Detection of circulating prostate cancer cells via prostate specific membrane antigen by chronoimpedimetric aptasensor

Objectives Sensitive and accurate techniques for early detection of prostate cancer, which has a good chance for successful treatment if detected early, are of utmost value. Our aim is to develop a sensitive chronoimpedimetric biosensor for detection of circulating prostatic tumor cells (CTCs) with an aptamer selective for prostate specific membrane antigen (PSMA). Methods Thiolated PSMA-specific aptamer was immobilized on the gold nanopArticle modified carbon screen-printed electrodes. After characterization with cyclic voltammetry and electrochemical impedance spectrometry, scanning electron microscopy and atomic force microscopy studies were conducted to confirm the modifications. LNCaP cells (androgen-sensitive human prostate adenocarcinoma cells), were then added to the serum samples and chronoimpedimetric detection of CTCs in samples were performed. Results Our study showed one cell detection capability in real serum samples with a linear range from 1 to 40 cells/mL. The incubation time was 130 s. LOD was found to be 0.62 cells/mL and relative standard deviations were lower than 2% RSD. Reproducibility tests indicated a regression coefficient as R-2 = 0.9963 +/- 0.0178. Conclusions This new biosensor enables rapid, accurate, precise, reproducible and highly sensitive detection of PSMA on CTCs in prostate cancer and paves the way to new diagnostic applications and research-based studies

Lipids as key players in Alzheimer disease - Alterations in metabolism and genetics

WOS: 000253935100002PubMed ID: 18288926Advances in Alzheimer Disease (AD) research suggest that central nervous system (CNS) lipids play a key role in the pathogenesis. This role is attributed to the rich lipid content of CNS structures and the presence of blood brain barrier which disables the exchange of lipids between CNS and plasma. Among these lipids, cholesterol is a unique molecule provided mainly by its de novo synthesis in the CNS. Special apolipoproteins used for its efficient recycling within the CNS and special oxysterols formed that are specific to brain all contribute to the unique properties of the molecule. Above all, the presence of cholesterol in the membrane enables it to function as a regulator of a number of protein related processes such as the amyloid precursor protein cleavage. Cholesterol reducing agents such as statins are recently proposed to have a protective role in AD. This review will focus on the role of cholesterol metabolism and genetics in AD. Current literature investigating the relationship between cholesterol and AD will be evaluated from the pathophysiological perspective. Genetic studies concerning proteins which are involved in the CNS cholesterol metabolism will also be summarized in the hope that genomics may stimulate further studies and thus contribute to a more clear understanding of the molecular mechanisms in the pathophysiology of AD

CRISPR-dCas9 powered impedimetric biosensor for label-free detection of circulating tumor DNAs

Uygun, Zihni Onur/0000-0001-9045-7271WOS: 000537663300005PubMed: 32493587Label-free biosensors which can be integrated into lab-on-a-chip platforms have the advantage of using small volumes for rapid and inexpensive measurements contrary to label-based technologies which are often more costly and time-consuming. in this study, graphene oxide screen printed electrodes (GPHOXE) were modified by deactivated Cas9 (dCas9) proteins and synthetic guide RNA (sgRNA) as the biorecognition receptor for label-free detection of circulating tumor DNAs (ctDNA). This was achieved by detection of a tumor related mutation (PIK3CA exon 9 mutation) via sequence-specific recognition followed by electrochemical impedance spectroscopy (EIS) analysis. the biosensor showed high specificity as there was no impedance signal for other ctDNA sequences, even the single nucleotide mismatch. dCas9-sgRNA modified biosensor demonstrated linear detection limits between 2 and 20 nM for 120 bp ctDNA's in 40 s. the calibration curve showed good linearity, LOD was calculated as 0.65 nM and LOQ was calculated as 1.92 nM. Selectivity and repeatability studies were carried out in real blood samples and the recovery was higher than 96%. in conclusion, dCas9-sgRNAwas effectively immobilized and optimized on GPHOXE as the selective biorecognition receptor of this ultrafast impedimetric biosensor. the CRISPRd-Cas9 powered impedimetric system showed good selectivity, high repeatability and good recovery properties. This is the first literature to report the use of CRISPR/Cas technology as a label-free tool that can be used in an impedimetric system for detection of ctDNA's. (C) 2020 Elsevier B.V. All rights reserved.Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TUBITAK-1001, 217S353]This study was supported by the Scientific and Technological Research Council of Turkey (TUBITAK-1001) with the project number of 217S353

A Novel Chronoimpedimetric Cytosine Modified Molecularly Imprinted Sensor for Label-Free Detection of 8-Hydroxydeoxyguanosine in Urine Samples

