144 research outputs found
Intramedullary Implants Coated With Cubic Boron Nitride Enhance Bone Fracture Healing in a Rat Model
No full textTanoglu, Oguzhan/0000-0001-8984-9008; ocak, mert/0000-0001-6832-6208; kaymaz, fevziye figen/0000-0001-8896-2471; Koca, Gokhan/0000-0003-2842-9223; OZMERIC, AHMET/0000-0001-5398-446X; Senes, Mehmet/0000-0002-7924-5478Background: Boron nitride is a biocompatible and an osteo-inductive material for orthopedic applications. The aim of this study was to evaluate the effects of two different allotrope boron nitride coated implants, cubic boron nitride and hexagonal boron nitride, on fracture healing. Methods: In this experimental study, a total of 24 rats were divided into three groups. Group A was the control group with Kirschner wire without coating, while the wires were coated dominantly by cubic boron nitride in Group B and hexagonal boron nitride in Group C. Then a mid-third femoral fracture was created. The fracture healing was examined in terms of new bone formation with micro-CT analysis and histopathological examination, quantitative measurement of bone turnover metabolites and scintigraphic examination of osteoblastic activity on 28th day post fracture. Results: Micro-CT measurement results revealed a statistically significant increase in bone volume/tissue volume ratio and bone surface values in group B compared to group A. Cortex diameter and osteoblast counts were statistically higher in group B compared to group A. Inflammatory response was increased in group C compared to groups A and B. Biochemical test results showed significantly increased alkaline phosphatase levels and decreased osteocalcin levels in group B compared to group A. The increase in serum phosphorus and decrease in serum calcium levels was statistically significant in group C compared to Group A. Conclusion: Both types of boron nitride coating had superior fracture healing features compared to control group. Therefore, c-BN coating can accelerate the fracture healing and could lead to shorten of union time.Ankara Research and Training HospitalWe would like to thank to Ankara Research and Training Hospital for the funding of this research. The authors would like to thank to the BOREN Center of Competence for Boron Coatings at the Metal Forming Center of Excellence in Atihm University, Ankara, TURKEY, for the use of facilities for boron nitride coatings on the Kirschner wires. BOREN Center of Competence for Boron Coatings have developed coating techniques for Boron Nitride in different proportions
Evaluation Of Ultrastructural Changes In The Rat Ovary After Internal Iliac Artery Ligation
No full textGestasyonel Diyabetli Gebe Plasentalarında Aqp8 ve Aqp9 Dağılımlarının İncelenmesi
No full textDuring pregnancy, fetal water requirements increase markedly due to the exponential growth of fetus. Physiological data indicate that both a transcellular and a paracellular pathway are available for water transport across the human placenta. Transcellular water flux may be facililated by aquaporins (AQPs), a family of small integral membrane proteins. Aquaporins transport either water alone or water and small solutes such as gliserol.
In mammals, there are at least 13 AQPs, which show a wide range distribution in organs that are actively involved in water transport. AQP9 is a member of aquaglyseroporin subfamily of AQPs and share the highest amino acid sequence homology with AQP3, AQP7 and AQP10. In addition to water, AQP9 transports small uncharged molecules like glycerol, urea, purines and pyrimidines.
It is generally accepted that in addition to stimulating glucose transport, binding of insulin to cell surface receptors alters the expression of numerous genes in a variety of tissues. In placental trophoblastic cells, insulin has no stimulatory effect on glucose uptake or glycogen synthesis, but it is involved in the synthesis of human placental lactogen (hPL) and hCG and the regulation of 3ß-hydroxysteroid dehidrogenase.
In literature, the relationship of AQP9 and insulin has been investigated. It has been reported that insulin decreased the molecular expression of AQP9 exclusively in explant from normal placentas in a concentration-dependent manner. TNF-alfa is an antiinflamatory cytokine. It is one of the reason of insulin resistance in the pregnancy. Treatment with TNF-alfa previous to insulin addition in normal placental explants, prevent the changes in AQP9 expression.
