Yahya ALTINKAYNAK

Oxidative modifications of lipoproteins are crucial in the early stages of cardiovascular diseases (CVD) like hypercholesterolemia. The major aim is to determine the effects of hazelnut consumption on the resistance of low- and high-density lipoproteins to oxidation in hypercholesterolemic subjects. Fifteen hypercholesterolemic subjects (13 men, 2 women) who did not require drug treatment according to the National Cholesterol Education Program Adult Treatment Panel III criteria and had serum levels of TC˃200 mg/dL were included in the study. This study was designed as a dual control sandwich model intervention with a single group, isoenergetic three periods. The periods were; Control Diet I (30 days), Hazelnut-Enriched Diet (30 days), and Control Diet II (30 days). The susceptibility of LDL and HDL to copper-mediated oxidation was determined spectrophotometrically by following conjugated diene formation. The resistance of lipoproteins, mainly LDL, was increased by hazelnut consumpti...

Background and ObjectiveDue to the frequency of meal ingestion, individuals spend the majority of the day, ~18 h, in a status of post-prandial (PP) stress. Remnant-like lipoprotein particles (RLPs) are predominant in PP phase playing an important role in the development of atherosclerosis. Endothelial progenitor cells (EPCs) have been suggested to play a role in vessel wall homeostasis and in reducing atherosclerosis. However, there is no information about peripheral blood EPCs number following PP stress. We investigated the association between circulating EPCs levels and extent of PP lipemia in healthy subjects following a high-fat meal.Materials and MethodsA total of 84 healthy subjects (42 men, 42 women) aged 17–55 years were included in the study. PP lipemic response of subjects was determined by Oral Fat-Loading Test (OFLT). All the subjects were classified on the basis of their plasma TG levels after PP lipemic stressors in categories 1 (low), 2 (moderate), and 3 (high). Circu...

 Amaç: Paraoksonaz-1 (PON1) HDL yapısında bulunan, HDL ve LDL’yi oksidasyondan koruyarak aterosklerotik lezyonlardaki oksidatif stresi azaltan antioksidan bir enzimdir. Bu çalışmanın amacı, sağlıklı kişilerin oral trigliserid tolerans testine (OTTT) verdikleri cevaba göre PON1 enziminin paraoksonaz, arilesteraz ve laktonaz aktivitelerini değerlendirmektir. Gereç ve Yöntem: Gönüllüler, yaşları 18-55 arasında değişen 45 kadın ve 51 erkek olmak üzere toplam 96 sağlıklı bireyden oluşmaktadır. Gönüllüler, açlık ve OTTT sonrası 2, 4 ve 6’ncı saatlerdeki TG seviyeleri kullanılarak hesaplanan eğri altındaki alan (AUC) değerlerine göre üç farklı gruba ayrılmıştır. PON1 enzim aktiviteleri ve diğer parametreler OTTT cevabı düşük olan grup ile yüksek olan grup arasında karşılaştırıldı. PON1 enzim aktiviteleri spektrofotometrik metodlarla belirlendi. Bulgular: Erkeklerde üst grup ile alt grup karşılaştırıldığında aterojenik lipid profili, artmış total kolesterol ve LDL-K ile azalmış HDL-K düzeyl...