Accumulation of α

Objective. The present study was conducted to evaluate the relationship between plasma oxidative stress markers such as malondialdehyde (MDA) and glutathione (GSH), inflammatory marker pentraxin-3 (PTX3), and cerebellar accumulation of α-synuclein in streptozotocin- (STZ-) induced diabetes model in rats. Methods. Twelve rats were included in the study. Diabetes (n=6) was induced with a single intraperitoneal injection of streptozotocin (STZ, 60 mg/kg). Diabetes was verified after 48 h by measuring blood glucose levels. Six rats served as controls. Following 8 weeks, rats were sacrificed for biochemical and immunohistochemical evaluation. Results. Plasma MDA levels were significantly higher in diabetic rats when compared with the control rats (p<0.01), while plasma GSH levels were lower in the diabetic group than in the control group (p<0.01). Also, plasma pentraxin-3 levels were statistically higher in diabetic rats than in the control rats (p<0.01). The analysis of cerebellar α-synuclein immunohistochemistry showed a significant increase in α-synuclein immunoexpression in the diabetic group compared to the control group (p<0.01). Conclusion. Due to increased inflammation and oxidative stress in the chronic period of hyperglycemia linked to diabetes, there may be α-synuclein accumulation in the cerebellum and the plasma PTX3 levels may be assessed as an important biomarker of this situation

The Preventive Effect of Oxytocin on Retinopathy in Streptozotocin- Induced Diabetic Rats

Objectives:The aim of this study was to investigate the impact of intravitreal and intraperitoneal use of oxytocin (OT) on retinopathy in streptozotocin-induced diabetic rats.Materials and Methods:Twenty-four 6-8-week-old adult male and female Sprague Dawley rats were used in the study. Diabetes was induced in the rats with a single injection of intraperitoneal streptozotocin. Diabetes was verified after 48 hours by measuring blood glucose levels of 260 mg/dl (14.4 mmol/L) or higher in diabetic rats. The rats were divided into 4 groups and treated as follows: intravitreal physiological saline group (0.01 mL saline weekly), intravitreal OT group (10 μU/μL OT weekly), intraperitoneal physiological saline group (1 mL daily), and intraperitoneal OT group (100 IU/kg OT daily). Hamilton syringes fitted with 27-gauge needles were used for intraperitoneal injections while 31-gauge needles were used for intravitreal injection. After 4 weeks of treatment the rats were euthanized to evaluate outer nuclear layer (ONL) thickness, vascular endothelial growth factor (VEGF) immunoexpression, and plasma VEGF levels from blood samples obtained by cardiac puncture.Results:Morphometric analysis of retinal cross-sections showed that intravitreal and intraperitoneal OT significantly increased ONL thickness compared to physiological saline-treated groups. Also, OT treatment significantly decreased VEGF protein expression compared with the physiological saline groups. Plasma VEGF level was significantly higher in the physiological saline treatment group compared to the OT treatment group.Conclusion:OT reduces diabetic retinopathy progression, particularly when administered intravitreally. To our knowledge, this is the first attempt to investigate the impact of OT on diabetic retinopathy and may provide a new area for further research

Contrubition of Laparoscopic Level Determination on Hirschsprung Disease Diagnosis and Management

Aim:Laparoscopic-assisted transanal pull-through (LATP) is a procedure that has gained increasing popularity in the management of Hirschsprung’s disease. The purpose of this study was to compare outcomes of patients treated with LATP and transanal pull-through (TPT).Methods:Records of 45 patients with Hirschsprung’s disease who underwent surgery between 2006 and 2017 were retrospectively evaluated.Results:LATP was performed in 16 patients [13 male (81%), three female (19%)]. The median age of the patients was four months (7 days-84 months). Twenty nine patients [21 male (72.4%), eight female (27.6%)] underwent TPT. The median age of the patients was 11 months (10 days-90 months). The mean time to start feeding in LATP and TPT groups was two days (one-three days) and 2.6 days, respectively (p=0.074). The mean operative time was 2.6 hours in the LATP group (two-four hours) and 2.7 hours in the TPT group (p=0.971). The mean length of hospital stay in for LATP and TPT groups was 4.8 days (two-nine days) and six days (3-14 days), respectively (p=0.305).Conclusion:The advantages of LATP include multiple sample collection from several segments of the colonn at the same time as well as shorter time to frozen section diagnosis. In addition, the possibility of intraabdominal dissection allows transanal surgery to be faster and more effective

