(3))GIPLys(16)PAL treatment also failed to significantly alter the glycaemic response to an i.p. glucose load or test meal, but insulin concentrations were significantly reduced (1.5-fold; p <0.05) after the glucose load. Insulin sensitivity was enhanced (1.3-fold; p <0.05) and pancreatic insulin was significantly reduced (p <0.05) in the (Pro(3))GIPLys(16)PAL-treated mice. These data demonstrate that acylation of Lys(16) with palmitic acid in (Pro(3))GIP does not improve its biological effectiveness as a GIP receptor antagonist.

Degradation, receptor binding, insulin secreting and antihyperglycaemic actions of palmitate-derivatised native and Ala(8)-substituted GLP-1 analogues

The hormone glucagonlike peptide-1(736)amide (GLP-1) is released in response to ingested nutrients and acts to promote glucosedependent insulin secretion ensuring efficient postprandial glucose homeostasis. Unfortunately, the beneficial actions of GLP-1 which give this hormone many of the desirable properties of an antidiabetic drug are short lived due to degradation by dipeptidylpeptidase IV (DPP IV) and rapid clearance by renal filtration. In this study we have attempted to extend GLP-1 action through the attachment of palmitoyl moieties to the epsilon-amino group in the side chain of the Lys(26) residue and to combine this modification with substitutions of the Ala(8) residue, namely Val or aminobutyric acid (Abu). In contrast to native GLP-1, which was rapidly degraded, [Lys(pal)(26)]GLP-1, [Abu(8),Lys(pal)(26)]GLP-1 and [Val(8),Lys(pal)(26)]GLP-1 all exhibited profound stability during 12 h incubations with DPP IV and human plasma. Receptor binding affinity and the ability to increase cyclic AMP in the clonal beta-cell line BRIN-BD11 were decreased by 86- to 167-fold and 15- to 62-fold, respectively compared with native GLP-1. However, insulin secretory potency tested using BRIN-BD11 cells was similar, or in the case of [Val(8),Lys(pal)(26)]GLP-1 enhanced. Furthermore, when administered in vivo together with glucose to diabetic (ob/ob) mice, [Lys(pal)(26)]GLP-1, [Abu(8),Lys(pal)(26)]GLP-1 and [Val8,Lys(pal)26]GLP-1 did not demonstrate acute glucoselowering or insulinotropic activity as observed with native GLP-1. These studies support the potential usefulness of fatty acid linked analogues of GLP-1 but indicate the importance of chain length for peptide kinetics and bioavailability.

Polymer-supported phosphoramidites: highly efficient and recyclable catalysts for asymmetric hydrogenation of dimethylitaconate and dehydroamino acids and esters

Several novel phosphoramidites have been prepared by reaction of the primary amines para-vinylaniline, ortho-anisidine, 2-methoxyphenyl(4-vinylbenzyl)amine, 8-aminoquinoline and 3-vinyl-8-aminoquinoline with (S)-1,1'-bi-2-naphthylchlorophosphite, in the presence of base. Rhodium(l) complexes of these phosphoramidites catalyse the asymmetric hydrogenation of dimethylitaconate and dehydroamino acids and esters giving ee values up to 95%. Soluble non-cross linked polymers of the para-vinylaniline and 3-vinyl-8-aminoquinoline-based phosphoramidites have been prepared by free radical co-polymerisation with styrene in the presence of AIBN as initiator. The corresponding [Rh(COD)](+) complexes serve as recyclable catalysts for the asymmetric hydrogenation dimethylitaconate and dehydroamino acids and esters to give ee values up to 80%. (C) 2003 Elsevier Science Ltd. All rights reserved.

Megaliths in Malta:Orme dei Giganti

Stoddart, S. K. F. and Malone, C. A. T. In: S. Tusa, C. Buccellato, and L. Biondo (eds.),, pp. 59–70. 2009. Palermo: Regione Siciliana---Assessorato dei beni culturali, ambientali e della pubblica istruzione---Dipartimento dei beni culturali e dell'educazione permanente

The inhibitor profiling of the caspase family of proteases using substrate-derived peptide glyoxals.

