Re approved by Firat University Local Ethical Committee, and all subjects
Re approved by Firat University Local Ethical Committee, and all subjects were recruited upon obtaining informed consent. Subjects’ history and physical examinations were documented. The diagnosis of LC was based on histopathologic findings. Nine out of 39 patients were small cell LC, 16 were squamous cell LC, 14 were adenocarcinoma type. Cases either study group or control, who had pathologies that could cause secondary lipid disorders, cardiovascular PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/28151467 diseases, diabetes mellitus, renal failure, chronic infection and inflammation, alcohol abuse, and those who used antilipidemic and antioxidant drugs were excluded from the study. Additionally, LC patients with previously performed chemotherapy, radiotherapy and surgery were also excluded from the study.Serum samples Blood samples were collected in tube (BD diagnostics-preanalytic systems, UK) at 0800?900 A.M. after 8?2 hours of fasting. Professional staff performed venipuncture, using vacutainers to obtain 10 mL of whole blood. Since calcium EDTA inhibits PON1 activity, calcium EDTA containing tubes were not used for collecting serum samples. The samples were centrifuged at 3500 rpm for 5 min. and serum samples were stored at -20 until assayed.Serum levels of total cholesterol, triglyceride, HDL-cholesterol and low density lipoprotein (LDL)-cholesterol were determined by means of an Olympus AU 600 autoanalyzer (Olympus Optical Co., Japan) using commercially available assay kits. Serum total cholesterol, triglyceride, HDL-cholesterol and LDL-cholesterol levels were measured at the same day that the blood was collected.Assay of serum paraoxonase and arylesterase activities Paraoxonase activity was determined spectrophotometrically using paraoxon (O, O-diethyl-o-p-nitro-phenylphosphate; Sigma Chemical Co) as the substrate and measured by increases in the absorbance at 412 nm due to the formation of 4-nitrophenol as already described [23]. Briefly, the activity was measured at 25 by adding 50 l of serum to 1 ml Tris-HCl buffer (100 nM at pH 8.0) containing 2 mM CaCl2 and 5.5 mM of paraoxon. The rate of generation of 4-nitrophenol was determined at 412 nm with a spectrophotometer (Techcomp 8500 II UV/VIS, China). PON1 activity is expressed in U/l serum. One unit of PON1 activity was defined as 1 nmol of 4-nitrophenol formed per minute under the above assay conditions.MethodsThe study population This case-control study was conducted at the Department of Internal Medicine of the Firat (Euphrates) University Hospital setting in Elazig, Turkey, between December 2004 and June 2005. A total of 44 patients were admitted during the period. However two of them were excluded from the study due to history of taking antilipidemic drug,Page 2 of(page number not for citation purposes)BMC Cancer 2007, 7:http://www.biomedcentral.com/1471-2407/7/Arylesterase activity was also measured spectrophotometrically using phenylacetate (Sigma Co, London, UK) as the substrate. The phenol formed after the purchase JC-1 addition of a 40-fold diluted serum sample was measured spectrophotometrically at 217 nm following an established procedure [24]. The activity of ARE was expressed in kU/l serum. One unit was defined as the enzyme quantity that disintegrates 1 nmol phenylacetate per minute.The phenotypic distribution of paraoxonase The phenotypic distribution of PON1 activity was determined by the dual substrate method. Three phenotypes were determined in the study groups by taking the ratio of PON1 activity to arylesterase activity.