Yazar "Karahan, Siyami" seçeneğine göre listele

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    Albino farelerde iyonlaştırıcı radyasyonun hepatosit morfolojisi ve prolifere hücre çekirdek antijeni (PCNA) ekspresyonu üzerindeki etkileri
    (2008) Karahan, Siyami; Çavuşoğlu, Kültiğin; Atmaca, Hasan Tarık; Yalçın, Emine
    Bu çalısmada, iyonlastırıcı radyasyonun albino farelerde hepatosit proliferasyon oranına etkisinin arastırılması amaçlandı. Normal ve iyonlastırıcı radyasyona maruz kalan albino fare hepatositlerindeki prolifere hücre çekirdek antijeni (PCNA) ekspresyonu immünoperoksidaz boyama teknigiyle belirlendi. Radyasyon grubundaki fareler, çalısmanın bir ve yedinci günlerinde 30 dakika süre ile Kobalt 60-gama (1,333 MeV) ısını ile 10 Gy dozunda radyasyona maruz bırakıldı ve onbesinci gün hayvanların nekropsileri yapıldı. Kontrol grubu fare hepatositlerinde PCNA immünopozitifligi sadece hücre çekirdeginde gözlenirken, radyasyon grubu albino farelerde hem çekirdek hem de sitoplazmada tespit edildi. Kontrol grubunda, PCNA immünopozitif hepatositlerin oranı (%27,7620,4), radyasyon grubuna oranla (%7,535,43) daha yüksekti (p0,007). Kontrol grubunda çift çekirdekli (dikaryotik) hepatositlerin yüzdesi (%10,22 3,54) radyasyon grubuna oranla (%16,617,01) daha düsüktü (p0,019). Radyasyona maruz kalan farelerin karacigerinde iri çekirdekli hepatositlere ve piknotik hepatositlere sıklıkla rastlandı. Çift çekirdekli hepatositlerdeki PCNA immunoreaktivitesi çogunlukla her iki çekirdekte, daha az sıklıkla da tek çekirdekte görüldü. Sonuç olarak, PCNA ekspresyonu normal albino fare hepatositlerinde çekirdekte eksprese olurken, radyasyona maruz kalmıs fare hepatositlerinde genellikle hem çekirdek hem de sitoplazmada gözlendi. Ayrıca,10 Gy iyonlastırıcı gama radyasyon prolifere olan hepatosit sayısında azalmaya ve çift çekirdekli hepatosit sayısında artısa neden olmaktadır.
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    Amino acid surface modified bioglass: A candidate biomaterial for bone tissue engineering1
    (Wiley, 2024) Ozkabadayi, Yasin; Turk, Mustafa; Kumandas, Ali; Karahan, Siyami
    Bioglasses are solid materials consisted of sodium oxide, calcium oxide, silicon dioxide and phosphorus in various proportions and have used in bone tissue engineering. There have been ongoing efforts to improve the surface properties of bioglasses to increase biocompatibility and performance. The aim of the present study is to modify the bioglass surface with an amino acid mixture consisting of arginine, aspartic acid, phenylalanine, cysteine, histidine and lysine, to characterize the surface, and to evaluate the performance and biocompatibility in vitro and in vivo. The untreated bioglass, bioglass kept in simulated body fluid (SBF), and modified bioglass were used in further evaluation. After confirmation of the surface modification with FT-IR analyses and SEM analyses, MC3T3-E1 preosteoblasts adhesion on the surface was also revealed by SEM. The modified bioglass had significantly higher ALP activity in colorimetric measurement, rate of calcium accumulations in Alizarin red s staining, lower rate of cell death in Annexin-V/PI staining to determine apoptosis and necrosis. Having higher cell viability rate in MTT test and absence of genotoxicity in micronucleus test (OECD 487), the modified bioglass was further confirmed for biocompatibility in vitro. The results of the rat tibial defect model revealed that the all bioglass treatments had a significantly better bone healing score compared to the untreated negative control. However, the modified bioglass exhibited significantly better bone healing efforts especially during the first and the second months compared to the other bioglass treatment treatments. As a result, the amino acid surface modification of bioglasses improves the surface biocompatibility and osteogenic performance that makes the amino acid modified bioglass a better candidate for bone tissue engineering. Research Highlights Bioglass surface modification with amino acids contributes to bioglass-tissue interaction with an improved cell attachment. Modified bioglass increases in vitro Alp activity and calcium accumulation, and also positively affects cell behavior by supporting cell adaptation. Bioglass exerts osteogenic potential in vivo especially during early bone healing.
