485 research outputs found
Codi-strat - an interdisciplinary network geared towards sustainable management of chronic and infective diseases
A collaborative effort of clinicians, infectologists, molecular biologists, pharmacologists,
veterinarians, bioinformaticians, management and education specialists is united in order to
develop novel strategies of detecting early stages of chronic and infective diseases, their
prevention and therapy. CODI-STRAT integrates 15 centers conducting leading–edge
research of chronic inflammatory/infective diseases from seven European (five
Mediterranean) countries and the USA, with specific aims to: i) establish long-standing
partner center cross-disciplinary collaborations for clinical studies and research, ii) provide
young investigators with broad and content-driven training and employability and iii)
promote scientists up-skilled in genomics, transcriptomics, tissue expression, human
serological and genetic studies, bioinformatics, chip technology, cell cultures and animal
models, all directed toward clinical translation and chronic/infective disease management.
This manuscript outlines the goals, partner roles and development of CODI-STRAT and its
programme.peer-reviewe
Mechanism of effector capture and delivery by the type IV secretion system from Legionella pneumophila
Legionella pneumophila is a bacterial pathogen that utilises a Type IV secretion (T4S) system to inject effector proteins into human macrophages. Essential to the recruitment and delivery of effectors to the T4S machinery is the membrane-embedded T4 coupling complex (T4CC). Here, we purify an intact T4CC from the Legionella membrane. It contains the DotL ATPase, the DotM and DotN proteins, the chaperone module IcmSW, and two previously uncharacterised proteins, DotY and DotZ. The atomic resolution structure reveals a DotLMNYZ hetero-pentameric core from which the flexible IcmSW module protrudes. Six of these hetero-pentameric complexes may assemble into a 1.6-MDa hexameric nanomachine, forming an inner membrane channel for effectors to pass through. Analysis of multiple cryo EM maps, further modelling and mutagenesis provide working models for the mechanism for binding and delivery of two essential classes of Legionella effectors, depending on IcmSW or DotM, respectively
The proteins DotY and DotZ modulate the dynamics and localization of the type IVB coupling complex of Legionella pneumophila
Legionella pneumophila is an opportunistic pathogen infecting alveolar macrophages and protozoa species. Legionella utilizes a Type IV Secretion System (T4SS) to translocate over 300 effector proteins into its host cell. In a recent study, we isolated and solved the cryo-EM structure of the Type IV Coupling Complex (T4CC), a large cytoplasmic determinant associated with the inner membrane that recruits effector proteins for delivery to the T4SS for translocation. The T4CC is composed of a DotLMNYZ hetero-pentameric core from which the flexible IcmSW module flexibly protrudes. The DotY and DotZ proteins were newly reported members of this complex and their role remained elusive. In this study, we observed the effect of deleting DotY and DotZ on T4CC stability and localization. Furthermore, we found these two proteins are co-dependent, whereby the deletion of DotY resulted in DotZ absence from the coupling complex, and vice versa. Additional cryo-EM data analysis revealed the dynamic movement of the IcmSW module is modified by the DotY/Z proteins. We therefore determined the likely function of DotY and DotZ and revealed their importance on T4CC function
Menopausal hormone use and ovarian cancer risk: individual participant meta-analysis of 52 epidemiological studies
Background Half the epidemiological studies with information about menopausal hormone therapy and ovarian cancer risk remain unpublished, and some retrospective studies could have been biased by selective participation or recall. We aimed to assess with minimal bias the effects of hormone therapy on ovarian cancer risk. Methods Individual participant datasets from 52 epidemiological studies were analysed centrally. The principal analyses involved the prospective studies (with last hormone therapy use extrapolated forwards for up to 4 years). Sensitivity analyses included the retrospective studies. Adjusted Poisson regressions yielded relative risks (RRs) versus never-use. Findings During prospective follow-up, 12 110 postmenopausal women, 55% (6601) of whom had used hormone therapy, developed ovarian cancer. Among women last recorded as current users, risk was increased even with <5 years of use (RR 1·43, 95% CI 1·31–1·56; p<0·0001). Combining current-or-recent use (any duration, but stopped <5 years before diagnosis) resulted in an RR of 1·37 (95% CI 1·29–1·46; p<0·0001); this risk was similar in European