Metabolites from the biodegradation of pharmaceutical residues of ibuprofen in biofilm reactors and batch experiments

The three metabolites hydroxyibuprofen (OH-Ibu), carboxyibuprofen (CA-Ibu), and carboxyhydratropic acid (CA-HA), also known from human metabolism of ibuprofen, could be identified in biodegradation experiments. Identification was based on EI mass spectra and comparison with literature data. Detection was performed by selective MS-MS measurements by GC-ion-trap MS and online methylation. Ibuprofen (Ibu), OH-Ibu, and CA-Ibu could be detected with a signal-to-noise ratio of 10:1 at a concentration of 2 nmol L(-1), CA-HA at 0.5 nmol L(-1). Degradation experiments in both biofilm reactors (BFR) and batch experiments with activated sludge (BAS) reveal OH-Ibu as the major metabolite under oxic conditions, and CA-HA under anoxic conditions. CA-Ibu was found under oxic and anoxic conditions almost only in the BAS. The metabolites together do not account for more than 10% of the initial concentration of Ibu.

Method optimization for the determination of carbonyl compounds in disinfected water by DNPH derivatization and LC-ESI-MS-MS

A method has been developed for quantitative determination of carbonyl disinfection by-products (DBP) from aqueous samples by derivatization with 2,4-dinitrophenylhydrazine combined with high-performance liquid chromatography (HPLC) and electrospray ionization (ESI) tandem mass spectrometry (MS-MS). The effect of excess of derivatization reagent and derivatization time, the effect of buffer and dry-gas temperature in the ESI process, and the effect of focus potential and collision energy in MS measurement are shown. Major fragment ions for compound identification on the basis of collision-induced dissociation (CID) mass spectra (MS) are given, as are common fragments for screening analyses by MS experiments such as the use of precursor ion scans. Detection limits in the microg x L(-1) range could be achieved by selected ion monitoring measurements without sample preconcentration. Solid-phase extraction improved the sensitivity by a factor of 25 to 250. The applicability of the method is illustrated by DBP analyses of samples from outdoor swimming pools after chlorination. Several carbonyl compounds, e.g. aldehydes, ketones, hydroxybenzaldehyde, and dicarbonyl compounds were identified.

PD-1 and TIM-3 differentially regulate subsets of mouse IL-17A-producing γδ T cells

IL-17A-producing γδ T cells in mice consist primarily of Vγ6+ tissue-resident cells and Vγ4+ circulating cells. How these γδ T cell subsets are regulated during homeostasis and cancer remains poorly understood. Using single-cell RNA sequencing and flow cytommetry, we show that lung Vγ4+ and Vγ6+ cells from tumor-free and tumor-bearing mice express contrasting cell surface molecules as well as distinct co-inhibitory molecules, which function to suppress their expansion. Vγ6+ cells express constitutively high levels of PD-1, whereas Vγ4+ cells upregulate TIM-3 in response to tumor-derived IL-1β and IL-23. Inhibition of either PD-1 or TIM-3 in mammary tumor-bearing mice increased Vγ6+ and Vγ4+ cell numbers, respectively. We found that genetic deletion of γδ T cells elicits responsiveness to anti-PD-1 and anti-TIM-3 immunotherapy in a mammary tumor model that is refractory to T cell checkpoint inhibitors, indicating that IL-17A-producing γδ T cells instigate resistance to immunotherapy. Together, these data demonstrate how lung IL-17A-producing γδ T cell subsets are differentially controlled by PD-1 and TIM-3 in steady-state and cancer.

Nanofiltration for enhanced removal of disinfection by-product (DBP) precursors in swimming pool water-retention and water quality estimation

Three nanofiltration (NF) membranes with a chlorine tolerance > or = 1 mg L-1 were applied to reduce DBPs and their precursors in swimming pool water. A lab scale plant with crossflow modules was installed in by-pass at the sand filter outlet of a swimming pool for a period of several weeks. The chlorine tolerances of the membranes SB90 and NP030 were found to be adequate for filtration under swimming pool water conditions over the given experimental period. Retention of dissolved organic carbon (DOC) and adsorbable organic halogens (AOX) were about 70% and 80% for SB90 and 50% and 40% for NP030, respectively. DOC accumulation in the pool and the expected fresh water consumption for a treatment system consisting of ultrafiltration (UF) and NF with backwash water treatment were estimated by mass balances based on the results. Mass balances were calculated also for a German public swimming pool with a conventional water treatment system (flocculation-sand filtration-chlorination) and were compared to DOC on-line measurements. Calculation of DOC mass balances for different UF-NF treatment scenarios showed that pool water quality could be improved significantly compared to the conventional treatment system.

NKG2D signaling regulates IL-17A-producing γδT cells in mice to promote cancer progression

γδT cells are unconventional T cells particularly abundant in mucosal tissues that play an important role in tissue surveillance, homeostasis, and cancer. γδT cells recognize stressed cells or cancer cells through the NKG2D receptor to kill these cells and maintain normality. Contrary to the well-established anti-tumor function of these NKG2D-expressing γδT cells, we show here that, in mice, NKG2D regulates a population of pro-tumor γδT cells capable of producing IL-17A. Germline deletion of Klrk1, the gene encoding NKG2D, reduced the frequency of γδT cells in the tumor microenvironment and delayed tumor progression. We further show that blocking NKG2D reduced the capability of γδT cells to produce IL-17A in the pre-metastatic lung and that co-culture of lung T cells with NKG2D ligand-expressing tumor cells specifically increased the frequency of γδT cells. Together, these data support the hypothesis that, in a tumor microenvironment where NKG2D ligands are constitutively expressed, γδT cells accumulate in an NKG2D-dependent manner and drive tumor progression by secreting pro-inflammatory cytokines, such as IL-17A.

Lack of effect of enoximone on the pharmacokinetics of digoxin in patients with congestive heart failure

The aim of this study was to investigate if the concomitant administration of the positive inotropic drug enoximone (100 mg tid) has any effect on the morning through levels of the cardiac glycoside digoxin in 17 patients with congestive heart failure (NYHA II-IV). Plasma concentrations of digoxin were 1.05 +/- 0.37 ng/mL before enoximone, 0.95 +/- 0.31 ng/mL at the end of the enoximone treatment period of 1 week and 0.95 +/- 0.36 ng/mL 1 week after cessation of enoximone treatment. Thus, concomitant administration of enoximone had no effect on plasma concentrations of digoxin while on the other hand the hemodynamics as assessed by NYHA-classification and determination of the heart volume improved significantly.