The central role of PAF in necrotizing enterocolitis development.

We have addressed two critical questions concerning NEC development. 1) Why is the neonatal intestine particularly susceptible to necrosis? and 2) Does PAF play a critical role in NEC development? We have found that intestinal tissue of the newborn has the highest specific activity for the acetyltransferase of the de novo pathway. It is suggested that the high capacity of this tissue to synthesize PAF may contribute to the fact that the necrosis of the newborn is more prevalent in this tissue.

Progestin regulation of interleukin-8 mRNA levels and protein synthesis in human endometrial stromal cells.

The migration of leukocytes into the human endometrium is a normal occurrence that appears to be linked to the hormonal events of the ovarian cycle. In addition, the appearance of large numbers of leukocytes in decidua accompanies normal human pregnancy and puerperal endometrial repair during uterine involution. These leukocytic investments in endometrial-decidual function are also affected by external stimuli, e.

Effect of estrogens on plasma platelet-activating factor acetylhydrolase and the timing of parturition in the rat.

In the present study we examined the effects of estrogens on plasma platelet-activating factor acetylhydrolase (PAF-AH) activity in pregnant rats in an attempt to further define the role of platelet-activating factor (PAF) in parturition. The plasma PAF-AH activity decreased starting on Day 13 of pregnancy and reached its lowest level by Day 19 (36.5 +/- 5.

Metabolic fate of platelet-activating factor in the rat enterocyte: the role of a specific lysophospholipase D.

The metabolism of platelet-activating factor (PAF) by isolated rat intestinal epithelial cells was investigated using 1-[3H]octadecyl-2-acetyl-sn-glycero-3-phosphocholine. The principal metabolite produced by the cells was 1-O-alkylglycerol, which was found in association with the cells and the medium. When similar studies were conducted employing an intestinal epithelial cell line (INT 407), PAF was almost quantitatively converted into 1-alkyl-2-acyl-sn-glycero-3-phosphocholine (AAGPC).

Platelet-activating factor acetylhydrolase in term and preterm human milk: a preliminary report.

Human milk may protect against necrotizing enterocolitis (NEC). Since platelet-activating factor (PAF) may participate in the pathophysiology of NEC, we measured PAF acetylhydrolase (PAF-AH), which metabolizes PAF, in term and preterm human milk. The activity of PAF-AH in term milk collected 2-4 days after delivery (n = 17) was 2.

Regulation of aromatase expression in human tissues.

Extraglandular conversion of C19 steroids to estrogens takes place primarily in the stromal cell compartments of adipose tissue and is catalyzed by aromatase cytochrome P450 (P450arom, the product of the CYP19 gene). CYP19 gene expression and aromatase activity in breast adipose stromal cells in culture are subject to complex hormonal regulation, which was recently found to be mediated in part by alternative use of tissue-specific promoters of the CYP19 gene. It has been proposed that increased local aromatase activity in breast adipose tissue may influence the growth of breast carcinomas.

Smoking and preterm labor: effect of a cigarette smoke extract on the secretion of platelet-activating factor-acetylhydrolase by human decidual macrophages.

Objective: Maternal smoking in pregnancy is associated with a significant increase in the incidence of preterm labor, premature rupture of membranes, and premature delivery. Our aim was to clarify the cause underlying this association.

Study Design: The effect of cigarette smoke extract on the secretion of platelet-activating factor-acetylhydrolase by both decidual macrophages and peripheral blood monocytes and macrophages was investigated.

Metabolism of hexadecanol by rat type II pneumonocytes.

Type II pneumonocytes isolated from adult rats incorporate radioactivity from 1-[3H]hexadecanol into either lipids. The radioactivity is distributed between the neutral lipids, phosphatidylcholines, and phosphatidylethanolamines. The neutral lipid fraction is almost exclusively composed of triradylglycerols.

Presence of platelet-activating factor-acetylhydrolase in milk.

Human milk contains numerous factors such as immunoglobulins, lactoferrin, lysozyme, macrophages, etc., which serve an immunoprotective role. Platelet-activating factor (PAF) is one of the most proinflammatory agents thus far described.

Platelet-activating factor-induced ischemic bowel necrosis: the effect of platelet-activating factor acetylhydrolase.

In the present investigation, the rat model of necrotizing enterocolitis (NEC) was further developed by injection of platelet-activating factor (PAF) in the descending aorta. The role of the plasma PAF-acetylhydrolase (PAF-AH) was examined in the prevention of this disease. PAF (0.

Regulation of interleukin-8 gene expression in human endometrial cells in culture.

In this study, we investigated the regulation of interleukin-8 (IL-8) gene expression in separated endometrial stromal and epithelial cells of human endometrium. This research was conducted as part of an analysis of the role of these cells in regulating the recruitment of leukocytes to the endometrium. Well-characterized model systems were used to study the regulation of endometrial IL-8 gene expression, namely, stromal cells in monolayer culture after first passage and glandular epithelium in primary culture.