ABSTRACT
Lysophosphatidylcholine (LPC) is the most abundant lysophospholipid in plasma and tissues, and its level increases in ischemia and inflammation. LPC induces various proinflammatory actions in leukocytes, endothelial cells, and smooth muscle cells, but its effects may vary, depending on the acyl chain. In the present study, we identified the molecular species of LPC in human plasma and studied their effects on human neutrophils. Unsaturated LPC species over a wide concentration range (5-200 microM) induced long-lasting superoxide production in neutrophils. The response was preceded by a >10-min lag time and lasted for 60-90 min. Superoxide production was prevented when albumin was added together with LPC at a molar ratio of 1:2 or higher, and significant inhibition was observed even when albumin was added 4-8 min after LPC. Saturation of albumin by fivefold molar excess of stearic acid reduced the inhibitory effect significantly. Saturated LPCs, particularly the most abundant 16:0 species, induced significantly less superoxide production than the unsaturated species and only at 5-10 microM concentrations. Saturated LPC species elicited a several-fold higher increase in cytoplasmic calcium and at >20 microM, increased plasma membrane permeability. A mixture of LPCs mimicking the plasma LPC composition induced nearly similar superoxide production as the most active LPC18:1 alone. These results indicate remarkable acyl chain-dependent differences in the cellular effects of LPC. Elevation of LPC level may increase inflammation through activation of neutrophil NADPH oxidase, particularly when the simultaneous increase of free fatty acids diminishes the ability of albumin to scavenge LPCs.
Subject(s)
Lysophosphatidylcholines/pharmacology , Neutrophils/drug effects , Albumins/pharmacology , Calcium Signaling/drug effects , Cell Membrane Permeability/drug effects , Cells, Cultured , Fatty Acids, Nonesterified/pharmacology , Humans , L-Lactate Dehydrogenase/metabolism , Lysophosphatidylcholines/blood , Neutrophils/cytology , Neutrophils/enzymology , Onium Compounds/pharmacology , Reactive Oxygen Species/metabolism , Trypan Blue/metabolismABSTRACT
The methods most often used for follow-up of ovarian cancer are physical examination, CA-125 measurement and ultrasonography or computed tomography. In the present study the role of cul-de-sac aspiration cytology as a supplementary method was evaluated. We analyzed the records of 110 stage I-IV ovarian cancer patients who had undergone cul-de-sac aspiration as a part of their follow-up schedule after the primary treatment. During the median follow-up of 5 years altogether 577 cul-de-sac aspirations were performed with a median interval of 9 months. Only in 2 cases the obtained sample was insufficient for evaluation. Twenty patients had cul-de-sac cytology > or = class III at some point during the follow-up. In 12 cases the preceding or subsequent CA-125 values taken within 3 months were < 35 U/l. In 7 cases CA-125 values increased later, but in 5 cases the tumour marker values remained within normal range during the entire follow-up. Nine out of these 12 patients had a clinical recurrence later on, but 3 patients had no evidence of the disease. Twenty-seven recurrences were detected during the follow-up. Cul-de-sac aspiration cytology was the first or the only indication of recurrence in 9 cases (33%) and is a useful supplementary method in the follow-up of ovarian cancer.
