Panton-Valentine Leukocidin and Staphyloccoccal Skin Infections in Schoolchildren1

The Panton-Valentine leukocidin is associated with staphylococcal skin and pulmonary infections. We describe a school outbreak of skin infections and the public health response to it. Nasal carriage of a Panton-Valentine leukocidin–positive Staphylococcus aureus clone was detected only in previously ill classmates and their family members

Clonal expansion of mtDNA deletions: different disease models assessed by digital droplet PCR in single muscle cells.

Deletions in mitochondrial DNA (mtDNA) are an important cause of human disease and their accumulation has been implicated in the ageing process. As mtDNA is a high copy number genome, the coexistence of deleted and wild-type mtDNA molecules within a single cell defines heteroplasmy. When deleted mtDNA molecules, driven by intracellular clonal expansion, reach a sufficiently high level, a biochemical defect emerges, contributing to the appearance and progression of clinical pathology. Consequently, it is relevant to determine the heteroplasmy levels within individual cells to understand the mechanism of clonal expansion. Heteroplasmy is reflected in a mosaic distribution of cytochrome c oxidase (COX)-deficient muscle fibers. We applied droplet digital PCR (ddPCR) to single muscle fibers collected by laser-capture microdissection (LCM) from muscle biopsies of patients with different paradigms of mitochondrial disease, characterized by the accumulation of single or multiple mtDNA deletions. By combining these two sensitive approaches, ddPCR and LCM, we document different models of clonal expansion in patients with single and multiple mtDNA deletions, implicating different mechanisms and time points for the development of COX deficiency in these molecularly distinct mitochondrial cytopathies

How context affects transdisciplinary research: insights from Asia, Africa and Latin America

Transdisciplinary research (TDR) has been developed to generate knowledge that effectively fosters the capabilities of various societal actors to realize sustainability transformations. The development of TDR theories, principles, and methods has been largely governed by researchers from the global North and has reflected their contextual conditions. To enable more contextsensitive TDR framing, we sought to identify which contextual characteristics affect the design and implementation of TDR in six case studies in Asia, Latin America, and Africa, and what this means for TDR as a scientific approach. To this end, we distinguished four TDR process elements and identified several associated context dimensions that appeared to influence them. Our analysis showed that contextual characteristics prevalent in many Southern research sites—such as highly volatile socio-political situations and relatively weak support infrastructure—can make TDR a challenging endeavour. However, we also observed a high degree of variation in the contextual characteristics of our sites in the global South, including regarding group deliberation, research freedom, and dominant perceptions of the appropriate relationship between science, society, and policy. We argue that TDR in these contexts requires pragmatic adaptations as well as more fundamental reflection on underlying epistemological concepts around what it means to conduct “good science”, as certain contextual characteristics may influence core epistemological values of TDR

Human papillomavirus genotype distribution and socio-behavioural characteristics in women with cervical pre-cancer and cancer at the start of a human papillomavirus vaccination programme: the CIN3+ plus study.

The Swiss Federal Office of Public Health has recommended vaccination against human papillomavirus (HPV) to prevent cervical cancer since 2008. To establish monitoring of the future public health impact of vaccination, baseline population-based data are required. The objectives of this study were to examine the distribution of oncogenic HPV genotypes in biopsies with cervical intraepithelial neoplasia stage 3 or more severe lesions (CIN3+) at the beginning of HPV vaccination programmes and to compare sociodemographic and behavioural factors of women with CIN3+ with women in the Swiss general population. We conducted a retrospective and prospective cross-sectional study with women diagnosed with CIN3+ in Switzerland. Ten pathology institutes from six cantons and three language regions participated. We conducted HPV typing on formaldehyde fixed-paraffin embedded specimens from 2014 and 2015. Women enrolled in 2015 were asked to complete a questionnaire. We described frequencies of HPV types. We also compared demographic characteristics and socioeconomic status in the CIN3 + plus group with the Swiss National Cohort in 2014 and compared risk factors for HPV infection with the Swiss Health Survey in 2012. We included 768 biopsies from 767 women. Four hundred and seventy-five (61.8%) biopsies were positive for HPV 16 and/or 18, 687 (89.5%) were positive for oncogenic HPV genotypes 16, 18, 31, 33, 45, 52, and/or 58 and five (0.7%) were HPV negative. Twenty-eight (10.3%) of the 273 women who completed the patient questionnaire reported having received at least one dose of an HPV vaccine. When compared with Swiss women in the six study cantons, fewer women in the CIN3+ plus study group were of Swiss nationality, more were born abroad and more were single. The study group also had a higher proportion of women with ≥2 partners in the last year, current smokers and was younger at age of first sexual intercourse. Introduction of the nonavalent vaccine could cover approximately 90% of CIN3+ lesions in Swiss women compared with around 60% with the quadrivalent vaccine. Surveillance of HPV genotype distribution in CIN3+, together with information about vaccination and CIN3+ incidence will allow monitoring of the public health impact of vaccination programmes. ClinicalTrials.gov, NCT02323997 . Registered 24 December 2014