Preliminary results of the Sofalaca-Şehitkamil Gaziantep (Mw:7.7) and Ekinözü Kahramanmaraş (Mw:7.6) earthquakes based on GNSS observations on February 6, 2023

Bu çalışmada 6 Şubat 2023 tarihinde sırasıyla yerel saat ile 04:17 ve 13:24’te artarda meydana gelen Sofalaca-Şehitkamil Gaziantep (Mw:7.7) ve Ekinözü Kahramanmaraş (Mw:7.6) depremlerinin öncül jeodezik sonuçları verilmiştir. Öncül jeodezik sonuçları elde etmek için deprem odak merkezleri etrafındaki ve etkili olduğu alandaki TUSAGA-Aktif istasyonlarına ait GNSS alıcılarından 30 sn (0,033 Hz) ve 1 sn’lik (1 Hz) GNSS gözlemleri kullanılmıştır. Deprem kaynaklı kosismik yer değiştirmeleri belirlemek için bağıl statik çözümler GAMIT/GLOBK yazılım takımında 30 sn’lik RINEX verileri kullanılarak yapılmıştır. Statik çözümlerde değerlendirmeye alınan istasyonlarda Sofalaca-Şehitkamil Gaziantep depreminde doğu bileşende atımın 1.1-23.4 cm, kuzey bileşende 1.1-30.9 cm aralığında değiştiği görülmüştür. Ekinözü Kahramanmaraş depreminde ise atım miktarı doğu bileşende 1.2-440.4 cm, kuzey bileşende 1.4-69.6 cm aralığında değişmiştir. Kinematik çözümler ise PPP yöntemiyle CSRS-PPP ve PRIDE PPP-AR yazılımları ile 1 sn’lik RINEX verileri kullanılarak elde edilmiştir. Her iki yazılımda seçilen istasyonlardaki deprem anı yer değiştirmeler (deplasman) ve ardışık epok farkları (hız) hesaplanmıştır. Seçilen tüm istasyonlarda hızlar Sofalaca-Şehitkamil Gaziantep depreminde doğu bileşen için 3-12.5 cm/sn, kuzey bileşen için 3.8 - 37.7 cm/sn aralığında; Ekinözü Kahramanmaraş depreminde ise doğu bileşende 3.7-20.5 cm/sn, kuzey bileşende 4.1-20.1 cm/sn tespit edilmiştir. Öncül sonuçların elde edilmesinden sonra bölgenin daha yakından takibi ve yeni noktalarda atımların tespiti için yeni bir GNSS ağı kurulmuştur. Kurulan yeni ağda TÜBİTAK 1002-C Doğal Afetler Odaklı Saha Çalışması Acil Destek Programı çağrısı kapsamında arazi çalışmalarına başlanmıştır.In this study, the earthquakes which took place on 6 February 2023, respectively at local time 04:17 and 13:24 preliminary geodetic results are given that occurred of Sofalaca-Şehitkamil (Gaziantep) (Mw:7.7) and of Ekinözü (Kahramanmaraş) (Mw: 7.6). In order to obtain preliminary geodetic results the GNSS observations were used at 30 s (0.033 Hz) and 1 s (1 Hz) intervals from the GNSS receivers in the network of Continuously Operating Reference Stations, Turkey (CORS-TR). Relative static solutions to determine earthquake-induced coseismic displacements were performed using 30-second RINEX data in the GAMIT/GLOBK software. In the GNSS stations evaluated in the static solutions, it was observed that the coseismic displacement in the Sofalaca-Şehitkamil Gaziantep earthquake varied between 1.1 - 23.4 cm in the eastern component and 1.1 - 30.9 cm and northern component. In the Ekinözü Kahramanmaraş earthquake, the amount of coseismic displacement varied between 1.2 - 440.4 cm in the eastern component and 1.4-69.6 cm in the northern component. Kinematic solutions were obtained by PPP method using CSRS-PPP and PRIDE PPP-AR software and 1 second RINEX data. In both software, earthquake displacements and consecutive epoch differences (velocity) at selected stations were calculated.During the Sofalaca Şehitkamil-Gaziantep earthquake velocities for all selected stations were detected approximately between 3.0-12.5 cm/s for the eastern component and 3.8 - 37.7 cm/sn for the northern component; during the Ekinözü Kahramanmaraş earthquake were detected approximately between 3.7-20.5 cm/sn for the eastern component and 4.1-20.1 cm/sn for the northern component. After the preliminary results were obtained, a new GNSS network was established to observation the region more closely and to detect displacement at new GNSS points. In study area has started new GNSS observations within the scope of TÜBİTAK 1002-C Natural Disasters Focused Field Study Emergency Support Program call in the new network established