A series of substrate-based a-keto-ß-aldehyde (glyoxal) sequences have been synthesised and evaluated as inhibitors of the caspase family of cysteine proteases. A number of potent inhibitor sequences have been identified. For example, a palmitic acid containing sequence pal-Tyr-Val-Ala-Asp-glyoxal was demonstrated to be an extremely effective inhibitor of caspase-1, inhibiting not only the action of the protease against synthetic fluorogenic substrates (Ki = 0.3 nM) but also blocking its processing of pro-interleukin-1beta (pro-IL-1ß). In addition, the peptide Ac-Asp-Glu-Val-Asp-glyoxal, which is based on the consensus cleavage sequence for caspase-3, is a potent inhibitor of this protease (Ki = 0.26 nM) yet only functions as a comparatively modest inhibitor of caspase-1 (Ki = 451 nM). Potent inhibitor sequences were also identified for caspases-6 and -8. However, the degree of discrimination between the family members is limited. The ability of Ac-Asp-Glu-Val-Asp-glyoxal to block caspase-3 like activity in whole cells and to delay the development of apoptosis was assessed. When tested against caspase-3 like activity in cell lysates, Ac-Asp-Glu-Val-Asp-glyoxal displayed effective inhibition similar to that observed against recombinant caspase-3. Treatment of whole cells with this potent caspase-3 inhibitor was however, not sufficient to significantly stall the development of apoptosis in-vitro.

A chiton without a foot

The palaeoloricate ‘polyplacophorans’ are an extinct paraphyletic group of basal chiton-like organisms known primarily from their fossilized valves. Their phylo- genetic placement remains contentious, but they are likely to include both stem-group Polyplacophora and stem- group Aplacophora. Candidates for the latter position include ‘Helminthochiton’ thraivensis from the Ordovician of Scotland, which we redescribe here through a combined optical and micro-CT (XMT) restudy of the type material. The 11 specimens in the type series are all articulated, presenting partial or complete valve series as well as moul- dic preservation of the girdle armature; they demonstrate a vermiform body plan. The valves are typically palaeolori- cate in aspect, but differ in detail from all existing palaeol- oricate genera; we hence erect Phthipodochiton gen. nov. to contain the species. The most notable feature of the fossils is the spicular girdle; this is impersistently preserved, but demonstrably wraps entirely around the ventral surface of the animal, implying that a ‘true’ (i.e. polyplacophoran like) foot was absent, although we do not exclude the pos- sibility of a narrow solenogastre-like median pedal groove having been present. Phthipodochiton thraivensis presents an apparent mosaic of aplacophoran and polyplacophoran features and as such will inform our understanding of the relationship between these groups of extant molluscs. An inference may also be drawn that at least some other pal- aeoloricates possessed an ‘armoured aplacophoran’ body plan, in contrast to the ‘limpet-like’ body plan of extant Polyplacophora.

All-cause mortality and periodontitis in 60-70-year-old men: A prospective cohort study

Objective To investigate the association between periodontitis and mortality from all causes in a prospective study in a homogenous group of 60- to 70-year-old West European men. Methodology A representative sample of 1400 dentate men, (mean age 63.8, SD 3.0 years), drawn from the population of Northern Ireland, had a comprehensive periodontal examination between 2001 and 2003. Men were divided into thirds on the basis of their mean periodontal attachment loss (PAL). The primary endpoint, death from any cause, was analysed using Kaplan-Meier survival plots and Cox's proportional hazards model. Results In total, 152 (10.9%) of the men died during a mean follow-up of 8.9 (SD 0.7) years; 37 (7.9%) men in the third with the lowest PAL (<1.8 mm) died compared with 73 (15.7%) in the third with the highest PAL (>2.6 mm). The unadjusted hazard ratio (HR) for death in the men with the highest level of PAL compared with those with the lowest PAL was 2.11 (95% CI 1.42-3.14), p < 0.0001. After adjustment for confounding variables (age, smoking, hypertension, BMI, diabetes, cholesterol, education, marital status and previous history of a cardiovascular event) the HR was 1.57 (1.04-2.36), p = 0.03. Conclusion The European men in this prospective cohort study with the most severe loss of periodontal attachment were at an increased risk of death compared with those with the lowest loss of periodontal attachment.

JPEG encoder system-on-a-chip demonstrator

The design of a System-on-a-Chip (SoC) demonstrator for a baseline JPEG encoder core is presented. This combines a highly optimized Discrete Cosine Transform (DCT) and quantization unit with an entropy coder which has been realized using off-the-shelf synthesizable IP cores (Run-length coder, Huffman coder and data packer). When synthesized in a 0.35 µm CMOS process, the core can operate at speeds up to 100 MHz and contains 50 k gates plus 11.5 kbits of RAM. This is approximately 20% less than similar JPEG encoder designs reported in literature. When targeted at FPGA the core can operate up to 30 MHz and is capable of compressing 9-bit full-frame color input data at NTSC or PAL rates.