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    Ankyloglossia in Dogs: A Morphological and Immunohistochemical Study
    (Wiley-Blackwell Publishing, Inc, 2009) Karahan, Siyami; Kul, Bengi Çınar
    Ankyloglossia is a congenital anomaly of the tongue that is usually characterized by a short and thick lingual frenulum. The genetic mutations such as in TBox genes and other foetal mechanism have still been under investigation as possible causes of ankyloglossia. This study describes morphology of anklyoglossia phenotype found in members of two closely bred Kangal dog families. Morphology of ankyloglossia and immunohistochemical localization of alpha B-crystallin, an anti-apoptotic protein, in the frenulum tissue collected during frenectomy was described. Grossly, the lingual frenulum was observed as it extended up to the tip or near the tip of the tongue. The tip of the tongue was often notched and appeared in 'W' shape. No other craniofacial anomalies were associated with ankyloglossia. Histologically, the frenulum tissue was covered by stratified squamous epithelia of variable thickness. Skeletal muscle fibres were often scattered in the vicinity of collagen fibres of the lamina propria. alpha B-crystallin was immunolocalized exclusively in skeletal muscle fibres. In conclusion, ankyloglossia in the dog generally occurs as a sole anomaly. The presence of alpha B-crystallin immunoreactivity exclusively in skeletal muscle fibres suggests that there may be a connection between occurrences of ankyloglossia in the dog and a delay or interference with apoptosis of the skeletal fibres in the frenulum tissue.
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    Anti-Ctgf Konjuge Edilmiş Gemsitabin Yüklü Kitosan Nanobaloncukların Hazırlanması ve Pankreas Kanserindeki İn Vivo Etkilerinin İncelenmesi
    (2022) Uzun, Lokman; Karahan, Siyami; Türk, Mustafa; Berk, Ahmet Burak; Avar, Eda Çinar
    Pankreas kanserine bağlı vaka sayısı diğer bazı kanser türlerine göre az olsa da, erken tanısının pek mümkün olmaması, oldukça hızlı metastaz yapabilmesi, birçok tedavi seçeneğine beklenen ölçüde yanıt vermemesi gibi nedenlerden dolayı ölüm oranı oldukça yüksektir. Pankreas kanseri, birçok tedavi seçeneğine güçlü bir şekilde direnç gösteren, Amerika Birleşik Devletleri? nde şu anda dördüncü sırada olup, 2030 yılında ikinci sırada olacağı düşünülen en agresif ve ölümcül kanser türüdür. Kullanılan geleneksel tedavi yöntemleri, sadece kanser hücrelerini hedeflemeye çalışmaktadır. Ancak son yıllardaki çalışmalar tümör mikroçevresi ve stromasının; tümörün gelişimi, invazyonu, kemorezistans ve metastaz süreçlerinde aktif rol oynadığını göstermektedir. Bu nedenle etkin bir tedavi için hem tümör hücrelerinin hem de tümör mikroçevresi ve stromasının hedeflenmesi gerekmektedir. Pankreas kanserinin tedavisinde sıklıkla kullanılan Gemsitabin kemoterapi ajanı, bir antimetabolit nükleosit analoğudur ve birçok solid tümörlü dokuda geniş bir spektrumda sitotoksik etkiye sahiptir. Gemsitabin?in kanda yarılanma süresi oldukça kısadır ve bu da biyoyararlanımının düşmesine neden olarak kullanımını sınırlamaktadır. Gemsitabin gibi düşük molekül ağırlığına sahip olan kanser ilaçlarının yüksek dozlarda kullanımı; vücutta kontrolsüz olarak dağılıma ve dolayısıyla hastalarda spesifik olmayan toksisiteye neden olmaktadır. Pankreatik duktal adenokarsinomu birçok kanser türüne göre yüksek stromal yapıya sahip olup, son yıllarda yapılan çalışmalar; kemoterapi ilaçlarına karşı kemorezistasın oluşmasından sorumlu tutulmaktadır. Bağ dokusu büyüme faktörü (Connective Tissue Growth Factor; CTGF), pankreas kanserinde tümör stromasının yoğun yapıda olmasında önemli ölçüde sorumludur, hücre göçünü ve hücre büyümesini modüle ederek fibroziste önemli bir rol oynar. Bu projede; Gemsitabin?nin in vivo stabilitesini ve biyoyararlanımını arttırmak için kitosan nanobaloncuk yapıları sentezlenmiştir. Gemsitabin HCl yüklü kitosan nanobaloncukları hedef dokuya yönlendirmek için nanobaloncukların yüzeyi Anti-CTGF ile konjuge edilmiştir. Hazırlanan nanobaloncukların yapısal ve morfolojik karakterizasyonları; FT-IR, parçacık büyüklüğü ve zeta potansiyeli ölçümü, Taramalı elektron mikroskobu (SEM) ve Geçirimli elektron mikroskobu (TEM) ile değerlendirilmiştir. Nanobaloncukların aynı zamanda enkapsülasyon verimleri ve ilaç yükleme kapasiteleri, in vitro Gemsitabin salım çalışmaları gerçekleştirilmiştir. İn vitro hücre kültürü deneyleriyle nanobaloncukların sitotoksisite testleri yapılmış olup, immün sistemi baskılanmış Nude farelerde pankreas kanser modeli oluşturularak etkinlikleri değerlendirilmiştir.
