Isolation and identification of hydroxyl-platelet-activating factor from natural sources.

Platelet-activating factor (PAF), a potent inflammatory mediator that has previously been detected in elevated levels in inflamed gingival tissues, in gingival crevicular fluid (GCF) and in saliva, is implicated in periodontal disease. The biologically active phospholipid detected in gingival crevicular fluid is a hydroxyl-PAF analogue. In a preliminary study this bioactive molecule was detected for the first time in human blood derived from volunteers with chronic periodontitis as well as from periodontally healthy volunteers.

Hydroxyl-platelet-activating factor exists in blood of healthy volunteers and periodontal patients.

Periodontal diseases are localized chronic inflammatory conditions of the gingival and underlying bone and connective tissue. Platelet-activating factor (PAF), a potent inflammatory phospholipid mediator that has been previously detected in elevated levels in inflamed gingival tissues, in gingival crevicular fluid and in saliva, is implicated in periodontal disease. Our results from previous studies showed that the biologically active phospholipid detected in gingival crevicular fluid is a hydroxyl-PAF analogue.

Identification of a new endogenous platelet-activating factor-like molecule in gingival crevicular fluid.

Periodontal disease is an inflammatory disease and the major cause of tooth loss in adults. Bacteria and their products are the causative agents of this disease. Endogenous molecules mediate the inflammatory process and play a major role in its amplification and perpetuation as well as in the ensuing tissue destruction.

Enhanced in-vitro activity of liposome-trapped penicillin-G against Pseudomonas aeruginosa.

The growth inhibition of four Pseudomonas aeruginosa strains by liposome-trapped penicillin-G was investigated. There were indications of an association of the efficacy of liposomal penicillin-G with the nature of the 0-antigenic polymeric side chain. Namely, P28-800 and PCF-95 strains, characterized by a rough polysaccharide chain, were the most susceptible, whereas strain P28-0, possessing an intact lipopolysaccharide, resisted the activity of the entrapped drug.

Structural properties of the cAMP-dependent protein kinase associated with rat synaptic plasma membranes--I. Configuration in situ and membrane association-derived influences on [3H]cAMP binding.

1. A geometry of molecular ordering in situ characterizes the synaptosomal membrane-bound cAMP kinase, which is revealed from the expression of two equal-size [3H]cAMP-binding domains of differing sensitivity to physical (freeze-thaw) and chemical (reconstitution following salt-effected peripheral protein depletion) treatment of the membrane. 2.

Outer membrane alterations in multiresistant mutants of Pseudomonas aeruginosa selected by ciprofloxacin.

Spontaneous mutants of Pseudomonas aeruginosa selected by ciprofloxacin were studied for outer membrane alterations. Acquisition of ciprofloxacin resistance was at least partially related to defects in lipopolysaccharide synthesis. When ciprofloxacin resistance was combined with resistance to beta-lactams and aminoglycosides, several alterations in outer membrane proteins were noted.

Effect of calcium on the binding in vitro of [3H]cAMP to synaptosomal membranes from rat brain.

1. The binding of [3H]cAMP in vitro to synaptosomal membranes from rat brain was resolved in two components; one saturable at 20 nM cAMP with dissociation constant (KD) of 4.7 nM, and another nonsaturable within the 5-133 nM cAMP concentration range with an estimated KD value of 0.

Targeting of liposomes containing methotrexate towards Tetrahymena pyriformis cells.

The uptake of liposomes containing methotrexate by Tetrahymena pyriformis cells was investigated with the aim of producing liposome-cell association enabling methotrexate to be introduced into the cytoplasm of intact cells. Incubation of liposomes containing methotrexate with tetrahymena pyriformis cells resulted in a time and concentration-dependent uptake of entrapped methotrexate by the cells. The uptake by Tetrahymena pyriformis cells (at 1 hr) of liposomes prepared by phospholipids and gangliosides extracted from Tetrahymena pyriformis cells was approximately three fold higher than that of liposomes prepared by commercial phospholipids.