The Palisades is a key reference site for the middle Pleistocene of eastern Beringia: New evidence from paleomagnetics and regional tephrostratigraphy

The Palisades, in central Alaska, is one of the most prominent exposures of Quaternary sediments on the Yukon River. Perennially-frozen silt and sand at the Palisades are presently thought to preserve paleoenvironmental records from the Holocene to ~Marine Isotope Stage (MIS) 8 and, beneath a major unconformity, the earliest Pleistocene (~2 Ma). We present new paleomagnetic and tephrochronologic constraints that substantially revise the age of the sediments at the Palisades. We describe 15 new tephra beds, including five beds below the prominent PAL tephra that correlate to known tephra with independent age control from other sites in eastern Beringia. These five known tephra include Chester Bluff tephra, which is present in east-central Alaska and the Yukon, and the newly named Alyeska Pipeline and Taylor Highway tephra from central Alaska; all are constrained to the middle Pleistocene. Paleomagnetic transects from the base of the bluff to the MIS 5e forest bed yield normal polarity, with the exception of a brief reversal event between Old Crow tephra (124 ± 10 ka) and the MIS 5e forest bed that is likely the first documentation of the Blake paleomagnetic event in Alaskan loess. The detailed tephrostratigraphy and paleomagnetic data collectively suggest that most of the sedimentary record at the Palisades is middle Pleistocene in age. The Palisades thus preserves a rare record of late to middle Pleistocene paleoenvironments with multiple regionally distributed tephra beds. © 2013 Elsevier Ltd.

A lesson in business: cost-effectiveness analysis of a novel financial incentive intervention for increasing physical activity in the workplace

Background: Recently both the UK and US governments have advocated the use of financial incentives to encourage healthier lifestyle choices but evidence for the cost-effectiveness of such interventions is lacking. Our aim was to perform a cost-effectiveness analysis (CEA) of a quasi-experimental trial, exploring the use of financial incentives to increase employee physical activity levels, from a healthcare and employer’s perspective.

Methods: Employees used a ‘loyalty card’ to objectively monitor their physical activity at work over 12 weeks. The Incentive Group (n=199) collected points and received rewards for minutes of physical activity completed. The No Incentive Group (n=207) self-monitored their physical activity only. Quality of life (QOL) and absenteeism were assessed at baseline and 6 months follow-up. QOL scores were also converted into productivity estimates using a validated algorithm. The additional costs of the Incentive Group were divided by the additional quality adjusted life years (QALYs) or productivity gained to calculate incremental cost effectiveness ratios (ICERs). Cost-effectiveness acceptability curves (CEACs) and population expected value of perfect information (EVPI) was used to characterize and value the uncertainty in our estimates.

Results: The Incentive Group performed more physical activity over 12 weeks and by 6 months had achieved greater gains in QOL and productivity, although these mean differences were not statistically significant. The ICERs were £2,900/QALY and £2,700 per percentage increase in overall employee productivity. Whilst the confidence intervals surrounding these ICERs were wide, CEACs showed a high chance of the intervention being cost-effective at low willingness-to-pay (WTP) thresholds.

Conclusions: The Physical Activity Loyalty card (PAL) scheme is potentially cost-effective from both a healthcare and employer’s perspective but further research is warranted to reduce uncertainty in our results. It is based on a sustainable “business model” which should become more cost-effective as it is delivered to more participants and can be adapted to suit other health behaviors and settings. This comes at a time when both UK and US governments are encouraging business involvement in tackling public health challenges.

The opportunities and limitations of using CFD in the development of wave energy converters

Most Wave Energy Converters (WECs) being developed are fundamentally different from known marine structures. Limited experience is a fundamental challenge for the design, especially issues concerning load assumptions and power estimates. Reynolds-Averaged Navier-Stokes (RANS) CFD methods are being used successfully in many areas of marine engineering. They have been shown to accurately simulate many hydrodynamic effects and are a helpful tool for investigating complex flows. The major drawback is the significant computational power required and the associated overhead with pre and post-processing. This paper presents the challenges and advantages in the application of RANS CFD methods in the design process of a wave energy converter and compares the time, labour and ultimately financial requirements for obtaining practical results.

Topochemical polymerization in self-assembled rodlike micelles of bisurea bolaamphiphiles

Rod-like micelles, formed from bolaamphiphiles with oligo(ethylene oxide) hydrophilic outer segments and a hydrophobic segment with diacetylene flanked by two urea moieties, were covalently fixated by topochemical photopolymerization to high degrees of polymerization by optimizing the hydrophobic core and the hydrophilic periphery of the bolaamphiphiles. Analysis of the polymerized product with dynamic light scattering in chloroform showed degrees of polymerization of approximately 250. Cryo-TEM of bolaamphiphiles before and after UV irradiation showed that the morphology of the rods was conserved upon topochemical polymerization. © 2014 The Royal Society of Chemistry.