Gestational diabetes mellitus (GDM) is a pregnancy releated metabolic disorder and it is characterized by impaired glucose tolerance. GDM is the most common metabolic disorder in the pregnancy. Pathology in the GDM can occurs because of different etiological reasons which cause the deficiency or peripheric resistance of insulin.
The objective of this study is to evaluate the expression of AQP8 and AQP9 in placentas with GDM. Samples from normal and gestational diabetic placentas which is regulated with diet or insulin were studied by immunohistochemical staining. Specific anti- AQP8 and anti-AQP9 antibody was used for cellular localization of the molecules.
In comparison to the other groups, AQP8 expression of mesenchymal cells in villi and Hofbauer cells were significantly decreased in the insulin regulated GDM group. In diet regulated GDM group, fetal capillary endothelial cells; there was a significant descrease in the AQP8 expression compared with the other groups. AQP9 expression of mesenchymal cells in villi in control group was lower in comparison to the other groups.
In syncytiotrophoblast cell layer, AQP8 and AQP9 immunoreactivitiy shows similar expression patterns when we compared the groups with each other. Our results support the data that ‘insulin descreased the molecular expression of AQP9 in placental explants’ .Gebelik boyunca fetusun büyümesiyle fetal su ihtiyacı belirgin olarak artar. Fizyolojik veriler suyun plasentadan geçişi için hem transsellüler hem de parasellüler yolun mümkün olduğunu belirtmektedir. Transsellüler yolun küçük integral membran proteinleri olan akuaporinler (AQP) aracılığıyla gerçekleştiği düşünülmektedir. Bu proteinler hem suya hem de gliserol gibi küçük eriyiklere geçirgen olabilirler.
Memeli dokusunda, organlarda geniş bir dağılım aralığı gösteren ve su transportunda aktif olarak rol oynayan 13 tane AQP bulunmuştur. AQP9 aquagliseroporin alt ailesinin bir üyesidir ve AQP3-7-8-10 ile en yüksek aminoasit sekansı homolojisini göstermektedir ve su geçirgenliğinin yanında gliserol, üre, pürin ve pirimidin gibi yüklü olmayan küçük moleküllere de geçirgendir.
İnsülin hormonunun, glukoz transportunu stimüle etmek dışında hücre yüzeyine bağlandığında birçok genin ekspresyonunu değiştirdiği bilinmektedir. Plasenta ve trofoblastik dokularda insülinin hücrelere glukoz alımını ya da glikojen sentezini stimüle etmek gibi bir etkisi yoktur. Buna karşılık insülinin plasentada hPL (human plasental lactogen) ve HCG (human chorionic gonadotropin) hormonlarının sentezini arttırdığı ve 3ß-OH steroid dehidrogenaz enzim regülasyonunda görev aldığı bilinmektedir
Akuaporin-insülin ilişkisi de araştırılmış, insülinin normal plasental eksplant kültürlerinde AQP9 ekspresyonunu azalttığı, ancak insulin rezistansı oluşturduğu bilinen bir molekül olan TNF-alfa uygulanmasından sonra bu etkinin ortadan kalktığı bildirilmiştir.
Gestasyonel Diyabetes Mellitus, Gebelikte ortaya çıkan ya da gebelikte fark edilen glukoz toleransının bozulması olarak tanımlanmıştır. Gebelikte en sık görülen metabolik bozukluktur. Hastalıkta patoloji; farklı etyolojik sebeplerden dolayı insülin hormonunun eksikliği ya da periferik rezistansından dolayı meydana gelir. Bu çalışma, AQP8 ve AQP9 ‘un GDM’li plasentalardaki immunohistokimyasal dağılımını incelemek amacıyla gerçekleştirildi.
Çalışmada; normal, insülinle regüle GDM’li ve diyetle regüle GDM’li hastalardan gruplar oluşturuldu ve villus yapısında bulunan hücreler AQP8 ve AQP9 ekspresyonu yönünden incelendi. Çalışmada toplanan doku örnekleri 38.-40. Gebelik haftasında doğum yapan bireylerden elde edildi.
