196 research outputs found
Macrophages Are Required for Dendritic Cell Uptake of Respiratory Syncytial Virus from an Infected Epithelium
We have previously shown that the respiratory syncytial virus [RSV] can productively infect monocyte derived dendritic cells [MoDC] and remain dormant within the same cells for prolonged periods. It is therefore possible that infected dendritic cells act as a reservoir within the airways of individuals between annual epidemics. In the present study we explored the possibility that sub-epithelial DCs can be infected with RSV from differentiated bronchial epithelium and that in turn RSV from DCs can infect the epithelium. A dual co-culture model was established in which a differentiated primary airway epithelium on an Air Liquid Interface (ALI) was cultured on a transwell insert and MoDCs were subsequently added to the basolateral membrane of the insert. Further experiments were undertaken using a triple co-culture model in which in which macrophages were added to the apical surface of the differentiated epithelium. A modified RSV [rr-RSV] expressing a red fluorescent protein marker of replication was used to infect either the MoDCs or the differentiated epithelium and infection of the reciprocal cell type was assessed using confocal microscopy. Our data shows that primary epithelium became infected when rr-RSV infected MoDCs were introduced onto the basal surface of the transwell insert. MoDCs located beneath the epithelium did not become infected with virus from infected epithelial cells in the dual co-culture model. However when macrophages were present on the apical surface of the primary epithelium infection of the basal MoDCs occurred. Our data suggests that RSV infected dendritic cells readily transmit infection to epithelial cells even when they are located beneath the basal layer. However macrophages appear to be necessary for the transmission of infection from epithelial cells to basal dendritic cells
Public health interventions for Aedes control in the time of Zikavirus- A metareview on effectiveness of vector control strategies
Background: There is renewed interest in effective control measures to control Zika and dengue vectors. A synthesis of published systematic reviews with a focus on grading of intervention evidence is warranted to determine the reliability of evidence for control strategies. Methodology: We conducted a meta-review (a systematic review of systematic reviews) assessing the effectiveness of any Aedes control measure. We searched Scopus and Medline for relevant reviews through to 11 May 2016. Titles, abstracts and full texts were assessed independently for inclusion by two authors. Data extraction was performed independently in duplicate using a standardised form and validity of the evidence in each review was assessed using GRADE criteria. Findings: 13 eligible systematic reviews that investigated the effect of community interventions on entomological parameters (such as vector density) or disease incidence were included. Quality of evidence was mostly low to very low due to poor reporting of study design, observational methodologies, heterogeneity, and indirect outcomes, hindering an evidence-based recommendation. Biological controls seem to achieve better reduction of entomological indices than chemical controls, while educational campaigns can reduce breeding habitats and interrupt disease transmission cycle. Integrated control strategies may not add efficiency to educational campaigns. Conclusions: Despite decades of Aedes mosquito abatement programmes, mosquito populations are widely established and abundant, and associated with a significant disease burden. The efficiency of any control programme is dependent on local settings and resources. More good quality primary studies for the control of Aedes transmitted diseases are still required
The Recognition of N-Glycans by the Lectin ArtinM Mediates Cell Death of a Human Myeloid Leukemia Cell Line
