Researcher:
Yazıcı, Duygu

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PhD Student

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Duygu

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Yazıcı

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Yazıcı, Duygu

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2018 - 201942020 - 202210

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Now showing 1 - 10 of 14
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    Evaluation of a standardized bakery product (SUTMEK) as a potential tool for baked-milk tolerance and immunotherapy research studies
    (Karger, 2019) Kiykim, Ayca; Karakoc-Aydiner, Elif; Gunes, Esra; Nain, Ercan; Ogulur, Ismail; Aktac, Sule; Bicer, Ayse Humeyra; Baris, Safa; Ozen, Ahmet; Yazıcı, Duygu; Saçkesen, Cansın; PhD Student; Faculty Member; Graduate School of Health Sciences; School of Medicine; N/A; 182537
    Background and Objectives: About 65-80% of children with IgE-mediated cow's milk allergy (CMA) can tolerate extensively heated milk. We have invested in the mass fabrication of a test product containing milk protein baked at 180 degrees C for 30 min (SUTMEK-milk) and a milk-free placebo (SUTMEK-placebo) to carry out a standardised double-blind placebo-controlled food challenge (DBPCFC) test in patients with CMA. Methods: We studied children with IgE-mediated CMA between 13 and 48 months of age. Specific IgEs (spIgE) to milk proteins were quantified. A DBPCFC with our bakery products was performed, and factors determining reactivity to extensively heated milk were evaluated. We also tested the applicability of SUTMEK products in baked-milk oral immunotherapy in a pilot assessment. Results: We studied 15 children (8 girls, 7 boys) with a median age of 26 months (range: 13-48 months). Nine (60%) patients tolerated a challenge with extensively heated milk, while 6 (40%) were found reactive (anaphylaxis: 2, wheezing: 2, urticaria: 2). spIgE to milk, alpha-lactalbumin, and casein, and the wheal diameter on skin prick testing were higher in the reactive group than the tolerant groups (p = 0.001, p = 0.001, p = 0.002, and p = 0.048, respectively). Receiver-operating characteristic curve analyses yielded the following cut-off values for spIgEs that would predict a reactivity to extensively heated milk; milk: 25 kU/L (area under curve, AUC: 0.981), casein: 32 kU/L (AUC: 0.983), and alpha-lactalbumin: 17 kU/L (AUC: 0.981). Nine patients have tolerated well a continued daily consumption of SUTMEK-milk or -placebo for 6 months at the desired doses. Conclusions: Our bakery products were successfully used in DBPCFC studies and qualified as an acceptable tool for use in the research of interventional tolerance induction. Although spIgE appears useful in determining children at high risk of reacting to extensively heated milk, the predictive cut-off values are still far from being perfect.
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    Cloning, expression and characterization of recombinant CagA protein of Helicobacter pylori using monoclonal antibodies: its potential in diagnostics
    (Elsevier, 2020) Salih, Barik A.; Karakus, Cebrail; Ulupinar, Zeynep; Akbas, Fahri; Uslu, Merve; Bolek, Bora Kazim; Bayyurt, Nizamettin; Turkay, Cansel; Yazıcı, Duygu; PhD Student; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); Graduate School of Health Sciences; N/A
    Helicobacter pylori CagA protein plays an important role in the severity of the gastric diseases. Our aims were to clone the cagA 5'conserved region of the gene, characterize the recombinant CagA (rCagA) protein by monoclonal antibodies (mAbs) and to use this protein for the detection of anti-CagA antibodies by an ELISA test. Our developed rCagA protein (67 kDa) showed an amino acid sequence homology of 83% and 80% with Western and East Asian type strains respectively. Two anti-rCagA (BS-53, CK-02) mAbs and 2 additional rCagA proteins of smaller sizes (60 kDa, 28 kDa) were developed for epitope determination. The BS-53 mAb recognized all 3 rCagA proteins while CK-02 mAb recognized only 2 of them indicating recognition of different epitopes. An in-house indirect ELISA using rCagA was developed to detect anti-CagA antibodies in sera of 59 patients. The ELISA results obtained when compared to those of the PCR gave a sensitivity, specificity and accuracy of 81%, 100% and 88% respectively. We have developed for the first time: a rCagA protein that showed high sequence homology with both Western and East Asian type strains and an indirect ELISA of high performance which can be used to detect anti-CagA antibodies in sera of infected patients worldwide.
