Underestimation of glyphosate intake by the methods currently used by regulatory agencies

The acceptable daily intake (ADI) is an estimate of the amount of a substance in food or beverages that can be consumed daily over a lifetime without presenting an appreciable risk to health. To assess the risk of ingesting glyphosate, regulatory agencies compare glyphosate daily intake to ADI. Based on published data on urine glyphosate levels measured according to known quantities of ingested glyphosate, our objectives were to test the robustness of the mathematical model currently used to calculate glyphosate daily intake, and to propose alternative models based on urinary excretion kinetics. Our results support that the quantity of ingested glyphosate is systematically underestimated by the model currently used by regulatory agencies, whereas the other models evaluated showed better estimations, with differences according to gender. Our results also show a great variability between individuals, leading to some uncertainties notably with regards to the ADI, and further support that glyphosate excretion varies significantly among individuals who follow a similar dosing regimen. In conclusion, our study highlights the lack of reliability of assessment processes carried out by regulatory agencies for glyphosate in particular, and pesticides in general, and questions the relevance of such processes supposed to safeguard human health and the environment.

Quantifiable urine glyphosate levels detected in 99% of the French population, with higher values in men, in younger people, and in farmers

France is the first pesticide-consuming country in Europe. Glyphosate is the most used pesticide worldwide and glyphosate is detected in the general population of industrialized countries, with higher levels found in farmers and children. Little data was available concerning exposure in France. Our objective was to determine glyphosate levels in the French general population and to search for an association with seasons, biological features, lifestyle status, dietary habits, and occupational exposure. This study includes 6848 participants recruited between 2018 and 2020. Associated data include age, gender, location, employment status, and dietary information. Glyphosate was quantified by a single laboratory in first-void urine samples using ELISA. Our results support a general contamination of the French population, with glyphosate quantifiable in 99.8% of urine samples with a mean of 1.19 ng/ml + / - 0.84 after adjustment to body mass index (BMI). We confirm higher glyphosate levels in men and children. Our results support glyphosate contamination through food and water intake, as lower glyphosate levels are associated with dominant organic food intake and filtered water. Higher occupational exposure is confirmed in farmers and farmers working in wine-growing environment. Thus, our present results show a general contamination of the French population with glyphosate, and further contribute to the description of a widespread contamination in industrialized countries.

The enpp4 ectonucleotidase regulates kidney patterning signalling networks in Xenopus embryos

The enpp ectonucleotidases regulate lipidic and purinergic signalling pathways by controlling the extracellular concentrations of purines and bioactive lipids. Although both pathways are key regulators of kidney physiology and linked to human renal pathologies, their roles during nephrogenesis remain poorly understood. We previously showed that the pronephros was a major site of enpp expression and now demonstrate an unsuspected role for the conserved vertebrate enpp4 protein during kidney formation in Xenopus. Enpp4 over-expression results in ectopic renal tissues and, on rare occasion, complete mini-duplication of the entire kidney. Enpp4 is required and sufficient for pronephric markers expression and regulates the expression of RA, Notch and Wnt pathway members. Enpp4 is a membrane protein that binds, without hydrolyzing, phosphatidylserine and its effects are mediated by the receptor s1pr5, although not via the generation of S1P. Finally, we propose a novel and non-catalytic mechanism by which lipidic signalling regulates nephrogenesis.

Massé and colleagues identify enpp4 as a key regulator in the development of the kidney in Xenopus. The gene signalling pathways regulated by this ectonucleotidase are described and lipidic signalling regulatory mechanisms are explored.

Anti-metastatic potential of human Vδ1(+) γδ T cells in an orthotopic mouse xenograft model of colon carcinoma

The role of human intraepithelial Vδ1(+) γδ T cell cytotoxic effectors in the immune surveillance against metastatic colon cancer has never been addressed, despite their reported capacity to infiltrate colon carcinomas and to kill colonic cancer cells in vitro. We previously showed that Vδ1(+) γδ T cells are enriched in blood in response to cytomegalovirus (CMV) infection, and that such increase may be protective against epithelial cancers. The objective of the present study was to investigate whether CMV-induced Vδ1(+) γδ T lymphocytes could inhibit the propagation of human colon tumors in vivo, in order to evaluate their immunotherapeutic potential in this context. Even though metastases are an important cause of death in various cancers including colorectal cancer (CRC), the anti-metastatic effect of immune effectors has been poorly analyzed. To this purpose, we set up a reliable model of metastatic colon cancer through orthotopic implantation of luciferase-expressing human HT29 cells in immunodeficient mice. Using bioluminescence imaging to follow the outcome of colonic cancer cells, we showed that a systemic treatment with CMV-induced Vδ1(+) γδ T cells could not only inhibit primary colon tumor growth but also the emergence of secondary tumor foci in the lungs and liver. Finally, our data lead to propose that Vδ1(+) γδ T lymphocytes may directly influence the appearance of metastases independently from their control of primary tumor size. These findings, which extend our previous work, pave the road for the potential manipulation of Vδ1(+) γδ T lymphocytes in novel anti-CRC immunotherapeutic protocols.

[Plasma Neutrophil Gelatinase-Associated Lipocalin (NGAL) predicts acute kidney injury in septic shock at ICU admission]

PURPOSE

To validate plasma Neutrophil Gelatinase-Associated Lipocalin (pNGAL) as an early biomarker in intensive care unit (ICU) for acute kidney injury (AKI) in critically ill adult with septic shock.

PATIENTS AND METHOD

Fifty consecutive patients with septic shock were included in this observational cohort study. AKI was defined if patients met any RIFLE or AKIN criteria. The main objective was to evaluate diagnosis value of pNGAL measured with a point-of-care device at admission (D0), at 24hours (D1) and at 48hours (D2).

RESULTS

Among the 50 patients enrolled, 86% had AKI, 48% had persistent renal AKI and 30% required renal replacement therapy (RRT) during their ICU stay. At D0, pNGAL concentration was significantly higher in patients with AKI compared to patients without AKI (471ng/mL versus 134ng/mL, P<0.001). This level remained significantly higher in the AKI population at D1 and D2 and pNGAL concentration at D0 among AKI patients increased with kidney failure level. At D1, pNGAL was significantly higher for persistent renal AKI rather than transient prerenal (570ng/mL versus 337ng/mL, P=0.027). pNGAL concentration below 348ng/mL at D1 was never seen in patients with RRT.

CONCLUSION

Plasma NGAL is a useful, sensitive and early biomarker to predict persistent AKI in septic shock at ICU admission and help to discuss RRT.

On the distribution of the search cost for the move-to-front rule with random weights

Consider a countable list of files updated according to the move-to-front rule. Files have independent random weights, which are used to construct request probabilities. Exact and asymptotic formulae for the Laplace transform of the stationary search cost are given for i.i.d. weights. Similar expressions are derived for the first two moments. Some results are extended to the case of independent weights.