Chemical Synthesis of the Fluorescent, Cyclic Dinucleotides c(th)GAMP

The cGAS-STING pathway is known for its role in sensing cytosolic DNA introduced by a viral infection, bacterial invasion or tumorigenesis. Free DNA is recognized by the cyclic GMP-AMP synthase (cGAS) catalyzing the production of 2',3'-cyclic guanosine monophosphate-adenosine monophosphate (2',3'-cGAMP) in mammals. This cyclic dinucleotide acts as a second messenger, activating the stimulator of interferon genes (STING) that finally triggers the transcription of interferon genes and inflammatory cytokines. Due to the therapeutic potential of this pathway, both the production and the detection of cGAMP via fluorescent moieties for assay development is of great importance. Here, we introduce the paralleled synthetic access to the intrinsically fluorescent, cyclic dinucleotides 2'3'-c(th)GAMP and 3'3'-c(th)GAMP based on phosphoramidite and phosphate chemistry, adaptable for large scale synthesis. We examine their binding properties to murine and human STING and confirm biological activity including interferon induction by 2'3'-c(th)GAMP in THP-1 monocytes. Two-photon imaging revealed successful cellular uptake of 2'3'-c(th)GAMP in THP-1 cells

Transhepatic left ventricular only pacing after left bundle branch area pacing attempt with high pacing threshold

A 50-year-old male with a permanent dual chamber pacemaker (DDD) 23 years ago was referred for a rapid increase in right ventricular (RV) pacing impedance. His left ventricular (LV) ejection fraction was 45%. Since the patient was pacemaker-dependent, the insertion of a new RV lead was planned. However, the venography and imaging studies revealed both left and right subclavian veins to be occluded/non-accessible. We failed also to cross the lesion by percutaneous approach. Then, we planned the extraction procedure as a first stage with the thought that it can provide a new venous route via extraction sheath; however, the patient did not accept the procedure as its high risk. Therefore, the surgical epicardial LV lead was implanted and connected to the left subpectoral pocket by using the previous functional right atrial (RA) lead for DDD pacing. Unfortunately, 1 month later, the patent presented with a left-sided pocket infection, and we had to remove all endocardial RA and RV leads using the lead extraction system. We could not again pass the calcified superior vena cava despite the successful lead extraction. Due to an active pocket infection, the surgically placed pacemaker was removed from the skin leaving the epicardial LV lead in place to remove or drain the infected fluid. A leadless pacemaker was an option, but due to financial constraints could not be done for this patient. The femoral venous access could not be taken due to the non-availability of 69 cm RV lead. The hepatic vein was the only available access to implant a DDD pacemaker

A Case Study of France: Religious Liberty of Muslim Women : How does the Contemporary Ban on the Burqa in France interfere with Religious Liberty?

In 2011, France was the first European country to enforce the Concealment Act which statesthat any type of face concealing clothing in the public sphere is banned. France is a memberof the European Union, and the right to freedom of thought, religion and conscience is one ofthe significant fundamental human rights. Thus, questions arise whether this legislationinterferes with the religious liberty of Muslim women. This research is evaluating how thecontemporary ban is related to religious liberty when accounting for the historicalbackground. The research addresses the continuous attempt of France, especially afterIslamic terror attacks, to restrict the Islamic clothing and assimilate the French andwesternized identity to Muslim women. The principle of laicite and France’s historicalbackground shows the country's strong separation of religion and state

A Case Study of France: Religious Liberty of Muslim Women : How does the Contemporary Ban on the Burqa in France interfere with Religious Liberty?

In 2011, France was the first European country to enforce the Concealment Act which statesthat any type of face concealing clothing in the public sphere is banned. France is a memberof the European Union, and the right to freedom of thought, religion and conscience is one ofthe significant fundamental human rights. Thus, questions arise whether this legislationinterferes with the religious liberty of Muslim women. This research is evaluating how thecontemporary ban is related to religious liberty when accounting for the historicalbackground. The research addresses the continuous attempt of France, especially afterIslamic terror attacks, to restrict the Islamic clothing and assimilate the French andwesternized identity to Muslim women. The principle of laicite and France’s historicalbackground shows the country's strong separation of religion and state

Evaluation of cyclic dinucleotides and their prodrugs in biochemical and cellular assays