Insulinle regüle GDM grubunun Hofbauer hücrelerinde ve villus içi bağ dokusu hücrelerinde AQP8 immunoreaktivitesi diğer gruplara gore daha zayıftı. Fetal kapiller endotel hücreleri ise diyetle regüle GDM grubunda daha zayıf bir immünoreaktiviteye sahipti. Kontrol grubunda AQP9 ekspresyonu villus içi bağ dokusu hücrelerinde diğer gruplara gore daha zayıftı. Sinsityotrofoblast hücreleri ise tüm gruplarda AQP8 ve AQP9 ekspresyonu açısından benzer özellikteydiler.
Çalışmamızda diyetle regüle ya da insulinle regüle GDM hastalarının sinsityotrofoblast tabakasında AQP8 ve AQP9 ekspresyonu, kontrol gruplarından farklı bir dağılım göstermemiştir. İnsulinin sinsityotrofoblast hücre tabakasında AQP9 ekspresyonunu azalttığı bilgisi göz önüne alındığında, çalışmamızda kullandığımız gestasyonel diyabeti olan ve kan glukoz seviyeleri diyetle ya da insülinle regüle edilmiş dolayısıyla insülin rezistansının da kırılmış olduğu kabul edilen hastalarda AQP’lerin immünohistokimyasal ifadelerinin kontrol grubuyla benzer özellik göstermesi beklenmelidir ki sonuçlarımız da bu yöndedir
Histology Laboratory Guide Book
No full textHistology and Embryology education and research are fundamental cornerstones of medical
science. Histology, which is the basis of many fields of preclinical and clinical medicine,
defines the visual components of cells, tissues and organs at the microscope level.
This book, which we have published in the third extended version, provides students with a
selection of micrographs created from archive preparations that Hacettepe University Faculty
of Medicine Department of Histology and Embryology has been carefully created for more
than 50 years. This selection has been prepared with the common effort of our academic staff,
research assistants and technicians. The purpose of the book is to guide medical and health
sciences students while examining the original preparations under the microscope in the
laboratory, to match the functional properties associated with the structure of healthy cells
with histochemical staining properties. Each chapter in the book contains brief information
of micrographs on the basis of organs, tissues and cells under the relevant technical title.
In this edition; we would respectfully like to thank the founder of our department and the
first woman dean of medical school of our country, Prof. İlhan Kerse and, all of our retired
professors who greatly contributed to our education by showing us the way of science. We
also thank our former heads of department Prof. Ülken Örs, Prof. Esin Aşan, Prof. Ayşe Nur
Çakar, Prof. Attila Dağdeviren, Prof. Sevda Fatma Müftüoğlu and Prof. Fevziye Figen Kaymaz.
On behalf of our department, we wish all our students sincere success.Histoloji ve Embriyoloji, tıp biliminin vazgeçilmez temel taşlarından birisini
oluşturur. Tıbbın birçok preklinik ve klinik alanına esas oluşturan histoloji, hücre,
doku ve organların mikroskop düzeyinde görsel bileşenlerini tanımlar.
Beşinci genişletilmiş basımını yaptığımız bu kitap, Hacettepe Üniversitesi Tıp Fakültesi Histoloji
ve Embriyoloji Anabilim Dalı’nın 50 yılı aşkın süredir özenle oluşturduğu arşiv preparatlarından
derlenmiş mikrograf seçkisini öğrencilere sunmaktadır. Bu seçki, anabilim dalımız öğretim
üyeleri, araştırma görevlileri ve teknisyenlerinin ortak emeği ile hazırlanmıştır. Kitabın amacı;
tıp ve sağlık bilimleri öğrencilerine laboratuvarda bu preparatları mikroskop altında incelerken
rehberlik etmek, sağlıklı hücrelerin yapıları ile ilişkili işlevsel özelliklerini, histokimyasal boyanma
özellikleriyle eşleştirmelerini sağlamaktır. Kitaptaki her bölüm, ilgili teknik başlık ya da sisteme
ait preparat mikrografları hakkında organ, doku, hücre temelinde kısa bilgiler vermektedir.
