Dreams reflect nocturnal cognitive processes: Early-night dreams are more continuous with waking life, and late-night dreams are more emotional and hyperassociative.

Contributions of specific sleep stages to cognitive processes are increasingly understood. Non-REM sleep is particularly implicated in episodic memory consolidation, whilst REM sleep preferentially consolidates and regulates emotional information, and gives rise to creativity and insight. Dream content reflects these processes: non-REM dreams are more likely to picture episodic memories, whereas REM dreams are more emotional and bizarre. However, across-the-night differences in the memory sources of dream content, as opposed to sleep stage differences, are less well understood. In the present study, 68 participants were awoken from sleep in the early and late night and recorded their dreams and waking-life activities. Early-night dreams were more clearly relatable to (or continuous with) waking life than late-night dreams. Late-night dreams were more emotional-important, more time orientation varied, and more hyperassociative, than early-night dreams. These dream content differences may underlie the mental content that accompanies sleep processes like memory consolidation, emotion-processing, and creativity.

T-lymphocyte-enriched murine peritoneal exudate cells. IV. Genetic control of cross-stimulation at the T-cell level.

Antibodies raised against many structurally related antigens have been shown to cross-react extensively. Manifestations of T-cell immunity, on the other hand, appear to be more restricted in their ability to be elicited by cross-reacting antigens, although examples have been reported. This paper explores the nature of the cross-reactions at the T-cell level among the branched-chain copolymers (T,G)-A--L, (phi,G)-A--L, (H,G)-A--L, and G-A--L, as well as a related linear terpolymer, GAT, in a variety of mouse strains using the peritoneal exudate T-lymphocyte-enriched cells (PETLES) proliferation assay. (T,G)-A--L, (phi,G)-A--L, and GAT could cross-stimulate cells immune to the other two antigens, whereas (H,G)-A--L, (T,G)-Pro--L, and G-A--L showed no cross-stimulations. The extent of the cross-reactions varied with the mouse strain and was shown to be under the control of immune response genes. It was necessary for the strain to be able to respond to both the immunogen and the cross-reacting antigen, when used as an immunogen, in order for cross-stimulation to occur; however, this was not always sufficient. Several examples of unequal or one-way cross-reactions were found. In addition, the immune responses to (H,G)-A--L and (phi,G)-A--L showed no cross-reactions with the other antigen even though their Ir genes were both mapped to the K region or I-A subregion. The problem of accounting for such fine specificity of T-cell recognition in lieu of the genetic evidence demonstrating only Ir gene control of the response is discussed.

Direct comparison of the N-acetyl-l-cysteine-sodium hydroxide and the trisodium phosphate digestion methods for the culture of mycobacteria.

Comparison of sputum digestion procedures utilizing acetylcysteine-sodium hydroxide (AC) and trisodium phosphate for the isolation and culture of mycobacteria indicated that the AC procedure provides faster growth, thus permitting the earlier detection of positives. Also, in untreated patients and those in whom treatment has been recently instituted, the number of positives was slightly larger with the use of the AC procedure. However, of greater interest was finding that the AC procedure provided a larger quantity of positive cultures with sputum from subjects who had been intensively treated with antimicrobials and other drugs. Contamination was higher with the AC procedure, but when the sputa were diluted 1:10 this interference due to contamination was decreased.