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    Aromatase expression in the cerebellum of the dog infected with canine distemper virus
    (Schluetersche Verlagsgesellschaft Mbh & Co Kg, 2010) Yarım, Murat; Gülbahar, Mustafa Yavuz; Güvenç, Tolga; Karahan, Siyami; Harada, Nobuhiro; Kabak, Yonca Betil; Karayiğit, Mehmet Önder
    Aromatase is the enzyme that catalyzes the biosynthesis of estrogens. It is implicated in neuroprotection. The present study investigated aromatase expression in the cerebellum of dogs infected with canine distemper virus (CDV), a disease characterized by demyelination in the white matter of the cerebellum. The presence of CDV infection was confirmed on the basis of histopathology and immunohistochemical localization of CDV antigen in glial cells of the white matter. The number of aromatase immunoreactive astrocytes were significantly (p < 0.05) higher in CDV-infected dogs compared to control dogs. The results suggest that astrocytes respond to invasion and persistence of CDV by means of increased estrogen production. The results also suggest that the high level of estrogen expression is maintained similarly throughout all stages of the disease since the number of aromatase immunoreactive astrocytes did not vary during the different stages of CDV infection.
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    Autologous stem cell-derived chondrocyte implantation with bio-targeted microspheres for the treatment of osteochondral defects
    (Bmc, 2019) Bozkurt, Murat; Asik, Mehmet Dogan; Gursoy, Safa; Turk, Mustafa; Karahan, Siyami; Gumuskaya, Berrak; Dogan, Metin
    Background Chondral injury is a common problem around the world. Currently, there are several treatment strategies for these types of injuries. The possible complications and problems associated with conventional techniques lead us to investigate a minimally invasive and biotechnological alternative treatment. Combining tissue-engineering and microencapsulation technologies provide new direction for the development of biotechnological solutions. The aim of this study is to develop a minimal invasive tissue-engineering approach, using bio-targeted microspheres including autologous cells, for the treatment of the cartilage lesions. Method In this study, a total of 28 sheeps of Akkaraman breed were randomly assigned to one of the following groups: control (group 1), microfracture (group 2), scaffold (group 3), and microsphere (group 4). Microspheres and scaffold group animals underwent adipose tissue collection prior to the treatment surgery. Mesenchymal cells collected from adipose tissue were differentiated into chondrocytes and encapsulated with scaffolds and microspheres. Osteochondral damage was conducted in the right knee joint of the sheep to create an animal model and all animals treated according to study groups. Results Both macroscopic and radiologic examination showed that groups 3 and 4 have resulted better compared to the control and microfracture groups. Moreover, histologic assessments indicate hyaline-like cartilage formations in groups 3 and 4. Conclusion In conclusion, we believe that the bio-targeted microspheres can be a more effective, easier, and safer approach for cartilage tissue engineering compared to previous alternatives.
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    Bilayer wound dressing composed of asymmetric polycaprolactone membrane and chitosan-carrageenan hydrogel incorporating storax balsam
    (Elsevier, 2024) Nakipoglu, Mustafa; Özkabadayı, Yasin; Karahan, Siyami; Tezcaner, Ayşen
    A comprehensive approach is needed to develop multifunctional wound dressing that is simple yet efficient. In this work, Liquidambar orientalis Mill. storax loaded hydroxyethyl chitosan (HECS)-carrageenan (kC) based hydrogel (HECS-kC) and polydopamine coated asymmetric polycaprolactone membrane (PCL-DOP) were used to develop a multifunctional and modular bilayer wound dressing. Asymmetric PCL-DOP membrane was prepared by non-solvent induced phase separation (NIPS) followed by polydopamine coating and demonstrated an excellent barrier against bacteria while allowing permeability for 5.45 ppm dissolved-oxygen and 2130 g/m2 water vapor transmission in 24 h in addition to 805 kPa tensile strength. Storax loaded HECS-kC hydrogel, on the other hand, demonstrated a pH-responsive degradation and swelling to provide necessary conditions to facilitate wound healing. The hydrogels showed stretchability above 140 %, mild adhesive strength on sheep skin and PCLDOP membrane, while the storax incorporation enhanced antibacterial and antioxidant activity. Furthermore, rat full-thickness skin defect model showed that the developed bilayer wound dressing could significantly facilitate wound healing compared to TegadermTM and control groups. This study shows that the bilayered wound dressing has the potential to be used as a simple and effective wound care system.