and American prospective studies and for oestrogen-only and oestrogen-progestagen preparations, but differed across the four main tumour types (heterogeneity p<0·0001), being definitely increased only for the two most common types, serous (RR 1·53, 95% CI 1·40–1·66; p<0·0001) and endometrioid (1·42, 1·20–1·67; p<0·0001). Risk declined the longer ago use had ceased, although about 10 years after stopping long-duration hormone therapy use there was still an excess of serous or endometrioid tumours (RR 1·25, 95% CI 1·07–1·46, p=0·005). Interpretation The increased risk may well be largely or wholly causal; if it is, women who use hormone therapy for 5 years from around age 50 years have about one extra ovarian cancer per 1000 users and, if its prognosis is typical, about one extra ovarian cancer death per 1700 users
Mouse DRG Cell Line with Properties of Nociceptors
In vitro cell lines from DRG neurons aid drug discovery because they can be used for early stage, high-throughput screens for drugs targeting pain pathways, with minimal dependence on animals. We have established a conditionally immortal DRG cell line from the Immortomouse. Using immunocytochemistry, RT-PCR and calcium microfluorimetry, we demonstrate that the cell line MED17.11 expresses markers of cells committed to the sensory neuron lineage. Within a few hours under differentiating conditions, MED17.11 cells extend processes and following seven days of differentiation, express markers of more mature DRG neurons, such as NaV1.7 and Piezo2. However, at least at this time-point, the nociceptive marker NaV1.8 is not expressed, but the cells respond to compounds known to excite nociceptors, including the TRPV1 agonist capsaicin, the purinergic receptor agonist ATP and the voltage gated sodium channel agonist, veratridine. Robust calcium transients are observed in the presence of the inflammatory mediators bradykinin, histamine and norepinephrine. MED17.11 cells have the potential to replace or reduce the use of primary DRG culture in sensory, pain and developmental research by providing a simple model to study acute nociception, neurite outgrowth and the developmental specification of DRG neurons
Elevated 1-hour plasma glucose levels are associated with dysglycemia, impaired beta-cell function, and insulin sensitivity: a pilot study from a real world health care setting
Worldwide trends in diabetes since 1980: a pooled analysis of 751 population-based studies with 4.4 million participants
BACKGROUND: One of the global targets for non-communicable diseases is to halt, by 2025, the rise in the age-standardised adult prevalence of diabetes at its 2010 levels. We aimed to estimate worldwide trends in diabetes, how likely it is for countries to achieve the global target, and how changes in prevalence, together with population growth and ageing, are affecting the number of adults with diabetes. METHODS: We pooled data from population-based studies that had collected data on diabetes through measurement of its biomarkers. We used a Bayesian hierarchical model to estimate trends in diabetes prevalence—defined as fasting plasma glucose of 7·0 mmol/L or higher, or history of diagnosis with diabetes, or use of insulin or oral hypoglycaemic drugs—in 200 countries and territories in 21 regions, by sex and from 1980 to 2014. We also calculated the posterior probability of meeting the global diabetes target if post-2000 trends continue. FINDINGS: We used data from 751 studies including 4 372 000 adults from 146 of the 200 countries we make estimates for. Global age-standardised diabetes prevalence increased from 4·3% (95% credible interval 2·4–7·0) in 1980 to 9·0% (7·2–11·1) in 2014 in men, and from 5·0% (2·9–7·9) to 7·9% (6·4–9·7) in women. The number of adults with diabetes in the world increased from 108 million in 1980 to 422 million in 2014 (28·5% due to the rise in prevalence, 39·7% due to population growth and ageing, and 31·8% due to interaction of these two factors). Age-standardised adult diabetes prevalence in 2014 was lowest in northwestern Europe, and highest in Polynesia and Micronesia, at nearly 25%, followed by Melanesia and the Middle East and north Africa. Between 1980 and 2014 there was little change in age-standardised diabetes prevalence in adult women in continental western Europe, although crude prevalence rose because of ageing of the population. By contrast, age-standardised adult prevalence rose by 15 percentage points in men and women in Polynesia and Micronesia. In 2014, American Samoa had the highest national prevalence of diabetes (>30% in both sexes), with age-standardised adult prevalence also higher than 25% in some other islands in Polynesia and Micronesia. If post-2000 trends continue, the probability of meeting the global target of halting the rise in the prevalence of diabetes by 2025 at the 2010 level worldwide is lower than 1% for men and is 1% for women. Only nine countries for men and 29 countries for women, mostly in western Europe, have a 50% or higher probability of meeting the global target. INTERPRETATION: Since 1980, age-standardised diabetes prevalence in adults has increased, or at best remained unchanged, in every country. Together with population growth and ageing, this rise has led to a near quadrupling of the number of adults with diabetes worldwide. The burden of diabetes, both in terms of prevalence and number of adults affected, has increased faster in low-income and middle-income countries than in high-income countries. FUNDING: Wellcome Trust
