Surgical vein occlusion--comparison of four different methods in a rat model.

Background: Among many aspects, wound healing depends on early restoration of venous blood flow across wound margins. The type of surgical occlusion of vein stumps during operations was assumed to have an influence on the early postoperative reunion of vein stumps and thereby on wound healing. Currently, there are different methods of vein stump occlusion available: ligation (e.

Selective inhibition of vitamin D hydroxylases in human keratinocytes.

Human keratinocytes convert 25(OH)D(3) to hormonally active 1alpha,25(OH)(2)D(3) and respond to its antiproliferative/prodifferentiating action in vitro and in vivo. Levels and activity of 1alpha,25(OH)(2)D(3) are short-lived. 1alpha,25(OH)(2)D(3) induces 24-hydroxylase (CYP24) that rapidly metabolizes the hormone, yielding a cascade of side-chain oxidized products and this eventually results in the loss of activity.

Therapeutic trial of lipid X in a canine model of septic shock.

Three groups of dogs were given lipid X (0, 1, or 10 mg/kg) every 8 h for for seven doses, starting simultaneously with the intraperitoneal placement of Escherichia coli-containing fibrin clots. All animals developed bacteremia, hypotension, and a pattern of decreased left ventricular ejection fraction characteristic of septic shock (P = .01).

Structural features that influence the ability of lipid A and its analogs to abolish expression of suppressor T cell activity.

Lipid A preparations derived from the lipopolysaccharides of several gram-negative bacteria, as well as chemically defined synthetic lipid A's and their analogs (both glucosamine mono- and disaccharides), were used to establish the chemical structures required for (i) abolishing the expression of suppressor T cell (Ts) function and (ii) inducing polyclonal activation of B cells. Salmonella minnesota R595 lipid A (diphosphoryl lipid A) possesses both of these activities. Decreasing the number of phosphate groups in lipid A from two to one (monophosphoryl lipid A) as well as decreasing the fatty acyl content, primarily by removing the residue at the 3 position, resulted in a progressive reduction in toxicity; however, these structural modifications did not influence its ability to abolish the expression of Ts function.

Antagonism of lipopolysaccharide-induced priming of human neutrophils by lipid A analogs.

Lipid X, a monosaccharide precursor of the lipid A component of LPS, has been found to antagonize LPS-induced priming of human neutrophils in a manner consistent with competitive inhibition. In this investigation, the inhibition of neutrophil priming by lipid A analogs was found to be specific for LPS-induced priming. Priming of neutrophils by TNF, IL-8, and C5a were all unaffected by increasing concentrations of 3-aza-lipid X-4-phosphate (compound 3), a monosaccharide LPS-antagonist.