Novel amperometric glucose biosensor based on covalent immobilization of glucose oxidase on poly(pyrrole propylic acid)/Au nanocomposite

Mehmet Şenel,Cevdet Nergiz 한국물리학회 2012 Current Applied Physics Vol.12 No.4

A glucose biosensor is fabricated with immobilization of glucose oxidase (GOx) on poly(pyrrole propylic acid)/Au nanocomposite by covalent attachment. Poly(pyrrole propylic acid) (PPyAA)/Au nanocomposite was prepared by chemical oxidation of pyrrole propylic acid monomer by using chloroauric acid (HAuCl4)as an oxidizing agent. The obtained nanocomposites were used to fabricate highly sensitive amperometric glucose biosensor which exhibited a high and reproducible sensitivity of 0.42 mA/mM, response time w2 s, linear dynamic range from 1 to 18 mM, correlation coefficient of R2= 0.9981, and limit of detection (LOD), based on S/N ratio (S/N = 3) of 0.05 mM. A value of 1.83 mM for the apparent Michaelis eMenten constant Kapp m was obtained. The high sensitivity, wider linear range, good reproducibility and stability make this biosensor a promising candidate for portable amperometric glucose biosensor.

Mechanisms of immune tolerance to allergens in children

Umut C. Kucukseze,Cevdet Ozdemir,Mübeccel Akdis,Cezmi A. Akdis 대한소아청소년과학회 2013 Clinical and Experimental Pediatrics (CEP) Vol.56 No.12

Because the prevalence of allergic diseases has significantly increased in recent years, understanding the causes and mechanisms of these disorders is of high importance, and intense investigations are ongoing. Current knowledge pinpoints immune tolerance mechanisms as indispensable for healthy immune response to allergens in daily life. It is evident that development and maintenance of allergenspecific T cell tolerance is of vital importance for a healthy immune response to allergens. Such tolerance can be gained spontaneously by dose-dependent exposures to allergens in nature or by allergen-specific immunotherapy. Allergen-specific immunotherapy induces regulatory T cells with the capacity to secrete interleukin-10 and transforming growth factor-β, limits activation of effector cells of allergic inflammation (such as mast cells and basophils), and switches antibody isotype from IgE to the noninflammatory type IgG4. Although allergen-specific immunotherapy is the only method of tolerance induction in allergic individuals, several factors, such as long duration of treatment,compliance problems, and life-threatening side effects, have limited widespread applicability of this immunomodulatory treatment. To overcome these limitations, current research focuses on the introduction of allergens in more efficient and safer ways. Defining the endotypes and phenotypes of allergic diseases might provide the ability to select ideal patients, and novel biomarkers might ensure new custom-tailored therapy modalities.

Case Reports : Benign Cephalic Histiocytosis: A Case Report

( Rafet Koca ),( Sibel Bektas ),( Cevdet Altinyazar ),( Tuna Sezer ) 대한피부과학회 2011 Annals of Dermatology Vol.23 No.4

Histiocytic skin disorders are usually classified as either Langerhans` cell histiocytosis (LCH) or non LCH, based on the pathology. Benign cephalic histiocytosis (BCH) is a rare type of non-Langerhans histiocytitic disorder and is characterized by self-healing multiple small eruptions of yellow to red-brown papules on the face and upper trunk. Histologic features of this disorder show dermal proliferation of histiocytes that have intracytoplasmic comma-shaped bodies, coated vesicles and desmosome-like structures. In this study, we report on a 7-month-old boy who contained small yellow-red papules on his face that spread to his upper trunk. The clinical and histologic features in this patient were consistent with BCH. (Ann Dermatol 23(4) 508~511, 2011)

Mechanisms of immune tolerance to allergens in children

Kucuksezer, Umut C.,Ozdemir, Cevdet,Akdis, Mubeccel,Akdis, Cezmi A. The Korean Pediatric Society 2013 Clinical and Experimental Pediatrics (CEP) Vol.56 No.12

Because the prevalence of allergic diseases has significantly increased in recent years, understanding the causes and mechanisms of these disorders is of high importance, and intense investigations are ongoing. Current knowledge pinpoints immune tolerance mechanisms as indispensable for healthy immune response to allergens in daily life. It is evident that development and maintenance of allergen-specific T cell tolerance is of vital importance for a healthy immune response to allergens. Such tolerance can be gained spontaneously by dose-dependent exposures to allergens in nature or by allergen-specific immunotherapy. Allergen-specific immunotherapy induces regulatory T cells with the capacity to secrete interleukin-10 and transforming growth factor-${\beta}$, limits activation of effector cells of allergic inflammation (such as mast cells and basophils), and switches antibody isotype from IgE to the noninflammatory type IgG4. Although allergen-specific immunotherapy is the only method of tolerance induction in allergic individuals, several factors, such as long duration of treatment, compliance problems, and life-threatening side effects, have limited widespread applicability of this immunomodulatory treatment. To overcome these limitations, current research focuses on the introduction of allergens in more efficient and safer ways. Defining the endotypes and phenotypes of allergic diseases might provide the ability to select ideal patients, and novel biomarkers might ensure new custom-tailored therapy modalities.

