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Dive into the research topics where Ali Osman Yildirim is active.

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Featured researches published by Ali Osman Yildirim.


Environmental Toxicology and Pharmacology | 2012

The protective effects of ozone therapy in a rat model of acetaminophen-induced liver injury

Husamettin Gul; Bulent Uysal; Erdinc Cakir; Halil Yaman; Enis Macit; Ali Osman Yildirim; Yusuf Emrah Eyi; Umit Kaldirim; Emin Oztas; Emin Ozgur Akgul; Mehmet Ozler; Turgut Topal; Sukru Oter; Ahmet Korkmaz; Mehmet Toygar; Suzi Demirbag

OBJECTIVES Acetaminophen (APAP) overdose may cause acute liver injury. Ozone therapy (OT) is shown to reduce inflammation and necrosis in several entities. Thus, we have designed this study to evaluate the efficacy of OT in a rat model of APAP-induced liver injury. METHODS Twenty-seven Sprague-Dawley rats were divided into three groups: sham, APAP and APAP+OT groups. In the APAP and the APAP+OT groups, liver injury was induced by oral administration of 1 g/kg APAP. The APAP+OT group received a single dose ozone/oxygen mixture (0.7 mg/kg) intraperitoneally 1h after APAP administration. All animals were killed at 24 hour after APAP administration. Blood samples and liver tissues were harvested to determine liver injury and oxidative stress parameters. Liver tissues and blood samples were obtained for biochemical and histopathological analyses. RESULTS APAP administration caused necrosis in the liver after 24h. The degrees of liver necrosis of the APAP group were higher than the other groups (in both p<0.05, respectively). In the APAP+OT group, liver antioxidant enzymes activities were significantly higher than the APAP group (p<0.05), but were lower than the sham group (p<0.05). In the sham group, serum neopterin, a marker of cell-mediated immunity, concentrations (4.8±1.2 nmol/L) were lower than the APAP (14.7±1.4 nmol/L) and APAP+OT groups (7.5±2.4 nmol/L) (in both p<0.05, respectively). CONCLUSION Our results showed that OT prevented liver necrosis in rats and reduced neopterin levels. These findings suggest that the use of OT as an adjuvant therapy which might improve the outcome in APAP induced liver injury.


European Journal of Emergency Medicine | 2011

Comparison of GlideScope video laryngoscope and intubating laryngeal mask airway with direct laryngoscopy for endotracheal intubation.

Orhan Cinar; Erdem Cevik; Ali Osman Yildirim; Mehmet Yasar; Erden Kilic; Bilgin Comert

The aim of this study was to determine whether GlideScope video laryngoscope (GVL) and intubating laryngeal mask airway (i-LMA) improve the intubation success rate and could be easily learned and performed by paramedic students when compared with the direct laryngoscopic (DL) method. The study was designed as a prospective randomized crossover trial that included 121 paramedic students. All participants were asked to intubate each Ambu Airway Management Trainer manikins after the lecture and demonstration. Successful intubation was defined as the passage of the tube through the vocal cord within 60 s. At the end of the study, a questionnaire survey was given to all participants about their preferences, and they were requested to define each method on an easy–difficult scale. Successful intubation was achieved by 95 students (78.5%) with DL, 112 students (92.6%) with i-LMA, and 111 students (91.7%) with GVL. Mean time of intubation was 25.06±14 s for DL, 22.32±12 s for i-LMA, and 22.63±10 s for GVL. Success rates of i-LMA and GVL were significantly higher compared with DL (P=0.005 and P=0.006, respectively). No significant difference was determined between i-LMA and GVL in terms of successful intubation (P>0.05). This study showed that GVL and i-LMA provided better intubation success rates and were easier for paramedic students when compared with the classic DL method.


Human & Experimental Toxicology | 2013

The protective effects of taurine on experimental acute pancreatitis in a rat model

Cemal Akay; Halil Yaman; Muzaffer Oztosun; Erdinc Cakir; Ali Osman Yildirim; Yusuf Emrah Eyi; Mehmet Agilli; Emin Ozgur Akgul; Ibrahim Aydin; Umit Kaldirim; Salim Kemal Tuncer; Ayşe Eken; E Oztas; Y Poyrazoglu; Mehmet Yasar; Y Ozkan

