The distribution of reducing substances between plasma and corpuscles; a comparison of various blood-sugar methods

Rational deuteration of dronedarone attenuates its toxicity in human hepatic HepG2 cells

Deuteration is a chemical modification strategy that has recently gained traction in drug development. The replacement of one or more hydrogen atom(s) in a drug molecule with its heavier stable isotope deuterium can enhance its metabolic stability and pharmacokinetic properties. However, it remains uninterrogated if rational deuteration at bioactivation "hot-spots" could attenuate its associated toxicological consequences. Here, our preliminary screening with benzofuran antiarrhythmic agents first revealed that dronedarone and its major metabolite N-desbutyldronedarone elicited a greater loss of viability and cytotoxicity in human hepatoma G2 (HepG2) cells as compared with amiodarone and its corresponding metabolite N-desethylamiodarone. A comparison of dronedarone and its in-house synthesized deuterated analogue (termed poyendarone) demonstrated that deuteration could attenuate its in vitro toxicity in HepG2 cells by modulating the extent of mitochondrial dysfunction, reducing the dissipation of mitochondrial membrane potential, and evoking a distinct apoptotic kinetic signature. Furthermore, although pretreatment with the CYP3A inducer rifampicin or the substitution of glucose with galactose in the growth media significantly augmented the loss of cell viability elicited by dronedarone and poyendarone, a lower loss of cell viability was consistently observed in poyendarone across all concentrations. Taken together, our preliminary investigations suggested that the rational deuteration of dronedarone at its benzofuran ring reduces aberrant cytochrome P450 3A4/5-mediated bioactivation, which attenuated its mitochondrial toxicity in human hepatic HepG2 cells.

A Year's Experience of Intravenous Insulin in the Hypoglycaemic Shock Treatment of Schizophrenia

In a preliminary report (Brit. Med. Journ.,2, 310, 1940), two modifications were introduced in Sakel's technique for the insulin treatment of schizophrenia, with the primary object of continuing the treatment under wartime conditions. The first and most important of these was concerned with the saving of sugar. This simple method, by which glucose is given intravenously and is followed by a drink of potato soup as soon as the patient is awake, has already been fully described by us. We discovered incidentally that this method effected a saving of insulin amounting to 46.6 per cent. in seven patients. Various critics have asked why other workers have not effected a saving by using intravenous insulin. Further, we have been asked what advantages are to be gained by giving insulin intravenously apart from this saving of the drug; whether intravenous insulin adds any dangers to the treatment, and whether it brings about a remission in schizophrenia comparable with intramuscular insulin. We have had more than a year's experience with the use of intravenous insulin, and this paper aims at describing our first year of this experience and answering the questions set out above. We may mention that in 24 additional patients treated, an average saving of 28.3 per cent. of insulin has been effected.