13 research outputs found
Abusive head trauma among children in Alaska: a population-based assessment
BackgroundSerious physical abuse resulting in a traumatic brain injury (TBI) has been implicated as an underreported cause of infant mortality. Nearly 80% of all abusive head trauma (AHT) occurs among children <2 years of age, with infants experiencing an incidence nearly 8 times that of 2-year olds.ObjectiveThis study describes the validation of the CDC Pediatric Abusive Head Trauma (PAHT) definitions when applied to a multi-source database at the state level and provides a robust annual incidence estimate of AHT among children <2 years of age in Alaska.DesignAHT cases among children residing in Alaska during 2005–2010 were identified by applying the PAHT coding schema to a multi-source database which included vital death records, the Violent Death Reporting System (AK-VDRS), the Maternal Infant Mortality Review – Child Death Review (MIMR-CDR), the Alaska Trauma Registry (ATR), the inpatient Hospital Discharge Database (HDD) and Medicaid claims. Using these data, we calculated statewide AHT annual incidence rates.ResultsThe databases with the highest case capture rates were the ATR and Medicaid systems, both at 51%, followed by HDD at 38%. Combined, the ATR, HDD and Medicaid systems captured 91% of all AHT cases. The linkage and use of the PAHT definitions yielded an estimated sensitivity of 91% and specificity of 98%. During the study period, we detected an annual average incidence of 34.4 cases per 100,000 children aged <2 years (95% CI 25.1, 46.1) and a case fatality proportion of 22% (10/45). Among the AHT cases, 82% were infants. Significant differences (p < 0.05) in AHT were noted by age and race, but not by sex.ConclusionsIn Alaska, applying the CDC PAHT definition to the multi-source database enabled us to capture 49% more AHT cases than any of the individual database used in this analysis alone
Silexan does not affect driving performance after single and multiple dose applications: Results from a double-blind, placebo and reference-controlled study in healthy volunteers
Anxiolytic drugs often have sedative effects that impair the ability to drive. Our double-blind, randomized crossover trial investigated the effect of Silexan, a non-sedating, anxiolytic herbal medicinal product, on driving performance in healthy volunteers. Part 1 aimed at demonstrating equivalence between 80 mg/d Silexan and placebo. Part 2 was performed to demonstrate superiority of 160 and 320 mg Silexan over 1 mg lorazepam and included a placebo arm for assay sensitivity. Driving performance was assessed in a validated, alcohol-calibrated simulator test. The primary outcome was the standard deviation of the lane position (SDLP). Secondary outcomes included driving errors and sleepiness. Fifty and 25 subjects were randomized in Parts 1 and 2, respectively. In Part 1, Silexan 80 mg was confirmed to be equivalent to placebo after single administration (equivalence range: δ = ±2 cm). The 95% confidence interval (CI) for the SDLP marginal mean value difference Silexan-placebo for single administration was -1.43; +1.38 and thus similar to the 95% CI of -1.45; +0.79 cm for 7 days' multiple dosing. In Part 2, 95% CIs for SDLP marginal mean value differences to lorazepam were -8.58; -5.42 cm for Silexan 160 mg and -8.65; -5.45 cm for 320 mg (p < 0.001). Confirmatory results were supported by secondary outcomes, where results for Silexan were comparable to placebo and more favorable than for lorazepam. The study demonstrates that single doses of up to 320 mg Silexan and multiple doses of 80 mg/d have no adverse effect on driving performance
Direct binding of hepatocyte growth factor and vascular endothelial growth factor to CD44v6
Volz Y, Koschut D, Matzke-Ogi A, et al. Direct binding of hepatocyte growth factor and vascular endothelial growth factor to CD44v6. Bioscience Reports. 2015;35(4): e00236.CD44v6, a member of the CD44 family of transmembrane glycoproteins is a co-receptor for two receptor tyrosine kinases (RTKs), Met and VEGFR-2 (vascular endothelial growth factor receptor 2). CD44v6 is not only required for the activation of these RTKs but also for signalling. In order to understand the role of CD44v6in Met and VEGFR-2 activation and signalling we tested whether CD44v6 binds to their ligands, HGF (hepatocyte growth factor) and VEGF (vascular endothelial growth factor), respectively. FACS analysis and cellular ELISA showed binding of HGF and VEGF only to cells expressing CD44v6. Direct binding of CD44v6 to HGF and VEGF was demonstrated in pull-down assays and the binding affinities were determined using MicroScale Thermophoresis, fluorescence correlation spectroscopy and fluorescence anisotropy. The binding affinity of CD44v6 to HGF is in the micromolar range in contrast with the high-affinity binding measured in the case of VEGF and CD44v6, which is in the nanomolar range. These data reveal a heparan sulfate-independent direct binding of CD44v6 to the ligands of Met and VEGFR-2 and suggest different roles of CD44v6 for these RTKs
Platelet lamellipodium formation is not required for thrombus formation and stability
During platelet spreading, the actin cytoskeleton undergoes rapid rearrangement, forming filopodia and lamellipodia. Controversial data have been published on the role of lamellipodia in thrombus formation and stability. The Wiskott-Aldrich syndrome protein-family verprolin-homologous protein (WAVE)-regulatory complex, which has been shown in other cells to drive lamellipodium formation by enhancing actin nucleation via the actin-related protein 2/3 (Arp2/3) complex, is activated by Ras-related C3 botulinum toxin substrate 1 (Rac1) interaction with the WAVE complex subunit cytoplasmic fragile X mental retardation 1–interacting protein 1 (Cyfip1). We analyzed Cyfip1flox/floxPf4-Cre mice to investigate the role of Cyfip1 in platelet function. These mice displayed normal platelet counts and a slight reduction in platelet volume. Activation of mutant platelets was only moderately reduced to all tested agonists as measured by αIIbβ3 integrin activation and P-selectin surface exposure. However, lamellipodium formation of mutant platelets was completely abolished on different matrices. Nevertheless, Cyfip1-deficient platelets formed stable thrombi on collagen fibers ex vivo and in 2 models of occlusive arterial thrombosis in vivo. Similarly, the hemostatic function and maintenance of vascular integrity during inflammation of the skin and lung were unaltered in the mutant mice. Investigation of platelet morphology in an induced thrombus under flow revealed that platelets rather form filopodia in the thrombus shell, and are flattened with filopodium-like structures when in direct contact to collagen fibers at the bottom of the thrombus. We provide for the first time direct evidence that platelet lamellipodium formation is not required for stable thrombus formation, and that morphological changes of platelets differ between a static spreading assay and thrombus formation under flow
Direct binding of hepatocyte growth factor and vascular endothelial growth factor to CD44v6
31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two
Background
The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd.
Methods
We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background.
Results
First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001).
Conclusions
In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival