Dopamine synthesis rate and cyclic AMP concentration were measured in synaptosomes prepared from rat striatum. Dopamine synthesis rate was decreased by the addition of either adenosine deaminase or 8-phenyltheophylline, an adenosine receptor blocker, and was increased by the addition of 2-chloroadenosine. The addition of L-glutamate in the absence of adenosine deaminase decreased both dopamine synthesis rate and cyclic AMP concentration; in the presence of adenosine deaminase, glutamate had no effect on basal dopamine synthesis, but enhanced K(+)-stimulated synthesis. Both these effects of glutamate were abolished in Ca2(+)-free medium or in the presence of 2-amino-5-phosphonovalerate, an N-methyl-D-aspartate (NMDA) receptor blocker. In Mg2(+)-free medium with adenosine deaminase, glutamate enhanced both basal and K(+)-stimulated synthesis. These results suggest that dopaminergic terminals have A2 adenosine receptors, whose activation can stimulate dopamine synthesis by a cyclic AMP-dependent mechanism, and NMDA receptors, which modulate dopamine synthesis by a Ca2(+)-dependent mechanism.
Brachial neuritis is a rare disorder affecting the brachial plexus. It is characterized by the acute onset of shoulder and arm pain followed by weakness, sensory loss and atrophy. Diagnosis is essentially clinical with electrophysiological investigations and imaging useful in excluding other differentials and supporting the diagnosis. Magnetic resonance imaging (MRI) usually does not show any pathology in the brachial plexus or spinal cord. We present a case of a patient who had brachial neuritis preceded by varicella zoster infection. This was supported by MRI which showed abnormal signal consistent with inflammatory changes in the brachial plexus.
Highlights
Almost one third of the sample had overweight/obese.
Women were 4 times more likely to have overweight/obesity.
Middle and high income individuals were 2 times more likely to have overweight/obesity.
The odds of having overweight/obesity increased with increasing age.
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