Novel Mutual Inductance Calculation of the Magnetically Coupled Coils

Slobodan. I. Babic,Cevdet. Akyel 한국자기학회 2008 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Bilateral Ureteral Stones and Spontaneous Perirenal Hematoma in a Patient with Chronic Idiopathic Thrombocytopenic Purpura

Mehmet Akyüz,Selahattin Çalışkan,Cevdet Kaya 대한비뇨의학회 2012 Investigative and Clinical Urology Vol.53 No.7

Idiopathic thrombocytopenic purpura (ITP) is an immune thrombocytopenia with a usually benign clinical course. Bleedings are mostly of the mucocutaneous type with mild symptoms. Massive bleedings requiring transfusion are rarely seen, unless the number of platelets decreases to extremely low levels. In this case, bilateral perirenal hematoma and bilateral distal ureteral stones were detected on a non-contrast computed tomography scan of a 57-year-old male patient who developed macroscopic hematuria during his treatment in the clinics of internal medicine because of left flank pain and diffuse petechial rashes all over his body. The patient, who had been receiving chronic ITP treatment for 1 year, had a very low platelet count (4,000/mm3). The patient was prescribed bed rest, and his platelet count increased to a safe level for surgical intervention of above 50,000/mm3 with administration of prednisolone, intravenous immune globulin, and platelet suspension. A stone-free state was achieved after bilateral ureterorenoscopy and pneumatic lithotripsy. A conservative approach was followed for the perirenal hematoma. Upon regression of the perirenal hematoma, the patient was discharged at 9 weeks postoperatively.

Influence of deposition conditions on nanostructured InSe thin films

Kübra Çınar Demir,Emre Demir,Seniye Yüksel,Cevdet Coşkun 한국물리학회 2019 Current Applied Physics Vol.19 No.12

In this study, nanostructured indium selenide (InSe) thin films were deposited on Indium tin oxide (ITO)-coated glass substrate using electrochemical deposition (ECD) from aqueous solution containing In(SO4)3.H2O and SeO2. The effects of deposition potential (−0.70 to −1.35 V), time (30-3600 s), temperature (25-80 °C) and pH (2.58 for A samples; 2 for B samples and 1.45 for C samples) on growth of the InSe thin films were examined in terms of their structural, morphological and optical properties. X-ray diffraction (XRD) analysis confirmed that the InSe thin films are in polycrystalline structure. It was found that the values of grain size decreased and the full width half maximum (FWHM) values increased with the increasing deposition potential. According to the absorption measurements, optical properties of the thin films varied with changes in deposition conditions. Based on the atomic force microscopy (AFM) and the scanning electron microscopy (SEM) images, surface morphology of the thin films was influenced by deposition potential and pH of the electrolyte, and nonhomogeneous depositions distributed across the entire surface were observed. In addition, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and fourier transform infrared spectroscopy (FT-IR) analyses were used to further examine crystal quality, vibration, chemical binding conditions, In/Se orientation and structure of the prepared InSe thin films. When Raman results are examined, the B12 sample shows a more intensity and narrow peak at 248 cm−1. XPS measurements sowed that A6 sample exhibited more growth in low potential for a long time and better film stoichiometry compared to the other three samples. Also, FT-IR studies prove the presence of InSe. According to the results, the film did not form at low temperatures and short times. However, the film formation began with the increasing deposition temperature and time at the low potential value of −0.730 V. But, it is clear that a high quality film can be obtained in cathodic potential with −1.3 V and shorter deposition time with 300 s at room temperature respectively. Overall results showed that the high quality thin films can be obtained by the ECD technique. However, deposition conditions must be sensitively adjusted to control morphology of the electrodeposited nanoparticles.

Ineffective Doses of Dexmedetomidine Potentiates the Antinociception Induced by Morphine and Fentanyl in Acute Pain Model

Unal, Mumin,Gursoy, Sinan,Altun, Ahmet,Duger, Cevdet,Kol, Iclal Ozdemir,Kaygusuz, Kenan,Bagcivan, Ihsan,Mimaroglu, Caner The Korean Society of Pharmacology 2013 The Korean Journal of Physiology & Pharmacology Vol.17 No.5