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    Cerebellum progesterone concentration decreased in canine distemper virus infection
    (Elsevier Sci Ltd, 2007) Yarim, Gül Fatma; Karahan, Siyami; Yarim, Murat
    Progesterone has neuroprotective effects including augmentation of myelination in the central and peripheral nervous system. This study was designed to determine if demyelinating lesions in the cerebellum resulting from canine distemper virus (CDV) infection are associated with progesterone levels. Progesterone was measured using radioinummoassay in samples of the cerebellum, corpus callosum, medulla oblongata, parietal, frontal, temporal, and occipital cortices as well as cerebrospinal fluid (CSF) and plasma collected from ten CDV infected and six non-infected dogs. The cerebellum progesterone level was significantly different between CDV infected (0.66 +/- 0.09 ng/g) and control dogs (1.14 +/- 0.09 ng/g) (p < 0.001); however, no difference was observed for the other CNS regions, plasma and CSF (p > 0.05). The cerebellum progesterone level was also significantly different between acute (0.71 +/- 0.05 ng/g) and chronic cases (0.61 +/- 0.09 ng/g) (p < 0.05). The CDV infected cerebella were also categorized histopathologically according to the severity of demyelinating lesions as mild (n = 5), moderate (n = 2), or severe (n = 3) among which the cerebellum progesterone level was significantly different (p < 0.05). Progesterone concentration was 0.71 +/- 0.05 ng/g in mild, 0.65 +/- 0.10 ng/g in moderate, and 0.56 +/- 0.07 ng/g in severe cases. In conclusion, progesterone concentration decreases in the cerebellum in CDV infection and the severity of demyelinating lesions is the greatest in cerebella with the lowest progesterone concentrations. The results suggest that local impairment of progesterone metabolism may be associated with the initiation and progression of cerebellar lesions in CDV infection. (c) 2006 Elsevier Ltd. All rights reserved.
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    Characterization and Evaluation of Triamcinolone, Raloxifene, and Their Dual-Loaded Microspheres as Prospective Local Treatment System in Rheumatic Rat Joints
    (Elsevier Science Inc, 2014) Ocal, Yigit; Kurum, Baris; Karahan, Siyami; Tezcaner, Aysen; Ozen, Seza; Keskin, Dilek
    In this study, injectable microspheres were developed for the local treatment of joint degeneration in rheumatoid arthritis (RA). Microspheres loaded with triamcinolone (TA), a corticosteroid drug, and/or raloxifene (Ral), a cartilage regenerative drug, were prepared with a biodegradable and biocompatible polymer, polycaprolactone (PCL). Microspheres were optimized for particle size, structural properties, drug release, and loading properties. In vitro release of Ral was very slow because of the low solubility of the drug and hydrophobic nature of PCL. However, when coloaded with TA, both drugs were released at higher amounts compared with their single forms. Smallest particle sizes were obtained in dual drug-loaded microspheres. In vitro cytotoxicity tests showed biocompatibility of microspheres. In vivo bioefficacy of these microspheres was also examined in adjuvant-induced arthritis model in rats. In vivo histological studies of control groups showed development of RA with high median lesion score (5.0). Compared with control and intra-articular free drug injections, microsphere treatment groups showed lower lesion scores and better healing outcomes in histological evaluations. Results suggest that a controlled delivery system of TA and RAL by a single injection in inflamed joints holds promise for healing and suppressing inflammation. (c) 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:2396-2405, 2014
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    Characterization of chondrocytes cultured on catechin-loaded alginate-chitosan scaffolds
    (Informa Healthcare, 2013) Turk, Mustafa; Karahan, Siyami; Cinar, Miyase; Kucuk, Sebnem; Dincel, Gungor Cagdas
    Bovine chondrocytes were seeded into scaffolds of a high molecular weight chitosan and alginate with a pore size of 50-350 mu m with or without catechin. In polymerase chain reaction (PCR), unlike type II, collagen type I was no longer expressed at day 14. The DNA content increased until day 8 and began declining, indicating cell detachment. The GAG content increased during the first 12 days. The percentage of round and collagen type II immunoreactive cells increased over the time. Catechin has some protective properties on chondrocytes seeded on the alginate-chitosan scaffolds during the first 12 days by means of DNA and chondrocyte morphology (p < 0.05).
