Attila Daǧdeviren | Baskent University (original) (raw)

Papers by Attila Daǧdeviren

Revista Internacional de Odontología Restauradora & Periodoncia, 2007

Resumen: No están muy claros los posibles efectos beneficiosos del plasma rico en plaquetas sobre... more Resumen: No están muy claros los posibles efectos beneficiosos del plasma rico en plaquetas sobre la curación de defectos aislados. En el presente estudio se han evaluado los efectos del PPP sobre la cicatrización del tejido óseo en cámaras óseas de titanio, ...

PubMed, Feb 1, 1994

The zinc iodide-osmium tetroxide (ZIO) fixation/staining method was applied for neurocytological ... more The zinc iodide-osmium tetroxide (ZIO) fixation/staining method was applied for neurocytological studies and also to examine several other tissue samples including epidermal Langerhans cells, blood and bone marrow cells and lymphoid tissue. Although precise specificity cannot be attributed to the staining reaction, interesting staining patterns for different cell types were observed by using one of the ZIO staining solutions. The significance of ZIO positivity is briefly discussed.

Turkish Journal of Veterinary & Animal Sciences, Mar 22, 2002

Thymic nurse cells are isolated thymic epithelial/thymocyte complexes described in vitro. Their i... more Thymic nurse cells are isolated thymic epithelial/thymocyte complexes described in vitro. Their in vivo existence is controversial. We examined rat thymi in order to distinguish thymic nurse cells in vivo using the zinc iodide-osmium tetroxide (ZIO) fixation/staining technique. There were mainly two types of strongly ZIO reactive cells in the thymic cortex: macrophages and small clusters of thymic epithelial cells. The latter group was composed of thymic epithelial cells and intact thymocytes forming complexes. Thus we suggest that these structures are in situ equivalents of thymic nurse cells.

PubMed, Oct 1, 2003

Objective: There is only limited data related to the subungual glomus body. We therefore studied ... more Objective: There is only limited data related to the subungual glomus body. We therefore studied the structure of this organ, aiming to obtain further evidence. Additionally, we encountered undefined receptor like structures in close association with these glomus cells, named them as lamellated bodies and examined both of the structures at light and electron microscopic levels. Methods: This study was carried out at the Faculty of Medicine, Hacettepe University, Ankara, Turkey, during the time period May 2001 to March 2002. In this study, the subungual tissues of 4 patients were examined. Results: Within subungual tissue, 2 groups of morphologically significant structures were determined by light microscopy. The first structure was described as glomus body. It was characterized as an encapsulated structure, rich in rounded clear cells filling its central compartment. The latter structure having a lamellated appearance was described as lamellated body. In the electron microscopic examination, lamellated bodies were characterized by central filament rich large cells and surrounding cytoplasmic processes of ensheathing cells, some of which were vacuolated. Glomus bodies were surrounded by a capsule and centrally located numerous rounded cells which reflected the structural features of an active cell. Conclusion: The lamellated bodies are very unusual structures and they are not found in any other part of the body. The structural organization of the ensheathing cells in the lamellated bodies greatly resembles many skin associated receptors. Therefore, we planned future studies by using immunohistochemistry, to reveal nervous elements for structural contribution.

International Endodontic Journal, 2001

AimThe objective of this study was to determine the tissue distribution of β1 integrin chains in ... more AimThe objective of this study was to determine the tissue distribution of β1 integrin chains in sound human dental pulps and to compare the findings with connective tissue compartments of other organs and to pulp tissue in teeth extracted due to periodontal disease.MethodologyFreshly frozen pulp tissue samples from teeth extracted for orthodontic reasons were examined and compared to samples from teeth extracted due to chronic (marginal) periodontitis. β1 integrin chains were determined using an indirect‐immunoperoxidase technique. Seven monoclonal antibodies recognizing α1, α2, α3, α4, α5, α6 and β1 chains of Very Late Activation Antigen (VLA) integrins were used for this purpose.ResultsVLA‐1, VLA‐2, VLA‐3 and VLA‐5 were expressed by vascular endothelium and vascular smooth muscle in varying intensities in both groups. VLA‐6 reactivity was observed in the basal surfaces of arterial, venous and capillary endothelia. Our results indicate that there was no significant difference in the expression of VLA integrins in sound pulp tissue when compared to the samples from chronic (marginal) periodontitis and the connective tissue compartments of other viscera.ConclusionThe present findings suggest that human dental pulp tissue is not different from other connective tissue compartments in the body with respect to VLA integrin expression, and chronic marginal periodontitis does not affect pulp tissue to a histopathologically detectable extent.

