The Critical Care Society of Southern Africa guidelines on the allocation of scarce critical care resources during the COVID-19 public health emergency in South Africa.

Letter by Gopalan et al. on article by Singh and Moodley (Singh JA, Moodley K. Critical care triaging in the shadow of COVID-19: Ethics considerations.

Cell-specific biotransformation of benzophenone-2 and bisphenol-s in zebrafish and human in vitro models used for toxicity and estrogenicity screening.

Several human and fish bioassays have been designed to characterize the toxicity and the estrogenic activity of chemicals. However, their biotransformation capability (bioactivation/detoxification processes) is rarely reported, although this can influence the estrogenic potency of test compounds. The fate of two estrogenic chemicals, the UV filter benzophenone-2 (BP2) and the bisphenol A substitute bisphenol S (BPS) was deciphered in eight human and zebrafish in vitro cell models, encompassing hepatic and mammary cellular contexts.

Use of the γH2AX assay for assessing the genotoxicity of bisphenol A and bisphenol F in human cell lines.

Bisphenol A (BPA) and bisphenol F (BPF) are widely used to manufacture plastics and epoxy resins. Both compounds have been shown to be present in the environment and are food contaminants, with, as a result, a low but chronic exposure of humans. However, the fate and possible bioactivation of these compounds at the level of human cell lines was not completely elucidated yet.

Metabolism of the endocrine disruptor BPA by Xenopus laevis tadpoles.

Metabolism of the plasticizer bisphenol A (BPA), a thyroid function disruptor, was investigated in Xenopus laevis tadpoles. Uptake and biotransformation of [(3)H]-BPA was followed over 72 h at 1 micromol/L and 10 micromol/L +/- triiodothyronine. A rapid decrease of radioactivity in media was observed after [(3)H]-BPA was added.

Biotransformation of the flame retardant tetrabromo-bisphenol A by human and rat sub-cellular liver fractions.

The comparative in vitro metabolism of the flame retardant tetrabromo-bisphenol A was studied in rat and human using a [(14)C]-radio-labelled molecule. Tetrabromo-bisphenol A is metabolised into the corresponding glucuronide (liver S9 fractions) and several other metabolites produced by cytochrome P450 dependent pathways (liver microsomes and liver S9 fractions). No major qualitative differences were observed between rat and human, regardless of the selected concentration, within the 20-200 microM range.