Bu baskıda; anabilim dalımızın kurucusu ve ülkemizin ilk kadın tıp fakültesi dekanı Sn. Prof.
Dr. İlhan Kerse başta olmak üzere, bizlere bilimin yolunu göstererek yetişmemize katkıda
bulunan anabilim dalı başkanlarımız Sn. Prof. Dr. Ülken Örs, Sn. Prof. Dr. Esin Aşan, Sn. Prof.
Dr. Ayşe Nur Çakar, Sn. Prof. Dr. Attila Dağdeviren, Sn. Prof. Dr. Sevda Fatma Müftüoğlu,
Sn. Prof. Dr. Fevziye Figen Kaymaz’a ve tüm emekli hocalarımıza teşekkür ediyoruz.
Anabilim dalımız adına tüm öğrencilerimize içten başarı dileklerimizle
Comparison of collagen biomatrix and omentum effectiveness on peripheral nerve regeneration
No full textDespite the presence of various nerve coaptation materials and techniques, achievement of the functional nerve regeneration is still inadequate. This study was aimed to compare the effectiveness of conduit composed of collagen biomatrix and omentum graft on peripheral nerve regeneration. Thirty-five male Wistar rats were divided into four groups. In the control group, the right sciatic nerve was skeletonized from the sciatic notch till the point of bifurcation. In the primary epineural repair group, the nerve was transected 1 cm proximal to the bifurcation with a sharp pair of micro scissors and then repaired with four epineural sutures. In the collagen biomatrix group, the epineural repaired nerve was wrapped with collagen biomatrix. In the collagen group, the epineural repaired nerve was wrapped with the nonpediculated omentum. Assessment of the nerve regeneration was based on functional (Walking Track Analysis, Electrophysiological Measurements), histological, and morphometric criteria. Light and electron microscopic examinations showed that collagen-biomatrix-wrapped specimens have the best regeneration. The electrophysiological study confirmed the recovery of electrical activity in the regenerated axons
Daylight in Underground Architecture
No full textThe use of natural light in (underground) architecture is beneficial for both the human wellbeing as well as the quality of the architecture. However innovative systems are needed to bring natural daylight in underground spaces. The daylighting systems, which are classified as light guiding systems and light transporting systems have been reviewed and compared. The advantages and disadvantages of each system are summarized in order to be able to choose a system that fits within the architecture of the underground ‘building’
The Relationship of Clinicopathological Findings and PDGFR-β Expression With Tumor Recurrence in Gastrointestinal Stromal Tumors
No full textConsidering the difficulty in predicting the biological behavior of gastrointestinal stromal tumors (GISTs) based on histological findings alone, genetic abnormalities have recently become an area of focus. Platelet-derived growth factor receptor (PDGFR), with 2 isoforms (α and β) is one of the mutations that play a role in the development of GIST. There are very little data determining the relationship of GIST with PDGFRβ which is associated with poor prognosis in other mesenchymal and epithelial tumors. In this study, we aimed to show the relationship between clinicopathological criteria and recurrence. We also wanted to evaluate the effect of PDGFRβ expression on recurrence and clinicopathological findings.We evaluated 40 GIST patients retrospectively for detailed clinicopathological findings, postoperative immunohistochemical tumor markers (CD117, Ki67), and also for tumor recurrence. Immunohistochemical examination for PDGFRβ was performed for the all GIST cases.Tumor recurrence was related to male gender (P = .003), serosal localization (P = .004), surgical margins positivity (P = .001), risk group (P = .011), mitotic activity (P = .000), and Ki67 proliferation index (P = .000). PDGFRβ was not significantly associated with tumor recurrence (P = .277).We can say that the most important parameters related with recurrence of GISTs are mitotic activity and the Ki67 proliferation index. The determination of the cut-off value of the Ki67 proliferation index as 13% instead of 10% would be much more specific and sensitive. Although PDGFRβ may be used for the diagnosis of GIST as an alternative for PDGFRα in cases with cKIT negativity, it is not an indicator of tumor recurrence as in other tumors
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