Anatomical Science International, Aug 28, 2018

The increase in autoimmune diseases in recent years has drawn attention back to the thymus, with ... more The increase in autoimmune diseases in recent years has drawn attention back to the thymus, with new approaches to improve and/or restore immune function being investigated. As the primary lymphoid organ responsible for functional T cell development, studies on the pre-/post-natal development of this organ and T lymphocytes in human and other species are of special interest. During our screening studies we observed structures that had not been described or mentioned previously, and named them "epitheliostromal sheaths". Associated with these unique structures were also small attached lobules (possibly reflecting the maturational stages of thymic lobules), which the authors consider as markers of histogenesis and the growth of the organ during early childhood; these findings are thus presented to researchers in this field. Approximately 1000 sections prepared from infantile thymic tissues of partial biopsy specimens were immunostained and examined. Specimens were taken from ten patients (with informed consent) in the age range of 4-9 years who underwent surgery due to congenital cardiovascular anomalies but were otherwise normal. Digital images of interest were captured to describe them in detail. Determining the immunophenotype of the compartments in these newly developing lobules assisted us greatly in defining compartments and their growth order. In summary, our findings suggest a niche-based thymus growth mechanism during childhood. We presented our findings, hoping to provide additional insight to researchers aiming to restore thymus function in adulthood and improve its immunological functions.

Okajimas Folia Anatomica Japonica, 1998

Zinc iodide-osmium tetroxide (ZIO) fixation/staining technique is a metallophilic technique which... more Zinc iodide-osmium tetroxide (ZIO) fixation/staining technique is a metallophilic technique which has been used for the examination of various tissues and cell types. We examined the ZIO (+) cell types in rat exocrine pancreas to obtain further evidence for the significance of the reaction. Among mostly non-reactive pancreatic acinar cells there were ZIO (+) acinar cells of varying staining intensity. Zymogenic granules and centroacinar cells were completely non-reactive. Our electron microscopic findings support the view that the reactivity of the technique used is cell specific but not cell type or organelle specific.

International Journal of Morphology, 2022

Trophoblasts perform different functions depending on their location. This study aimed to obtain ... more Trophoblasts perform different functions depending on their location. This study aimed to obtain structural clues about the functions of villous and extravillous trophoblasts by using light and electron microscopy. Term placenta samples were obtained from 10 healthy pregnant women following cesarean sections. Frozen sections were stained with hematoxylin-eosin, semithin sections were stained with toluidine blue and examined with a light microscope, while thin sections were contrasted using uranyl acetate-lead citrate and evaluated under an electron microscope. Fine structural features of villous trophoblasts overlapped some villous stromal cells. In addition to the usual appearance of mature capillaries in villous stroma, we demonstrated and reported maturational stages of angiogenetic sprouts in term placenta. Extravillous trophoblasts were classified according to their location: fibrinoid, chorion, trophoblastic, column, maternal vascular endothelium, or decidua. All of these trophoblasts shared some ultrastructural features but also were distinct from each other. In decidua, it was noted that the endothelial lining of some vessels was invaded by a few endovascular trophoblasts with irregular microvilli. These cells shared some ultrastructural properties with both villous trophoblasts and stromal cells. Examination showed that angiogenesis was still present in term placentas and that trophoblasts, endothelial and stromal cells have very similar properties ultrastructurally, suggesting they represent transformational forms.

Journal of Child Neurology, Sep 1, 2002

Cell adhesion molecules and extracellular matrix molecules have important roles in cell migration... more Cell adhesion molecules and extracellular matrix molecules have important roles in cell migration and connection. Their developmental expression has not been fully described in humans. In this report, these molecules were examined by immunohistochemistry in frontal tissue samples from 14- to 28-week-old fetuses aborted for obstetric reasons (n = 20) and four fetuses with nervous system abnormalities. Neural cell adhesion molecule (NCAM), tenascin, and laminin were expressed after 17 weeks. Neural cell adhesion molecule was observed in the neuropil, whereas tenascin and laminin also had cellular and vascular expression. Thrombospondin and fibronectin, apparent after 14 weeks, showed a redistribution from periventricular to outer cortical layers after midgestation. N-cadherin and integrin were observed in mid- and late gestation. Maternal or environmental conditions seemed to influence the pattern of expression. Fetuses with nervous system abnormalities had altered expression of several molecules. The descriptive data obtained in this study might constitute a basis for further studies investigating the role of these molecules in developmental abnormalities of the brain. (J Child Neurol 2002;17:707-713).