In vitro characterization and inhibition of the CXCR4/CXCL12 chemokine axis in human uveal melanoma cell lines

<p>Abstract</p> <p>Purpose</p> <p>The CXCR4/CXCL12 chemokine axis may play a critical role in guiding CXCR4+ circulating malignant cells to organ specific locations that actively secrete its ligand CXCL12 (SDF-1) such as bone, brain, liver, and lungs. We sought to characterize the presence of the CXCR4/CXCL12 axis in five uveal melanoma (UM) cell lines in vitro. The ability of TN14003, a synthetic peptide inhibitor that targets the CXCR4 receptor complex, to inhibit this axis was also assessed.</p> <p>Methods</p> <p>Immunocytochemistry was performed against CXCR4 to confirm expression of this chemokine receptor in all five UM cell lines. Flow cytometry was preformed to evaluate CXCR4 cell surface expression on all five UM cell lines. A proliferation assay was also used to test effects TN14003 would have on cellular proliferation. Inhibition of cellular migration by specifically inhibiting the CXCR4/CXCL12 axis with TN14003 was also investigated. The binding efficacy of TN14003 to the CXCR4 receptor was assessed through flow cytometric methods.</p> <p>Results</p> <p>The CXCR4 receptor was present on all five UM cell lines. All five cell lines expressed different relative levels of surface CXCR4. TN14003 did not affect the proliferation of the five cell lines (p > 0.05). All cell lines migrated towards the chemokine CXCL12 at a level greater than the negative control (p < 0.05). All 5 cell lines pre-incubated with TN14003 prevented cellular migration towards chemokine CXCL12 (p < 0.01). TN14003 preferentially binds CXCR4 to native ligand CXCL12.</p> <p>Conclusion</p> <p>Interfering with the CXCR4/CXCL12 axis, using TN14003 was shown to effectively down regulate UM cell migration in vitro. Knowing that UM expresses the CXCR4 receptor, these CXCR4+ cells may be less likely to colonize distant organs that secrete the CXCL12 ligand, if treated with an inhibitor that binds CXCR4. Further studies should be pursued in order to test TN14003 efficacy in vivo.</p

Toll-Like Receptor 8 Agonist and Bacteria Trigger Potent Activation of Innate Immune Cells in Human Liver

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.The study was supported by a Grant core funding from the Agency for Science Technology and Research (A*STAR, Singapore) and a Singapore Translational Research Investigator Award (NRMC/StaR/013/2012) to AB as well as NIHR Biomedical Centre, Oxford, WT 091663MA, NIAID1U19AI082630-01, Oxford Martin School funding and an NIHR Senior Investigator award to PK

Targeting Vascular NADPH Oxidase 1 Blocks Tumor Angiogenesis through a PPARα Mediated Mechanism

Reactive oxygen species, ROS, are regulators of endothelial cell migration, proliferation and survival, events critically involved in angiogenesis. Different isoforms of ROS-generating NOX enzymes are expressed in the vasculature and provide distinct signaling cues through differential localization and activation. We show that mice deficient in NOX1, but not NOX2 or NOX4, have impaired angiogenesis. NOX1 expression and activity is increased in primary mouse and human endothelial cells upon angiogenic stimulation. NOX1 silencing decreases endothelial cell migration and tube-like structure formation, through the inhibition of PPARα, a regulator of NF-κB. Administration of a novel NOX-specific inhibitor reduced angiogenesis and tumor growth in vivo in a PPARα dependent manner. In conclusion, vascular NOX1 is a critical mediator of angiogenesis and an attractive target for anti-angiogenic therapies