A novel amperometric glucose biosensor based on poly(glycidyl methacrylate-co-(3-thienylmethylmethacrylate))

Osman Karagollu,Mesut Gorur,Ali Turkan,Busra Sengez,Fethiye Gode,Faruk Yilmaz 한국물리학회 2013 Current Applied Physics Vol.13 No.4

Two novel glucose oxidase (GOx) enzyme electrodes based on the copolymer of glycidyl methacrylate with 3-thienylmethyl methacrylate (poly(GMA-co-MTM)) with and without polypyrrole (PPyr) coating were prepared and employed in the amperometric determination of glucose levels. The effect of PPyr coating on the electrode properties was investigated in detail. Cyclic voltammetry studies showed that electrical conductivity of electrode B with PPyr coating (poly(GMA-co-MTM)/GOx/PPyr) was substantially higher than that of electrode A (poly(GMA-co-MTM)/GOx). On the other hand, electrode A showed better results in terms of sensitivity (10 nA/mM), limit of detection (50.2 mM), and response time (5 s). Electrodes A and B gave linear responses to the glucose concentrations in the range of 2e20 and 2e14 mM, respectively. The ranges of linearity for both enzyme electrodes are sufficient for the determination of physiological glucose concentrations in human blood. Moreover, PPyr coating of electrode B did not result in further stabilization of the enzyme electrode.

Chromosome Imbalances and Alterations of AURKA and MYCN Genes in Children with Neuroblastoma

Inandiklioglu, Nihal,Yilmaz, Sema,Demirhan, Osman,Erdogan, seyda,Tanyeli, Atila Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.11

Background: Neuroblastoma (NB), like most human cancers, is characterized by genomic instability, manifested at the chromosomal level as allelic gain, loss or rearrangement. Genetics methods, as well as conventional and molecular cytogenetics may provide valuable clues for the identification of target loci and successful search for major genes in neuroblastoma. We aimed to investigate AURKA and MYCN gene rearrangements and the chromosomal aberrations (CAs) to determine the prognosis of neuroblastoma. Methods: We performed cytogenetic analysis by G-banding in 25 cases [11 girls (44%) and 14 boys (66%)] and in 25 controls. Fluorescence in situ hybridization (FISH) with AURKA and MYCN gene probes was also used on interphase nuclei to screen for alterations. Results: Some 18.4% of patient cells exhibited CAs., with a significant difference between patient and control groups in the frequencies (P<0.0001). Some 72% of the cells had structural aberrations, and only 28% had numerical chnages in patients. Structural aberrations consisted of deletions, translocations, breaks and fragility in various chromosomes, 84% and 52% of the patients having deletions and translocations, respectively. Among these expressed CAs, there was a higher frequency at 1q21, 1q32, 2q21, 2q31, 2p24, 4q31, 9q11, 9q22, 13q14, 14q11.2, 14q24, and 15q22 in patients. 32% of the patients had chromosome breaks, most frequently in chromosomes 1, 2, 3, 4, 5, 8, 9, 11, 12, 19 and X. The number of cells with breaks and the genomic damage frequencies were higher in patients (p<0.001). Aneuploidies in chromosomes X, 22, 3, 17 and 18 were most frequently observed. Numerical chromosome abnormalities were distinctive in 10.7% of sex chromosomes. Fragile sites were observed in 16% of our patients. Conclusion: Our data confirmed that there is a close correlation between amplification of the two genes, amplification of MYCN possibly contributing significantly to the oncogenic properties of AURKA. The high frequencies of chromosomal aberrations and amplifications of AURKA and MYCN genes indicate prognostic value in children with neuroblastomas and may point to contributing factors in their development.

The Relationship of Leptin (+19) AG, Leptin (2548) GA, and Leptin Receptor Gln223Arg Gene Polymorphisms with Obesity and Metabolic Syndrome in Obese Children and Adolescents

Bilge, Serap,Yilmaz, Resul,Karaslan, Erhan,Ozer, Samet,Ates, Omer,Ensari, Emel,Demir, Osman The Korean Society of Pediatric Gastroenterology 2021 Pediatric gastroenterology, hepatology & nutrition Vol.24 No.3

Purpose: Obesity is defined as the abnormal or excessive accumulation of fat over acceptable limits. Leptin is a metabolic hormone present in the circulation in amounts proportional to fat mass. Leptin reduces food intake and increases energy expenditure, thus regulating body weight and homeostasis. Various polymorphisms are present in the leptin gene and its receptor. These polymorphisms may be associated with obesity. This study aimed to show the association of leptin (+19) AG, leptin (2548) GA, and Gln223Arg leptin receptor polymorphisms with obesity and metabolic syndrome in Turkish children aged 6-17 years, and to conduct further investigations regarding the genetic etiology of obesity. Methods: A total of 174 patients diagnosed with obesity and 150 healthy children who were treated at Tokat Gaziosmanpasa Medical School Hospital between September 2014 and March 2015 were included in this study. The ages of the children were between 6 and 17 years, and anthropometric and laboratory results were recorded. Genotyping of leptin (+19) AG, leptin (2548) GA, and leptin receptor Gln223Arg polymorphisms was performed by polymerase chain reaction. Results: An association between leptin receptor Gln223Arg gene polymorphism and obesity was detected. Conclusion: Further studies are needed to determine the role of genetic etiologies and to indicate the role of leptin signal transmission impairment in the pathogenesis of obesity. We hope that gene therapy can soon provide a solution for obesity.

