Wos İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/11727/4807
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Item Implications for thymus growth in childhood: histogenesis of cortex and medulla(2019) Fidan, Pinar Ayran; Kaymaz, F. Figen; Dagdeviren, Atilla; 0000-0003-3047-0305; 0000-0001-8990-8282; 30155680; ABG-5365-2020; P-2877-2014The 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 4-9years 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.Item Antiproliferative and anti-apoptotic effect of astaxanthin in an oxygen-induced retinopathy mouse model(2019) Kucukoduk, Ali; Helvacıoglu, Fatma; Haberal, Nihan; Dagdeviren, Atilla; Bacanli, Didem; Yilmaz, Gursel; Akkoyun, Imren; 0000-0001-8990-8282; 30851776; P-2877-2014Objective: To evaluate the impact of intravitreal (IV) and intraperitoneal (IP) astaxanthin (AST) injections on neovascular development (ND), retinal morphology, and apoptotic activity in a C57BL/6J mouse model with hyperoxia-induced retinopathy (HIR). Design: C57BL/6J mouse model. Methods: Two negative control groups (n = 6 each; one of which received IV sterile dimethyl sulfoxide [DMSO]) of C57BL/6J-type mice were exposed to room air. The HIR groups included 36 C57BL/6J-type mice exposed to 75% +/- 2% oxygen from postnatal day (PD) 7 to PD 12. On PD 12, these mice were randomized into 6 groups (n = 6 each): 2 HIR control groups (one of which received IV-DMSO), 2 IV-AST groups (10 and 100 mu g/mL), and 2 IP-AST groups (0.5 and 5 mg/kg). We measured ND by counting neovascular tufts in cross sections and examined histological, ultrastructural changes via light and electron microscopy. Apoptosis was detected using terminal deoxynucleotidyl transferase-mediated nick end-labeling. Results: No ND was detected in the negative control groups. ND levels were not significantly different between high- and low-dose AST for either means of administration. However, ND levels were significantly lower in the AST groups, regardless of delivery, compared to the control groups. The means of delivery (IP versus IV) also yielded significant differences in ND. The incidence of mitochondrial dysmorphology and apoptosis were lower in groups receiving AST. Conclusions: AST seems to suppress ND and has anti-apoptotic activity in the HIR mouse model.Item Effect of intravitreal and intraperitoneal cyanidin-3-glucoside injection in oxygen-induced retinopathy mouse model(2019) Ercan, Zeynep E.; Haberal, Nihan; Helvacioglu, Fatma; Dagdeviren, Atilla; Yİlmaz, Gursel; 0000-0002-9915-3781; 31124490; AAQ-3136-2020Purpose: To evaluate the effect of cyanidin-3-glucoside (C3G) in oxygen-induced retinopathy (OIR) mouse model. Methods: In this experimental study, 10 C57BL / 6J type mice exposed to room air comprised two control groups (n = 5 each; a negative control and a group receiving intravitreal sterile dimethyl sulfoxide [IVS DMSO]). Thirty C57BL / 6J type mice exposed to 75% +/- 2% oxygen from postnatal day 7 to postnatal day 12 comprised the OIR groups. On postnatal day 12, these mice were randomized into six groups (n = 5 each): two OIR control groups (negative control and IVS DMSO), two intravitreal C3G groups (300 and 600 ng/mu L), and two intraperitoneal C3G groups (0.05 and 0.1 mg/kg). We quantified neovascularization by counting endothelial cell proliferation on the vitreal side of the inner limiting membrane of the retina and examined histological and ultrastructural changes via light and electron microscopy and apoptosis by terminal deoxynucleotidyl transferase deoxy-UTP-nick end labeling. Results: The intravitreal C3G groups yielded lower endothelial cell counts compared with the intravitreal DMSO group. The intraperitoneal high-dose group had lower cell counts compared with the OIR control groups. Electron microscopy revealed significantly less mitochondrial dysmorphology in intravitreal groups and the high-dose intraperitoneal mice. We noted no difference in apoptotic cell count between the controls, low-dose intravitreal, and both intraperitoneal groups. However, apoptotic cell