Maternal retinol asetat (vitamin A) uygulanımı takiben yenidoğan rat hipokampus Ca1 bölgesinin ışık, elektron, immunohistokimyasal ve morfometrik yöntemlerle incelenmesi

Bu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır. Yayınlanma izni olmayan tezlerin basılı kopyalarına Üniversite kütüphaneniz aracılığıyla (TÜBESS üzerinden) erişebilirsiniz.SUMMARY In our study it was aimed to study the ultrastructural variatons caused by dose dependant teratogenic effect of maternally applied retinol acetate (Vit A) on central nerve system and especially on tissue of the hippocampus. After maternally application of single doses of 40000 IU/kg retinol acetate, 160000 IU/kg retinol acetate and %0.9 serum physiologic (control group) waited until the pregnancy was over. After the postnatal first day intracardiac perfusion process, the hippocampal CA1 tissues of newborn rats dissected and after their routine immunohistochemical follow-ups under a light microscope were done, the parts were examined by a light and transmission electron microscope ( TEM). For our immunohistochemical study it was worked with determinants called vimentin and neuron specific enolase. The following findings detected in control group; evident cell proliferation, euchromatic neuronal nucleus, nucleolus with evident and well arranged settlement, systematic cell membrane, structure of systematic nuclear nembrane, sound mitochondrial structure. In addition, while transverse cross- sections belong to axon and dendrite were being reviewed, in the groups retinol icetate was applied an increasing neurotoxicity in parallel with dose elavation was found, which was significantly different from control group. The following findings were detected;disorganized accumulation in leurotubulus and neurofilaments, pyknotic nucleus, cytoplasmic protrusion, interstitial, intracytoplasmic and intraaxonal edema, advanced configuration irregularity in nuclear membrane, endoplasmic reticulum structures with enlarged granules, axoaxonal and axodendritic synapse, utensive vesicular structures in the axon that has presynaptic membrane [specially in the group 160000 IU/kg retinol acetate was applied), swelling ind lysis in mitochondria and crista, fibrous astrocyter extansions, -ibosomal distribution, short branched dendrit, apparent intercelluler lissociarion (specially in the group 160000 IU/kg retinol acetate was ipp!ied).The results of the immunohistochemical research have supportive characteristic against results obtained from light and electron microscope. rhe determinants called neuron specific enolase and neuronal heterogenity, axon ind dendrit damaging were considerably more obvious comparing to control şroup. In the study performed with vimentin that was intracell protein, in the >eriphery of the edema and damaged area different from in the control group liffusion in a way of disorganized radial was obvious.In addition to these the cells with edema and the cells within the normal configuration were counted and the morphometric analysis statistically achieved. Statistically significantly differences were encountered between control group and retinol acetate given groups.In the quantitative analysis of cell groups with edema the most impressive results were obtained in the last group, that is, the group 160000 IU/kg retinol acetate was applied. From totally counted 924 cells edema detected in 503, this was equal to a rate of % 54.43 and it was detennining the elevation of edema and the cell damage in parallel with dose increase. In control group the rate of %8.79 and the increase of this rate to % 54.43 by application of high dose retinol acetate was important from the view of retinol acetate and teratogenity. When it was studied to find out whether there was a statistically significant difference between groups, a statistically significant difference was detected between control group and the group 40000IU/kg retinol acetate was applied (*), a highly statistically significant difference was found between countrol group and the group 160000 IU/kg retinol acetate was applied (***), and there was a statistically significant difference between control group and the group 40000 IU/kg retinol acetate was applied (*).