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    Choroid epithelial cells: Source cerebrospinal fluid progesterone in sheep?
    (2007) Karahan, Siyami; Yarım, Gül F.; Yarım, Murat
    The present study was conducted to immunolocalize 3?-hydroxysteroid dehydrogenase (3?-HSD), an enzyme metabolizing pregnenolone to progesterone in the choroid plexus of the lateral ventricle in sheep, as well as to measure progesterone concentration in cerebrospinal fluid (CSF) and plasma using radioimmunoassay (RIA). Akkaraman breed rams (n = 16) and ewes (n = 16) were utilized in the study. 3?-HSD was immunolocalized in choroid epithelial cells of the choroid plexus with an apparent cytoplasmic immunoreactivity. Progesterone was detected in CSF with no significant differences between the ewes (0.76 ± 0.14 ng/mL) and rams (0.74 ± 0.13 ng/mL) (p > 0.05). However, the plasma progesterone concentration in the ewes (0.27 ± 0.04 ng/mL) was significantly higher than that of the rams (0.11 ± 0.02 ng/mL) (p < 0.001). Consequently, CSF in sheep contains progesterone in significant levels. As evidenced by 3?-HSD immunoreactivity, choroid epithelial cells may be a site of progesterone synthesis in sheep.
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    Comparison of a manual walking platform and the CatWalk gait analysis system in a rat osteoarthritis model
    (Wroclaw Medical Univ, 2021) Kara, Halil; Caglar, Ceyhun; Asilturk, Mehmet; Karahan, Siyami; Ugurlu, Mahmut
    Background. Effects of osteoarthritis (OA) are observed in experimental animal models using different gait analysis systems. Objectives. The aim of this study was to determine whether the Noldus CatWalk XT v. 10.9 gait analysis sys-tem (CatWalk) device can be used effectively in a chemically induced rat OA model and to reveal the strengths and weaknesses of the system compared to manual gait analysis. Materials and methods. Ten Wistar rats were run on a manual walking platform as well as on the CatWalk and the basal values were recorded. For OA induction, monosodium iodoacetate (MIA) was injected into the left knee of all rats under anesthesia. After a period of 4 weeks for OA development, the rats were again run on both the manual and CatWalk gait platforms. For manual gait analysis, the stride length, paw print width and paw print length were measured on both knees. In addition to these parameters, the average run speed, run duration, maximum contact intensity, paw print area, mean stance, and swing speed were measured on the left knee (affected knee) using the CatWalk device. Results. Significant differences were observed in the stride width (p = 0.0272), left stride length (p = 0.0344), and left paw print length (p = 0.0233) recorded before and after OA via the manual walking platform. For CatWalk, a significant difference was detected in the left knee's average run speed (p = 0.0010), maximum contact intensity (p = 0.0155), paw print length (p = 0.0058), paw print width (p = 0.0324), and swing speed (p = 0.0066) based on data obtained before and after OA. Conclusions. The CatWalk gait analysis system is suitable for the evaluation of OA rat models and related interventions. It also provides additional parameters compared to the manual system and minimizes human-related variation.
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    Contribution of amniotic membrane to the healing of iatrogenic vas deferens injury
    (Tubitak Scientific & Technological Research Council Turkey, 2021) Demir, Sabri; Erturk, Ahmet; Zengin, Mehmet; Yildiz, Dincer; Karahan, Siyami; Senel, Emrah
    Background/aim: Iatrogenic vas deferens injury is one of the most serious complications of operations in the inguinal region. Vasovasostomy is performed as treatment. However, stenosis is common after vasovasostomy. Oligospermia or azoospermia may develop and result in infertility. This study aimed to investigate the effect of amniotic membrane on healing in vas deferens injuries. Materials and methods: Four groups consisting of 10 rats each were formed. No procedure was performed in Group-I. In Group -II, the left vas deferens was transected and left to spontaneous healing. In Group-III, the left vas deferens was transected, and end -to-end anastomosis was performed. In Group-IV, the left vas deferens was transected, end-to-end anastomosis was performed, and it was closed with a wrapping of amniotic membrane on the anastomosis line. Rats were sacrificed after 60 days, and each left vas deferens was evaluated. Lumen patency was checked by passing methylene blue through the vas deferens. Subsequently, the vas deferens was evaluated both macroscopically and histopathologically. Data were evaluated using SPSS version 21.0. p < 0.05 was considered statistically significant for all variables. Results: The anastomosis lines in Group-IV healed better than those in Group-III, and less stenosis was observed. There were differences between the groups in terms of luminal patency (p = 0.009), adhesions to surrounding tissues (p = 0.02) and separation of the ends of the vas deferens (p = 0.03). Conclusion: We observed improvement on luminal patency and histology of rat vas deferens injury after surrounding human amniotic membrane on the transected and repaired surface. Further studies are needed to apply this promising result on human beings.
