Occurrence and fate of an emerging drug pollutant and its by-products during conventional and advanced wastewater treatment: Case study of furosemide.

Conventional wastewater treatment systems are not designed to remove pharmaceutical compounds from wastewater. These compounds can be degraded into many other transformation products which are hardly, if at all, studied. In this context, we studied the occurrence and degradation of furosemide, a very frequently detected diuretic, along with its known degradation products in several types of wastewater. Influent and effluent from the Seine-Centre Wastewater Treatment Plant (WWTP) (Paris, France) as well as outlet of residential care homes (Dordogne, France) were analyzed by Ultra-Performance Liquid Chromatography-tandem Mass Spectrometry (UPLC-MS/MS) to quantify furosemide and its known degradation products, saluamine and pyridinium of furosemide. Oxidation experiments (chlorination, ozonation and UV photolysis with hydrogen peroxide) were then performed on furosemide solutions and on water from residential care facilities to study the degradation of furosemide by potential advanced processes, and also to identify unknown oxidation products by high-resolution mass spectrometry. Furosemide was well degraded in Seine-Centre WWTP (>75%) but did not increase the concentrations of its main degradation products. Saluamine and pyridinium of furosemide were already present at similar concentrations to furosemide in the raw wastewater (∼2.5-3.5 µg.L-1), and their removal in the WWTPs were very high (>80%). Despite their removal, the three compounds remained present in treated wastewater effluents at concentrations of hundreds of nanograms per liter. Chlorination degraded furosemide without pyridinium production unlike the other two processes. Chlorination and ozonation were also effective for the removal of furosemide and pyridinium in residential care home water, but they resulted in the production of saluamine. To our knowledge this is the first evidence of saluamine and pyridinium of furosemide in real water samples in either the particulate or dissolved phase.

A new human pyridinium metabolite of furosemide, inhibitor of mitochondrial complex I, is a candidate inducer of neurodegeneration.

Pharmaceuticals and their by-products are increasingly a matter of concern, because of their unknown impacts on human health and ecosystems. The lack of information on these transformation products, which toxicity may exceed that of their parent molecules, makes their detection and toxicological evaluation impossible. Recently we characterized the Pyridinium of furosemide (PoF), a new transformation product of furosemide, the most widely used diuretic and an emerging pollutant. Here, we reveal PoF toxicity in SH-SY5Y cells leading to alpha-synuclein accumulation, reactive oxygen species generation, and apoptosis. We also showed that its mechanism of action is mediated through specific inhibition of striatal respiratory chain complex I, both in vitro by direct exposure of striatum mitochondria to PoF, and in vivo, in striatal mitochondria isolated from mice exposed to PoF for 7 days in drinking water and sacrificed 30 days later. Moreover, in mice, PoF induced neurodegenerative diseases hallmarks like phospho-Serine129 alpha-synuclein, tyrosine hydroxylase decrease in striatum, Tau accumulation in hippocampus. Finally, we uncovered PoF as a new metabolite of furosemide present in urine of patients treated with this drug by LC/MS. As a physiopathologically relevant neurodegeneration inducer, this new metabolite warrants further studies in the framework of public health and environment protection.

Bisphenol A release from an orthodontic resin composite: A GC/MS and LC/MS study.

OBJECTIVES: First, to analyse the in vitro release of BPA and Bis-GMA from an orthodontic resin composite (Transbond XT, 3M Unitek), stored in various conditions, by gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS); then to extrapolate the data to the clinical situation. Secondly, to explore the thermal stability of Bis-GMA. METHODS: Cylinders of resin composite were prepared and stored according to 3 different protocols: (1) they were light-cured 20s, then placed in artificial saliva; (2) they were light-cured 2s, then placed in acetonitrile; (3) they were light-cured 2s, then placed in methanol. For each group, BPA and Bis-GMA release were determined with GC/MS and/or LC/MS at least after one week. Besides, 120 brackets (10 of each type) were bonded over metal teeth, then debonded, and the weight and the surface of resin composite residues were measured. BPA and Bis-GMA release of adhesive residues were extrapolated from the data obtained with the cylinders. Besides, BPA release from a heated Bis-GMA solution was measured. RESULTS: With GC/MC, BPA was detected in all samples. With LC/MS, BPA was detected only from samples immersed in MeOH; Bis-GMA was detected, in varying amount according to the extraction media and the light-curing time. BPA was found after heating of the Bis-GMA solution. SIGNIFICANCE: Contamination risk and the heat applied in GC/MS may overestimate the BPA release from resin composite. Based on the LC/MS results, the risk of BPA release after orthodontic bonding would be more than 42000 times lower than the TDI for a 30-kg child.

Antibacterial properties of the mammalian L-amino acid oxidase IL4I1.

L-amino acid oxidases (LAAO) are flavoproteins that catalyze the oxidative deamination of L-amino acids to a keto-acid along with the production of H2O2 and ammonia. Interleukin 4 induced gene 1 (IL4I1) is a secreted LAAO expressed by macrophages and dendritic cells stimulated by microbial derived products or interferons, which is endowed with immunoregulatory properties. It is the first LAAO described in mammalian innate immune cells. In this work, we show that this enzyme blocks the in vitro and in vivo growth of Gram negative and Gram positive bacteria. This antibiotic effect is primarily mediated by H2O2 production but is amplified by basification of the medium due to the accumulation of ammonia. The depletion of phenylalanine (the primary amino acid catabolized by IL4I1) may also participate in the in vivo inhibition of staphylococci growth. Thus, IL4I1 plays a distinct role compared to other antibacterial enzymes produced by mononuclear phagocytes.

[Metastatic renal failure]. / Insuffisance rénale aiguë métastatique.

A 52-year-old man, treated 15 months earlier for a poorly differentiated bronchial adenosquamous carcinoma, was admitted for oligoanuric renal failure preceded by macroscopic hematuria. Clinical and paraclinical investigations were unremarkable except ++proteinuria and mild echographic enlargement of both kidneys. Bilateral renal biopsy disclosed replacement of normal renal tissue by an adenocarcinomatous proliferation. Despite transient improvement and cessation of hemodialysis, the patient died one month later. Analysis of literature reveals that secondary kidney tumours -especially of bronchial origin- are more frequent than primary ones, but that cases of renal failure are uncommonly reported, probably because of underdiagnosis, poor prognosis and limited therapeutic issues. Features of previously published cases are listed in a synthetic table.