ÖZET Çalışmamızda ; maternal olarak uygulanan Retinol Asetat (VitA)'m loza bağımlı teratojenik etkisinin, santral sinir sistemi ve özellikli olarak ripokampus dokusunda oluşturduğu ultrastrüktürel değişikliklerin incelenmesi maç edinilmiştir. Maternal olarak tek doz 40000Ü/kg Retinol Asetat (VitA), 160000Ü/kg tetinol Asetat (VitA) ve %0.9 serum fizyolojik (kontrol grubu) uygulanımını akiben gebelik sonlanana dek beklenip, postnatal l.gün intrakardiak perfüzyon işleminden sonra yenidoğan sıçanların hipokampal dokuları çıkarılıp ışık elektron mikroskobik, immünohistokimyasal rutin takipleri yapıldı, parçalar ışık re transmisyon elektron mikroskobu (TEM) ile incelendi. İmmünohistokimyasal çalışmamız için vimentin ve nöron spesifik enolaz adlı belirleyiciler ile çalışıldı. Kontrol grubunda belirgin hücre proliferasyonu, ökromatik nöronal nükleus, belirgin ve düzgün yerleşimli nükleoluslar, düzenli hücre membranı, düzenli nükleer mebran yapısı, sağlam mitokondrial yapılar, akson ve dendrite ut transvers kesitler izlenirken kontrol grubundan anlamlı derecede farklı olarak Retinol Asetat uygulanan gruplarda doz artışına paralel biçimde artan nörotoksisite bulguları saptandı. Bu bulgular nörotubulus ve nörofilamentlerde dezorganize akümülasyon, piknotik nükleus, sitoplazmik protrüzyon,, interstisyel, ntrasitoplazmik ve intraaksonal ödem, nükleer membranda ilerlemiş tonfigürasyon düzensizliği, genişlemiş granüllü endoplazmik retikulum yapıları, aksoaksonal ve aksodendritik sinaps, presinaptik membrana sahip aksonda yoğun veziküler yapılar (özellikle 160000Ü/kg retinol asetat uygulanan grupta), mitokondri ve krista yapılarında şişme ve lizis, fıbröz astrositer uzantılar, ribozomal dağılma, kısa dallantılı dendrit, belirgin intersellüler ayrışma (özellikle 160000Ü/kg retinol asetat uygulanan grupta) olarak izlendi. İmmünohistokimyasal incelemedeki sonuçlar ışık ve elektron mikroskobik sonuçları destekler nitelikte idi. Nöron spesifik enolaz adlı belirleyici ile nöronal heterojenite, akson ve dendrit hasarlanması kontrol grubuna kıyasla oldukça belirgindi, hücre içi iskelet proteini olan vimentin ile yapılan çalışmada kontrol grubundan farklı olarak ödem ve hasarlı alan çevresi dezorganize radial tarzda tutulum belirgindi. Tüm bunlara ilave olarak ödemli hücre ve normal konfigürasyondaki hücreler sayıldı ve morfometrik analizi istatistiksel olarak yapıldı. Kontrol grubu ile retinol asetat verilen gruplar arasında anlamlı düzeydestatistiksel farklılıklara rastlandı. Ödemli hücre grupları sayısal analizinde en çarpıcı sonuçlar son grupta yani 160000IU/kg retinol asetat uygulanan grupta bulundu, toplam sayılan 924 hücreden 503 tanesinde idem bulgusuna rastlandı bu % 54.43 gibi bir orana denk geliyordu ve doz artışına paralel olarak hücre hasarlanması ve ödem artışını kantitatif olarak belirtiyordu. Kontrol grubundaki % 8.79'luk oran ve bu oranın yüksek doz retinol asetat uygulanımı ile % 54.43 'e çıkması retinol asetat ve teratojenite anlamında önemliydi. Gruplar arasında istatistiksel olarak anlamlı farklılık olup olmadığı incelendiğinde; kontrol grubu ve 40000 IU/kg retinol asetat uygulanan grup ırasında anlamlı (*),kontrol grubu ve 160000 IU/kg retinol asetat uygulanan grup arasında oldukça anlamlı (***) ve retinol asetat uygulanan gruplar arasında anlamlı (*) istatistiksel farklılık saptand

