Huddle Up: Using Mediation to Help Settle the National Football League Labor Dispute

In a patient transferred from Togo to Cologne, Germany, Lassa fever was diagnosed 12 days post mortem. Sixty-two contacts in Cologne were categorised according to the level of exposure, and gradual infection control measures were applied. No clinical signs of Lassa virus infection or Lassa specific antibodies were observed in the 62 contacts. Thirty-three individuals had direct contact to blood, other body fluids or tissue of the patients. Notably, with standard precautions, no transmission occurred between the index patient and healthcare workers. However, one secondary infection occurred in an undertaker exposed to the corpse in Rhineland-Palatinate, who was treated on the isolation unit at the University Hospital of Frankfurt. After German authorities raised an alert regarding the imported Lassa fever case, an American healthcare worker who had cared for the index patient in Togo, and who presented with diarrhoea, vomiting and fever, was placed in isolation and medevacked to the United States. The event and the transmission of Lassa virus infection outside of Africa underlines the need for early diagnosis and use of adequate personal protection equipment (PPE), when highly contagious infections cannot be excluded. It also demonstrates that larger outbreaks can be prevented by infection control measures, including standard PPE

A novel mode of operation of SLC22A11: Membrane insertion of estrone sulfate versus translocation of uric acid and glutamate

Estrone sulfate alias estrone-3-sulfate (E3S) is considerably larger and much more hydrophobic than typical substrates of SLC22 transporters. It is puzzling that many otherwise unrelated transporters have been reported to transport E3S. Here we scrutinized the mechanism of transport of E3S by SLC22A11 (alias OAT4), by direct comparison with uric acid (UA), an important physiological substrate. Heterologous expression of SLC22A11 in human 293 cells gave rise to a huge unidirectional efflux of glutamate (Glu) and aspartate, as determined by LC-MS/MS. The uptake of E3S was 20-fold faster than the uptake of UA. Yet, the outward transport of Glu was inhibited by extracellular E3S, but not by UA. The release of E3S after preloading was trans-stimulated by extracellular dehydroepiandrosterone sulfate (DHEAS), but neither by UA nor 6-carboxyfluorescein (6CF). The equilibrium accumulation of E3S was enhanced 3-fold by replacement of chloride with gluconate, but the opposite effect was observed for UA. These results establish that SLC22A11 provides entirely different transport mechanisms for E3S and UA. Therefore, E3S must not be used as a substitute for UA to assay the function of SLC22A11. In equilibrium accumulation experiments, the transporter-mediated uptake was a linear function of the concentration of UA and 6CF. By contrast, in the same concentration range the graph for E3S was hyperbolic. This suggests that SLC22A11 inserts E3S into a small volume with limited capacity, the plasma membrane. Our data support the notion that the reverse process, extraction from the membrane, is also catalyzed by the carrier. (C) 2017 Elsevier Inc. All rights reserved

Cyanobacteria produce high levels of ergothioneine

Ergothioneine (ET) is a unique natural antioxidant. We have examined the origin of ET in zebrafish. There was virtually no ET, measured by LC-MS, in most tank vegetation (plant, green and red alga). However, ET was detected in a Phormidium sample, a cyanobacterium. In commercial fish feed preparations, ET content increased with the content of cyanobacteria Arthrospira platensis or Arthrospira maxima (Spirulina). High levels of ET (up to 0.8 mg per g dry mass) were measured in cyanobacteria preparations sold as dietary supplements for humans and in fresh Scytonema and Oscillatoria cultures. Cyanobacteria contained as much ET as King Oyster mushrooms (Pleurotus eryngii). All samples with substantial ET content also contained the biosynthesis intermediate hercynine; this strongly suggests that cyanobacteria synthesise ET de novo. In conclusion, our data establish that cyanobacteria can produce high levels of ergothioneine. Spirulina is a novel, safe, accessible, and affordable source of ergothioneine for humans. (C) 2011 Elsevier Ltd. All rights reserved

SLC22A13 catalyses unidirectional efflux of aspartate and glutamate at the basolateral membrane of type A intercalated cells in the renal collecting duct

