Non-HIV-Related Progressive Multifocal Leukoencephalopathy (PML): A Tertiary Cancer Center Experience

In the course of 1 year at a tertiary cancer center, 3 patients (2 men; 1 woman; age 51-75 years) were seen in neurological consultation (1.5% of all consultations). Clinical course in all patients was of a progressive neurologic disorder not consistent with either a primary or secondary malignancy. Magnetic resonance (MR) imaging was most informative with respect to diagnosis and subsequent management. Brain biopsy was performed in all patients to assist in both diagnosis and prognostication. All patients were determined to have progressive multifocal leukoencephalopathy (PML) by brain biopsy.     

Sympathetic preganglionic neurons projecting to the adrenal medulla and aorticorenal ganglion in the rabbit.

The distribution of sympathetic preganglionic neurons (SPN) projecting to the adrenal medulla and the aorticorenal ganglion in the rabbit was studied using a dual retrograde transport technique. The B subunit of cholera toxin (CTB) was injected into the left adrenal medulla and wheatgerm agglutinin-apo-horseradish peroxidase-7 nm gold (WGA-apo-HRP-gold) was injected into the left aorticorenal ganglion. Retrogradely transported CTB was detected by immunohistochemistry, while gold particles were detected by silver intensification. SPN projecting to the adrenal medulla were observed in segments T2-L2 of the spinal cord in 5 rabbits, with the majority of cells within segments T6-T11 (79%). SPN projecting to the aorticorenal ganglion were seen in segments T2-L1 of the spinal cord in 5 rabbits, with the greatest number of the cells within T6-T11 (81%). Only a small number of doubly labelled cells (1%) were found in two rabbits. The results suggest that despite their similar segmental distribution SPN projecting to the adrenal medulla or the aorticorenal ganglion belong to separate populations and few, if any, individual SPN have axonal projections to both locations.     

Correlation between fall in blood pressure and in vivo amine release after alpha-methylDOPA

Blood pressure (BP), hypothalamic tissue concentrations and the in vivo overflow of endogenous and alpha-methylated catecholamines were measured in urethane anaesthetised rats after alpha-methylDOPA (mDOPA) administration (200 mg/kg i.p.). Four hours after mDOPA, BP fell to its lowest value, 60% of control, and slowly returned towards control levels by 24 h. This was closely correlated with the evoked overflow of alpha-methylnoradrenaline (mNA, r = 0.9) and noradrenaline (NA, r = 0.7) but not dopamine (DA) or alpha-methyldopamine (mDA). However, the tissue content of mNA rose much more gradually and was not maximal until after 12 h while mDA content followed the development of the hypotension. The results provide direct evidence for a false transmitter role for mNA in the brain, and suggest that the release of newly synthesised mNA is responsible for the hypotensive effect of mDOPA. Differences in the time course of overflow and storage of NA and mNA suggest the presence of separate transmitter storage and releasable pools.