The innate immune pathways gained more importance since the discovery of the extended role of type I interferons. Type I interferons are produced primarily upon viral and bacterial invasions and function by inducing immune responses. As a result, innate and adaptive immune cells are differentiated, activated and recruited to the pathogen-invaded cells for destruction. Type I interferons are also produced by cancer cells and immune cells regulating the cancer immunity cycle. The cGAS-STING pathway is one of the key pathways resulting in type I interferon mediated immune response. The cGAS-STING pathway is activated by double-stranded DNA (dsDNA) leaking into the cytosol. When cGAS (cytosolic-Guanosine-Adenosine-Synthase) binds to dsDNA, ATP and a GTP are utilised for the production of cyclic guanosine monophosphate-adenosine monophosphate (cGAMP). cGAMP binds to STING (Stimulator of Interferon Genes), initiating a signalling cascade. The high rate of chromosomal instabilities in cancer cells as well as the instability of genetic material in aged cells are reasons for dsDNA to leak out from the nucleus and localise in the cytosol. Hence, the cGAS-STING pathway is activated and immune cells are recruited to the site of danger. In recent years, targeting the cGAS STING pathway has been an emerging strategy for drug discovery and led to the development of cGAMP analogues. The group of Carell has designed and synthesised cyclic dinucleotides as STING agonists. In the first part of this thesis, the cyclic dinucleotides and their developed prodrugs were evaluated using cellular and biochemical assays. Their rate of inducing type I interferon production was monitored in THP 1 monocytic cells. Their effective concentration 50 (EC50) were measured and promising cGAMP analogues were tested for their stability against currently known cGAMP degrading enzymes. Two compounds, the 2’,3’-dideoxy-cGAMP and 2’,3’-dideoxy-cAAMP, were identified to be stable against poxins, which are viral enzymes from the poxvirus family. Two prodrugs of 2’,3’-dideoxy-cAAMP were synthetically developed by the group of Carell, one of them containing the SATE linkers, named PRO1, another one bearing an additional photocleavable group named PC-PRO1. These were also evaluated regarding their rate of type I interferon production. With an EC50 value of 49 nM, PRO1 shows a 1500-fold increase in interferon production in THP-1 monocytic cells compared to its precursor 2’,3’ dideoxy cAAMP and a 200-fold increase compared to natural cGAMP (2’,3’ cGAMP). Overactivation of STING and overproduction of type I interferons is related to specific diseases, aging, and metastatic activity in cancers. Therefore, besides STING agonists, STING antagonists also carry a therapeutic potential. For the development of a STING antagonist, G. Ganazzoli from the Carell group used the PROTAC (Proteolysis Targeting Chimera) approach utilising 2’,3’-dideoxy-cGAMP as a STING recruiter. This compound named PROTAC1, was evaluated in the second part of this thesis for its ability to degrade STING in different time frames. The analysis was done on THP-1 monocytic cells and western blotting was used in which the degree of STING degradation was measured by the intensity of the STING-antibody bound bands. As an internal control, the CoxIV of each sample was targeted and their band intensities were used for normalisation of the STING signal. A successful degradation of STING in THP-1 monocytic cells was observed when 25-50 nM of PROTAC1 was applied to the cells for 16 hours. In the published work in section 5 of this thesis, the chemical synthesis of a fluorescent cGAMP analogue, cthGAMP, was introduced. The successful entry of cthGAMP was observed in THP-1 monocytic cells with two-photon excitation microscopy. Interferon production was observed when cthGAMP was transfected in the THP-1 monocytic cells, providing proof of biological activity. This compound was suggested for assay development purposes concerning the cGAS-STING pathway, due to its scalability of its synthetic route and biological activity. In the second research article presented in section 5, the supply mechanism of α-ketoglutarate to the dioxygenase TET3 by the metabolic enzyme Gdh was described in hippocampal neurons for the oxidation process of 5’ methylcytosine. The oxidation of 5’ methylcstosine to 5’ hydroxymethylcytosine was observed upon Gdh localisation in the nucleus together with TET3. A functional Gdh was required for this conversion in activated hippocampal neurons. In this study, HEK293 cells were used for expression and co-expression of natural and modified enzymes, which were used for immunocytochemistry experiments. Hippocampus slices from mice were used for neural activation, immunohistochemistry and proximity ligation assays. Observations were made by confocal microscopy, whereas quantification of 5’ methylcytosine and its oxidation products were done by UHPLC-QQQ-MS

Assessment of direct and fluid mediated cold atmospheric plasma treatment efficacy on squamous cell carcinoma at three-dimensional skin culture model Direkt ve sıvı aracılı plazma muamele yöntemlerinin skuamöz hücreli karsinom üzerindeki etkinliğinin üç boyutlu deri kültür modelinde değerlendirilmesi

