EPR characterisation of the triplet state in photosystem II reaction centers with singly reduced primary acceptor Q(A).

The triplet states of photosystem II core particles from spinach were studied using time-resolved cw EPR technique at different reduction states of the iron--quinone complex of the reaction center primary electron acceptor. With doubly reduced primary acceptor, the well-known photosystem II triplet state characterised by zero-field splitting parameters |D|=0.0286 cm(-1), |E|=0.

Leukoencephalopathy associated with a disturbance in the metabolism of polyols.

In vivo proton magnetic resonance spectroscopy of the brain demonstrated highly elevated levels of arabitol and ribitol in a 14-year-old boy with a white matter disorder and neuropathy of unknown origin. These polyols also were shown to be elevated in body fluids, suggesting an inborn error in polyol metabolism. The strong plasma/ cerebrospinal fluid/brain gradient, with concentrations increasing in that order, suggests a primary neurometabolic disorder.

[Headache and chronic sleep deprivation: an often missed relationship in children and also in adults].

Three children, two girls aged 9 and 13 years and a boy aged 9 years, and a man aged 22, presented with headache of migrainoid character. The complaints resolved after attention had been given to sleeping habits, notably problems with falling asleep. The literature on the relationship between lack of sleep and headache is scarce.