Paramagnetic macrocyclic complexes as contrast agents for MR imaging: proton nuclear relaxation rate enhancement in aqueous solution and in rat tissues

Paramagnetic macrocyclic chelates show promise as magnetic resonance (MR) imaging contrast agents due to stability and relaxivity comparable to those of DTPA-type chelates. For the three copper and manganese macrocyclic complexes studied in aqueous solution, T1 and T2 relaxivities ranged from 0.14 to 5.88 mM-1sec-1 at 6.25 MHz. In rats, the intravenous administration of 16 mumol/kg of Mn(cyclam) caused the liver T1 relaxation rate to double at 15 minutes after injection. T1 measurements by pulsed MR imaging and manganese analyses on excised tissue showed that both relaxation rate (1/T1) and manganese content of liver and kidney increase linearly with the dosage of Mn(cyclam). The linear relationship between 1/T1 and manganese content can be considered an "in tissue" relaxivity plot for the agent. The resulting relaxivity is 54 mM-1sec-1 in liver, compared with 3.1 mM-1sec-1 in aqueous solution. Although this work is preliminary, the implication for medical MR imaging applications is that macrocyclic contrast agents can be effective at approximately one-tenth the current typical dose used for gadolinium DTPA.     

UK food and nutrition security during and after the COVID‐19 pandemic

The COVID‐19 pandemic is a major shock to society in terms of health and economy that is affecting both UK and global food and nutrition security. It is adding to the ‘perfect storm’ of threats to society from climate change, biodiversity loss and ecosystem degradation, at a time of considerable change, rising nationalism and breakdown in international collaboration. In the UK, the situation is further complicated due to Brexit. The UK COVID‐19 Food and Nutrition Security project, lasting one year, is funded by the Economic and Social Research Council and is assessing the ongoing impact of COVID‐19 on the four pillars of food and nutrition security: access, availability, utilisation and stability. It examines the food system, how it is responding, and potential knock on effects on the UK’s food and nutrition security, both in terms of the cascading risks from the pandemic and other threats. The study provides an opportunity to place the initial lessons being learnt from the on‐going responses to the pandemic in respect of food and nutrition security in the context of other long‐term challenges such as climate change and biodiversity loss.     

Margaret Sanger: birth control's successful revolutionary.

The year 1979 marked the centennial of Margaret Sanger, birth control pioneer. Sanger worked to secure two new human rights: the right to decide whether to have a child and the right of a child to be wanted. Beginning in 1873, antipornography crusader Anthony Comstock lobbied through Congress and the state legislatures laws forbidding the distribution of contraceptive devices and even information. He equated these with erotic postcards as "obscene, lewd, lascivious, filthy, indecent and disgusting." Sanger's strategy was to challenge the Comstock laws in the courts. She studied birth control methods abroad and published a pamphlet, Family Limitation, in 1914. It was the first modern marriage manual; it was also illegal. The publicity her trial generated was immense and highly sympathetic. The government dropped its case when it saw it could only make her a martyr. An obstetrical nurse, Sanger had seen the plight of factory women in the poorest sections of New York City. In order to provide the medical advice and supplies women clamored for, Sanger opened the first U.S. birth control clinic, in Brooklyn in 1916. The New York City Vice Squad raided and closed it, and jailed Sanger. Margaret Sanger underwent other trials, raids, and harassments, but each time won additional public support for her organization--Planned Parenthood--and her cause.