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Dive into the research topics where Saadettin Sel is active.

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Featured researches published by Saadettin Sel.


Development | 2007

Ptf1a is essential for the differentiation of GABAergic and glycinergic amacrine cells and horizontal cells in the mouse retina.

Hassan Nakhai; Saadettin Sel; Jack Favor; Lidia Mendoza-Torres; Friedrich Paulsen; Gernot I.W. Duncker; Roland M. Schmid

Basic helix-loop-helix (bHLH) transcription factors are important regulators of retinal neurogenesis. In the developing retina, proneural bHLH genes have highly defined expressions, which are influenced by pattern formation and cell-specification pathways. We report here that the tissue-specific bHLH transcription factor Ptf1a (also known as PTF1-p48) is expressed from embryonic day 12.5 of gestation (E12.5) to postnatal day 3 (P3) during retinogenesis in the mouse. Using recombination-based lineage tracing, we provide evidence that Ptf1a is expressed in precursors of amacrine and horizontal cells. Inactivation of Ptf1a in the developing retina led to differentiation arrest of amacrine and horizontal precursor cells in addition to partial transdifferentiation of Ptf1a-expressing precursor cells to ganglion cells. Analysis of late cell-type-specific markers revealed the presence of a small population of differentiated amacrine cells, whereas GABAergic and glycinergic amacrine cells, as well as horizontal cells, were completely missing in Ptf1a-knockout retinal explants. We conclude that Ptf1a contributes to the differentiation of horizontal cells and types of amacrine cells during mouse retinogenesis.


American Journal of Human Genetics | 2009

WNT10A Mutations Are a Frequent Cause of a Broad Spectrum of Ectodermal Dysplasias with Sex-Biased Manifestation Pattern in Heterozygotes

Axel Bohring; Thomas Stamm; Christiane Spaich; Claudia Haase; Kerstin Spree; Ute Hehr; Mandy Hoffmann; Susanne Ledig; Saadettin Sel; Peter Wieacker; Albrecht Röpke

Odonto-onycho-dermal dysplasia (OODD), a rare autosomal-recessive inherited form of ectodermal dysplasia including severe oligodontia, nail dystrophy, palmoplantar hyperkeratosis, and hyperhidrosis, was recently shown to be caused by a homozygous nonsense WNT10A mutation in three consanguineous Lebanese families. Here, we report on 12 patients, from 11 unrelated families, with ectodermal dysplasia caused by five previously undescribed WNT10A mutations. In this study, we show that (1) WNT10A mutations cause not only OODD but also other forms of ectodermal dysplasia, reaching from apparently monosymptomatic severe oligodontia to Schöpf-Schulz-Passarge syndrome, which is so far considered a unique entity by the findings of numerous cysts along eyelid margins and the increased risk of benign and malignant skin tumors; (2) WNT10A mutations are a frequent cause of ectodermal dysplasia and were found in about 9% of an unselected patient cohort; (3) about half of the heterozygotes (53.8%) show a phenotype manifestation, including mainly tooth and nail anomalies, which was not reported before in OODD; and (4) heterozygotes show a sex-biased manifestation pattern, with a significantly higher proportion of tooth anomalies in males than in females, which may implicate gender-specific differences of WNT10A expression.


Journal of Cataract and Refractive Surgery | 2010

Significance of the riboflavin film in corneal collagen crosslinking

Gregor Wollensak; Henning Aurich; Christopher Wirbelauer; Saadettin Sel

PURPOSE: To evaluate the role of the preocular riboflavin film in ultraviolet‐A (UVA) absorption in corneal collagen crosslinking (CXL). SETTING: Eye Laser Institute, Department of Ophthalmology, Martin‐Luther‐University, Halle, Germany. METHODS: The absorption of UVA light was measured in human donor and porcine postmortem corneas with and without riboflavin film using 3 solutions: standard dextran–riboflavin, methylcellulose–riboflavin, and hypoosmolar riboflavin–sodium chloride without dextran. The breakup time of the solutions and their absorbance were also determined. RESULTS: After 30‐minute instillation of riboflavin solution, the corneal absorption coefficient of the combined stroma–riboflavin film system was 56.36 cm−1 in human corneas and 51.46 cm−1 in porcine corneas using dextran–riboflavin; 69.87 cm−1 and 53.86 cm−1, respectively, using methylcellulose–riboflavin; and 48.19 cm−1 and 42.68 cm−1, respectively, using hypoosmolar riboflavin. For the stroma alone without riboflavin film, the absorption coefficient was reduced to 36.95 cm−1 in human corneas and 28.91 cm−1 in porcine corneas using dextran–riboflavin; 38.26 cm−1 and 32.49 cm−1, respectively, using methylcellulose–riboflavin; and 38.88 cm−1 and 28.42 cm−1, respectively, using hypoosmolar riboflavin solution. The breakup time was 22 minutes for the dextran–riboflavin film, 32 minutes for methylcellulose, and 90 seconds for the hypoosmolar solution. CONCLUSION: Results indicate that the cornea including the riboflavin film can be considered a composite 2‐compartment system and that the riboflavin film is an integral part of the CXL procedure and important in achieving the correct stromal and endothelial UVA irradiance. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.