The aim of this study was to evaluate the synergistic potentiation effect of ineffective doses of dexmedetomidine on antinociception induced by morphine and fentanyl in acute pain model in rats. Seventy albino Wistar rats were separated into 7 groups. Data for the control and sham groups were recorded. The ineffective dose of dexmedetomidine was investigated and found to be 3 ${\mu}g/kg$. Each group was administered the following medications: 3 mg/kg morphine (intraperitoneal) to Group 3, 5 ${\mu}g/kg$ fentanyl (intraperitoneal) to Group 4, dexmedetomidine 3 ${\mu}g/kg$ (subcutaneously) to Group 5, dexmedetomidine 3 ${\mu}g/kg$ (subcutaneous)+3 mg/kg morphine (intraperitoneal) to Group 6 and finally 3 ${\mu}g/kg$ dexmedetomidine (subcutaneous)+5 ${\mu}g/kg$ fentanyl (intraperitoneal) to Group 7. Just before the application and 15, 30, 60, 90 and 120 min after the administration of medication, two measurements of tail flick (TF) and hot plate (HP) tests were performed. The averages of the measurements were recorded. TF and HP latencies were the main outcomes. The analgesic effect of the combinations with dexmedetomidine+morphine (Group 6) and dexmedetomidine+fentanyl (Group 7), compared to the analgesic effect of morphine alone and fentanyl alone was significantly higher at 15, 30, 60 and 90 minutes after administration. In this study, dexmedetomidine in ineffective doses, when combined with morphine and fentanyl, potentiates the effects of both morphine and fentanyl.

Ineffective Doses of Dexmedetomidine Potentiates the Antinociception Induced by Morphine and Fentanyl in Acute Pain Model

Mumin Unal,Sinan Gursoy,Ahmet Altun,Cevdet Duger,Iclal Ozdemir Kol,Kenan Kaygusuz,Ihsan Bagcivan,Caner Mimaroglu 대한약리학회 2013 The Korean Journal of Physiology & Pharmacology Vol.17 No.5

The aim of this study was to evaluate the synergistic potentiation effect of ineffective doses of dexmedetomidine on antinociception induced by morphine and fentanyl in acute pain model in rats. Seventy albino Wistar rats were separated into 7 groups. Data for the control and sham groups were recorded. The ineffective dose of dexmedetomidine was investigated and found to be 3 μ g/kg. Each group was administered the following medications: 3 mg/kg morphine (intraperitoneal) to Group 3,5 μg/kg fentanyl (intraperitoneal) to Group 4, dexmedetomidine 3 μ g/kg (subcutaneously) to Group 5, dexmedetomidine 3 μg/kg (subcutaneous)+3 mg/kg morphine (intraperitoneal) to Group 6 and finally 3 μg/kg dexmedetomidine (subcutaneous)+5μg/kg fentanyl (intraperitoneal) to Group 7. Just before the application and 15, 30, 60, 90 and 120 min after the administration of medication, two measurements of tail flick (TF) and hot plate (HP) tests were performed. The averages of the measurements were recorded. TF and HP latencies were the main outcomes. The analgesic effect of the combinations with dexmedetomidine+morphine (Group 6) and dexmedetomidine+fentanyl (Group 7), compared to the analgesic effect of morphine alone and fentanyl alone was significantly higher at 15, 30, 60 and 90minutes after administration. In this study, dexmedetomidine in ineffective doses, when combined with morphine and fentanyl, potentiates the effects of both morphine and fentanyl.

Comparison of total plasma lysophosphatidic acid and serum CA-125 as a tumor marker in the diagnosis and follow-up of patients with epithelial ovarian cancer

TUGAN BESE,Merve Barbaros,Elif Baykara,Onur Guralp,Salih Cengiz,Fuat Demirkiran,Cevdet Sanioglu,Macit Arvas 대한부인종양학회 2010 Journal of Gynecologic Oncology Vol.21 No.4

Objective: To evaluate the role of lysophosphatidic acid (LPA) as a tumor marker in diagnosis and follow-up of patients with epithelial ovarian cancer. Methods: Eighty-seven epithelial ovarian cancer patients, 74 benign ovarian tumor patients, and 50 healthy women were enrolled in the study. Twenty-nine of 87 epithelial ovarian cancer patients were followed up for 6 cycles of paclitaxel-carboplatin chemotherapy. CA-125 and total plasma LPA levels were measured preoperatively and before each chemotherapy cycle. Results: Preoperative total plasma LPA and serum CA-125 levels were significantly higher in patients with epithelial ovarian cancer compared to patients with benign ovarian tumors and healthy women. Cut-off value for LPA was determined as 1.3 μmol/L and sensitivity, specificity, positive predictive value and negative predictive value were 95%,92%, 95% and 92%, respectively. Mean total plasma LPA level of 29 patients who received chemotherapy was 7.21±6.63μmol/L preoperatively and 6.84±6.34 μmol/L, 6.34±5.92 μmol/L, 6.14±5.79 μmol/L, 5.86±5.68 μmol/L, 5.23±5.11μmol/L and 5.21±5.32 μmol/L in measurements held just before the 1st, 2nd, 3rd, 4th, 5th and 6th chemotherapy cycles,respectively (ANOVA, p=0.832). Total plasma LPA levels decreased slightly with chemotherapy administration and there was a weak negative correlation (Spearman, rs=−0.151, p=0.034), compared to a significant negative correlation in CA-125 (Spearman, rs=−0.596, p<0.001). Conclusion: LPA is a better biomarker for diagnosis of epithelial ovarian cancer compared to CA-125. However, measurement of total plasma LPA levels during chemotherapy administration have no superiority to the serum CA-125 levels.