Evaluation of different internal standards for precious metals quantification

The current study involved the evaluation of five different internal standards (Sc, Co, Y, In and La) as well as normal external or direct calibration methods in the simultaneous quantification of all six platinum group metals (PGMs) and gold (precious metals). The use of Sc as internal standard in the quantitative determination of precious metals in a liquid reference material (RM) and the geological Pyroxenite CRM was shown to yield excellent recoveries (> 99%) compared to the other metals used as internal standard in this study and the direct calibration method (> 91 %).Os recovered only 89% of the expected metal content. The evaluation of different proposed models (wavelength combinations, ionization and/or excitation energy) did not succeed in identifying or discriminating between the unsuccessful and successful internal standards. The robustness of the Sc internal standard addition method was evaluated with the variation in solution matrix (addition of HCl and NaCl). The analytical method (total metal recovery) proved to be very sensitive to elevated unmatched HCl matrix levels (above 1.0 mL of HCl (32% v/v) added) and Na+ addition larger than 4 ppm sodium using ICP-OES. KEY WORDS: Internal standard, Scandium, Precious metals, Spectrometric techniques, ICP-OES Bull. Chem. Soc. Ethiop. 2016, 30(1), 55-70.DOI: http://dx.doi.org/10.4314/bcse.v30i1.

Characterization of a novel fusion gene EML4-NTRK3 in a case of recurrent congenital fibrosarcoma

We describe the clinical course of a recurrent case of congenital fibrosarcoma diagnosed in a 9-mo-old boy with a history of hemimelia. Following complete surgical resection of the primary tumor, the patient subsequently presented with bulky bilateral pulmonary metastases 6 mo following surgery. Molecular characterization of the tumor revealed the absence of the prototypical ETV6-NTRK3 translocation. However, tumor characterization incorporating cytogenetic, array comparative genomic hybridization, and RNA sequencing analyses, revealed a somatic t(2;15)(2p21;15q25) translocation resulting in the novel fusion of EML4 with NTRK3. Cloning and expression of EML4-NTRK3 in murine fibroblast NIH 3T3 cells revealed a potent tumorigenic phenotype as assessed in vitro and in vivo. These results demonstrate that multiple fusion partners targeting NTRK3 can contribute to the development of congenital fibrosarcoma

Factors affecting diet, habitat selection and breeding success of the African Crowned Eagle Stephanoaetus coronatus in a fragmented landscape

This study aimed to identify variables that affect habitat selection and nesting success of the African Crowned Eagle Stephanoaetus coronatus, the largest forest raptor, in north-eastern South Africa. A preference for nesting in the Northern Mistbelt Forest vegetation type was established and 82% of all nests were located in indigenous trees. Nest abandonment was less common when distances to the nearest neighbour were greater. The diet of this species was investigated by examination of prey remains beneath nests and verified by comparison with museum specimens. In total, 156 remains were found, representing a minimum of 75 prey individuals. The diet of African Crowned Eagles constituted almost entirely mammals (99%), which were predominantly antelopes (61%) and monkeys (25%). It was also found that the proportion of primates in the diet correlates with latitude: populations in equatorial latitudes have a higher proportion of primates in their diets, whereas further south antelopes are a much more common diet component

Livelihoods, Land and Political Economy: Reflections on Sam Moyo’s Research Methodology

This article focuses on the methodological lessons from Sam Moyo’s scholarship. Sam’s research is characterised by a combination of detailed empirical investigation, deep knowledge of the technical and practical aspects of agricultural production and farming livelihoods, and bigpicture political economy analysis and theory. Sam’s method is an insightful contemporary application of the method originally set out in Marx’s Grundrisse. Many contemporary explorations of agrarian political economy fail to sustain the important tension and dialectical debate, between diverse empirical realities and their ‘multiple determinations and relations’ and wider theorisation of the ‘concrete’ features of emergent processes of change. The implications of Sam’s methodological approach for the analysis of Zimbabwe’s land reform are discussed, especially in relation to the land occupations and the politics of agrarian reform since 2000

Interstitial fluid: the overlooked component of the tumor microenvironment?