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    Determination of antioxidants in bovine oviduct epithelial cell culture isolated at different periods of the estrous cycle
    (Scientific Technical Research Council Turkey-Tubitak, 2019) Kurum, Aytul; Karahan, Siyami; Kocamis, Hakan; Cinar, Miyase; Ergun, Emel
    Oxidative stress interferes with oviduct functions including oocyte maturation, capacitation, fertilization, and embryo and gamete transport. This study aimed to determine activity of the antioxidants glutathione peroxidase (GPX-I), superoxide dismutase (SOD), and catalase (CAT) in bovine oviduct epithelial cells (BOEC) isolated from the isthmus and ampulla of the oviduct at estral (n = 7) and luteal phases (n = 7) of the estrous cycle. The antioxidant activity was measured at the primary, first, and second passages of the cell culture, and was characterized by cytokeratin expression. The GPX activity increased over the passages in samples of the ampulla and the isthmus of each sexual phase without statistical significance. The SOD activity remained steady through the cell passages in both sexual phases. CAT activity at the primary culture was higher in the ampulla compared to the isthmus in both sexual phases with a significant difference for the estral phase (P < 0.05), and it decreased over the passages with no significant differences. In conclusion, the antioxidant enzyme activity profile of BOEC did not differ by region or sexual cycle except for that of CAT, which was higher in the ampulla. Further studies should focus on SOD, GPX, and CAT activity for the mechanism of BOEC adaptation to an in vitro environment.
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    Effects Of Ankaferd Blood Stopper-Reinforced Platelet-Rich Fibrin Membrane On Guided Tissue Regeneration In Experimental Bone Defects
    (2019) Özer, Taha; Aktaş, Alper; Karahan, Siyami
    Background and Aim: To evaluate the effects of AnkaferdBlood Stopper added platelet-rich fibrin administered incranial bone defects created in rabbits via histomorphometricassessment.Materials and Method: Four circular 5 mm defects werecreated in the crania of 16 New Zealand rabbits. Each defect ineach animal received one of four treatments: no treatment (ECgroup), platelet-rich fibrin administration (PRF group), AnkaferdBlood Stopper added platelet-rich fibrin administration(PRF ABS group) and collagen membrane administration (CMgroup). Histomorphometric assessment was conducted at 4and 8 weeks after surgery.Results: Between-group comparisons of the new bone arearevealed significant differences between the PRF ABS groupand the remaining three groups at 4 weeks. The new bonearea was significantly larger at 8 weeks than at 4 weeks in allgroups.Conclusion: The use of Ankaferd Blood Stopper in conjunctionwith platelet-rich fibrin improves bone healing, strengthens themembrane property of platelet-rich fibrin and promotes betterossification.
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    Effects of Local Low-Dose Alendronate Injections Into the Distraction Gap on New Bone Formation and Distraction Rate on Distraction Osteogenesis
    (Lippincott Williams & Wilkins, 2017) Alp, Yunus Emre; Taskaldiran, Alper; Onder, Mustafa Ercument; Karahan, Siyami; Kocyigit, Ismail Doruk; Atil, Fethi; Tekin, Umut
    Bisphosphonates that constrain bone resorption have a direct effect on osteoclast function. In this experimental study, the effects of low-dose local alendronate injections on the distraction gap (DG) in rabbit mandible at 2 different rates were evaluated. The experimental study was conducted on 20 male, New Zealand white rabbits. The animals were divided into 3 experimental groups and 1 control group. Group 1 consisted of animals with distraction at the rate of 1 mm/day, receiving postoperative local low-dose alendronate local injections into the DG. Group 2 consisted of animals with distraction at the rate of 2 mm/day, receiving postoperative 0.75 mu g/kg of alendronate local injections into the DG. Group 3 consisted of animals with distraction at the rate of 2 mm/day, receiving postoperative 0.2 mL local saline injections into the DG. Group 4 consisted of animals with distraction at the rate of 1 mm/day, receiving postoperative 0.2 mL local saline injections into the DG. All the injections were performed immediately postoperatively and for all groups at 1, 2, 3, and 4 weeks following surgery. The distraction zones were evaluated using dual-energy X-ray absorptiometry and histological analysis. Histologically, bone healing was found to be significantly accelerated in Groups 1 and 4 compared with Groups 2 and 3 (P<0.05). Bone healing was superior in Group 1 and the difference was statistically significant compared with Group 4. There was a significant increase in mean bone mineral density in the 1 mm daily rate groups (Groups 1 and 4) compared with the 2 mm daily rate groups (Groups 2 and 3) (P<0.05). Local low-dose alendronate injections could be an effective way for improving bone formation in distraction osteogenesis. Furthermore, the results of this study did not support the hypothesis that injections of local low-dose alendronate may allow 2 mm/day instead of 1 mm/day of elongation in the rabbit mandible.
