Inactivation of PI(3)K p110δ breaks regulatory T-cell-mediated immune tolerance to cancer.

Inhibitors against the p110δ isoform of phosphoinositide-3-OH kinase (PI(3)K) have shown remarkable therapeutic efficacy in some human leukaemias. As p110δ is primarily expressed in leukocytes, drugs against p110δ have not been considered for the treatment of solid tumours. Here we report that p110δ inactivation in mice protects against a broad range of cancers, including non-haematological solid tumours. We demonstrate that p110δ inactivation in regulatory T cells unleashes CD8(+) cytotoxic T cells and induces tumour regression. Thus, p110δ inhibitors can break tumour-induced immune tolerance and should be considered for wider use in oncology

Mast Cells and Gastrointestinal Dysmotility in the Cystic Fibrosis Mouse

BACKGROUND: Cystic fibrosis (CF) has many effects on the gastrointestinal tract and a common problem in this disease is poor nutrition. In the CF mouse there is an innate immune response with a large influx of mast cells into the muscularis externa of the small intestine and gastrointestinal dysmotility. The aim of this study was to evaluate the potential role of mast cells in gastrointestinal dysmotility using the CF mouse (Cftr(tm1UNC), Cftr knockout). METHODOLOGY: Wild type (WT) and CF mice were treated for 3 weeks with mast cell stabilizing drugs (ketotifen, cromolyn, doxantrazole) or were treated acutely with a mast cell activator (compound 48/80). Gastrointestinal transit was measured using gavage of a fluorescent tracer. RESULTS: In CF mice gastric emptying at 20 min post-gavage did not differ from WT, but was significantly less than in WT at 90 min post-gavage. Gastric emptying was significantly increased in WT mice by doxantrazole, but none of the mast cell stabilizers had any significant effect on gastric emptying in CF mice. Mast cell activation significantly enhanced gastric emptying in WT mice but not in CF mice. Small intestinal transit was significantly less in CF mice as compared to WT. Of the mast cell stabilizers, only doxantrazole significantly affected small intestinal transit in WT mice and none had any effect in CF mice. Mast cell activation resulted in a small but significant increase in small intestinal transit in CF mice but not WT mice. CONCLUSIONS: The results indicate that mast cells are not involved in gastrointestinal dysmotility but their activation can stimulate small intestinal transit in cystic fibrosis

Reproducibility of histopathological findings in experimental pathology of the mouse: a sorry tail

Reproducibility of $\textit{in vivo}$ research using the mouse as a model organism depends on many factors, including experimental design, strain or stock, experimental protocols, and methods of data evaluation. Gross and histopathology are often the endpoints of such research and there is increasing concern about the accuracy and reproducibility of diagnoses in the literature. To reproduce histopathological results, the pathology protocol, including necropsy methods and slide preparation, should be followed by interpretation of the slides by a pathologist familiar with reading mouse slides and familiar with the consensus medical nomenclature used in mouse pathology. Likewise, it is important that pathologists are consulted as reviewers of manuscripts where histopathology is a key part of the investigation. The absence of pathology expertise in planning, executing and reviewing $\textit{in vivo}$ research using mice leads to questionable pathology-based findings and conclusions from studies, even in high-impact journals. We discuss the various aspects of this problem, give some examples from the literature and suggest solutions.This work was supported in part by US National Institutes of Health grants R01 AR049288, CA089713 and R21 AR063781 (to J.P.S.) and by The Warden and Fellows of Robinson College, Cambridge (to P.N.S.)

Environmental Geotechnics: Challenges and Opportunities in the Post COVID-19 World

The outbreak of the COVID-19 pandemic not only created a health crisis across the world but is expected to negatively impact the global economy and societies at a scale that maybe larger than the 2008 financial crisis. Simultaneously, it has inevitably exerted many negative consequences on the geoenvironment upon which human beings depend. The current article articulates the role of environmental geotechnics to elucidate and mitigate the effects of the current pandemic. It is the belief of all authors that the COVID-19 pandemic presents significant challenges, but also opportunities for the development of our field. Our discipline should make full use of our professional skills and expertise to look for development opportunities from this crisis, to highlight our discipline’s irreplaceable position in the global fight against pandemics, and to contribute to the health and prosperity of our communities, so as to better serve humankind. In order to reach this goal, while taking into account the specificity of the SARS-CoV-2 and the uncertainty of its environmental effects, it is believed that more emphasis should be placed on the following research directions: pathogen-soil interactions, isolation and remediation technologies for pathogen-contaminated sites, new materials for pathogen-contaminated soil, recycling and safe disposal of medical wastes, quantification of uncertainty in geoenvironmental and epidemiological problems, emerging technologies and adaptation strategies in civil, geotechnical, and geoenvironmental infrastructure, pandemic-induced environmental risk management, and model pathogen transport and fate in geoenvironment, among others. Moreover, COVID-19 has made it clear to the environmental geotechnics community the importance of urgent international cooperation and of multidisciplinary research actions that must extend to a broad range of scientific fields, including medical and public health disciplines, in order to meet the complexities posed by the COVID-19 pandemic

Determination of fumonisins B1 and B2 in Portuguese maize and maize-based samples by HPLC with fluorescence detection

Abstract Fumonisins B1 (FB1) and fumonisin B2 (FB2) are the main members of a family of mycotoxins produced by Fusarium verticillioides, Fusarium proliferatum, and other fungi species of the section Liseola. The present work shows the results of comparative studies using two different procedures for the analysis of fumonisins in maize and maize-based samples. The studied analytical methods involve extraction with methanol/water, dilution with PBS, and clean-up through immunoaffinity columns. Two reagents (o-phthaldialdehyde and naphthalene-2,3-dicarboxaldehyde) were studied for formation of fluorescent derivatives. The separation and identification were carried out by high-performance liquid chromatography with fluorescence detection. The optimized method for analysis of fumonisins in maize involved extraction with methanol/water (80:20), clean-up with an immunoaffinity column, and derivatization with naphthalene-2,3-dicarboxaldehyde (NDA). The limit of detection was 20 µg kg-1 for FB1 and 15 µg kg-1 for FB2. Recoveries of FB1 and FB2 ranged from 79% to 99.6% for maize fortified at 150 µg kg-1 and 200 µg kg-1, respectively, with within-day RSDs of 3.0 and 2.7%. The proposed method was applied to 31 samples, and the presence of fumonisins was found in 14 samples at concentrations ranging from 113 to 2,026 µg kg-1. The estimated daily intake of fumonisins was 0.14 µg kg-1 body weight per day