The aim of this study was to investigate the protective effects of taurine (Tau) on experimental acute pancreatitis (AP) in a rat model by measuring cytokines and oxidant stress markers. Forty rats were randomly divided into four groups: sham, AP, Tau and AP + Tau. AP was induced with sodium taurocholate. No treatment was given to the AP. All rats were killed 5 days later. Pancreatic tissues of rats and blood samples were obtained. Tau treatment significantly decreased serum amylase activity (p < 0.001), total injury score (p < 0.001), malondialdehyde levels (p < 0.001) and myeloperoxidase (MPO) activity (p < 0.001). There was no significant difference between the Tau and AP + Tau groups in serum and pancreatic tumor necrosis factor-α, interleukin (IL)-1β and IL-6 levels (p = 1.000). Histopathologic scores in the AP + Tau and Tau groups were significantly lower compared with the AP group (both p < 0.001). These results showed that Tau reduces lipid peroxidation, amylase and MPO activities and the concentrations of proinflammatory cytokines secondary to AP and also increases superoxide dismutase and glutathione peroxidase activities in rats with sodium taurocholate-induced AP. It also has a marked ameliorative effect at histopathologic lesions. With these effects, Tau protects the cells from oxidative damage, reduces inflammation and promotes regression of pancreatic damage.


Renal Failure | 2012

Hyperbaric Oxygen Therapy Alleviates Oxidative Stress and Tissue Injury in Renal Ischemia/Reperfusion Injury in Rats

Haluk Ilhan; Murat Eroglu; Volkan Inal; Yusuf Emrah Eyi; Ibrahim Arziman; Ali Osman Yildirim; Ali Tansel; Gunalp Uzun; Levent Yamanel

Hyperbaric oxygen (HBO) therapy has been shown to attenuate renal ischemia/reperfusion (I/R) injury in rats, when applied in the early reperfusion period. The aim of this study was to elucidate possible beneficial effects of HBO therapy on renal I/R injury, when applied 24 h after ischemia. Rats were randomized into three groups: (1) control group (n = 20), (2) I/R group (n = 20), and (3) I/R + HBO group (n = 20). Renal I/R injury was created by interrupting renal blood flow for 30 min with a non-traumatic vascular clamp. HBO therapy was administered 24 h after I/R injury and continued for 5 days. At the end of the study, rats were sacrificed under anesthesia, blood was drawn, and right kidneys were harvested for analysis. Renal I/R injury increased serum and tissue malondialdehyde (MDA) levels and reduced superoxide dismutase (SOD) and glutathione peroxidase (GPx) levels. HBO therapy attenuated MDA levels by increasing SOD and GPx activities. HBO therapy also prevented neutrophil infiltration and tissue injury in kidneys. Taken together, HBO therapy has been found to be effective in the delayed period of I/R injury.


European Journal of Clinical Investigation | 2013

Soluble TWEAK plasma levels increase after renal transplantation and associate with the improvement of endothelial function

Mahmut Ilker Yilmaz; Alper Sonmez; Mutlu Saglam; Halil Yaman; Hilmi Umut Unal; Mahmut Gok; Hakki Cetinkaya; Tayfun Eyileten; Yusuf Oguz; Sebahattin Sari; Ali Osman Yildirim; Abdulgaffar Vural; Juan Jesus Carrero; Luis Miguel Blanco-Colio

Soluble TWEAK (sTWEAK) and asymmetric dimethyl arginine (ADMA) concentrations have been associated with endothelial function in patients with chronic kidney disease (CKD). We tested the hypothesis that the improvement in endothelial function observed after renal transplantation is directly linked to the normalization of both sTWEAK and ADMA.


Angiology | 2017

The Relation Between No-Reflow Phenomenon and Complete Blood Count Parameters

Turgay Celik; Sevket Balta; Dimitri P. Mikhailidis; Cengiz Ozturk; Ibrahim Aydin; Duran Tok; Ali Osman Yildirim; Mustafa Demir; Atila Iyisoy

The no-reflow (NR) phenomenon represents an acute reduction in coronary blood flow without coronary vessel obstruction, coronary vessel dissection, spasm, or thrombosis. No reflow is an important complication among patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI). The complete blood count (CBC) is one of the most frequently ordered laboratory tests in clinical practice. Various studies have evaluated the performance of CBC parameters to predict disease severity and mortality risk. Automated cell counters are routinely available in many clinical laboratories and can be used to determine red blood cell distrubiton width (RDW), platetecrit, platelet count, and and some ratios like the neutrophil–lymphocyte ratio and RDW-platelet ratio. These hematological markers have been reported to be independent predictors of impaired angiographic reperfusion and long-term mortality among patients with STEMI undergoing pPCI. In this context, we reviewed the role of admission CBC parameters for the prediction of NR in patients with STEMI undergoing pPCI.