Avrupa Topluluğu Ortak Tarım Politikasının Türk Tarımına Etkileri

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Sosyal Bilimler Enstitüsü, 1997Thesis (M.A.) -- İstanbul Technical University, Institute of Social Sciences, 1997Avrupa Topluluğu Ortak Tarım politikasının Türk tarımına etkileri konulu bu tez üç ana bölümden oluşmaktadır. Birinci bölüm, Ortak taran politikası ve bileşenlerini incelemektedir. Ortak tarım politikası incelenirken asıl olarak, politikanın refah etkileri ve bunun kesimler üzerindeki dağılımına önem verilmiştir. Bu da, tezi, aynı konulu diğer çalışmalardan önemli ölçüde farklılaştırmaktadır. Birinci bölümün son kısmı, topluluk ortak tarım politikasından ayrılan ve farklılaşan, ortak balıkçılık politikasına ayrılmıştır. İkinci bölüm; Türkiye'de tarımsal gelişmenin tarihini inceleyerek başlamaktadır. Gelişimleri 1946lardan itibaren incelenmeye başlanan tarımsal göstergeler, 1980'li yıllardan sonra ayrıntılandırılmış ve genel politika bileşenleri içinde, bu bileşenler ile sebep sonuç ilişkileri gözlenmiştir. Bu noktada bizim için önemli olan tarımsal politikalar ile onların bir sonucu olması gerekli tarımsal göstergeler arasındaki ilişkidir. Tarımsal politikalar gerçekten göstergelerin belirleyicisi olabilmekte midir? Üçüncü bölüm, tüm dünya ekonomisinin gelecekteki en önemli yönlendiricisi olacak GATT Uruguay Round'u, Türk tarımı ve Ortak Tarım politikası açısından inceleyip sonuçlan, anlaşmanın muhtemel etkileri ile karşılaştırmaktadır. Tezin son kısmında ekler bölümü yer almaktadır. Ekler bölümünde AT-Türkiye ilişkilerini düzenleyen anlaşmaların tarım ile ilgili hükümleri, FEOGA ve bir tarım ürünleri terminolojisi yer almaktadır.Community. For the US it would have been a major opportunity missed for securing form protection cuts in Western Europe and Northeast Asia, as well as for using the president's fast-track authority to get reforms to its own costly farm programs through the Congress via the Uruguay Round omnibus legislation. For the EC, the extent of agricultural policy reform likely to be required under on Uruguay Round agreement would be no more than the EC, as it widens its membership, would undertake in any case during the remainder of 1990's. Agreement in the Round to reduce agricultural protection in industrial countries ensures that the beneficial flow-on effects to the rest of the world are enormous. In short, the prospects ahead in the absence of a successful conclusion to the Uruguay Round would have been for more uncertain, less stable agricultural trade relations. Those relations would have been characterized by more-managed bilateral trades, more focus on discriminatory regional integration amongements, further US-EC form export subsidy wars, greater tension between Eastern and Western Europe, and a smaller unmanaged international market less capable of absorbing gyrations in excess demand, particularly by former communist countries. xv political economic, social and environmental factors lies behind the creation of the common fishes policy which has operated since 1983 and is now in its second decade. The CFP is a fully fledged EC policy, one of the very few, like agriculture, with common rules through EC member countries covering all aspects of the fishing industry from the sea to the consumer. But tins does not mean that European Commission in Brussels manages the policy of its own. A corner stone of the present strategy is the shared responsibility for decisions, their application and their enforcement by all those concerned- EC institutions, national governments, regional and local authorities, fishermen and fishing organizations. Nor can CFP be isolated from other EC activities. Increasingly, its objectives have to be taken into account when regional, social, environmental, commercial and research priorities are being determined. The communities responsibility and involvement were further confirmed in 1986 Single European Act, the first major review of the Treaty of Rome. It underlined the communities role in promoting the social and economic welfare of all its citizens and regions a commitment which clearly passed fishing communities. History suggests that major changes in domestic political conditions are needed for a multilateral agreement to be reached. Some observers, frustrated by the slow pace of the Uruguay Round negotiations, suggested that agriculture be dropped from the round's agenda as had been done previous GATT-sponsored rounds. This time two things ruled out this option. First, it would have been unacceptable to many smaller and newer developing country members of GATT. Since an agreement requires consensus among the more than 100 contracting parties, the Round would