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Scandinavian Journal of Clinical & Laboratory Investigation | 2010

Comparison of the effect of topical and systemic melatonin administration on delayed wound healing in rats that underwent pinealectomy

Mehmet Ozler; Kemal Simsek; Cansel Kose Ozkan; Emin Ozgur Akgul; Turgut Topal; Sukru Oter; Ahmet Korkmaz

Abstract Objectives. Melatonin is a hormone which has many systemic effects in addition to its strong antioxidant properties. The aim of the present study was to investigate the difference between sytemic and topical administration of melatonin by forming a chronic wound model in rats whose release of basal melatonin was supressed by pinealectomy. Material and methods. Experimental animals used in the study were divided into four equal groups: (i) a group of normal animals with wound formation (control), (ii) a group of animals who underwent pinelaectomy and wound formation (PINx), (iii) a group that underwent PINx + systemic melatonin administration, and (iv) a group that underwent PINx + topical melatonin administration. Fifteen days after pinealectomy, a bipediculed flap was formed on the back of the rats under anesthesia and then six excisional skin wounds were produced in all groups. Following the treatment that lasted 7 days, on day 8 the wound surface areas were measured and wound tissues were removed under anesthesia. In these tissues the levels of malondialdehit (MDA) and hydroxyproline (OH-proline) and the activities of superoxide dismutase(SOD) and glutathion peroxidase (GSH-Px) were measured. Results. In the PINx group, OH-prolin levels decreased significantly compared to the control group and wound surface areas increased. MDA levels increased compared to the control group, and SOD and GSH-Px decreased accordingly. Conversely, in two melatonin groups in which melatonin was administered systemically or topically MDA decreased while SOD ve GSH-Px enzymes increased. Conclusion. In conclusion, in the present study it was shown that wound healing was prolonged in experimental animals deprived of melatonin through pinealectomy. Melatonin exerts positive effects on wound healing, whether it is administered topically or systemically.


Inhalation Toxicology | 2011

Long-term exposure to repetitive hyperbaric oxygen results in cumulative oxidative stress in rat lung tissue

Kemal Simsek; Hakan Ay; Turgut Topal; Mehmet Ozler; Bulent Uysal; Ergun Ucar; Cengiz Han Acikel; Ozgur Yesilyurt; Ahmet Korkmaz; Sukru Oter; Senol Yildiz

Context: Despite its known benefits, hyperbaric oxygen (HBO) is also reported to enhance the production of reactive oxygen species and can cause oxidative stress in several tissues. Previous studies had shown that HBO-induced oxidative stress is directly proportional to both its exposure pressure and duration. Nevertheless, these studies were usually performed with single-session HBO exposure but its clinical use commonly depends on long-term exposure periods. Objective: To clarify the oxidative effect of long-term repetitive HBO in the lung tissue of rats. Materials and methods: Male Sprague-Dawley rats were divided into six study groups exposed to consecutive HBO sessions (2.8 atm/90 min) for 5, 10, 15, 20, 30, and 40 days. Animals were sacrificed 24 h after the last HBO session. An additional control group was set to obtain normal data. Lung malondialdehyde (MDA) and carbonylated protein (PCC) levels were determined as measures of oxidative stress along with the activities of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase. Results: None of the measured parameters showed any changes among the groups exposed to 5–15 HBO sessions. However, MDA, PCC, and SOD were found to be significantly increased in the 20 to 40 session groups. Discussion and conclusion: These results indicate that repetitive treatment with HBO may cause oxidative stress in critical tissues including the lung. Although HBO-mediated free radicals are accepted to be responsible for the benefits of this therapeutic modality, especially in cases with prolonged exposure, possible injurious effects of supranormal values of bio-oxidative products need to be considered.


Journal of Investigative Surgery | 2015

Effects of Hyperbaric Oxygen and Preconditioning on Wound Healing in Colonic Anastomoses

Yavuz Poyrazoglu; Turgut Topal; Ramazan Yuksel; Filiz Sezen Bircan; Kemal Simsek; Ercan Göçgeldi; Nail Ersoz; Ahmet Korkmaz