Mechanical properties of blended cements at elevated temperatures predicted using a fuzzy logic model

Ahmet Beycioğlu,Adil Gültekin,Hüseyin Yilmaz Aruntaş,Osman Gencel,Magdalena Dobiszewska,Witold Brostow 사단법인 한국계산역학회 2017 Computers and Concrete, An International Journal Vol.20 No.2

This study aimed to develop a Rule Based Mamdani Type Fuzzy Logic (RBMFL) model to predict the flexural strengths and compressive strengths of blended cements under elevated temperatures. Clinoptilolite was used as cement substitution material in the experimental stage. Substitution ratios in the cement mortar mix designs were selected as 0% (reference), 5%, 10%, 15% and 20%. The data used in the modeling process were obtained experimentally, after mortar specimens having reached the age of 90 days and exposed to 300C, 400C, 500C temperatures for 3 hours. In the RBMFL model, temperature (C) and substitution ratio of clinoptilolite (%) were inputs while the compressive strengths and flexural strengths of mortars were outputs. Results were compared by using some statistical methods. Statistical comparison results showed that rule based Mamdani type fuzzy logic can be an alternative approach for the evaluation of the mechanical properties of concrete under elevated temperature.

Impact of increased aspartate aminotransferase to alanine aminotransferase (De Ritis) ratio in prognosis of testicular cancer

Sacit Nuri Gorgel,Yigit Akin,Esra Meltem Koc,Osman Kose,Serkan Ozcan,Yuksel Yilmaz 대한비뇨의학회 2019 Investigative and Clinical Urology Vol.60 No.3

Purpose: Imaging studies can show metastasis in testicular cancer (TCa); however, a test for risk of metastasis in TCa has not been described. The ratio of aspartate aminotransferase to alanine aminotransferase, also called the De Ritis ratio (DRR), is used for many other malignancies. We aimed to evaluate the association between preoperatively assessed DRR and prognosis in patients with TCa. Materials and Methods: One hundred twenty-eight patients with TCa were enrolled in a retrospective study between March 2007 and January 2017. Clinical, biochemical, and pathological data were recorded. Univariate and multivariate logistic regression analyses were used. The prognostic value of DRR and the threshold value were assessed by use of receiver operating characteristic curves. Significance was defined as p<0.05. Results: Mean follow-up was 37±9.7 months. There were 45 and 73 TCa patients with and without lymph node metastasis, respectively. Lung metastases and other solid organ metastases occurred in 14 and 4 patients, respectively. The optimal DRR threshold was 1.30 for both retroperitoneal lymph node involvement and metastasis. DRR was determined as an independent prognostic factor for retroperitoneal lymph node involvement and organ metastasis in univariate and multivariate analyses (p<0.001, p=0.006 and p=0.002, p=0.047, respectively). Conclusions: A preoperative DRR greater than 1.30 may be an independent risk factor for retroperitoneal lymph node involvement and organ metastases in patients with TCa.

Roles for Paraoxonase but not Ceruloplasmin in Peritoneal Washing Fluid in Differential Diagnosis of Gynecologic Pathologies

Yildirim, Mustafa,Demirpence, Ozlem,Kaya, Vildan,Suren, Dinc,Karaca, Mehmet,Evliyaoglu, Osman,Yilmaz, Necat,Gunduz, Seyda Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15

Background: Intraperitoneal spread of gynecologic cancers is a major cause of mortality and morbidity and often presents with malignant ascites. Microscopic tumor spread can be demonstrated by a peritoneal wash cytology and help assess the prognosis of the disease. In our study, the roles of paraoxonase and ceruloplasmin, measured in peritoneal washing fluid of patients operated for gynecologic pathologies in differential diagnosis was investigated. Materials and Methods: Patients operated for malign or benign gynecologic pathologies in Antalya Education and Research Hospital Gynecology Clinic between 2010-2012 were included in the study. Samples were obtained during surgery. Results: A statistically significant difference was detected between patients with benign and malign diseases with regards to PON1 levels measured in peritoneal washing fluid (p:0.044), the average values being $64.2{\pm}30.8$ (Range 10.8-187.2) and $41.4{\pm}21.4$ (Range 10.4-95.5), respectively. No significant variation was evident for ceruloplasmin. Conclusions: Paraoxonase levels measured in peritoneal washing fluid may contribute to the differentiation of malign-benign diseases in gynecologic pathologies.

The Effect of Insulin Like Growth Factor-1 on Recovery of Facial Nerve Crush Injury

Asuman Feda Bayrak,Yuksel Olgun,Ayla Ozbakan,Safiye Aktas,Can Ahmet Kulan,Gonca Kamaci,Emine Demir,Osman Yilmaz,Levent Olgun 대한이비인후과학회 2017 Clinical and Experimental Otorhinolaryngology Vol.10 No.4

Objectives. The aim of this study is to investigate the efficacy of locally applied insulin-like growth factor 1 (IGF-1) on the recovery of facial nerve functions after crush injury in a rabbit model. Methods. The rabbits were randomly assigned into three groups. Group 1 consisted of the rabbits with crush injury alone; group 2, the animals applied saline solution onto the crushed facial nerve and group 3, IGF-1 implemented to the nerve in the same manner. Facial nerve injury was first electrophysiologically studied on 10th and 42nd days of the procedure. The damage to the facial nerves was then investigated histopathologically, after sacrification of the animals. Results. In the electrophysiological study, compound muscle action potential amplitudes of the crushed nerves in the second group were decreased. In pathological specimens of the first and second groups, the orders of axons were distorted; demyelination and proliferation of Schwann cells were observed. However, in IGF-1 treated group axonal order and myelin were preserved, and Schwann cell proliferation was close to normal (P<0.05). Conclusion. Local application of IGF-1 in a slow releasing gel was found efficacious in the recovery of the facial nerve crush injury in rabbits. IGF-1 was considered worthy of being tried in clinical studies in facial nerve injury cases.