In autoshaping experiments, we quantified the acquisition of anticipatory head poking in individual mice, using an algorithm that finds changes in the slope of a cumulative record. In most mice, upward changes in the amount of anticipatory poking per trial were abrupt, and tended to occur at session boundaries, suggesting that the session is as significant a unit of experience as the trial. The...

Effects of salivary gland extract (SGE) from Rhipicephalus sanguineus on immunoglobulin class productivity of canine peripheral blood lymphocytes (PBL) in vitro were studied. The detectable limit of the ELISA for canine total immunoglobulin, IgM and A was at least 1, 1 and 15 ng/ml, respectively, and it seems to be useful for the evaluation of non-specific immunoglobulin class productivity in v...

1. The pokeweed antiviral protein, previously identified in two forms (PAP and PAP II) in the leaves of Phytolacca americana (pokeweed) [Obrig. Irvin & Hardesty (1973) Arch. Biochem. Biophys. 155, 278-289; Irvin, Kelly & Robertus (1980) Arch. Biochem. Biophys. 200, 418-425] is a protein that prevents replication of several viruses and inactivates ribosomes, thus inhibiting protein synthesis. 2....

Sensitization of defensive responses following noxious stimulation occurs in diverse species, but no demonstration of nociceptive sensitization in insects has been reported. A set of defensive behavior patterns in larval Manduca sexta is described and shown to undergo sensitization following noxious mechanical stimulation. The striking response is a rapid bending that accurately propels the hea...

AIMS To assess the aetiological factors associated with the occurrence of perforating ocular injuries in children in an urban setting and to assess the visual outcomes of such injuries. METHODS All cases of perforating ocular injury presenting to a single paediatric hospital (age less than 16 years) over a 17 year period were identified by a medical record search. All new cases of perforating...

The faster drugs of abuse reach the brain, the more addictive they can be. It is not known why this is. Environmental stimuli associated with drugs can promote the development and persistence of addiction by invigorating and precipitating drug-seeking behaviour. We determined, therefore, whether cues associated with the self-administration of rapidly delivered cocaine (injected intravenously ov...

Purified helper-inducer (T4+) and suppressor-cytotoxic (T8+) lymphocytes from eight patients with acquired immunodeficiency syndrome (AIDS) and eight healthy heterosexual donors were examined by limiting dilution analysis for their ability to be clonally expanded. It was demonstrated that viable T4+ and T8+ lymphocytes from patients with AIDS had markedly reduced proportions of clonable cells c...

The phase diagrams of some cholesterol-lipid mixtures exhibit two immiscibility regions along with a sharp cusp, pointing to a particular stoichiometry for possible lipid/cholesterol complex formation. It has been hypothesized that reactive cholesterol monomers are present in mixtures with cholesterol content greater than that at the cusp. To test this hypothesis, we have examined how the prese...

We tried to establish an assay system £or screening and assessment of immunoregulatory factors using whole cell cultures of mouse splenocytes and found that splenic adhesiye cells markedly increased immunogobulin (Ig) production of splenocytes. In the absence of adhesiye cells, lipopolysaccharides, pokeweed mitogen, and phytohemagglutinin stimulated the prod"ction of IgA, IgG, and IgM in a clas...