ArtinM, a d-mannose-binding lectin from Artocarpus heterophyllus (jackfruit), interacts with N-glycosylated receptors on the surface of several cells of hematopoietic origin, triggering cell migration, degranulation, and cytokine release. Because malignant transformation is often associated with altered expression of cell surface glycans, we evaluated the interaction of ArtinM with human myelocytic leukemia cells and investigated cellular responses to lectin binding. The intensity of ArtinM binding varied across 3 leukemia cell lines: NB4>K562>U937. The binding, which was directly related to cell growth suppression, was inhibited in the presence of Manα1-3(Manα1-6)Manβ1, and was reverted in underglycosylated NB4 cells. ArtinM interaction with NB4 cells induced cell death (IC50 = 10 µg/mL), as indicated by cell surface exposure of phosphatidylserine and disruption of mitochondrial membrane potential unassociated with caspase activation or DNA fragmentation. Moreover, ArtinM treatment of NB4 cells strongly induced reactive oxygen species generation and autophagy, as indicated by the detection of acidic vesicular organelles in the treated cells. NB4 cell death was attributed to ArtinM recognition of the trimannosyl core of N-glycans containing a ß1,6-GlcNAc branch linked to α1,6-mannose. This modification correlated with higher levels of N-acetylglucosaminyltransferase V transcripts in NB4 cells than in K562 or U937 cells. Our results provide new insights into the potential of N-glycans containing a β1,6-GlcNAc branch linked to α1,6-mannose as a novel target for anti-leukemia treatment
Blood pressure and associated factors in a North African adolescent population. a national cross-sectional study in Tunisia
<p>Abstract</p> <p>Background</p> <p>In southern and eastern Mediterranean countries, changes in lifestyle and the increasing prevalence of excess weight in childhood are risk factors for high blood pressure (BP) during adolescence and adulthood. The aim of this study was to evaluate the BP status of Tunisian adolescents and to identify associated factors.</p> <p>Methods</p> <p>A cross-sectional study in 2005, based on a national, stratified, random cluster sample of 1294 boys and 1576 girls aged 15-19 surveyed in home visits. The socio-economic and behavioral characteristics of the adolescents were recorded. Overweight/obesity were assessed by Body Mass Index (BMI) from measured height and weight (WHO, 2007), abdominal obesity by waist circumference (WC). BP was measured twice during the same visit. Elevated BP was systolic (SBP) or diastolic blood pressure (DBP) ≥ 90th of the international reference or ≥ 120/80 mm Hg for 15-17 y., and SBP/DBP ≥ 120/80 mm Hg for 18-19 y.; hypertension was SBP/DBP ≥ 95th for 15-17 y. and ≥ 140/90 mm Hg for 18-19 y. Adjusted associations were assessed by logistic regression.</p> <p>Results</p> <p>The prevalence of elevated BP was 35.1%[32.9-37.4]: higher among boys (46.1% vs. 33.3%; <it>P </it>< 0.0001); 4.7%[3.8-5.9] of adolescents had hypertension. Associations adjusted for all covariates showed independent relationships with BMI and WC: - obesity vs. no excess weight increased elevated BP (boys OR = 2.1[1.0-4.2], girls OR = 2.3[1.3-3.9]) and hypertension (boys OR = 3.5[1.4-8.9], girls OR = 5.4[2.2-13.4]), - abdominal obesity (WC) was also associated with elevated BP in both genders (for boys: 2nd vs. 1st tertile OR = 1.7[1.3-2.3], 3rd vs.1st tertile OR = 2.8[1.9-4.2]; for girls: 2nd vs. 1st tertile OR = 1.6[1.2-2.1], 3rd vs.1st tertile OR = 2.1[1.5-3.0]) but only among boys for hypertension. Associations with other covariates were weaker: for boys, hypertension increased somewhat with sedentary lifestyle, while elevated BP was slightly more prevalent among urban girls and those not attending school.</p> <p>Conclusion</p> <p>Within the limits of BP measurement on one visit only, these results suggest that Tunisian adolescents of both genders are likely not spared from early elevated BP. Though further assessment is likely needed, the strong association with overweight/obesity observed suggests that interventions aimed at changing lifestyles to reduce this main risk factor may also be appropriate for the prevention of elevated BP.</p
PI3Kinase signaling in glioblastoma
Glioblastoma (GBM) is the most common primary tumor of the CNS in the adult. It is characterized by exponential growth and diffuse invasiveness. Among many different genetic alterations in GBM, e.g., mutations of PTEN, EGFR, p16/p19 and p53 and their impact on aberrant signaling have been thoroughly characterized. A major barrier to develop a common therapeutic strategy is founded on the fact that each tumor has its individual genetic fingerprint. Nonetheless, the PI3K pathway may represent a common therapeutic target to most GBM due to its central position in the signaling cascade affecting proliferation, apoptosis and migration. The read-out of blocking PI3K alone or in combination with other cancer pathways should mainly focus, besides the cytostatic effect, on cell death induction since sublethal damage may induce selection of more malignant clones. Targeting more than one pathway instead of a single agent approach may be more promising to kill GBM cells
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