Synergistic Effects of a Mixture of Glycosaminoglycans to Inhibit Adipogenesis and Enhance Chondrocyte Features in Multipotent Cells
Background/Aims: Multipotent mesenchymal stem cells affect homeostasis of adipose and joint tissues. Factors influencing their differentiation fate are of interest for both obesity and joint problems. We studied the impact of a mixture of glycosaminoglycans (GAGs) (hyaluronic acid: dermatan sulfate 1:0.25, w/w) used in an oral supplement for joint discomfort (Oralvisc™) on the differentiation fate of multipotent cells. Methods: Primary mouse embryo fibroblasts (MEFs) were used as a model system. Post-confluent monolayer MEF cultures non-stimulated or hormonally stimulated to adipogenesis were chronically exposed to the GAGs mixture, its individual components or vehicle. The appearance of lipid laden cells, lipid accumulation and expression of selected genes at the mRNA and protein level was assessed. Results: Exposure to the GAGs mixture synergistically suppressed spontaneous adipogenesis and induced the expression of cartilage extracellular matrix proteins, aggrecan core protein, decorin and cartilage oligomeric matrix protein. Hormonally-induced adipogenesis in the presence of the GAGs mixture resulted in decreased adipogenic differentiation, down-regulation of adipogenic/lipogenic factors and genes for insulin resistance-related adipokines (resistin and retinol binding protein 4), and up-regulation of oxidative metabolism-related genes. Adipogenesis in the presence of dermatan sulfate, the minor component of the mixture, was not impaired but resulted in smaller lipid droplets and the induction of a more complete brown adipocyte-related transcriptional program in the cells in the adipose state. Conclusions: The Oralvisc™ GAGs mixture can tip the adipogenic/chondrogenic fate balance of multipotent cells away from adipogenesis while favoring chondrocyte related gene expression. The mixture and its dermatan sulfate component also have modulatory effects of interest on hormonally-induced adipogenesis and on metabolic and secretory capabilities of adipose cells
Risk of brain tumours in relation to estimated RF dose from mobile phones: results from five Interphone countries
OBJECTIVES: The objective of this study was to examine the associations of brain tumours with radio frequency (RF) fields from mobile phones. METHODS: Patients with brain tumour from the Australian, Canadian, French, Israeli and New Zealand components of the Interphone Study, whose tumours were localised by neuroradiologists, were analysed. Controls were matched on age, sex and region and allocated the 'tumour location' of their matched case. Analyses included 553 glioma and 676 meningioma cases and 1762 and 1911 controls, respectively. RF dose was estimated as total cumulative specific energy (TCSE; J/kg) absorbed at the tumour's estimated centre taking into account multiple RF exposure determinants. RESULTS: ORs with ever having been a regular mobile phone user were 0.93 (95% CI 0.73 to 1.18) for glioma and 0.80 (95% CI 0.66 to 0.96) for meningioma. ORs for glioma were below 1 in the first four quintiles of TCSE but above 1 in the highest quintile, 1.35 (95% CI 0.96 to 1.90). The OR increased with increasing TCSE 7+ years before diagnosis (p-trend 0.01; OR 1.91, 95% CI 1.05 to 3.47 in the highest quintile). A complementary analysis in which 44 glioma and 135 meningioma cases in the most exposed area of the brain were compared with gliomas and meningiomas located elsewhere in the brain showed increased ORs for tumours in the most exposed part of the brain in those with 10+ years of mobile phone use (OR 2.80, 95% CI 1.13 to 6.94 for glioma). Patterns for meningioma were similar, but ORs were lower, many below 1.0. CONCLUSIONS: There were suggestions of an increased risk of glioma in long-term mobile phone users with high RF exposure and of similar, but apparently much smaller, increases in meningioma risk. The uncertainty of these results requires that they be replicated before a causal interpretation can be made
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