Annals of Anatomy-anatomischer Anzeiger, Sep 1, 2002

Journal of Endodontics, Mar 1, 2000

Expression of some leukocyte antigens (including CD45) and its isoforms (CD2, CD4, CD5, CD6, CD7,... more Expression of some leukocyte antigens (including CD45) and its isoforms (CD2, CD4, CD5, CD6, CD7, and CD8) was examined in the human periapical granulation tissue samples in the present study. The majority of the infiltrating cells expressed heavy molecular-weight isoforms of the CD45 antigen. Expression of CD2, CD5, CD6, and CD7 antigens was also detected, implying significant roles for these antigens in the immune reaction taking place in periapical lesions. This suggests that the immune response taking place at the periapical region is predominantly cellular and the humoral responses to antigenic challenge are conducted mainly by regional lymph nodes.

Archives of Gynecology and Obstetrics, Jul 24, 2013

Purpose To assess the effects of amifostine, N-acetyl cysteine (NAC), and leuprolide as a scaveng... more Purpose To assess the effects of amifostine, N-acetyl cysteine (NAC), and leuprolide as a scavenger in a rat endometriosis model. Methods This is a prospective randomized animal study. Setting The Animal Laboratory of Medical University. Animals 40 rats were used for transplantation of an autologous fragment of endometrial tissue onto the inner surface of the abdominal wall. After allowing 3 weeks for growth, laparotomies were performed to check the implants. Then animals were randomized into four groups: Group I amifostine (200 mg/day loading dose after 20 mg/kg/day, p.o.); Group II NAC (200 mg/day, p.o.); Group III leuprolide acetate 1 mg/kg single dose, sc; and Group IV (controls) no medication. Three weeks later, implants were evaluated morphologically. Serum and peritoneal TNFalpha levels were evaluated. The transmission electron microscopic examination of the peritoneal samples and ovaries was also performed. Results Leuprolide acetate, amifostine and NAC caused significant decreases in the mean implant areas and significant decreases in serum and peritoneal TNF-alpha levels. On comparing all groups, these reductions were higher in Group II. According to the transmission electron microscopic findings, leuprolide seems to be protecting normal structure of peritoneum best when compared to the other groups. Conclusions Amifostine, NAC and leuprolide caused regression of endometriosis in this experimental rat model by a yet unsettled mechanism.

Journal of Endodontics, Feb 1, 2000

Folia Histochemica Et Cytobiologica, Jun 10, 2010

Thromboangiitis obliterans is an inflammatory disease possibly resulting from cigarette smoking a... more Thromboangiitis obliterans is an inflammatory disease possibly resulting from cigarette smoking as a primary etiologic factor, perhaps as a delayed type of hypersensitivity or toxic angiitis. As little is known about the pathogenesis of the disease, we aimed to determine novel antigens that might be responsible from the local inflammatory reactions and structural changes observed in this disease. An indirect immunoperoxidase technique is used to examine the tissue samples obtained from the dorsalis pedis artery of affected individuals with twenty monoclonal antibodies. Among these several antigens which are not previously reported in TAO like CD34, CD44 and CD90 were determined in the tissue samples examined. On the other hand, many other antigens like cytokine/chemokine receptors, several enzymes and leukocyte/lymphocyte antigens were lacking giving some clues about the local pathological reactions. We briefly discussed our findings for several critical antigens those first described in the present work, possibly having roles in the development of the disease. Expression of the CD90/CD11c receptor/ligand pair seems to play an important role in mononuclear cell recruitment to the damage site. Vascular invasion of not only tunica intima but also the tunica media in affected vessels is clearly demonstrated using endothelial cell specific antigens.

Acta histochemica, Sep 1, 2008

Small plaque parapsoriasis (SPP) is one of the cutaneous T-cell lymphoproliferative disorders. Th... more Small plaque parapsoriasis (SPP) is one of the cutaneous T-cell lymphoproliferative disorders. The aim of the present study was to show the antigenic profile of a subset of dendritic cells and lymphocytes in SPP in comparison with normal cells to provide data on the role of these two cell types in the pathogenesis of SPP. Skin biopsy specimens of lesions were obtained from 8 patients with SPP. Biopsies of the healthy skin from 9 control individuals were also analyzed. Immunohistochemistry was performed on the frozen tissue sections to reveal binding of anti-HLA Class II, anti-CD1a, anti-CD4, anti-CD8, anti-CD44, anti-CD45, and anti-CD68 monoclonal antibodies. There was a statistically significant increase in the number of CD1a(+), Langerhans cells (LCs), HLA-DR-immunoreactive and, CD1a-positive dermal dendritic cells and CD68(+) macrophages in the SPP group (p ¼ 0.008, 0.008, 0.002 and o0.0009, respectively). The number of lymphocytes positive for CD4, CD8 and CD45 was significantly higher than normal in the SPP group (p ¼ 0.015, o0.0009 and o0.0009, respectively). Our study demonstrates that both peptide-and lipid-based antigens are involved in the persistent antigenic exposure in SPP. Dendritic cells play a pivotal role in SPP by presenting antigens by both LC and dermal dendritic cells via MHC Class II and CD1a molecules. The CD68(+) macrophages are thought to be involved in the immune response in this pathology as an antigen-presenting cell.