International Journal of Cardiology | 2015

Computed tomography guided percutaneous transapical closure of cardiac apex after prosthetic mitral paravalvular leak closure.

Cengiz Ozturk; Atila Iyisoy; Turgay Celik; Sevket Balta; Ugur Bozlar; Mustafa Demir; Ali Osman Yildirim; Adem Güler

The transapical transcatheter approach for percutaneous interventions is performed in high-risk patients with peripheral vascular disease and when transseptal attempt failed. The apical access is traditionally performed through a left minithoracotomy at the fifth intercostal space under general anesthesia. But, there are some complications and risks like ventricular arrhythmias, ventricular tear and life-threatening surgical bleeding in the apical access even though it is a minimally invasive procedure [1]. Although new apical closure devices have been developed and tested in animals and humans, the apical closure remains a challenge in recent studies [2]. The cardiologists started to use the occluders to close the percutaneous apical accesses [3–11]. We report a case of a successful percutaneous closure of the apical access with a 4 mm ADO-II device after a standard transapical mitral paravalvular leak closure procedure without minithoracotomy with the computed tomography guidance. This case is the second from Turkey, so the first one was published recently in this journal [12]. In this second case, we used the CT guidance for optimal puncture of cardiac apex. A 44 year old female was admitted to our department with severe dyspnea (NHYA classes II–III). She had hemolytic anemia (hemoglobin level 8.0 g/dL, lactate dehydrogenase level was high). She had a history ofmitralmetallic prosthesis valve replacement in 1994. Transesophageal echocardiography (TEE) showed two severe mitral paravalvular leaks (6 and 9mm) of themitral valve prosthesis. Transesophageal echocardiography (TEE) showed two severe mitral paravalvular leaks (6 and


Indian Journal of Biochemistry & Biophysics | 2015

Serum neuron-specific enolase and S-100β levels as prognostic follow-up markers for oxygen administered carbon monoxide intoxication cases.

Ali Osman Yildirim; Murat Eroglu; Umit Kaldirim; Yusuf Emrah Eyi; Kemal Simsek; Murat Durusu; Levent Yamanel; Ibrahim Arziman; Salim Kemal Tuncer; Mehmet Toygar; Arzu Balkan; Seref Demirbas; Sukru Oter; Cumhur Bilgi

O of ribonucleotide reductase subunit M2 (RRM2), involved in deoxyribonucleotide synthesis, predominantly drives the chemoresistance of pancreatic cancer to nucleoside analogs (e.g., gemcitabine). While silencing RRM2 by synthetic means has shown promise in reducing chemoresistance, targeting endogenous molecules, especially microRNAs (miRNAs), to advance chemotherapeutic outcomes has been poorly explored. Based on computational predictions, we hypothesized that the let-7 tumor suppressor miRNAs will inhibit RRM2-mediated gemcitabine chemoresistance in pancreatic cancer. Reduced expression of the majority of let-7 miRNAs with an inverse relationship to RRM2 expression was identified in innately gemcitabine-resistant pancreatic cancer cell lines. Direct binding of let-7 miRNAs to the 3’ UTR of RRM2 transcripts identified post-transcriptional regulation of RRM2 influencing gemcitabine chemosensitivity. Intriguingly, overexpression of human precursor-let-7 miRNAs led to differential RRM2 expression and chemosensitivity responses in a poorly differentiated pancreatic cancer cell line, MIA PaCa-2. Defective processing of let-7a precursors to mature forms explained the discrepancies observed with let-7a expressional outcomes. Consistently, the ratios of mature to precursor let-7a were progressively reduced in gemcitabine-sensitive L3.6pl and Capan-1 cell lines induced to acquire gemcitabine resistance. Besides known regulators of let-7 biogenesis (e.g., LIN-28), short hairpin RNA library screening identified several novel RNA binding proteins, including the SET oncoprotein, to differentially impact let-7 biogenesis and chemosensitivity in gemcitabine-sensitive versus -resistant pancreatic cancer cells. Further, LIN-28 and SET knockdown in the cells led to profound reductions in cellular proliferation and colony-formation capacities. Finally, defective processing of let-7a precursors with a positive correlation to RRM2 overexpression was identified in patient-derived pancreatic ductal adenocarcinoma (PDAC) tissues. These data demonstrate an intricate posttranscriptional regulation of RRM2 and chemosensitivity by let-7a and that the accumulation of let-7a precursors as a favorable biomarker for judging chemoresistance in pancreatic cancer.W the use of screening mammography, the diagnosis of ductal carcinoma in situ (DCIS) is increasing worldwide. Patients diagnosed with DCIS either have not yet developed or may never develop invasive breast cancer (IBC). Presently, an indolent tumor can not be distinguished from a progressive tumor, making the appropriate treatment of DCIS patients, a major clinical dilemma. We are interested in developing tissue biomarkers (BM) to determine the likelihood that initial breast tumor identified on diagnostic biopsy remains contained in situ, as opposed to becoming invasive. Molecular studies predicted that the transition from in situ to invasive disease was associated with quantitative rather than qualitative differences in gene and protein expression. We developed imaging-based method to measure protein expression as a continuous variable in fixed tissue. We assumed that DCIS accompanying microinvasive carcinoma (T1mic) represented an early progressive DCIS, because invasion increases the likelihood of metastasis. We theorized that molecular BMs of progressive DCIS are the measurable parameters that distinguish cells in in situ component of T1mic from cells in normal/benign epithelium. We performed quantitative protein profiling on 210 archived tissues: 42 histologically normal, 19 benign, 54 cancer in situ, and 95 IBC. Our measurements in DCIS revealed previously unidentified quantitative differences in the insulin-like growth factor I receptor, Ras oncogene like protein 1, and Rho GTPase guanine nucleotide exchange factor VAV2, the proteins implicated in the regulation of invasion in preclinical models. These new findings may open doors to molecular-based predictions of individualized risk for developing invasion in DCIS.High quality biospecimens with appropriate clinical annotation are critical in the era of biomarker discovery in personalized medicine. Several pre-analytical variables affect human biospecimen integrity for biomarker research in cancer. This situation is applicable to a variety of biospecimens including plasma/serum and fixed cancer tissues used for biomarker analysis. The U.S. National Cancer Institute (NCI) Biorepositories and Biospecimen Research Branch (BBRB) was established in 2005 to coordinate NCI’s biospecimen resource activities and address those issues that affect access to the high quality specimens for biomarker research. A Biospecimen Research Network (BRN) was established to fund research to develop additional evidence-based practices used to develop serum and tissue biomarkers for human biospecimen integrity. We describe the development of assays and identification of biomarkers that may be used as sentinel markers of plasma/tissue stability in biobanks using mass-spectroscopy proteomics, circulating miRNA and immunostaining of FFPE tissues (AQUA technology). The first NCI/BBRB-funded project involves the identification of protein biomarkers using mass-spectrometry and illumina arrays in serum obtained from breast cancer and matched normal subjects, to develop guidelines for blood collection and storage. A second project studied effects of pre-analytical variables on circulating miRNA and identification and validation of new and improved housekeeping miRNA and biomarkers associated with breast cancer. In another study, a series of biomarkers have been validated by construction of tissue microarray (TMA) from 93 breast cancer specimens with known time to fixation as a pre-analytical variable. A tissue quality index (TQI) model was generated to predict the time to fixation and tissue quality by studying a subset of biomarker proteins in breast cancer tissues using AQUA scores. This presentation will outline the progressive efforts taken by BRN, investigator-led projects to identify and validate biomarkers for human biospecimen integrity.F of bioactive lipids by oxygenases is known to play both a protective and pro-thrombotic role in circulation. 12-lipoxygenase (12-LOX) and its oxidized products play an important but unresolved role in regulation of platelet function. 12-LOX oxidation of the fatty acid, dihomo-γ-linolenic acid (DGLA), produces the novel bioactive metabolite 12-hydroxyeicosatetrienoic acid (12(S)-HETrE). Recent work suggests that while 12(S)-HETE (produced from 12-LOX oxidation of AA) is pro-thrombotic to the platelet, 12(S)-HETrE acts in a protective manner in platelets to limit activation. Therefore, we sought to identify the mechanism by which DGLA inhibits platelet activation through 12(S)-HETrE. Delineating the mechanism by which this previously unknown metabolite regulates cellular activity is essential to begin to understand how 12-LOX oxidation of DGLA can potentially lead to regulation of a number of physiological processes including thrombosis. To address these questions, we have employed pharmacological and whole animal studies. Pharmacological intervention has confirmed an integral role of 12-HETrE production through 12-LOX to negatively regulate activity in the platelet. These observations have been confirmed in mice lacking the 12-LOX gene. Further, dietary supplementation of DGLA-enriched chow supports our ex vivo studies exogenously adding DGLA and/or 12-HETrE to attenuate agonist-induced platelet activation. Hence, these studies are the first to begin to elucidate the underlying mechanisms by which omega-3 and 6 fatty acids are protective against cardiovascular disease and stroke.P genetics has been unable to replicate studies which link genotype with treatment outcome. In large measure the difficulty in producing reliable markers has been a consequence of the heterogeneity of depression. Almost all depression trials or genetic studies use “response” as the surrogate outcome measure. By definition, response is defined as a 50% reduction on analytical metric when comparing entry and exit from the trial. This implies that subjects remain symptomatic for their presenting symptoms. We have analyzed The Sequenced Treatment Alternatives for Relieving Depression (STAR*D) NIMH multicenter clinical. An endophenotype was defined by baseline depression severity and minimal co-morbidity. The outcome metric we utilized compared non-responders with true remitters. No subjects defined as responders were included in our genotypic analysis. Polymorphic markers were chosen before genotypic analysis. We identified 255 subjects of European/Caucasian ancestry who met our inclusion criteria with 66% non-responders and 33% true remitters. To our knowledge this is the first genetic analysis of depression subjects where the relevant surrogate clinical outcome of symptom relief was used. Our analysis identified 27 SNPs in 12 genes within muscarinic, nicotinic, adrenergic, serotonergic, dopaminergic, reward and signal transduction pathways. A haplotype analysis indicates that certain alleles can predict true remission. Our findings demonstrate using an endophenotypic analysis can identify biomarkers predicting relevant clinical outcomes in depression. Further work is underway to validate the original findings in additional data sets and novel depressed patients.Biological samples from patients are invaluable. Ideally the samples should be preserved for the same period of time as the duration of their corresponding medical records. Urine is a body fluid that can be non-invasively acquired and contains important biological information about the patient. Simple and inexpensive urinary protein sample preservation can be the starting point for comprehensive biological sample storage just like medical record of patients. Here, we propose a method to adsorb urinary proteins to a membrane named Urimem that can then be dried and stored. This method is very simple and inexpensive and requires minimal sample handling. It does not use organic solvents. The proteins on the membrane are dry and are prevented from degradation. The membrane may even be able to be stored at room temperature at least for weeks. The quantity of eluted proteins from a membrane is sufficient for biomarker validation experiments. Comprehensive historical biological information can also be used in retrospective studies to understand the pathophysiology of disease and the relationships among diseases as well as to monitor the long-term efficacy and side effects of treatments. With this information, medical research can be conducted more easily, considerably faster, and more economically, ultimately benefiting the patients who provided the samples. Thus, we believe that it is possible to preserve urinary protein samples from each stage of disease development for every consenting patient in a hospital. This can potentially change the landscape of medical research and medical practice in the future.Phosphatidylserine (PS) exposure is one of the most prominent and ubiquitous fingerprints of dying cells, making it an attractive biomarker for molecular imaging. Synthetic bis-zinc(II)-dipicolylamine (Zn-DPA) derivatives have high selectivity for biological membranes enriched with PS. Our study aims to apply PET/NIRF imaging with a novel DPA-containing probe ( 18 F-MTTI-170) to visualize and evaluate cell death induced by Paclitaxel in a U87MG tumor xenograft model. In vitro toxicity of Paclitaxel to U87MG cells was determined by a colorimetric assay. The response of U87MG cells to Paclitaxel treatment was determined by flow cytometry, fluorescence staining, and cell uptake study. Established U87MG tumors in nude mice were daily treated with a combination of All-Trans Retinoic Acid (ATRC) (1.5 μg/kg) and Paclitaxel (45 μg/kg). Longitudinal PET imaging was performed with 18 F-MTTI-170 before treatment and at day 3, 6, and 9 after treatment. NIRF imaging was carried out with 19 F-MTTI-170 before treatment and at day 4, 7, and 11 after treatment. Our data demonstrated that U87MG human glioma cells are sensitive to Paclitaxel treatment. After being treated with Paclitaxel for 15 h, U87MG cells were stained with PSVue643 (Cy5-Zn-DPA). The strong red fluorescence signal was identified in the cytosol of the treated cells but not on the untreated cells. Besides, the fluorescent signal was effectively blocked by co-incubation with excess amount of unlabeled Zn-DPA. For cell uptake study, about 1.5% of 18 F-MTTI-170 uptake in Paclitaxel-treated U87MG cells was determined after 1 hr incubation, which is significantly higher than 0.69% and 0.39% observed for 18 F-FP-DPA (single modality compound) and F-FP-Dye (negative control), suggesting that the Zn-DPA moiety is indeed the component binding to PS, and the cell uptake of 18 F-MTTI-170 is significantly higher than that of 18 F-FP-DPA. Daily treatment with ATRC and Paclitaxel effectively inhibited the growth of U87MG tumors by inducing cell death. The cell death was clearly visualized by 18 F-MTTI-170 PET. The tumor uptake, which was observed at day 9 after treatment, was significantly higher than that in the untreated tumors with a ratio of 6.70. The NIRF imaging results are consistent with the findings by PET. In conclusion, PET/NIRF imaging with MTTI-170 is sensitive enough to allow visualization of Paclitaxel induced cell death in U87MG tumor xenograft model. Fully quantitative imaging of tumor response to therapy with MTTI-170 offers the potential to provide early assessment of cancer treatment efficacy leading to individually tailored therapeutic plans with improved outcomes.Serum neuron-specific enolase (NSE) and S-100β levels are considered novel biochemical markers of neuronal cell injury. In this study, the initial and post-treatment levels of NSE and S-100β were compared in carbon monoxide (CO) poisoning patients, who received normorbaric oxygen (NBO) or hyperbaric oxygen (HBO) therapy. Forty consecutive patients with acute CO poisoning were enrolled in this prospective, observational study. According to their clinical symptoms and observations, twenty patients were treated with NBO, and the other twenty with HBO. Serum S-100β and NSE levels were measured both at time of admission and 6 h later (post-treatment). Serum NSE and S-100β values decreased significantly in both of the therapeutic modalities. The initial and post-treatment values of NSE and S-100β in NBO or HBO patients were comparable. A clear negative correlation was observed between the decrease of NSE and S-100β levels and initial blood carboxyhemoglobin levels. In conclusion, the present results suggested the use of serum S-100β and NSE levels as indicators for brain injury. Due to the significant increase of their values with oxygen therapy, they may also be useful as prognostic follow-up markers. However, the current findings reflected no difference between the efficacy of NBO or HBO therapy.T activation of NFκB, a central coordinator of immune responses, is tightly regulated in order to achieve its normal transient activation in response to stress. In cancer, NFκB is activated abnormally, contributing to oncogenesis and progression. The regulation of transient activation is complex, and we are still learning the details of how the essential fine control is achieved. Here, we uncover a novel regulatory pathway for NFκB that is driven by cycles of lysine methylation and demethylation. Using a novel lentiviral Validation-Based Insertional Mutagenesis (VBIM) method, we identified the F-box leucine repeat rich protein 11 (FBXL11), a known histone H3 lysine 36 (H3K36) demethylase, as a potent negative regulator of NFκB. Deletion of the demethylase domain of FBXL11 abolishes this activity. Knocking the expression of FBXL11 down activates NFκB, as does over-expression of the corresponding histone H3K36 methylase, NSD1. The p65 subunit of NFκB binds to NSD1 and FBXL11, and significant methylation of K218 and K221 of p65 was detected in cells with constitutively active NFκB or upon cytokine stimulation. Importantly, FBXL11 is transcribed in response to NFκB activation and thus, like the well known inhibitor IκB, FBXL11 participates in an auto-regulatory negative feedback loop. We show that lysine methylation is an important regulatory post-translational modification of NFκB that is mediated by the FBXL11-NSD1 enzyme pair. Furthermore, we demonstrate that the VBIM technique is a powerful tool for gene discovery that has broad applications in many different systems.H we report a core-shell plasmonic nanoparticle (NP) design based on silver nanodecahedrons (Ag NDs). We have developed a new photo-assisted synthesis process to prepared the Ag NDs and a self-assembly procedure to coat the Ag NDs with a uniform layer of silica in which Raman tags may be incorporated. This core-shell Ag nano-composite exhibits strong surface enhanced Raman scattering (SERS) because of its localized surface plasmon resonance (LSPR). A unique property offered by the Ag NDs is their widely tunable LSPR peak between 420 660 nm. Until now, there are very few reported cases of Ag nanoparticles that exhibit LSPR in the RED region since the natural plasmonic resonance of Ag occurs in the UV-blue region. This has led to problems with most Raman-active tags as they only produce transition-enhanced Raman signal in the REDGREEN region. The core-shell design also ensures that the Ag nano-particles are completely protected against degradation due to oxidation. As a result of the reported core-shell Ag NDs, the use of Raman tags for labeling biomolecules now has a much better prospect. Raman-based labeling is known to be a better choice than the common fluorescence approach because of the wide spectral diversity offered by Raman tags. In addition, field enhancement due to LSPR in the core-shell Ag NDs may lead to a variety of applications including non-linear harmonics generation, photo-induced reaction with long wavelength radiation and florescence enhancement.Personalized and molecular-based cancer treatment depends on biomarkers. Biomarker research and assay development is becoming increasingly important because it drives drug discovery, clinical diagnostics, prognostics and treatment decisions. Immunohistochemistry (IHC), which examines protein localization with preserved tissue morphology, is one of the most important assays to detect protein biomarkers. This technique has been applied in many facets of biological science, especially in assays required using archival formalin-fixed, paraffin embedded (FFPE) tissues. The major challenges for IHC are sensitivity and quantification. AQUA (Automatic Quantitative Analysis) is a fluorescence IHC imaging analysis technology that could automatically quantify protein expression in tissues with high sensitivity and accuracy. We have applied AQUA technology for both basic and clinical research. Using this technology, we identified biomarkers that related to cetuximab treatment in a mouse xenograft model. We determined the expression of certain proteins in cancer patient cohorts and correlated the protein expression levels with pathologic and clinical outcomes. We found several proteins that could serve as prognostic or predictive biomarkers. With the emergence of new biomarkers from recent genetic discoveries, numerous novel targeted therapies for cancer are already in clinical trials, with many more to be developed in the coming decades. Personalized medicine is about the identification of patients that are most likely to benefit from treatment and assess treatment response. AQUA technology can dramatically speed up the progress of such challenges and therefore represents the future for biomarker research. Biography Yang is an Assistant Professor at Fox Chase Cancer Center, where she takes charge of the Tissue Research Service at the Biosample Repository Core Facility. She is a leading expert in the field of immunohistochemistry (IHC) and quantitative analysis. She has applied IHC to study the molecular alterations of known and novel signaling pathways that regulate embryogenesis, organ morphogenesis and tumorigenesis. Her research results can be found in prestigious journals such as Development, Am. J. Path., JBC et. al. Recently Dr. Yang extended the automatic quantitative analysis (AQUA) IHC assay system for tumor biomarker research. Dr. Yang serves in the editorial board of the Journal of Cancer Research Updates and the Journal of Analytical Oncology. She is ad hoc reviewers in a number of journals including Biomarkers, Biochemical Pharmacology, Current Pharmaceutical Biotechnology, Current Proteomics, Experimental Neurology et.al.M technologies have recently come to the fore in the context of biomarker discovery. Metabolic dysfunction is a noted hallmark in numerous disease states, and thus multivariate measurement and analysis of metabolite parameters provides a potential window into both diagnostic as well as prognostic realms. In this presentation, the advantages and disadvantages of biomarker discovery by NMR metabolomics methods will be discussed. In particular, the use of quantitative methods for metabolite analysis will be contextulized against other tools such as mass spectrometry based metabolite discovery. A biological context will be provided in our clinical oncology studies in the areas of pancreatic, colorectal, lung and brain cancer.O of the HER2/neu receptor occurs in 15 to 30 percent of breast tumors and is linked to poorer prognosis. Currently HER2/neu expression status determines whether patient will receive trastuzumabbased treatment. In clinical practice, overexpression of HER2/neu is identified using IHC or FISH, both of which are invasive approaches requiring tissue samples. Serum assays for HER2/neu receptor have been reported but the use is very limited due to serum interference factors (e.g. human anti-animal antibodies) that lead to false test results and inconsistency with tissue Her2 status. We have developed an ELISA based approach implementing an MBB buffer to eliminate false results and to obtain more accurate assessment of HER2/neu levels. Using this refined assay we retroactively measured HER2/neu levels from 56 patients. Pre-treatment (e.g. surgery, radiation, or chemotherapy) samples were available from 12 patients, of which 6 patients were tissue HER2/neu positive and the other six were negative. All the HER2/ neu positive samples had higher serum levels than negative ones (p < 0.05). We observed a decrease in serum HER-2/neu values after surgery in two out of 5 patients. In 5 patients experienced recurrence or metastasis, HER2/neu level significantly increased from the treatment-established baseline, accompanying recurrence and before metastasis. Our results indicate that we can monitor HER2 ECD as a biomarker over the course of disease progression and treatment.N antibodies against viruses represent a major mechanism of host protection against viral infections. Most if not all marketed vaccines elicit neutralizing antibodies. Currently, neutralizing anti-viral therapeutic monoclonal antibodies are being developed for the treatment and/or the prevention of viral diseases. Standard neutralization assays to assess the viral neutralization activities of antibodies have historically been functional plaque assays. Plaque assays are time-consuming, laborintensive and challenging to implement in clinical studies especially those involving a large number of patients. Here we described the development and implementation of fast and robust Fluorescent Foci (FFA)-based microneutralization (MN) assays. These assays, using viruses expressing enhanced green fluorescence protein (EGFP), allow for higher throughput, better precision, and shorter assay turn-around time making them suitable for use in large clinical studies. We will first describe the establishment of a novel FFA-based MN assay to detect and quantify neutralizing antibodies against EBV. This assay uses EBV-GFP and an engineered epithelial cell line. All assay conditions impacting assay performance were optimized and the assay was automated using liquid handling and high-content imaging systems. The robustness and precision of the optimized assay were demonstrated using serum samples from mice, rabbits and humans (n > 600). In addition, a companion EBV-specific IgG ELISA assay was developed. Significant correlation (r2 = 0.89) between both assays was demonstrated using 358 rabbit serum samples. A MN assay was similarly developed for Respiratory Syncytial virus (RSV) to support the development of MedImmune’s anti-RSV therapeutic mAbs and RSV vaccine candidates. The 2-year assay control trending of RSV MN assay will be presented to demonstrate the robustness and precision of this assay.


The Scientific World Journal | 2012

Evaluation of the Oxidative Effect of Long-Term Repetitive Hyperbaric Oxygen Exposures on Different Brain Regions of Rats

Kemal Simsek; Mehmet Ozler; Ali Osman Yildirim; Serdar Sadir; Seref Demirbas; Muzaffer Oztosun; Ahmet Korkmaz; Hakan Ay; Sukru Oter; Senol Yildiz

Hyperbaric oxygen (HBO2) exposure affects both oxidative and antioxidant systems. This effect is positively correlated with the exposure time and duration of the treatment. The present study aims enlightening the relation of HBO2 with oxidative/antioxidant systems when administered in a prolonged and repetitive manner in brain tissues of rats. Sixty rats were divided into 6 study (n = 8 for each) and 1 control (n = 12) group. Rats in the study groups were daily exposed 90-min HBO2 sessions at 2.8 ATA for 5, 10, 15, 20, 30 and 40 days. One day after the last session, animals were sacrificed; their whole brain tissue was harvested and dissected into three different regions as the outer grey matter (cortex), the inner white matter and cerebellum. Levels of lipid peroxidation and protein oxidation and activities of superoxide dismutase and glutathione peroxidase were measured in these tissues. Malondialdehyde, carbonylated protein and glutathione peroxidase levels were found to be insignificantly increased at different time-points in the cerebral cortex, inner white matter and cerebellum, respectively. These comparable results provide evidence for the safety of HBO treatments and/or successful adaptive mechanisms at least in the brain tissue of rats, even when administered for longer periods.


International Journal of Cardiology | 2016

The progressed atrioventricular block associated with ticagrelor therapy may not require permanent pacemaker after acute coronary syndrome; it may be reversible

Cengiz Ozturk; Murat Unlu; Ali Osman Yildirim; Sıddık Erdogan; Mustafa Demir; Sevket Balta; Sait Demirkol; Turgay Celik; Atila Iyisoy

Article history: Received 3 November 2015 Accepted 4 November 2015 Available online 5 November 2015 (ACS) [1]. Ticagrelor has more rapid onset of action on platelet inhibition and was superior to clopidogrel. It decreases major adverse cardiac events compared to the clopidogrel. According to the PLATO trial, ticagrelor may lead to increased incidence of asymptomatic ventricular pauses [1–4]. In addition, there are some reports about the side effects of ticagrelor like bradycardia and dyspnea [5–8]. It is considered that the inhibition of the re-uptake of adenosin from the red cells

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Cengiz Ozturk

Military Medical Academy

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Mustafa Demir

Military Medical Academy

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Sevket Balta

Military Medical Academy

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Turgay Celik

Military Medical Academy

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Mustafa Aparci

Military Medical Academy

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Sait Demirkol

Military Medical Academy

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Murat Eroglu

Military Medical Academy

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Umit Kaldirim

Military Medical Academy

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