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    Effects of water quality and fish size on toxicity of methiocarb, a carbamate pesticide, to rainbow trout
    (Elsevier, 2006) Altınok, İlhan; Çapkın, Erol; Karahan, Siyami; Boran, Muhammet
    The acute toxicity of methiocarb in juvenile rainbow trout (Oncorhynchus mykiss, 3.25 +/- 0.79 g) was evaluated in glass aquaria under static conditions. Nominal concentrations of methiocarb in the toxicity test ranged from 1.25 to 7.50 mg L-1. The concentrations of methiocarb that killed 50% of the rainbow trout within 24-h (24-h LC50), 48-h LC50, 72-h LC50, and 96-h LC50 were 5.43 +/- 0.19, 5.04 +/- 0.18, 4.95 +/- 0.19, and 4.82 +/- 0.21 mg L-1 (95% confidence limits), respectively. Mortality of fish increased with increasing water temperature. Increasing alkalinity from 19 mg L-1 as CaCO3 to 40, 60, or 90 mg L-1 as CaCO3 significantly decreased mortality of fish. Total hardness ranging from 50 mg L-1 as CaCO3 to 147 mg L-1 as CaCO3 did not affect mortality of fish exposed to methiocarb. Fish exposed to methiocarb had histological alterations such as lamellar edema, separation of epidermis from lamellae, and lamellar fusion. Methiocarb exposed fish had necrosis between molecular and granular layer of cerebellum where Purkinje cells present. Results indicate that alkalinity, temperature, and fish size affect methiocarb toxicity of rainbow trout. (c) 2005 Elsevier B.V. All rights reserved.
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    Elektroeğirme Yöntemiyle Üretilmiş ve Biyouyumluluğu İyileştirilmiş Nanofiberlerin Menisküs Tedavisinde Uygulama Potansiyeli
    (2018) Karahan, Siyami; Garipcan, Bora; Kürüm, Aytül; Kürüm, Barış; Türk, Mustafa; Uğurlu, Mahmut
    Bu çalısmanın amacı; biyouyumlulugu iyilestirilmis nanofiberlerin sentezlenmesi ve mezensimal kök hücre ekerek bu nanofiberlerin kondrojenik potansiyele etkisinin ve mesensimal kök hücreli veya hücresiz menisküs doku mühendisliginde kullanım potansiyelinin in vitro ve in vivo olarak arastırılmasıdır. Amino asit ilavesi ve antikor immobilizasyonu yapılarak PHEMA (poli(2-Hidroksietil metakrilat)?dan elektroegirme ile 190 ile 390 nm çaplarında nanofiberler üretilerek karakterize edildi. Nanofiberde kültüre edilmek üzere yag dokudan mezenkimal kök hücre izole edildi. Elde edilen hücrelerin % 36,6?sının kök hücre oldugu flow sitometri ile belirlendi. Ikili boyama ve Annexin- V ile yapılan degerlendirmede; nanofibere ekilen hücrelerin 5. günde canlılık oranı sırasıyla % 75,54 ve % 72 bulundu. Ayrıca 5. gün metabolik aktiviteleri Alamar Blue ile ölçüldü ve redüksiyon oranı % 74,93 bulundu. GAG/ DNA oranı belirlendi ve oranın 10. gününde en yüksek degerde oldugu görüldü. ELISA ile ölçülen COMP konsantrasyonun nanofibere ekimi müteakip 10. günde artıs kaydettigi tespit edildi. Real Time PCR?de Tip-I kollagen, Tip-II kollagen, Sox-9 ve Aggrecan sentezine bakıldı. Iki boyutlu hücre kültürüne nazaran nanofibere ekilen hücrelerdeki sentezin kısmen daha fazla oldugu belirlendi. In vivo mezensimal kök hücrelerin takibi amacıyla Green Floresan Protein (GFP) geni transfeksiyonu yapıldı ve semikantitatif olarak transfenksiyon oranı % 45 ± 10,41 bulundu. Transfekte hücreler nanofibere ekilerek hayvan deneylerinde kullanıldı. Hayvan deneylerinin sonunda menisküs histolojik ve immünohistokimyasal (tip I ve tip II kollagen) olarak degerlendirildi. Mezensimal Kök hücre tasıyan ve tasımayan nanofiber uygulanmıs olan menisküslerde hasarlı bölgede gelisen dokularda fokal olarak kondrosit morfolojisi tasıyan hücrelere ve kıkırdak matriksi özelligi gösteren yapılara rastlandı. Buna ragmen, in vitro çalısmalardaki tatmin edici sonuçlar, yapılan histolojik ve immünohistokimyasal çalısmaların istatistiksel degerlendirmelerine yansımadı. Sonuç olarak; elektroegirme yöntemiyle elde edilmis pHEMA nanofiberlerin kondrojenik ve menisküs doku mühendisliginde kullanım potansiyeli in vitro olarak gösterilmistir. Kondrojenik potansiyele dair histolojik ve immünohistokimyasal isaretler olmasına ragmen mezensimal kök hücre ekilmis ve ekilmemis nanofiberler in vivo çalısmada bu potansiyeli yeterine gösterememistir.