Archives Italiennes De Biologie, 2019

Ultrastructural evaluation of myelin coat helps to understand the possible background of patholog... more Ultrastructural evaluation of myelin coat helps to understand the possible background of pathological changes leading to deterioration or complete loss of nerve functions. A number of terms were previously introduced to describe the fine structural changes in myelin under various conditions. We believe that using a common terminology will be helpful to interpret the structure/function relationship in neurological disorders empowering the diagnosis and possible therapeutical approaches. In this paper, we present examples of ultrastructural changes in myelin during myelination, demyelination, re-myelination and dysmyelination processes and we reviewed the terminology previously used.We tried to include all studies reporting ultrastructural findings with no limitation to the experimental conditions, the species used and the disorders. The terminology used to describe the structural findings included compacted myelin, partially compacted myelin, noncompacted myelin, redundancy (hypermyelination, tomacula, myelinosome), splitting, complete circular splitting, myelin degradation, concentric lamellar bodies (myelin figures), loss of myelin lamellae, polyaxonal Schwann cells and necrotic cell debris.Ultrastructural data described in this paper aimed to provide a guide for future studies. We concluded that the evaluation of ultrastructural changes in any neurological disorder is greatly valuable for a better understanding of pathological and physiological changes occured. We also believe that supporting the ultrastructural findings with quantitative methods in the future will be of great value.

Annals of Anatomy-anatomischer Anzeiger, Apr 1, 2003

Canadian journal of ophthalmology, Feb 1, 2019

OBJECTIVES: Nigella sativa oil and thymoquinone were comparatively tested in vitro for their effe... more OBJECTIVES: Nigella sativa oil and thymoquinone were comparatively tested in vitro for their effects on human cancer cell lines (glioma,T98; prostate, LnCaP) as well as mouse embryonic fi broblast cell lines (3T3), and for the induction of apoptosis. METHODS: Individual cell lines were treated with thymoquinone and N. sativa oil for 24 and 48 hr. Survival rate with MTT, apoptosis with fl ow cytometry and caspase-9 mRNA enzyme levels with RT-PCR were determined in vitro. RESULTS: Application of respective concentrations of N. sativa oil (excluding 100 μg/mL for 48 hr) did not change the number of tested cell lines, however, treatment with thymoquinone reduced the number of all cells signifi cantly. Thymoquinone also exerted its apoptosis inducing effect through the activation of caspase-9. CONCLUSION: Differing with the type of cancer cells, thymoquinone posseses a strong contentration and time dependent survival reducing effect on cancer cells via apoptosis (Fig. 6, Ref. 22).

Uludağ Üniversitesi Tıp Fakültesi Dergisi

Tavuk koryoallantoik membran (CAM) modeli, anjiyogenez çalışmalarında gelişimsel süreçleri takip ... more Tavuk koryoallantoik membran (CAM) modeli, anjiyogenez çalışmalarında gelişimsel süreçleri takip etmek için yaygın olarak kullanılan bir modeldir. Bu çalışmada, CAM kullanılarak, embriyonik gelişimin 7. ve 20. günleri (E7 ve E20) arasında görülen anjiyogenez süreci ışık ve transmisyon elektron mikroskop analizleri ile takip edilmiştir. Ayrıca, aynı günlerde alınan CAM örnekleri kullanılarak, anjiyogenez meka-nizmalarında görevli [Vasküler Endotelyal Büyüme Faktörü (VEGF)-A ve Fibroblast Büyüme Faktörü (FGF)-2] ve reseptörlerinin [Vasküler Endotelyal Büyüme Faktörü Reseptörü (VEGFR)-2 ve Fibroblast Büyüme Faktörü (FGFR)-2] yanı sıra, insan C-tipi natriüretik peptid (CNP) homoloğu olan tavuk CNP-3 ve reseptörü natriüretik peptid reseptörü (NPR)-B'nin mRNA ifade düzeylerinin zamana bağımlı değişimi analiz edilmiştir. Işık mikroskobu ve elektron mikroskobu analizleri, endotel tüp benzeri vasküler yapıları yoğun olarak E7-E8 günlerinde ve koryonik mezenşim içinde bulunduğunu göstermi...

Journal of Anatomy

ABSTRACT