have risked failing to conclude with an agreement. Second, dropping agriculture would have been unwise politically from the viewpoint of the two main parties in dispute, the United States and the European XIV Community. For the US it would have been a major opportunity missed for securing form protection cuts in Western Europe and Northeast Asia, as well as for using the president's fast-track authority to get reforms to its own costly farm programs through the Congress via the Uruguay Round omnibus legislation. For the EC, the extent of agricultural policy reform likely to be required under on Uruguay Round agreement would be no more than the EC, as it widens its membership, would undertake in any case during the remainder of 1990's. Agreement in the Round to reduce agricultural protection in industrial countries ensures that the beneficial flow-on effects to the rest of the world are enormous. In short, the prospects ahead in the absence of a successful conclusion to the Uruguay Round would have been for more uncertain, less stable agricultural trade relations. Those relations would have been characterized by more-managed bilateral trades, more focus on discriminatory regional integration amongements, further US-EC form export subsidy wars, greater tension between Eastern and Western Europe, and a smaller unmanaged international market less capable of absorbing gyrations in excess demand, particularly by former communist countries. xv political economic, social and environmental factors lies behind the creation of the common fishes policy which has operated since 1983 and is now in its second decade. The CFP is a fully fledged EC policy, one of the very few, like agriculture, with common rules through EC member countries covering all aspects of the fishing industry from the sea to the consumer. But tins does not mean that European Commission in Brussels manages the policy of its own. A corner stone of the present strategy is the shared responsibility for decisions, their application and their enforcement by all those concerned- EC institutions, national governments, regional and local authorities, fishermen and fishing organizations. Nor can CFP be isolated from other EC activities. Increasingly, its objectives have to be taken into account when regional, social, environmental, commercial and research priorities are being determined. The communities responsibility and involvement were further confirmed in 1986 Single European Act, the first major review of the Treaty of Rome. It underlined the communities role in promoting the social and economic welfare of all its citizens and regions a commitment which clearly passed fishing communities. History suggests that major changes in domestic political conditions are needed for a multilateral agreement to be reached. Some observers, frustrated by the slow pace of the Uruguay Round negotiations, suggested that agriculture be dropped from the round's agenda as had been done previous GATT-sponsored rounds. This time two things ruled out this option. First, it would have been unacceptable to many smaller and newer developing country members of GATT. Since an agreement requires consensus among the more than 100 contracting parties, the Round would have risked failing to conclude with an agreement. Second, dropping agriculture would have been unwise politically from the viewpoint of the two main parties in dispute, the United States and the European XIV Community. For the US it would have been a major opportunity missed for securing form protection cuts in Western Europe and Northeast Asia, as well as for using the president's fast-track authority to get reforms to its own costly farm programs through the Congress via the Uruguay Round omnibus legislation. For the EC, the extent of agricultural policy reform likely to be required under on Uruguay Round agreement would be no more than the EC, as it widens its membership, would undertake in any case during the remainder of 1990's. Agreement in the Round to reduce agricultural protection in industrial countries ensures that the beneficial flow-on effects to the rest of the world are enormous. In short, the prospects ahead in the absence of a successful conclusion to the Uruguay Round would have been for more uncertain, less stable agricultural trade relations. Those relations would have been characterized by more-managed bilateral trades, more focus on discriminatory regional integration amongements, further US-EC form export subsidy wars, greater tension between Eastern and Western Europe, and a smaller unmanaged international market less capable of absorbing gyrations in excess demand, particularly by former communist countries.Yüksek LisansM.A

