A European evidence-based guideline for the prevention of type 2 diabetes

BACKGROUND

The prevalence and socioeconomic burden of type 2 diabetes (T2DM) and associated co-morbidities are rising worldwide.

AIMS

This guideline provides evidence-based recommendations for preventing T2DM.

METHODS

A European multidisciplinary consortium systematically reviewed the evidence on the effectiveness of screening and interventions for T2DM prevention using SIGN criteria.

RESULTS

Obesity and sedentary lifestyle are the main modifiable risk factors. Age and ethnicity are non-modifiable risk factors. Case-finding should follow a step-wise procedure using risk questionnaires and oral glucose tolerance testing. Persons with impaired glucose tolerance and/or fasting glucose are at high-risk and should be prioritized for intensive intervention. Interventions supporting lifestyle changes delay the onset of T2DM in high-risk adults (number-needed-to-treat: 6.4 over 1.8-4.6 years). These should be supported by inter-sectoral strategies that create health promoting environments. Sustained body weight reduction by >or= 5 % lowers risk. Currently metformin, acarbose and orlistat can be considered as second-line prevention options. The population approach should use organized measures to raise awareness and change lifestyle with specific approaches for adolescents, minorities and disadvantaged people. Interventions promoting lifestyle changes are more effective if they target both diet and physical activity, mobilize social support, involve the planned use of established behaviour change techniques, and provide frequent contacts. Cost-effectiveness analysis should take a societal perspective.

CONCLUSIONS

Prevention using lifestyle modifications in high-risk individuals is cost-effective and should be embedded in evaluated models of care. Effective prevention plans are predicated upon sustained government initiatives comprising advocacy, community support, fiscal and legislative changes, private sector engagement and continuous media communication.

Sequence alignment reveals possible MAPK docking motifs on HIV proteins

Over the course of HIV infection, virus replication is facilitated by the phosphorylation of HIV proteins by human ERK1 and ERK2 mitogen-activated protein kinases (MAPKs). MAPKs are known to phosphorylate their substrates by first binding with them at a docking site. Docking site interactions could be viable drug targets because the sequences guiding them are more specific than phosphorylation consensus sites. In this study we use multiple bioinformatics tools to discover candidate MAPK docking site motifs on HIV proteins known to be phosphorylated by MAPKs, and we discuss the possibility of targeting docking sites with drugs. Using sequence alignments of HIV proteins of different subtypes, we show that MAPK docking patterns previously described for human proteins appear on the HIV matrix, Tat, and Vif proteins in a strain dependent manner, but are absent from HIV Rev and appear on all HIV Nef strains. We revise the regular expressions of previously annotated MAPK docking patterns in order to provide a subtype independent motif that annotates all HIV proteins. One revision is based on a documented human variant of one of the substrate docking motifs, and the other reduces the number of required basic amino acids in the standard docking motifs from two to one. The proposed patterns are shown to be consistent with in silico docking between ERK1 and the HIV matrix protein. The motif usage on HIV proteins is sufficiently different from human proteins in amino acid sequence similarity to allow for HIV specific targeting using small-molecule drugs.

Plasmonic nanorod metamaterials for biosensing

Label-free plasmonic biosensors rely either on surface plasmon polaritons or on localized surface plasmons on continuous or nanostructured noble-metal surfaces to detect molecular-binding events. Despite undisputed advantages, including spectral tunability, strong enhancement of the local electric field and much better adaptability to modern nanobiotechnology architectures, localized plasmons demonstrate orders of magnitude lower sensitivity compared with their guided counterparts. Here, we demonstrate an improvement in biosensing technology using a plasmonic metamaterial that is capable of supporting a guided mode in a porous nanorod layer. Benefiting from a substantial overlap between the probing field and the active biological substance incorporated between the nanorods and a strong plasmon-mediated energy confinement inside the layer, this metamaterial provides an enhanced sensitivity to refractive-index variations of the medium between the rods (more than 30,000 nm per refractive-index unit). We demonstrate the feasibility of our approach using a standard streptavidin-biotin affinity model and record considerable improvement in the detection limit of small analytes compared with conventional label-free plasmonic devices.

