METHODS: Human pulmonary microvascular endothelial cells were treated with VEGF and a VEGF/anti-VEGF combination. The effects of the treatments were studied using an endothelial permeability assay and microarray gene expression profiling. In the permeability assay, the fluorescein isothiocyanate (FITC)-dextran fluorescence signal across the endothelial monolayer was recorded, and the cells were stained with PECAM-1 to detect gap formation. RNA was extracted from treated cells for microarray gene profiling and analysis. The results were analyzed for differentially expressed genes (DEGs) and gene enrichment analysis. The DEGs were subjected to STRING to construct the protein-protein interaction network and then Cytoscape to identify the hub genes.
RESULTS: VEGF-treated endothelial cells showed greater movement of FITC-dextran across the monolayer than VEGF/anti-VEGF-treated cells. There were 111 DEGs for VEGF-treated cells and 118 DEGs for VEGF/anti-VEGF-treated cells. The genes upregulated in VEGF-treated cells were enriched in inflammatory responses and regulation of the endothelial barrier, nitric oxide synthesis, angiogenesis, and the nucleotide-binding oligomerization domain-like receptor signaling pathway. Top 10 hub genes were identified from the DEGs.
CONCLUSIONS: VEGF treatment increased permeability across endothelial cells, while anti-VEGF reduced this leakage. Analysis of VEGF-treated endothelial cells identified hub genes implicated in severe dengue. The top 10 hub genes were TNF, IL1B, IL6, CCL2, PTGS2, ICAM1, CXCL2, CXCL1, CSF2, and TLR2. The results of this study show that using anti-VEGF antibodies to neutralize VEGF may be a promising therapy to prevent the progression of dengue to severe dengue.
METHODS: As a preliminary work, water droplets of 1.5 μL were placed on the surfaces of hydroxyapatite (HA) discs of different densities. The water droplet profile was dynamically recorded every second over a period of 10 s using a contact angle meter to determine the relationship between sorptivity and density. To measure and calculate sorptivity on enamel surfaces, varnish was painted on the labial surface of 96 extracted caries-free human teeth, leaving two 1.4 ± 0.1 mm diameter circular exposed test sites. The specimens were randomly divided into 6 groups (n = 16) and subjected to 0(G0), 7(G7), 14(G14), 21(G21), 28(G28) and 35(G35) days of pH cycling, respectively. A 0.7 μL water droplet was placed on each exposed site and Optical Coherence Tomography was used to measure its height every 10 seconds for 2 min. Sorptivity was computed by considering sorption equations and Washburn's analysis of capillary kinetics and correction for evaporation was also performed. Micro-Computed Tomography scans of the specimens were obtained and delta Z (ΔZ) is the parameter used to measure mineral loss. ΔZ at 10 μm (ΔZ10) and 50 μm (ΔZ50) from the surface were calculated. One-way ANOVA and Post-hoc Tukey tests were used to compare sorptivity between groups and bivariate correlations were used to analyze the association between sorptivity and ΔZ.
RESULTS: Sorptivity was found to be inversely and linearly correlated with HA density with R2 value of 0.95. With enamel, there is a general trend of increase in mean sorptivity from G0 to G35, except for a decrease in G21. The same trends were observed for both ΔZ10 and ΔZ50. The decrease in sorptivity in G21 coincided with the presence of a surface hypermineralized layer in G21 samples. Post-hoc Tukey showed significant differences in mean sorptivity between G0 and G14, G0 and G21 as well as G14 and G21. Post-hoc Dunnett's T3 showed significant differences for ΔZ10 between G0 and G14 as well as G14 and G21. Significant correlation between mean sorptivity and ΔZ10 was detected with Pearson correlation coefficient of 0.461. For ΔZ50, post-hoc Tukey showed significant differences between G0 and G14 but no significant difference was detected between G14 and G21. No correlations were detected between mean sorptivity and ΔZ50.
SIGNIFICANCE: Sorptivity was found to be inversely and linearly correlated with HA density with R2 value of 0.95. With enamel, there is a general trend of increase in mean sorptivity from G0 to G35, except for a decrease in G21. The same trends were observed for both ΔZ10 and ΔZ50. The decrease in sorptivity in G21 coincided with the presence of a surface hypermineralized layer in G21 samples.
METHODS: Various databases were used to search relevant articles since 1995. Studies included were cohort and cross-sectional studies, all patients with dengue infection and must report the number of death or case fatality rate. The Joanna Briggs Institute appraisal checklist was used to evaluate the risk of bias of the full-texts. The studies were grouped according to the classification adopted: WHO 1997 and WHO 2009. Meta-regression was employed using a logistic transformation (log-odds) of the case fatality rate. The result of the meta-regression was the adjusted case fatality rate and odds ratio on the explanatory variables.
RESULTS: A total of 77 studies were included in the meta-regression analysis. The case fatality rate for all studies combined was 1.14% with 95% confidence interval (CI) of 0.82-1.58%. The combined (unadjusted) case fatality rate for 69 studies which adopted WHO 1997 dengue case classification was 1.09% with 95% CI of 0.77-1.55%; and for eight studies with WHO 2009 was 1.62% with 95% CI of 0.64-4.02%. The unadjusted and adjusted odds ratio of case fatality using WHO 2009 dengue case classification was 1.49 (95% CI: 0.52, 4.24) and 0.83 (95% CI: 0.26, 2.63) respectively, compared to WHO 1997 dengue case classification. There was an apparent increase in trend of case fatality rate from the year 1992-2016. Neither was statistically significant.
CONCLUSIONS: The WHO 2009 dengue case classification might have no effect towards the case fatality rate although the adjusted results indicated a lower case fatality rate. Future studies are required for an update in the meta-regression analysis to confirm the findings.