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    Investigation of the effects of tumor necrosis factor-alpha, H2o2, ethanol and butyrate on intestinal epithelial cell permeability
    (Wiley, 2019) Yazıcı, Duygu; Süer, Hande; Yılmaz, Özlem; Karahüseyinoğlu, Serçin; Saçkesen, Cansın; PhD Student; PhD Student; Master Student; Faculty Member; Faculty Member; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); Graduate School of Health Sciences; Graduate School of Health Sciences; Graduate School of Sciences and Engineering; School of Medicine; School of Medicine; N/A; N/A; N/A; 110772; 182537
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    Association of TNF-ALPHA (-308g/a) gene polymorphism with circulating TNF-ALPHA levels and excessive daytime sleepiness in adults with coronary artery disease and concomitant obstructive sleep apnea
    (Amer Thoracic Soc, 2021) Thelander, T.; Yucel-Lindberg, T.; Thunstrom, E.; Behboudi, A.; N/A; N/A; N/A; Peker, Yüksel; Yazıcı, Duygu; Çelik, Yeliz; Faculty Member; PhD Student; Researcher; N/A; N/A; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); School of Medicine; Graduate School of Health Sciences; N/A; 234103; N/A; N/A
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    Development of an in-house capture ELISA: an attempt to detect CagA antigen in sera of Helicobacter pylori infected patients
    (Elsevier, 2021) Salih, Barik A.; Karakus, Cebrail; Ulupinar, Zeynep; Akbas, Fahri; Yucel, Fatima; Akcael, Esin; Akcan, Yusuf; Yazıcı, Duygu; PhD Student; Graduate School of Health Sciences; N/A
    The CagA protein one of the key virulence factors of Helicobacter pylori plays an important role in the pathogenesis of peptic ulcer diseases. Unfortunately the cagA gene status can only be determined by PCR while serology is an alternative approach to detect antigens or antibodies. Our aim is to detect the CagA antigen in sera of infected subjects by the development of an in-house capture ELISA test. Gastric antral biopsies and serum samples were collected from 63 patients. PCR was used to determine the cagA status. Our previously developed recombinant CagA protein and monoclonal antibody were used for setting up the capture ELISA test. H. pylori positive [(38 gastritis, 14 duodenal ulcers (DU), 11 gastric ulcer (GU)] patients were determined by PCR. The cagA gene was detected in 21 (55%) of gastritis, 11 (78%) of DU and 7 (60%) of GU patients. The reagents used in setting up the capture ELISA test following optimization displayed high performance. This study showed that our developed in-house capture ELISA has the potential to detect the CagA antigen at very low concentrations even though not detected in our H. pylori infected patients sera but we are also intended to use it in saliva and stool samples.
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    Investigation of heat and matrix effect on milk proteins' allergenicity and the development of hypoallergenic food products
    (Wiley, 2018) N/A; N/A; Department of Chemical and Biological Engineering; N/A; Süer, Hande; Yazıcı, Duygu; Erman, Burak; Saçkesen, Cansın; PhD Student; PhD Student; Faculty Member; Faculty Member; Department of Chemical and Biological Engineering; Graduate School of Health Sciences; Graduate School of Health Sciences; College of Engineering; School of Medicine; N/A; N/A; 179997; 182537
    Background: Cow's milk allergy is one of the most common foodallergies during childhood. It has been shown that high heat can reduce some milk proteins’allergenicity (ß‐lactoglobulin). In this pro-ject we aimed to investigate the effect of heat and matrix on differ-ent milk protein fractions through Maillard reaction and eventuallydevelop hypoallergenic food products that have milk protein withlow reaction risk.Method: Milk cake matrix is prepared in different flour/sugar (F/S)ratio (2F/1S, 1F/1S, 0.5F/1S) and baked 30 minutes at 180°C. Pro-teins that cake contains are separated using SDS PAGE and stainedwith coomassie blue to check total protein. In parallel specific pro-teins are detected by western blotting using pooled sera frompatients with milk specific IgE>60kU/L for incubation. Results: In normal milk cake recipe (2F/1S)ß‐lactoglobulin bandsare disappeared but casein bands did not differ in size. In order toinvestigate the matrix effect F/S ratio is changed and it is found thatwhen this ratio decreases, with the affect of heat and maillard reac-tion, milk casein bands’intensities also decrease in SDS gel coomas-sie staining. In western blot experiments it is also shown that milkspecific IgE bound weakly to casein bands in low F/S ratio cake(0.5F/1S) whereas in cakes that have high F/S (2F/1S) ratio it boundsignificantly higher. Conclusion: Heat and matrix effect cause disruptions in milk caseinandß‐lactoglobulin proteins’structure and lower the milk specificIgE bindings to milk proteins in low F/S ratio cake through Maillard reaction.
