University of Crete

About: University of Crete is a education organization based out in Rethymno, Greece. It is known for research contribution in the topics: Population & Galaxy. The organization has 8681 authors who have published 21684 publications receiving 709078 citations. The organization is also known as: Panepistimio Kritis.

A Rapid, Nongenomic, Signaling Pathway Regulates the Actin Reorganization Induced by Activation of Membrane Testosterone Receptors

Abstract: The human prostate cancer cell line LNCaP bears functional membrane testosterone receptors, which modify the actin cytoskeleton and increase the secretion of prostate-specific antigen (PSA) within minutes. Membrane steroid receptors are, indeed, a newly identified element of steroid action that is different from the classical intracellular sites. In the present work, using a nonpermeable analog of testosterone (testosterone-BSA), we investigated the signaling pathway that is triggered by the membrane testosterone receptors' activation and leads to actin cytoskeleton reorganization. We report that exposure of cells to testosterone-BSA resulted in phosphorylation of focal adhesion kinase (FAK), the association of FAK with the phosphatidylinositol-3 (PI-3) kinase, and the subsequent activation of the latter as well as the activation of the small guanosine triphosphatases Cdc42/Rac1. Pretreatment of cells with the specific PI-3 kinase inhibitor wortmannin abolished both the activation of the small guanosine triphosphatases and the alterations of actin cytoskeleton, whereas it did not affect the phosphorylation of FAK. These findings indicate that PI-3 kinase is activated downstream of FAK and upstream of Cdc42/Rac1, which subsequently regulate the actin organization. Moreover, wortmannin diminished the secretion of PSA, implying that the signaling events described above are responsible for the testosterone-BSA-induced PSA secretion. Our results are discussed under the prism of a possible implication of these membrane receptors in prostate cancer chemotherapy.

A new automated method for the determination of the Total Antioxidant Capacity (TAC) of human plasma, based on the crocin bleaching assay

Abstract: Antioxidant molecules, which scavenge free radical species to prevent or delay oxidative damage of important macromolecules, membrane lipids and lipoproteins, are prevalent in plasma and other biological fluids. Among them, bilirubin, uric acid and protein thiols are the major endogenous antioxidants, while vitamins C and E, as well as a number of food-derived (poly)aromatic substances, belonging to stilbens, flavonoids and phenolic acids, are the main classes of nutritional antioxidants. Assays for total antioxidant capacity in plasma differ in their type of oxidation source, target and measurement used to detect the oxidized product. In the present work we present an automated assay for the estimation of blood total antioxidant capacity (TAC assay), based on the crocin bleaching (oxidation) method. This method was adapted on a modern autoanalyzer, was linear over a wide range of values (0–3 mmol/L), and performed using an end point measurement. The TAC method presented a linear correlation with another automated commercial Total Antioxidant Status (TAS) test. Detection of the interference of different metabolites revealed a significant participation of TAC from uric acid, bilirubin, albumin, a minor interference from ascorbic acid, and no interference from hemoglobin. TAC was not modified by two freeze/thawing cycles, and was stable in samples stored at room temperature for 4 hours. K-EDTA and heparin were the best anticoagulants, while citrate decreased TAC by 20%. Reference values derived from samples of normal blood donors was 1.175 ± 0.007 mmol/L (mean ± SEM), while a diet rich in antioxidants more than doubled this value. The proposed TAC assay, is fully automated, stable and reliable, and could be of value in the estimation of the AC of plasma. It is further proposed to calculate the antioxidant capacity of plasma after a subtraction of all interference deriving from endogenous and/or exogenous metabolites. The antioxidant capacity of plasma thus calculated can be used as a useful indicator of the antioxidant value of foods and beverages in the daily diet.

Smoking and smoking cessation during early pregnancy and its effect on adverse pregnancy outcomes and fetal growth

Abstract: Maternal smoking during pregnancy is a significant threat to the fetus. We examined the association between active maternal smoking and smoking cessation during early pregnancy with newborn somatometrics and adverse pregnancy outcomes including preterm delivery, low birth weight, and fetal growth restriction. One thousand four hundred mother–child pairs with extensive questionnaire data were followed up until delivery, within the context of a population-based mother–child cohort study (Rhea study), in Crete, Greece, 2007–2008. Comparing smokers to nonsmokers, the adjusted odds ratio (OR) was 2.8 [95% confidence interval (CI), 1.7, 4.6] for low birth weight and 2.6 (95%CI: 1.6, 4.2) for fetal growth restriction. This corresponded to a 119-g reduction in birth weight, a 0.53-cm reduction in length, and a 0.35-cm reduction in head circumference. Smoking cessation early during pregnancy modified significantly these pregnancy outcomes indicating the necessity for primary smoking prevention.

PD-L1 is commonly expressed and transcriptionally regulated by STAT3 and MYC in ALK-negative anaplastic large-cell lymphoma.

Abstract: PD-L1 is commonly expressed and transcriptionally regulated by STAT3 and MYC in ALK-negative anaplastic large-cell lymphoma