Background: The interstitium, situated between the blood and lymph vessels and the cells, consists of a solid or matrix phase and a fluid phase, together constituting the tissue microenvironment. Here we focus on the interstitial fluid phase of tumors, i.e., the fluid bathing the tumor and stromal cells. Novel knowledge on this compartment may provide important insight into how tumors develop and how they respond to therapy. Results: We discuss available techniques for interstitial fluid isolation and implications of recent findings with respect to transcapillary fluid balance and uptake of macromolecular therapeutic agents. By the development of new methods it is emerging that local gradients exist in signaling substances from neoplastic tissue to plasma. Such gradients may provide new insight into the biology of tumors and mechanistic aspects linked to therapy. The emergence of sensitive proteomic technologies has made the interstitial fluid compartment in general and that of tumors in particular a highly valuable source for tissue-specific proteins that may serve as biomarker candidates. Potential biomarkers will appear locally at high concentrations in the tissue of interest and will eventually appear in the plasma, where they are diluted. Conclusions: Access to fluid that reliably reflects the local microenvironment enables us to identify substances that can be used in early detection and monitoring of disease

Systematic MicroRNA Analysis Identifies ATP6V0C as an Essential Host Factor for Human Cytomegalovirus Replication

Recent advances in microRNA target identification have greatly increased the number of putative targets of viral microRNAs. However, it is still unclear whether all targets identified are biologically relevant. Here, we use a combined approach of RISC immunoprecipitation and focused siRNA screening to identify targets of HCMV encoded human cytomegalovirus that play an important role in the biology of the virus. Using both a laboratory and clinical strain of human cytomegalovirus, we identify over 200 putative targets of human cytomegalovirus microRNAs following infection of fibroblast cells. By comparing RISC-IP profiles of miRNA knockout viruses, we have resolved specific interactions between human cytomegalovirus miRNAs and the top candidate target transcripts and validated regulation by western blot analysis and luciferase assay. Crucially we demonstrate that miRNA target genes play important roles in the biology of human cytomegalovirus as siRNA knockdown results in marked effects on virus replication. The most striking phenotype followed knockdown of the top target ATP6V0C, which is required for endosomal acidification. siRNA knockdown of ATP6V0C resulted in almost complete loss of infectious virus production, suggesting that an HCMV microRNA targets a crucial cellular factor required for virus replication. This study greatly increases the number of identified targets of human cytomegalovirus microRNAs and demonstrates the effective use of combined miRNA target identification and focused siRNA screening for identifying novel host virus interactions

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

Avian viral pathogens in swallows, Zimbabwe infectious diseases in <em>Hirundinidae</em>: A risk to swallow?

International audienceWe sampled 417 swallows in a wetland ecosystem of Zimbabwe in February 2010 and October 2011. RT-PCR tests revealed circulation of avian paramyxovirus type I, avian influenza and West Nile disease viruses in these populations. We discuss the relevance of these findings in relation to what is known on the epidemiology of these viruses in these hosts and in relation to the host ecology. We conclude with recommendations to focus more research on Passeriformes in disease ecology and in particular on the hirundinidae family

Report on a five-year avian influenza survey in the manyame catchment

We report on an avian influenza virus (AIV) project implemented in the Manyame catchment between 2007 and 2011. This project was undertaken as collaboration between two larger programmes, GRIPAVI (Cirad) and SA-GAINS (PFIAO, Univ. of Cape Town). We found persistence of low pathogenic AIV in waterfowl between May 2007 and November 2008 and potential for AIV transmission between wild and domestic birds. The approach that we developed in this project, which integrated ecology and epidemiology (both academic and applied), has tremendous potential for future work in the domain of disease ecology at the wildlife/domestic animal interface