Embriyoner gelişimde transkripsiyonel ağlar ve hücre sinyalleri

The formation of the three lineages of the mouse blastocyst provides an important model system to study behavior of cells in the early stage of the development process, internal and external factors which play a role in this process and the interaction between them. With the establishment of a stable polarized outer epithelium, the signal differences between the inner and outer cells of the early cleavage stages lead to the establishment of the inner cell mass (embryoblast) and the trophectoderm. Events in the stages of embryonic development including cell polarity, cell position, effects of local microenvironment, transcriptional factors and their interaction processes are involved in determining cell fate. The slow pace of development of the mouse during this time, the ability to culture embryos, the development of tools for live cell imaging and the ability to modify the expression of genes that enable the elucidation of the process.Fare blastokistindeki üç germ tabakasının oluşumu, hücrelerin gelişim sürecinin erken dönemindeki davranışlarını, hangi iç ve dış etkenlerin bu süreçte rol oynadığı ve bunlar arasındaki etkileşimleri çalışmak için önemli bir model sistemi sağlamaktadır. Stabi l polarize dış epitelin oluşmasıyla birlikte, erken yarıklanma aşamasının iç ve dış hücreleri arasındaki sinyal farklılıkları iç hücre kitlesi (ICM), embriyoblast ve trofoektodermin kurulmasına yol açar. Embriyonik gelişim aşamalarında gerçekleşen hücre polaritesi, hücre pozisyonu, lokal mikroçevre etkileri, transkripsiyonel faktörler ve bunların karşılıklı etkileşimlerini içeren süreçler hücre kaderinin belirlenmesinde rol oynamaktadır. Bu süre içerisinde fare gelişiminin yavaş ilerlemesi, kültür embriyo y eteneği, canlı hücre görüntüleme araçlarının geliştirilmesi ve gen ekspresyonlarını modifiye edebilme yeteneği bu süreçlerin aydınlatılabilmesini sağlamaktadır

Maternal olarak yüksek doz retinol asetat uygulanımını takiben, sıçan hipokampus CA1 hasarlanmasının kantitatif değerlendirilmesi

In this study quantitative examination of dose dependent teratogenic effect of maternally applied Retinol Acetate (Vit A) on central nerve system and especially on variations caused at the tissue of the hippocampus was aimed. After maternally intraperitoneal application of single doses of 40000 ID/kg retinol asetat, 160000 IU/kg retinol acetate and %0.9 serum physiologic (control group) waited until the pregnancy was over. Postnatal first day after the intracardiac perfusion process, the hippocampal tissues of newborn rats dissected and after their follow-ups under a light microscope were accomplished the preparations made were examined as 100 times magnified. the cells with edema and the cells within the normal configuration were counted and the morphometric analysis statistically accomplished. Statistically significant differences between control group and retinol acetate given groups were detected.6u çalışmada, maternal olarak uygulanan Retinol Asetat (Vit A)'ın doza bağımlı teratojenik etkisinin, merkezi sinir sistemi ve özellikli olarak hipokampus dokusunda oluşturduğu değişikliklerin kantitatif olarak incelenmesi amaç edinilmiştir. Maternal olarak intraperitoneal yolla tek doz 40000 iÜ/kg retinol asetat, 160000 iÜ/kg retinol asetat ve %0.9 serum fizyolojik (kontrol grubu) uygulanımını takiben gebelik sonlanana dek beklenip, postnatal l.gün intrakardiak perfüzyon işleminden sonra yerıidoğan sıçanların hipokampal dokuları çıkarılıp ışık mikroskobik takiplerinden sonra hazırlanan preparatlar 100'lük büyütme altında incelenmiştir. Ödemli hücre ve normal konfigürasyondaki hücreler sayılmış ve morfometrik analizleri istatistiksel olarak yapılmıştır. Kontrol grubu ile retinol asetat verilen gruplar arasında anlamlı düzeyde istatistiksel farklılıklar saptanmıştır