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    Higher airborne pollen concentrations correlated with increased SARS-CoV-2 infection rates, as evidenced from 31 countries across the globe
    (National Academy of Sciences, 2021) Damialis, Athanasios; Gilles, Stefanie; Sofiev, Mikhail; Sofieva, Viktoria; Kolek, Franziska; Bayr, Daniela; Plaza, Maria P.; Leier-Wirtz, Vivien; Kaschuba, Sigrid; Ziska, Lewis H.; Bielory, Leonard; Makra, László; del Mar Trigo, Maria; Traidl-Hoffmann, Claudia; Oliver, Gilles; Pham-Thi, Nhân; Thibaudon, Michel; Arino, Arturo H.; Belmonte, Jordina; Cervigon Morales, Patricia; De Linares, Concepción; Fernández, Delia; Fernández-Rodriguez, Santiago; Gabaldón Arguisuelas, Antonia; Galán, Carmen; González-Alonso, Mónica; Lara, Beatriz; Moreno Grau, José María; Oteros, José; Pérez-Badia, Rosa; Pérez-De-Zabalza, Anabel; Picornell, Antonio; Recio, Marta; Robles, Estrella; Rodríguez-Fernández, Alberto; Rodríguez-Rajo, F. Javier; Rojo, Jesús; Ruiz Valenzuela, Luis; Bergmann, Karl-Christian; Werchan, Barbora; Werchan, Matthias; Buters, Jeroen T.M.; Bastl, Maximilian; Dunker, Susanne; Hornick, Thomas; González Roldán, Nestor; Gilge, Stefan; Clot, Bernard; Finemann, Stanley; Ford, Linda; Gomez, Robert Anthony; Kamboj, Sanjay; Wilhelm, Wayne; Beggs, Paul J.; Burton, Pamela; Davies, Janet M.; Haberle, Simon Graeme; Katelaris, Constance Helen; Keaney, Ben; Milic, Andelija; Miller, Victoria; van Haeften, Shanice; Bonini, Maira; Bordin, Anna; Ceriotti, Valentina; Cristofolini, Fabiana; Cristofori, Antonella; Gottardini, Elena; Marcer, Guido; Marraccini, Paolo; Mascagni, Paolo; Meriggi, Antonio; Pace, Loretta; Pini, Alberto; Tacca, Maria Cristina; Bruffaerts, Nicolas; Hoebeke, Lucie; Adams-Groom, Beverley; Pashley, Catherine H.; Satchwell, Jack; Skjøth, Carsten; Symon, Fiona A.; Antunes, Celia M.; Caeiro, Elsa; Camacho, Irene Gomes Câmara; Costa, Ana R.; Deus, Ricardo João Ratola Capela; Ferreira, Manuel Branco; Fonseca, Joao Almeida Lopes; Galveias, Ana; Ribeiro, Helena; Tavares, Beatriz; Grewling, Łukasz; Grinn-Gofroń, Agnieszka; Jurkiewicz, Dariusz; Kalinowska, Ewa; Lipiec, Agnieszka; Myszkowska, Dorota; Piotrowska-Weryszko, Krystyna; Puc, Malgorzata; Rapiejko, Anna; Rapiejko, Piotr; Weryszko-Chmielewska, Elzbieta; Ziemianin, Monika; Berman, Dilys; Hoek, Werner; Manjra, Ahmed Ismail; Peter, Jonathan; Dahl, Åslög; Ekebom, Agneta; Stjepanovic, Barbara; Večenaj, Ana; Çelenk, Sevcan; Göksel, Özlem; Göksel, Tuncay; Güvensen, Aykut A.; Munevver, Nur; Acar Şahin, Aydar; Uğuz, Ulaş U.; Kajtor-Apatini, Dóra; Magyar, Donat; Szigeti, Tamas; Sikoparija, Branko; Kofol Seliger, Andreja; Simčič, Anja; Oh, Jae; Charalampopoulos, Athanasios; Vokou, Despoina; Rasmussen, Karen; Barrionuevo, Laura Beatriz; Ramon, German Dario; de Weger, Letty A.; Koenders, Mieke M.J.F.; van Vliet, Arnold J.H.; Dušička, Jozef; Lafférsová, Janka; Šèevkováč, Jana; Rybníček, Ondøej; Coates, Frances; Jurgens, Dawn; Šauliene, Ingrida; Severova, Elena; Rodinkova, Victoria; Bortnyk, Mykyta; Palamarchuk, Olena; Yasniuk, Maryna; Louna-Korteniemi, Maria; Pätsi, Sanna; Saarto, Annika; Toiviainen, Linnea; Sozinova, Olga; Jia, Peng; N/A; N/A; Yazıcı, Duygu; Saçkesen, Cansın; PhD Student; Faculty Member; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); Graduate School of Health Sciences; School of Medicine; N/A; 182537
    Pollen exposure weakens the immunity against certain seasonal respiratory viruses by diminishing the antiviral interferon response. Here we investigate whether the same applies to the pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is sensitive to antiviral interferons, if infection waves coincide with high airborne pollen concentrations. Our original hypothesis was that more airborne pollen would lead to increases in infection rates. To examine this, we performed a cross-sectional and longitudinal data analysis on SARS-CoV-2 infection, airborne pollen, and meteorological factors. Our dataset is the most comprehensive, largest possible worldwide from 130 stations, across 31 countries and five continents. To explicitly investigate the effects of social contact, we additionally considered population density of each study area, as well as lockdown effects, in all possible combinations: without any lockdown, with mixed lockdown−no lockdown regime, and under complete lockdown. We found that airborne pollen, sometimes in synergy with humidity and temperature, explained, on average, 44% of the infection rate variability. Infection rates increased after higher pollen concentrations most frequently during the four previous days. Without lockdown, an increase of pollen abundance by 100 pollen/m3 resulted in a 4% average increase of infection rates. Lockdown halved infection rates under similar pollen concentrations. As there can be no preventive measures against airborne pollen exposure, we suggest wide dissemination of pollen−virus coexposure dire effect information to encourage high-risk individuals to wear particle filter masks during high springtime pollen concentrations.