British Journal of Cancer | 1999

Interleukin 10 (IL-10) : an immunosuppressive factor and independent predictor in patients with metastatic renal cell carcinoma

F. Wittke; R Hoffmann; Jan Buer; I Dallmann; K Oevermann; Saadettin Sel; T Wandert; Arnold Ganser; Jens Atzpodien

SummaryInterleukin 10 (IL-10) is an immunosuppressive factor and has been detected in tumour cell cultures of renal cell carcinoma and of malignant melanoma. IL-10 has been described as a cytokine of the Th2 response; it is able to suppress antigen-presenting cells (APCs) and may lead to down-regulation of HLA class I and II molecules on dendritic cells and to anergy of T-lymphocytes. We evaluated pretreatment serum levels of soluble IL-10 and various clinical parameters to determine their prognostic value in 80 advanced renal cell carcinoma patients seen at our institution between May 1990 and April 1996. For statistical evaluation we used both univariate and multivariate Cox proportional hazards models. An elevated pretreatment serum level of IL-10 was a statistically independent predictor of unfavourable outcome (P < 0.0028), in addition to the well-known clinical and biochemical risk factors. These data support risk stratification for future therapeutic trials and identify a predictor which needs to be validated in prospective studies and may potentially influence decision making in palliative management of patients with metastatic renal cell carcinoma. These data also suggest a potential role of IL-10 in the development of advanced renal cell carcinoma and in the future design of therapeutic strategies.


British Journal of Ophthalmology | 2011

Interlamellar cohesion after corneal crosslinking using riboflavin and ultraviolet A light

Gregor Wollensak; E. Spörl; C Mazzotta; Thomas Kalinski; Saadettin Sel

Aims Collagen crosslinking treatment of progressive keratoconus using the photosensitiser riboflavin and ultraviolet A light of 370 nm wavelength has been shown to increase significantly the tensile strength of corneal collagen by about 300%. In keratoconus, interlamellar and interfibrillar slippage have been proposed as pathogenetic mechanisms. Therefore, the aim of this study was to assess the impact of collagen crosslinking on the interlamellar cohesive force. Methods 72 post mortem porcine eyes were divided into six different treatment groups: the untreated control group, the standard crosslinking group, the hypo-osmolar crosslinking group, the stromal swelling group, the formaldehyde group and the α-amylase group. An anterior 9×4 mm strip of 400 μm thickness was prepared using a lamellar rotating microkeratome. For interlamellar cohesive force measurements a splitting plane was created at 50% depth. Force–distance profiles were recorded using a microcomputer-controlled biomaterial testing machine. Results The mean interlamellar cohesive force was 0.24 N/mm in the untreated control group, 0.26 N/mm in the standard crosslinking group, 0.25 N/mm in the hypo-osmolar crosslinking group, 0.23 N/mm in hydrated corneas, 0.27 N/mm in the formaldehyde group without statistically significant difference. Only the values of the α-amylase group were statistically significantly lowered by 31.5% to 0.16 N/mm. Conclusions Surprisingly, corneal crosslinking does not increase the interlamellar cohesive force. In the α-amylase group the cohesive force was mainly decreased because of the digestion of proteoglycans. Crosslinking seems to stabilise only inter- and intrafibrillar, but not interlamellar cohesion.