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    Evaluation of Burn Wound Healing Efficacy and Biocompatibility of Centella asiatica Mediated Synthesised AgNPs Loaded Hybrid Nanofiber Scaffold: In Vitro and In Vivo Studies
    (Wiley-V C H Verlag Gmbh, 2024) Bozkaya, Ogun; Bozkaya, Esra; Ekici, Husamettin; Alcigir, Mehmet Eray; Sahin, Yasar; Cerci, Nebahat Aytuna; Karahan, Siyami
    The aim of this study is to evaluate the cell responses, potential skin reactions during the treatment process and burn wound healing efficacy of electrospun polycaprolactone/polyethylene oxide (PCL/PEO) nanofibers (NFs) containing Centella asiatica mediated synthesized silver nanoparticles (CA-AgNPs) by in vitro and in vivo studies. Apoptosis-necrosis, genotoxicity, hemolysis, and cell attachment studies are carried out within the scope of in vitro tests, and irritation, sensitivity, and burn wound studies are carried out within the scope of in vivo tests. The apoptotic index value of CA-AgNPs-[PCL/PEO] NFs material on L929 fibroblast cells is determined as 5.0 +/- 1.0% at the highest concentration and the necrotic index value is 5.0 +/- 0.3%. Micronucleus rates (%) of NFs treated with CHO (Chinese Hamster Ovary) cells are not at genotoxic level. The hemolytic index value of NFs dressing is determined as 0.23 +/- 0.03%, The primary irritation index (PII) value of NFs wound dressing is calculated as 0.36 by irritation tests. In addition, the potential sensitization reaction of NFs extract on guinea pigs is evaluated and the sensitization score is determined as 0.9. The healing efficacy of NFs material on second-degree burn wounds compared to a commercial product is supported by pathomorphological findings.
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    Evaluation of melamine and cyanuric acid cytotoxicity: an in vitro study on L929 fibroblasts and CHO cell line
    (ANKARA UNIV PRESS, 2020) Melekoglu, Abdullah; Ekici, Husamettin; Arat, Esra; Karahan, Siyami
    Melamine and its metabolites pose health concern as they are used in various industrial products including feed and drugs. There are a limited number of studies on melamine and cyanuric acid cytotoxicity and cellular damage without a certain conclusion. The present study aimed to evaluate melamine, cyanuric acid and its combined cytotoxic effects using 3-(4.5-dimethylthiazol-2-yl) methyl thiazole tetrazolium (MTT) bromide test. The study also evaluated apoptotic and necrotic effect using a double staining method of Hoechst 33342 and propidium iodide. Melamine, cyanuric acid and their combination (1:1) were applied to L929 fibroblasts and Chinese hamster ovary (CHO) cells at various concentrations (1000 mu g/mL, 500 mu g/mL, 250 mu g/mL, 125 mu g/mL and 62.5 mu g/mL). At the highest concentration (1000 mu g/mL), the cell viability dropped down approximately to 50% both in CHO cells and L929 cells. Melamine, cyanuric acid and their mixture caused cytotoxicity in CHO cells and L929 fibroblasts in dose-dependent manner Cell death occurred through both apoptosis and mainly necrosis. Both cell types were more sensitive to the mixture of melamine and cyanuric acid and, furthermore, CHO cells were more sensitive than L929 fibroblasts. As a result, melamine, cyanuric acid and their combination caused cytotoxicity in CHO cells and L929 fibroblasts. Further studies should be conducted in different cell lines. These studies should also aim to reveal the mechanism of cytotoxicity and related pathways.