Toward a biochemical classification of depressive disorders--VIII. Platelet monoamine oxidase activity in subtypes of depressions

Platelet monoamine oxidase (MAO) activity was examined in 77 depressed patients (40 males and 37 females) and 28 controls (14 males and 14 females). Patients were compared across increasingly specific diagnostic groupings in a four-step data analytic procedure. In step 1, MAO activity in the total sample of depressed patients was compared with that of control subjects. In step 2, Unipolar depressed patients were compared with Bipolar (Bipolar I and Bipolar II) depressed patients. In step 3, Unipolar depressed patients with and without schizotypal features were compared. In step 4, both the nonschizotypal Unipolar patients and compared. In step 4, both the nonschizotypal Unipolar patients and nonschizotypal Bipolar patients were separated into those who met RDC criteria for a definite Endogenous depression and those who did not; and platelet MAO activity was compared in the resulting four groups. Results indicated significantly higher platelet MAO activity in nonschizotypal Unipolar Endogenous depressed patients than in nonschizotypal Bipolar Endogenous depressed patients or nonschizotypal Unipolar Other patients. In addition, the presence of a definite Endogenous depressive syndrome was associated with greater overall symptom severity in both Unipolar and Bipolar depressed patients. Findings are discussed with respect to the conflicting results reported in previous studies of MAO activity in patients with depressive disorders.

Toward a biochemical classification of depressive disorders, VI: Platelet MAO activity and clinical symptoms in depressed patients

The authors compared platelet monoamine oxidase (MAO) activity with clinical signs and symptoms in 32 patients with unipolar depressions. There was a statistically significant positive correlation between platelet MAO activity and scores on the Hamilton Rating Scale for Depression and between platelet MAO activity and specific clinical signs and symptoms in the spheres of depression, psychic anxiety, and somatic complaints. The clinical items found to be related to platelet MAO activity correspond to symptoms reported by other investigators to be associated with favorable responses to treatment with MAO inhibitors.

Polarization by gratings used at grazing incidence

The polarization introduced by gold-coated and aluminum-coated concave reflection gratings used in a grazing incidence monochromator has been measured over the spectral range from 20 nm to 130 nm. In every case the polarization ratio (P = R(p)/R(s)) is greater than 0.8 for wavelengths less than 40 nm and appears to be approaching unity below 20 nm. For both new and aged or contaminated gratings, the observed polarizations are consistent with those calculated assuming reflection occurs at a plane thin multilayer region with the optical constants chosen to simulate the grating surface.

Vacuum ultraviolet research

Some applications of vacuum uv radiation to basic research problems are discussed, with emphasis on the interaction of vacuum uv radiation with gases and solids.