In vertebrates, SLC22A13 is an evolutionarily conserved transport protein of the plasma membrane. In humans and rat, it is principally expressed in the kidney. The precise localization and physiological function are unknown. In the present study, immunohistochemistry revealed that expression of SLC22A13 is confined to the basolateral membrane of type A intercalated cells in rat kidney. Double-staining confirmed that SLC22A13 co-localizes with anion exchanger 1. LC-MS difference shading showed that heterologous expression of human and rat SLC22A13 in HEK (human embryonic kidney)-293 cells stimulates efflux of guanidinosuccinate, aspartate, glutamate and taurine. Time courses of uptake of [H-3]aspartate and [H-3]glutamate revealed that SLC22A13 counteracted endogenous uptake. By contrast, OAT2 (organic anion transporter 2), a bidirectional glutamate transporter, increased accumulation of [H-3]glutamate. Thus SLC22A13 catalyses unidirectional efflux. Velocity of efflux of standard amino acids was measured by LC-MS/MS. Expression of SLC22A13 strongly stimulated efflux of aspartate, taurine and glutamate. When the intracellular concentrations of aspartate and taurine were increased by pre-incubation, velocities of efflux increased linearly. We propose that in type A intercalated cells, SLC22A13 compensates luminal exit of protons by mediating the basolateral expulsion of the anions aspartate and glutamate. In this context, unidirectional efflux is essential to avoid anion reentering. Loss of SLC22A13 function could cause distal tubular acidosis

Knockout of the ergothioneine transporter ETT in zebrafish results in increased 8-oxoguanine levels

Ergothioneine (ET) is a natural compound that humans and other vertebrates must absorb from dietary sources. In general, ET is considered an intracellular antioxidant. However, the precise physiological purpose of ET and the consequences of ET deficiency are still unclear. The ergothioneine transporter ETT (human gene symbol SLC22A4) is a highly specific transporter for the uptake of ET. Here, we sought to identify and knock out ETT from zebrafish (Danio rerio) to determine the function of ET. We cloned and assayed three related proteins from zebrafish, only one of which catalyzed the uptake of ET. RT-PCR analysis revealed that the protein is strongly expressed in the skin, brain, kidney, intestine, and eye. In ETT-knockout animals generated by retroviral insertion into exon 1, ET content was reduced by more than 1000-fold compared to the wild type. Thus, ETT is the sole transporter responsible for uptake of ET into zebrafish. ETT-knockout fish did not exhibit obvious differences in morphology or behavior. In whole-fish homogenates, an increase in 4-hydroxy-2,3-trans-nonenal and malondialdehyde was observed, but only after stress caused by incubation with Pb2+ or Cu2+. Comparison of unstressed fish at the level of small molecules by LC-MS difference shading revealed a 3.8-fold increase in 8-oxoguanine (8-oxo-7,8-dihydroguanine) in the skin of ETT-knockout animals. Our knockout represents a new model for examining the consequences of complete absence of ET. Based on the phenotype observed here, we hypothesize that the specific purpose of ET could be to eliminate singlet oxygen. (C) 2015 Elsevier Inc. All rights reserved

Ergothioneine stands out from hercynine in the reaction with singlet oxygen: Resistance to glutathione and TRIS in the generation of specific products indicates high reactivity

The candidate vitamin ergothioneine (ET), an imidazole-2-thione derivative of histidine betaine, is generally considered an antioxidant. However, the precise physiological role of ET is still unresolved. Here, we investigated in vitro the hypothesis that ET serves specifically to eradicate noxious singlet oxygen (O-1(2)). Pure O-1(2) was generated by thermolysis at 37 degrees C of N, N'-di(2,3-dihydroxypropyl)-1,4-naphthalenedipropanamide 1,4-endoperoxide (DHPNO2). Assays of DHPNO2 with ET or hercynine (= ET minus sulfur) at pH 7.4 were analyzed by LC-MS in full scan mode to detect products. Based on accurate mass and product ion scan data, several products were identified and then quantitated as a function of time by selected reaction monitoring. All products of hercynine contained, after a [4 + 2] cycloaddition of O-1(2), a carbonyl at position 2 of the imidazole ring. By contrast, because of the doubly bonded sulfur, we infer from the products of ET as the initial intermediates a 4,5-dioxetane (after [2 + 2] cycloaddition) and hydroperoxides at position 4 and 5 (after Schenck ene reactions). The generation of single products from ET, but not from hercynine, was fully resistant to a large excess of tris (hydroxymethyl) aminomethane (TRIS) or glutathione (GSH). This suggests that O-1(2) markedly favors ET over GSH (at least 50-fold) and TRIS (at least 250-fold) for the initial reaction. Loss of ET was almost abolished in 5 mM GSH, but not in 25 mM TRIS. Regeneration of ET seems feasible, since some ET products - by contrast to hercynine products - decomposed easily in the MS collision cell to become aromatic again