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    Effects of hydrogen peroxide and butyrate on A549 cell viability and permeability
    (European Respiratory Soc Journals Ltd, 2019) N/A; N/A; Konyalılar, Nur; Yıldız, Abdullah Burak; Yazıcı, Duygu; Bayram, Hasan; PhD Student; Undergraduate Student; PhD Student; Faculty Member; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); Graduate School of Health Sciences; School of Medicine; School of Medicine; School of Medicine; N/A; N/A; N/A; 4890
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    Differentiation of bronchial epithelial spheroids in the presence of IL-13 recapitulates characteristic features of asthmatic airway epithelia
    (Wiley, 2022) Pat, Yağız; Ruckert, Beate; Öğülür, İsmail; Perez-Diego, Mario; Küçükkase, Ozan C.; Li, Manru; Akdiş, Cezmi A.; Yazıcı, Duygu; PhD Student; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM)
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    Effect of high-risk Obstructive sleep apnea on clinical outcomes in adults with Coronavirus Disease 2019: a multicenter, prospective, observational cohort study
    (American Thoracic Society (ATS), 2021) Işık, Sacide Rana; Balcan, Baran; Çetin, Betül; OSACOVID-19 Study Collaborators; Ertuğ, Elif; Peker, Yüksel; Çelik, Yeliz; Arbatlı, Semih; Baygül, Arzu Eden; Yazıcı, Duygu; Bayram, Hasan; Karataş, Ferhan; Uzel, Fatma Işıl; İliaz, Sinem; Tabak, Levent; Öztürk, Ayşe Bilge; Atasoy, Kayhan Çetin; Kapmaz, Mahir; Durmaz Çetin, Birsen; Çağlayan, Benan Niku; Faculty Member; Researcher; PhD Student; PhD Student; Faculty Member; Doctor; Doctor; Doctor; Faculty Member; Faculty Member; Faculty Member; Faculty Member; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); School of Medicine; Graduate School of Health Sciences; Koç University Hospital; 234103; N/A; N/A; 272290; N/A; 4890; N/A; N/A; 168584; N/A; 147629; N/A; N/A; 111719; 230719
    Rationale: obstructive sleep apnea (OSA) may contribute to poor outcomes in adults with Coronavirus Disease 2019 (COVID-19). Objective: to determine the effect of OSA on clinical outcomes in patients with COVID-19. Methods: the current prospective observational study was conducted in three hospitals in Istanbul, Turkey from March 10 to June 22, 2020. The participants were categorized as modified high-risk (mHR), or low-risk (mLR)-OSA according to a modified version of the Berlin questionnaire. Snoring patterns (intensity and/or frequency), breathing pauses and morning/daytime sleepiness, without taking obesity and hypertension into account, were used in the regression models. Results: the primary outcome was clinical improvement defined as a decline of 2 categories from admission on a 7-category ordinal scale. Secondary outcomes included worsening (increase of 1 category), need for hospitalization, supplemental oxygen and intensive care. In total, 320 eligible patients were enrolled. According to the modified scoring, 70 (21.9%) had mHR-OSA. Among 242 patients requiring hospitalization, clinical improvement within 2 weeks occurred in 75.4 % of the mHR-OSA group compared to 88.4 % of the modified low-risk (mLR-OSA) group (P = 0.014). In multivariate regression analyses, mHR-OSA (adjusted OR 0.42; 95% CI 0.19-0.92) predicted the delayed clinical improvement. In the entire study population (n=320), mHR-OSA was associated with clinical worsening and need for supplemental oxygen. Snoring patterns, especially louder snoring, were significantly predicted delayed clinical improvement, worsening, need for hospitalization, supplemental oxygen, and intensive care. Conclusions: adults with mHR-OSA in our Covid-19 cohort had poorer clinical outcomes than those with mLR OSA independent of age, sex and comorbidities.