Host sequence motifs shared by HIV predict response to antiretroviral therapy

BACKGROUND

The HIV viral genome mutates at a high rate and poses a significant long term health risk even in the presence of combination antiretroviral therapy. Current methods for predicting a patient's response to therapy rely on site-directed mutagenesis experiments and in vitro resistance assays. In this bioinformatics study we treat response to antiretroviral therapy as a two-body problem: response to therapy is considered to be a function of both the host and pathogen proteomes. We set out to identify potential responders based on the presence or absence of host protein and DNA motifs on the HIV proteome.

RESULTS

An alignment of thousands of HIV-1 sequences attested to extensive variation in nucleotide sequence but also showed conservation of eukaryotic short linear motifs on the protein coding regions. The reduction in viral load of patients in the Stanford HIV Drug Resistance Database exhibited a bimodal distribution after 24 weeks of antiretroviral therapy, with 2,000 copies/ml cutoff. Similarly, patients allocated into responder/non-responder categories based on consistent viral load reduction during a 24 week period showed clear separation. In both cases of phenotype identification, a set of features composed of short linear motifs in the reverse transcriptase region of HIV sequence accurately predicted a patient's response to therapy. Motifs that overlap resistance sites were highly predictive of responder identification in single drug regimens but these features lost importance in defining responders in multi-drug therapies.

CONCLUSION

HIV sequence mutates in a way that preferentially preserves peptide sequence motifs that are also found in the human proteome. The presence and absence of such motifs at specific regions of the HIV sequence is highly predictive of response to therapy. Some of these predictive motifs overlap with known HIV-1 resistance sites. These motifs are well established in bioinformatics databases and hence do not require identification via in vitro mutation experiments.

Heritable interleukin-17F (IL17F) gene variation and overall survival (OS) in pancreatic cancer patients (pts): Results from a genome-wide association study (GWAS) in CALGB 80303

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Background: CALGB 80303 was a randomized, phase III study in 602 advanced pancreatic cancer (PC) pts treated with gemcitabine plus either bevacizumab or placebo. No difference in OS was observed between the two arms (Kindler, ASCO 2007). As part of the study, we prospectively collected germline DNA for pharmacogenetic studies, originally focusing on the association of candidate genes with OS and toxicity. We subsequently amended the study to conduct a GWAS in order to identify other associations. Methods: Germline DNA was isolated from peripheral blood on 352 pts, and was typed for more than 550,000 SNPs using the Illumina550 platform. The associations between OS and SNPs were investigated using the log-rank test. A review of the clinical data and ancestry genomic analysis identified 294 pts who were clinically eligible and determined to be genetically European, and this subset was used for the primary analysis. Results: For the analysis of OS, pts in both arms were pooled, and two SNPs were associated with OS using genome-wide criteria (p≤10–7). This included an intergenic SNP on chromosome 15 (rs7174643), and a nonsynonymous SNP in the IL17F gene ( rs763780 ) with an allelic frequency of 3.9% (H161R, p<2.7x10–8). Median OS was significantly shorter for the H/R heterozygotes (3.1 months, 95% CI 2.3–4.3, n=23), as compared to the H/H homozygotes (6.8 months, 95% CI 5.8–7.3, n=271). This association remained highly significant when the analysis was stratified by extent of disease or previous radiotherapy. There was no evidence of an interaction with bevacizumab, suggesting that this SNP is prognostic rather than predictive. Conclusions: Heritable variation in IL17F may be a prognostic marker for PC. Wildtype (161H) IL17F is a pro-inflammatory, anti-angiogenic cytokine (Starnes, J Immunol 2001). The 161R mutant IL17F antagonizes wildtype IL17F (Kawaguchi, J Allergy Clin Immunol, 2006), potentially resulting in a pro-angiogenic effect. Replication studies in PC and other solid tumors are indicated.

[Table: see text]

Prediction of HIV-1 virus-host protein interactions using virus and host sequence motifs

Background

Host protein-protein interaction networks are altered by invading virus proteins, which create new interactions, and modify or destroy others. The resulting network topology favors excessive amounts of virus production in a stressed host cell network. Short linear peptide motifs common to both virus and host provide the basis for host network modification.

Methods

We focused our host-pathogen study on the binding and competing interactions of HIV-1 and human proteins. We showed that peptide motifs conserved across 70% of HIV-1 subtype B and C samples occurred in similar positions on HIV-1 proteins, and we documented protein domains that interact with these conserved motifs. We predicted which human proteins may be targeted by HIV-1 by taking pairs of human proteins that may interact via a motif conserved in HIV-1 and the corresponding interacting protein domain.

