Summary and conclusionsNecropsy brain tissue from normal (control) patients and patients with depression and dementia was examined for activities of various cholinergic components, and these related to the degree of senile plaque formation and extent of intellectual impairment. Choline acetyltransferase and acetylcholinesterase activities decreased significantly as the mean plaque count rose, and in depressed and demented subjects the reduction in choline acetyltransferase activity correlated with the extent of intellectual impairment as measured by a memory information test; muscarinic cholinergic receptor binding activity remained unchanged with increasing senile plaque formation but butyrylcholinesterase activity increased.The results suggest a close relation between changes in the cholinergic system and Alzheimer's dementia, but the precise role of the system in this disease remains to be elucid'ated.

Spectrophotometry was employed to study binding of methylene blue (MB) dye to sodium montmorillonite (NaM) in dilute aqueous suspension. The adsorption isotherm may be expressed u = h + fee1/", the first term (k, = 80 meq. MB/100 g. NaM) arising from ion exchange, the second from physical adsorption. Large spectral changes (metachromasy) were found to accompany changes in the coverage, u, at values well below k¡. These are similar to the spectral shift accompanying dimerization of MB in aqueous solution and are attributed to dye-dye interactions. The spectral properties showed large aggregates were formed at moderate coverage. The spectra of free MB monomer and dimer were determined quantitatively. The peak molar absorbancy index of the monomer was found to be 9.5 X 104 at 6640 A. The spectral variations up to concentrations of 2 X 10 "4 M were interpreted quantitatively in terms of a monomer-dimer equilibrium, with a dimer dissociation constant of 1.7 X 10-4 at 25°. The dimer spectrum was found to contain a long wave length peak which can be explained by a sandwich structure having the monomer transition moments at a mean angle of about 13°to each other. Trimethylthionme, formed by base-catalyzed demethylation, was found chromatographically to be a common impurity in methylene blue; a spectral criterion for this impurity was introduced and an extraction procedure was developed for removing it.

An extreme-ultraviolet (EUV) radiation source near the 13-nm wavelength generated in a small (1.1 J) pinch plasma is presented. The ignition of the plasma occurs in a pseudosparklike electrode geometry, which allows for omitting a switch between the storage capacity and the electrode system and for low inductive coupling of the electrically stored energy to the plasma. Thus energies of only a few joules are sufficient to create current pulses in the range of several kiloamperes, which lead to a compression and a heating of the plasmas to electron densities of more than 10(17) cm(-3) and temperatures of several tens of electron volts, which is necessary for emission in the EUV range. As an example, the emission spectrum of an oxygen plasma in the 11-18-nm range is presented. Transitions of beryllium- and lithium-like oxygen ions can be identified. Current waveform and time-resolved measurements of the EUV emission are discussed. In initial experiments a repetitive operation at nearly 0.2 kHz could be demonstrated. Additionally, the broadband emission of a xenon plasma generated in a 2.2-J discharge is presented.

Eight cases of resistant recurrent depression were treated with a combination of nortriptyline and a new serotonin reuptake inhibitor, with or without concurrent lithium therapy. Significant improvement was seen in all patients where other drug regimes and ECT had been ineffective. No adverse reactions occurred in any of our patients, seven of whom were elderly. The combination treatment was more effective than individual therapies alone.