First time in the literature, we imprinted 8-hydroxyguanosine (8OHG) to engineer an impedimetric sensor on a polymer from three different main non-covalent structures. Considering the chemical structure of the molecule and its potential non-covalent bonding behaviors, we designed a special electrode with molecular imprinting technology (MIT). Therefore, 8OHG, which serves as an important biomarker of oxidative stress, was imprinted on an electrode to form an 8OHG sensor. In this imprinting method, firstly, a gold electrode was modified with Cytosine-1yl-acetic acid (CAA) to increase selectivity and form DNA hydrogen bond-like structures. Afterward, pyrrole and aminophenyl boronic acid monomers were polymerized from three different points by electropolymerization, and a selective and sensitive sensor technology was developed. 8OHG measurement was carried out impedimetrically in six minutes (R-2 value in the range of 500-10000 pg ml(-1) is 0.9928 +/- 0.006). LOD and LOQ was calculated 155.8 pg ml(-1) and 472 pg ml(-1), respectively. In conclusion, a sensitive, low-cost, fast and innovative technique with higher selectivity has been introduced. We believe that novel imprinting techniques will provide the important potential for MIP techniques for medical diagnostics.Ege University [TGA-2020-21888]This study was supported by Ege University (zmir, Turkiye) Scientific Research Department by the number of TGA-2020-21888 and authors are thankful for Dokuz Eylul University Center for Fabrication and Application of Electronic Materials (zmir, Turkiye)

Leukocyte cell surface antigens in Gaucher disease: New implications for B-cell proliferation and pathogenesis of myelomatosis

11th Annual WORLD Symposium of the Lysosomal-Disease-Network -- FEB 09-13, 2015 -- Orlando, FLWOS: 000348973100246Lysosomal Dis Networ

Reflections from Ege University Medical School’s clinical internship mentoring program (2011–2018)

Objectives: Ege University Medical School initiated sys- tem based integrated clinical internship in 2011. The need for a mentor who would closely monitor and guide the student in knowledge and skill gains for every clinical internship block and who would be an academic role model was well established. The aim of this study reports the results of the clinical internship mentoring program in the Ege University Medical School. Methods: The Clinical Internship Counseling Committee reviewed similar programs in the literature, conducted focus group discussions, determined the wishes and needs of the students, and developed a mentoring program. Results: The program was initiated by announcing the student-mentor matches and the procedure which was based on meetings of the student-mentor at the 1st, 8th and 13th weeks of the integrated internship. This meeting was designed to be a time for the mentor to guide the student to achieve the internship goals, to establish his/her intern- ship progress file and to be an academic role model. At the final evaluation of the mentor, communication between student and the progress in the establishment of the internship progress file contributed to the 5% of the final internship success grade. Conclusions: Evaluation of 7 years of experience led to the agreement that the goals of clinical internship program should be integrated into the newly established “Student Mentorship Program” that starts at the 1st year of the medical school

The role of cholesteryl ester transfer protein TaqIB polymorphism in young atherosclerotic heart disease

Objectives: There is growing evidence that oxidative modification of low-density lipoprotein (LDL) plays a central role in the pathogenesis of atherosclerosis, which is increasingly seen at younger ages, and that high-density lipoprotein (HDL) levels are inversely associated with the risk of coronary artery disease (CAD). Cholesteryl ester transfer protein (CETP) has a role in the regulation of plasma HDL levels. the most studied polymorphism in the CETP gene is the Taq1B polymorphism, which has consistently been correlated with HDL levels. This case control study of a young (<50 years) Turkish population group with CAD was designed to assess whether there is a relationship between LDL oxidation and CETP Taq1B polymorphism. Methods: A total of 97 patients with CAD and 43 healthy volunteers were included in the study. Traditional risk factors for CAD (age, gender, smoking, hypertension) were evaluated in the patient group. Oxidative markers of LDL were determined in both groups, as well as routine biochemical parameters. Following DNA extraction from white cells, CETP Taq1B polymorphism was determined using polymerase chain reaction amplification and restriction enzyme digestion. Fragments 174 and 361bp were identified as B1, and unrestricted 535 bp fragments as B2. Results: There was no statistical significance between the B1B1, B1B2, B2B2 genotypes in the patient group in terms of body mass index, waist-to-hip ratio, or biochemical parameters. Though the HDL cholesterol levels were higher in the B2B2 genotype, there was no statistically significant difference in comparison with the control group. Conclusion: the genetic polymorphism of CETP had no significant effect on CETP function and the CETP polymorphism should not be proposed as an independent risk factor for cardiovascular events