Journal of Biological Chemistry | 2008

Intestinal Trefoil Factor/TFF3 Promotes Re-epithelialization of Corneal Wounds

Friedrich Paulsen; Chee Wai Woon; Deike Varoga; Anne Jansen; Fabian Garreis; Kristin Jäger; Marita Amm; Daniel K. Podolsky; Philipp Steven; Nick Barker; Saadettin Sel

Disorders of wound healing characterized by impaired or delayed re-epithelialization are a serious medical problem. These conditions affect many tissues, are painful, and are difficult to treat. In this study using cornea as a model, we demonstrate the importance of trefoil factor 3 (TFF3, also known as intestinal trefoil factor) in re-epithelialization of wounds. In two different models of corneal wound healing, alkali- and laser-induced corneal wounding, we analyzed the wound healing process in in vivo as well as in combined in vivo/in vitro model in wild type (Tff3+/+) and Tff3-deficient (Tff3-/-) mice. Furthermore, we topically applied different concentrations of recombinant human TFF3 (rTFF3) peptide on the wounded cornea to determine the efficacy of rTFF3 on corneal wound healing. We found that Tff3 peptide is not expressed in intact corneal epithelium, but its expression is extensively up-regulated after epithelial injury. Re-epithelialization of corneal wounds in Tff3-/- mice is significantly prolonged in comparison to Tff3+/+ mice. In addition, exogenous application of rTFF3 to the alkali-induced corneal wounds accelerates significantly in in vivo and in combined in vivo/in vitro model wound healing in Tff3+/+ and Tff3-/- mice. These findings reveal a pivotal role for Tff3 in corneal wound healing mechanism and have broad implications for developing novel therapeutic strategies for treating nonhealing wounds.


American Journal of Clinical Pathology | 2008

Virtual 3D Microscopy Using Multiplane Whole Slide Images in Diagnostic Pathology

Thomas Kalinski; Ralf Zwönitzer; Saadettin Sel; Matthias Evert; Thomas Guenther; Harald Hofmann; Johannes Bernarding; Albert Roessner

To reproduce focusing in virtual microscopy, it is necessary to construct 3-dimensional (3D) virtual slides composed of whole slide images with different focuses. As focusing is frequently used for the assessment of Helicobacter pylori colonization in diagnostic pathology, we prepared virtual 3D slides with up to 9 focus planes from 144 gastric biopsy specimens with or without H pylori gastritis. The biopsy specimens were diagnosed in a blinded manner by 3 pathologists according to the updated Sydney classification using conventional microscopy, virtual microscopy with a single focus plane, and virtual 3D microscopy with 5 and 9 focus planes enabling virtual focusing. Regarding the classification of H pylori, we found a positive correlation between the number of focus planes used in virtual microscopy and the number of correct diagnoses as determined by conventional microscopy. Concerning H pylori positivity, the specificity and sensitivity of virtual 3D microscopy using virtual slides with 9 focus planes achieved a minimum of 0.95 each, which was approximately the same as in conventional microscopy. We consider virtual 3D microscopy appropriate for primary diagnosis of H pylori gastritis and equivalent to conventional microscopy.


American Journal of Ophthalmology | 2011

Impact of Clinical Factors on the Long-Term Functional and Anatomic Outcomes of Osteo-odonto-keratoprosthesis and Tibial Bone Keratoprosthesis

Maria Fideliz de la Paz; Juan Alvarez de Toledo; Victor Charoenrook; Saadettin Sel; Jose Temprano; Rafael I. Barraquer; Ralph Michael

PURPOSE To report the long-term functional and anatomic outcomes of osteo-odonto-keratoprosthesis and tibial bone keratoprosthesis; to analyze the influence of clinical factors, such as surgical technique, primary diagnosis, age, and postoperative complications, on the final outcome. DESIGN Retrospective cohort study. METHODS setting: Centro de Oftalmología Barraquer, between 1974 and 2005. PARTICIPANTS Two hundred twenty-seven patients. intervention: Biological keratoprosthesis using osteo-odonto-keratoprosthesis or tibial bone keratoprosthesis. main outcome measures: Functional survival with success defined as best-corrected visual acuity ≥0.05; anatomic survival with success defined as retention of the keratoprosthesis lamina. RESULTS Osteo-odonto-keratoprosthesis and tibial bone keratoprosthesis have comparable anatomic survival at 5 and 10 years of follow-up, but osteo-odonto-keratoprosthesis has a significantly better functional success than tibial bone keratoprosthesis at the same time periods. Among the primary diagnoses, Stevens-Johnson syndrome, chemical burn, and trachoma have generally good functional and anatomic outcomes and the least favorable prognosis is for ocular cicatricial pemphigoid. Younger patients fared better than those in older age groups. The most frequent complications were extrusion (28%), retinal detachment (16%), and uncontrolled glaucoma (11%). The glaucoma group had the best anatomic success but the worst functional results, only exceeded by the retinal detachment group in terms of functional outcome. CONCLUSION Clinical factors, such as surgical technique, primary diagnosis, age, and postoperative complications, can affect the long-term anatomic and functional successes of biological keratoprosthesis. Knowledge about the impact of each of these factors on survival can help surgeons determine the best approach in every particular case.