ABSTRACT Aim: The purpose of this study was to evaluate the effects of hyperbaric oxygen (HBO) and HBO preconditioning (pre-HBO) on experimental wound healing and tensile strength in the colonic anastomosis of rats. Materials and Methods: A total of 21 Sprague–Dawley rats were divided into three random groups of equal numbers: sham operation, pre-HBO, and HBO. Sham group was given standard left colon resection and end-to-end anastomosis; pre-HBO group received HBO as one dose + colonic resection + anastomosis; HBO group was given colonic resection + anastomosis + HBO. HBO was administrated at 24-hr intervals and relaparatomy was performed on the fifth day. Malondialdehyde (MDA), myeloperoxidase (MPO), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), interleukin (IL)-10, IL-6, tumor necrosis factor-alpha (TNF-α), and hydroxy (OH)-proline levels and anastomotic burst pressure were evaluated. Results: Burst pressure and OH-proline levels markedly increased in the HBO group compared with the sham and pre-HBO groups. When compared with the sham group, MDA and MPO levels were significantly decreased in the HBO and pre-HBO groups. In contrast to these findings, SOD and GSH-Px levels were increased in the HBO group as compared with the sham and pre-HBO groups. TNF-α, IL-6, and IL-10 values were detected at low levels in the HBO group as compared with other groups. Conclusions: HBO administration accelerated wound healing and strengthened the anastomotic tissue. In the light of these results, the HBO administration has beneficial effects and contributed to wound healing in colonic anastomosis. But, as expected, pre-HBO did not alter the results significantly.


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.


Journal of Experimental and Integrative Medicine | 2015

Starting the fifth year of publication: switching from road to highway -

Sukru Oter; Kemal Simsek

With the beginning of 2011, the “Journal of Experimental and Integrative Medicine” launched the medical literature with the motto “from cell to system, from mechanism to disease” [1]. The scope of the journal covered the entire field of biomedical research with particular interest on integrating experimental data to clinical applications; in other words, the so-called “bench-to-bedside” or “translational medicine” area. During its finalized 4 years of publication, 16 quarterly issues were published on time, covering nearly 200 articles of which at least one-third were cited by journals listed in the Web of Science. The journal seems to be very close to hit its mark and warrants to attract much more attention in the near future. In order to reach a higher scientific value, in the long run, our editorial team...


Balkan Military Medical Review | 2014

Benefits of hyperbaric oxygen therapy in a patient with multifocal osteonecrosis mimicking septic arthritis.

Seref Demirbas; Mehmet Ince; Erol Arslan; Kemal Simsek; Salim Ozenc; Seyit Ahmet Ay; Murat Karaman; Sebahattin Sari; Bayram Koc

Osteonecrosis is a progressive disease characterized with bone damage. Glucocorticosteroids, which are used in treatment of many diseases, are believed to be the most important reason for development of non-traumatic osteonecrosis. Osteonecrosis(ON) generally does not affect multiple joints simultaneously and mimic septic arthritis. In this article, we reported a 48-year-old woman with osteonecrosis who received glucocorticosteroids due to autoimmune hepatitis. The onset of the osteonecrosis was mimicking septic arthritis with multiple joint involvements after corticosteroid therapy. Physical examination; there was mild erythema, effusion, warmth, and diffuse tenderness on palpation in bilateral ankles and knees. Significantly intensity changes were compatible with ON in the femur and the tibia, increased fluid in the knee joint and edema in muscle groups and fatty tissue that are around the knee joint were seen on MRI. Other tests were negative for artiritis.Hyperbaric oxygen treatment was used effectively for the treatment of the patient. Patients complaint of pain was ceased acoording to Visual Analogue Scale and she did no need to much painkiller. The main purpose of the treatment of ON is intended to protect the patients natural joint structure. HBO and other medical approaches were provided benefit to patients with ON. Because HBO restores tissue oxygenation, reduces oedema, and induces angioneogenesis. By reducing the intraosseous pressure, venous drainage is restored, and the microcirculation is improved.


Journal of Medical Biochemistry | 2013

Response of Rat Erythrocyte Oxidative Stress Markers to Repetitive Hyperbaric Oxygen Exposures Up to 40 Daily Sessions / Odgovor Markera Oksidativnog Stresa U Eritrocitima Pacova Na Višestruko Izlaganje Hiperbaričnom Kiseoniku Do 40 Seansi Dnevno