count was significantly higher in the high-dose intravitreal group. Conclusion: C3G suppresses endothelial cell proliferation in an OIR mouse model, leads to a reduced hyperoxia-induced mitochondrial dysmorphology, but increases apoptotic cell death in high concentrations.Item Intussusceptive Growth of Vascular Bed in Human Placenta(2019) Fidan, Pinar Ayran; Helvacioglu, Fatma; Dagdeviren, Atilla; 0000-0003-3047-0305; ABG-5365-2020Objective: Normal embryonic and fetal development is strictly bound to maternal health and functioning placenta. Besides the invasion and differentiation of trophoblastic cell lineage; development of effective vasculature is crucial for the function of placenta. Placental vessels first arise by vasculogenesis in early development of villi and then succeeded by angiogenesis during fetal life. In the recent decades a new form of angiogenesis, "intussusceptive angiogenesis", besides classical sprouting angiogenesis is well documented. The presence of intussusception was shown at multiple organs but in placenta, in recent literature. We aimed to determine whether intussusceptive angiogenesis is present in human placenta to obtain further evidence on the development of vascular bed. Methods: The term placenta samples were obtained from 10 healthy pregnancies following caesarean sections. Tissues were processed using routine plastic embedding technique; thin sections were contrasted with uranyl acetate & lead citrate; observed and photographed by transmission electron microscope. Results: Our examinations revealed that both sprouting and intussusceptive angiogenesis is present in floating villi of term placenta. Phases of intussusception were documented in various samples. Conclusion: The presence of intussusceptive angiogenesis will help our understanding of microvascular bed remodeling during pregnancy. We believe that this new finding will help us to determine the relation of microvascular bed development in normal and abnormal placentas.Item Histomorphometric and Ultrastructural Evaluation of Long-Term Alpha Lipoic Acid and Vitamin B12 Use After Experimental Sciatic Nerve Injury in Rats(2016) Arikan, Murat; Togral, Guray; Hasturk, Askin Esen; Horasanli, Bahriye; Helvacioglu, Fatma; Dagdeviren, Atilla; Tekindal, Mustafa Agah; Parpucu, Murat; 0000-0002-6026-0045; 0000-0002-4060-7048; 0000-0003-0376-5589; 0000-0003-3142-1011; 27476916; AAH-8887-2021; AAE-5065-2019; U-9270-2018; S-4175-2018AIM: To analyze the therapeutic effects of long-term alpha lipoic acid (A-LA) and vitamin B12 use via histomorphometric methods and electron microscopy in the transected sciatic nerves of rats. MATERIAL and METHODS: Forty rats were randomized into five groups (n=8/group). In group I, 1 cm segment of sciatic nerve was resected without any other intervention. In group II (sham), following right sciatic nerve transection, primary epineurial anastomosis was performed by placing the edges of the nerve end-to-end. In group III (saline), after right sciatic nerve transection, the ends of the nerves were brought together and closed after application of intraperitoneal physiologic saline. In group IV, 2 mg/kg of alpha lipoic acid and in group V, 2 mg/kg of vitamin B12 was administered intraperitoneally before surgical intervention. RESULTS: Histomorphometric and electron microscopic analyses revealed that vitamin 312 did not prevent structural changes, abnormal myelination and g-ratio deviations regarding the functional aspects of the sciatic nerve. Alpha lipoic acid was more effective in restructuring the histomorphometric and structural aspects of the nerve with more myelinated fibers with optimal values (0.55-0.68) than vitamin B12 groups, in which the number of myelinated nerve fibers significantly decreased at optimal intervals (0.55-0.68). CONCLUSION: A-LA administration following peripheral nerve transection injury is more effective in promoting nerve healing regarding the structural aspects of the sciatic nerve compared to vitamin B12 and also myelination of nerve fibers by increasing g-values.