Results

Our predictions were enriched with host proteins known to interact with HIV-1 proteins ENV, NEF, and TAT (p-value < 4.26E-21). Cellular pathways statistically enriched for our predictions include the T cell receptor signaling, natural killer cell mediated cytotoxicity, cell cycle, and apoptosis pathways. Gene Ontology molecular function level 5 categories enriched with both predicted and confirmed HIV-1 targeted proteins included categories associated with phosphorylation events and adenyl ribonucleotide binding.

Conclusion

A list of host proteins highly enriched with those targeted by HIV-1 proteins can be obtained by searching for host protein motifs along virus protein sequences. The resulting set of host proteins predicted to be targeted by virus proteins will become more accurate with better annotations of motifs and domains. Nevertheless, our study validates the role of linear binding motifs shared by virus and host proteins as an important part of the crosstalk between virus and host.

Is there a link between problem-based learning and emotional intelligence?

A brief description of problem-based learning is given and reference is made to the difficulties in demonstrating its value in terms of 'accumulated knowledge' with respect to the literature. The author suggests that problem-based learning may be a suitable curriculum component for developing a student's emotional intelligence.

Guided plasmonic modes in nanorod assemblies: strong electromagnetic coupling regime

We demonstrate that the coupling between plasmonic modes of oriented metallic nanorods results in the formation of an extended (guided) plasmonic mode of the nanorod array. The electromagnetic field distribution associated to this mode is found to be concentrated between the nanorods within the assembly and propagates normally to the nanorod long axes, similar to a photonic mode waveguided by an anisotropic slab. This collective plasmonic mode determines the optical properties of nanorod assemblies and can be tuned in a wide spectral range by changing the nanorod array geometry. This geometry represents a unique opportunity for light guiding applications and manipulation at the nanoscale as well as sensing applications and development of molecular plasmonic devices.

Occurrence of synchronous invasive lobular breast carcinoma and poorly differentiated ovarian carcinoma in a single peritoneal deposit

The synchronous occurrence of breast and ovarian cancers within individual omental metastases has not been reported in the available medical literature. We report such a finding in a patient with previously diagnosed invasive lobular carcinoma of the right breast. After 5 years of surveillance and disease-free interval, there was development of ovarian cancer, ascites and peritoneal metastases. Ultrasound-guided biopsy of a peritoneal metastasis confirmed dual histology from breast and ovarian carcinoma. Despite the presence of a prolonged disease-free survival from the primary breast cancer, the subsequent finding of advanced ovarian cancer highlights the potential diagnostic and therapeutic dilemmas which persist in the management of these patients.

Cortisol secretory activity in older people in relation to positive and negative well-being

Secretion of the hormone cortisol, a physiological correlate of affect, has been studied mostly in relation to negative states, especially stress. By contrast, policy initiatives aimed at older populations now routinely emphasise well-being and a 'positive ageing' perspective. In this study, we examined diurnal salivary cortisol profiles from 50 active seniors recruited into a wider community research project (mean age 74 years; 34 F/16 M). Participants' wrist activity was continuously monitored by actimeters in their homes over a 48 h period. During this time two diurnal cycles of cortisol data were collected (8 samples per day); with actimeter data providing a compliance check in regard to timing of self-administered saliva collections. Prior to the trial, participants had completed the GHQ-30 which was scored separately to yield both positive and negative well-being scores which matched closely normative data from over 6000 cases in a large survey. Our data suggest that positive and negative psychological well-being are quite strongly and inversely correlated. However, neither on their own was associated with basal levels of cortisol. Rather, for cortisol secretion in the 45-min period following awakening, but not during the rest of the day, we found a significant interaction between positive and negative well-being (p<0.024). Further analysis of this interaction showed that among participants low on negative well-being, higher positive well-being was significantly associated with lower cortisol; equally, among participants high on positive well-being, lower negative well-being was significantly associated with lower cortisol. Thus, a powerful synergy seemed to be operating in this early morning period such that cortisol secretion was 27% lower in participants with both higher-than-average positive well-being and lower-than-average negative well-being (comprising 34% of the sample). We conclude that cortisol secretion in the first 45 min following awakening is distinct from the rest of the day and most able to discriminate well-being states.