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

Summary Background: Studies with single-session hyperbaric oxygen exposures have shown that HBO-induced oxidative stress is proportional to exposure pressure and duration. Since the efficacy of hyperbaric oxygen mainly depends on repetitive exposures, this study aimed to investigate the oxidative effect of hyperbaric oxygen administered for 5 to 40 sessions. Methods: Sixty rats were divided into one control and 6 study groups. Study groups were exposed to 5, 10, 15, 20, 30, and 40 daily consecutive 2.8 atm/90 min hyperbaric oxygen sessions. Animals were sacrificed 24 h after the last hyperbaric oxygen administration. Malondialdehyde and carbonylated protein levels as well as superoxide dismutase activities were determined in isolated rat erythrocytes. Results: Carbonylated protein levels increased significantly after just 5 hyperbaric oxygen exposures; reached a peak level with 10 exposures; were still significantly higher than controls after 15 sessions; and decreased to normal limits after 20 exposures. Malondialdehyde levels were found to be significantly increased in the 10 to 30, but not in the 5 and 40-session groups. Superoxide dismutase activity showed elevated levels only in the 5 and 10 times hyperbarical oxygen-exposed groups. Conclusions: The suppressed oxidative stress level after 40 exposures suggests an effective endogenous antioxidant defense in repetitive HBO administrations. Kratak sadržaj Uvod: Studije o jednostrukom izlaganju hiperbaričnom kiseoniku pokazale su da je oksidativni stres izazvan izlaganjem hiperbaričnom kiseoniku srazmeran pritisku i trajanju izlaganja. Pošto efikasnost izlaganja hiperbaričnom kiseoniku uglavnom potiče od višestrukog izlaganja, cilj ove studije bio je da se istraži oksidativni efekat izlaganja hiperbaričnom kiseoniku utrajanju od 5 do 40 seansi. Metode: Šezdeset pacova podeljeno je na jednu kontrolnu i 6 eksperimentalnih grupa. Eksperimentalne grupe podvrgnute su uzastopnim seansama udisanja hiperbaričnog kiseonika (2,8 atm/90 min) po 5, 10, 15, 20, 30 i 40 puta dnevno. Životinje su žrtvovane 24 časa posle poslednje seanse. U izolovanim eritrocitima pacova određeni su nivoi malondialdehida i karboniliranog proteina kao i aktivnosti superoksid-dizmutaze. Rezultati: Nivoi karboniliranog proteina značajno su porasli posle samo 5 izlaganja hiperbaričnom kiseoniku; dostigli vrhunac nakon 10 izlaganja; ostali značajno povišeni u odnosu na kontrolu posle 15 seansi; i vratili se u normalne okvire posle 20 izlaganja. Nivoi malondialdehida bili su značajno povišeni u grupama sa 10 do 30 izlaganja, ali ne i sa 5 i 40 seansi. Aktivnost superoksid-dizmutaze pokazala je povišene nivoe samo u grupama sa 5 i 10 izlaganja hiperbaričnom kiseoniku. Zaključak: Sniženi nivo oksidativnog stresa nakon 40 izlaganja ukazuje na efikasnu endogenu antioksidantnu odbranu kod višestruke primene hiperbaričnog kiseonika.


Kaohsiung Journal of Medical Sciences | 2009

Urethral stripping caused by stent removal and its successful treatment with hyperbaric oxygen therapy: a case report.

Lütfü Tahmaz; Hasan Cem Irkilata; Kemal Simsek; Murat Zor; Seref Basal; Hakan Ay

Urethral stents usually provide initial, dramatic relief from obstructive voiding symptoms. However, complications such as recurrent urinary tract infections, stent migration, encrustation and recurrent urethral strictures are not rare, and stents should be removed when complications occur. Urethral stent removal is associated with potential risks of urethral injury, bleeding and external sphincter trauma. Hyperbaric oxygen therapy (HBO) accelerates wound healing by increasing tissue microcirculation, decreasing capillary pressure and resolving tissue edema. Although HBO has been used in various urologic applications, there is no report of HBO therapy being used to treat isolated urethral injuries. Here we present a case of urethral stripping caused by endoscopic stent removal, and its conservative treatment with HBO therapy.


Journal of Experimental and Integrative Medicine | 2011

Effects of topical melatonin and vitamin E in a rat ischemic wound model

Mehmet Ozler; Ahmet Korkmaz; Bulent Uysal; Kemal Simsek; Cansel Kose Ozkan; Turgut Topal; Sukru Oter

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Sukru Oter

Military Medical Academy

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Ahmet Korkmaz

Military Medical Academy

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Mehmet Ozler

Military Medical Academy

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Turgut Topal

Military Medical Academy

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Bulent Uysal

Military Medical Academy

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Seref Demirbas

Military Medical Academy

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Serdar Sadir

Military Medical Academy

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Senol Yildiz

Military Medical Academy

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