British Journal of Cancer | 1999

Prognostic impact of in vivo soluble cell adhesion molecules in metastatic renal cell carcinoma

R Hoffmann; Anke Franzke; Jan Buer; Saadettin Sel; K Oevermann; A Duensing; M Probst; S. Duensing; H Kirchner; Arnold Ganser; Jens Atzpodien

SummaryThe purpose of the study was to determine prognostic significance of pretreatment serum levels of different molecules involved in cell to cell interactions along with other clinical parameters in patients with metastatic renal cell carcinoma. sICAM-1, sVCAM-1 and sELAM-1 serum levels were determined by ELISA assays in sera from 99 patients with histologically confirmed progressive metastatic renal cell carcinoma prior to initiation of systemic therapy. Kaplan–Meier survival analysis, log-rank statistics and two-proportional Cox regression analyses were employed to identify risk factors and to demonstrate statistical independence. In univariate analyses, the following pretreatment risk factors could be identified: serum sICAM-1 level > 360 ng ml–1, erythrocyte sedimentation rate > 70 mm h–1, serum C-reactive protein level > 8 mg l–1, serum lactic dehydrogenase level > 240 U/ l and neutrophil count > 6000 μl–1. Multivariate analyses demonstrated statistical independence for serum sICAM-1 level, erythrocyte sedimentation rate (ESR) and serum C-reactive protein (CRP) level as pretreatment predictors of overall patient survival. The prognostic significance of sICAM-1 might indicate a role of this molecule for tumour progression, potentially in association with the abrogation of anti-tumour immune responses. The possibility of defining a pretreatment risk model based on sICAM-1 level, ESR and CRP also warrants further investigation, with regard to a possible linkage between acute phase proteins and sICAM-1 levels.


American Journal of Rhinology & Allergy | 2013

Detection of surfactant proteins A, B, C, and D in human nasal mucosa and their regulation in chronic rhinosinusitis with polyps.

Martin Schicht; Stephan Knipping; Roman Hirt; Stephanie Beileke; Saadettin Sel; Friedrich Paulsen; Lars Bräuer

Backround The nasal mucosa is characterized by a multirow high prismatic ciliated epithelium representing the first barrier of the immune defense system against microbial and other environmental pathogenic influences. A number of nonspecific defense mechanisms, including the presence of lactoferrin, peroxidases, proteases, interferons, and lysozymes in nasal secretions, act to counter inflammatory processes. The surfactant proteins (SPs) known from the lungs are important components of the innate immune system. They also influence the rheology of fluids and reduce the surface tension of gas–fluid interphases. The objective of this study was to investigate the protein expression of all four SPs. A specific aim was detection and characterization of SP-C, which had previously not been confirmed in human nasal mucosa. Methods The expression of mRNA for SP-A, -B, -C and -D was investigated using reverse transcriptase polymerase chain reaction on samples of both healthy nasal mucosa and nasal mucosa altered by inflammatory processes (allergic rhinitis and chronic rhinosinusitis). The distribution of all four proteins was determined with monoclonal antibodies using Western blot analysis as well as immunohistochemical methods. Results The results show that all four SPs, including SP-C not detected before this, are nasal mucosa components. A shift was also observed in the expression behavior of the SP-A, -B, and -D in nasal mucosa with inflammatory changes. Conclusion Based on these results, SPs appear to have an important function in immunologic and rheological process of the nasal mucosa and support the prospective therapeutic use of liposomal nasal sprays.

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Friedrich Paulsen

University of Erlangen-Nuremberg

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Thomas Kalinski

Otto-von-Guericke University Magdeburg

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Norbert Nass

Otto-von-Guericke University Magdeburg

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Lars Bräuer

University of Erlangen-Nuremberg

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Martin Schicht

University of Erlangen-Nuremberg

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Albert Roessner

Otto-von-Guericke University Magdeburg

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Fabian Garreis

University of Erlangen-Nuremberg

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Ulrike Hampel

University of Erlangen-Nuremberg

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