xvi, 84 pages29 cm. 1 CDABSTRACTSquamous cell carcinoma (SCC) is the second most seen type of non-melanoma skin cancers after basal cell carcinoma (BCC). Prevalence of non-melanoma skin cancer increases rapidly and it’s expected to account for 50 of all cancer types in near future. It takes attention and carries importance due to higher risk of metastasis. Even though various methods are being used, those methods may either fall short or cause serious side effects. Plasma is defined as the fourth state of matter and cold atmospheric plasma (CAP) can be produced at atmospheric pressure under high electrical field. The selective efficacy of CAP on cancer by inducing apoptosis without damaging healthy cells has also been demonstrated. Liquids, which are treated by CAP may gain particular activity similar to the plasma treatment shows by itself. In this study, anticancer efficacy of direct and fluid-mediated plasma treatment on SCC has been evaluated in vitro. For this purpose, the selective effect of different plasma treatment methods on cell lines has been demonstrated. Studies have been carried out to determine the oxidative and nitrosative stress caused by reactive oxygen species (ROS) and reactive nitrogen species (RNS) released due to plasma treatment in keratinocyte and SCC cell lines and to associate them with apoptotic behavior. Besides the effects of the species formed after plasma on different mechanisms were evaluated. Also, these effects evaluated on the three-dimensional (3D) tissue culture model. Our results show that both plasma treatments have selective activity on the cancer cell.ÖZETSkuamöz hücreli karsinom (Squamous cell carcinoma, SCC), bazal hücreli karsinomdan (Basal cell carcinoma, BCC) sonra en fazla görülen melanom olmayan deri kanseridir. Melanom olmayan deri kanserleri vakalarında hızlı bir artış gözlemlenmekte olup yakın gelecekte, tüm kanserlerin 50’sini oluşturacağı düşünülmektedir. SCC yüksek metastaz riski taşımasından dolayı daha fazla önem taşımakta ve dikkat çekmektedir. Her ne kadar SCC’nin tedavisine yönelik farklı yöntemler kullanılmaktaysa da hastalığın evresi, hastanın komorbiditeleri gibi parametrelere bağlı olarak tedavi yöntemi yetersiz kalabilmekte ya da ciddi yan etkilere neden olabilmektedir. Plazma, maddenin dördüncü hali olarak tanımlanmakta ve atmosferik basınçta, yüksek elektrik alan altında, oda sıcaklığında üretilebilmektedir. Plazmanın farklı sağlıklı hücreler üzerinde yıkıcı etkiler göstermeden kanser hücre hatları üzerinde apoptozu indükleyerek kanser tedavisine yönelik selektif etkinliği olabileceği gösterilmiştir. Ek olarak, plazma muamelesi görmüş olan sıvıların da kimyasal modifikasyona uğrayarak plazmanın tek başına oluşturduğu farklı etkinlikleri oluşturabileceği gösterilmiştir. Bu çalışmada, doğrudan plazma muamelesi ve sıvı aracılı plazma muamele yöntemlerinin SCC üzerindeki antikanser etkinliği in vitro olarak değerlendirilmiştir. Bu amaç doğrultusunda hücre hatları üzerinde farklı plazma muamele yöntemlerinin selektif etkisi gösterilmiş, plazma muamelesi sonucu açığa çıkan reaktif oksijen ve nitrojen türlerinin keratinosit ve SCC hücre hatlarında sebep olduğu oksidatif ve nitrozatif stresin belirlenerek hücrelerin apoptotik davranışı ile ilişkilendirilmesine yönelik çalışmalar yürütülmüştür. Bunun yanında plazma sonrası oluşan türlerin farklı mekanizmalara etkileri değerlendirilmiştir. Aynı zamanda bu etkilerin, üç boyutlu doku kültürü modeli üzerinde değerlendirilmiştir. Çalışma kapsamında elde edilen sonuçlara göre her iki plazma uygulamasının kanser hücre hattı üzerinde selektif etkinliğe sahip olduğu belirlenmiştir

Toplumda Yaşayan Yaşlılarda Mini-Cog Testinin Demans Taramasındaki Etkinliğinin Mmse, Q-Mcı ve Moca Testleriyle Kıyası: Bir Saha Çalışması

It is important to screen the common dementia along with aging population with an effective and easy test. In this field study, it is aimed to compare the success of Mini-Cog in diagnosis with the common cognitive function screening tests and to be used it in primary care if it is found effective. In this study, a total of 4 family health centers with different sociocultural levels were identified, 115 patients, 65 years and older, who had dysmnesia were screened and the study was completed with 51 patients who met the criteria. After detailed medical history, Mini-Cog test was applied to all patients and the patients who couldn’t have the full score were performed routine blood tests and other cognitive screen tests called MMSE, Qmci-TR, MoCA and their cognitive and extensive geriatric evaluation were done in Hacettepe University, Department of Internal Medicine, Geriatri Polyclinic. As a result of the evaluation, 42 of 51 patients were accepted as mild cognitive disorder and 9 patients were diagnosed with dementia according to DSM-V criteria. According to the results, the difference of total score between dementia patients and normal patients was not statistically significant (MiniCog (p = 0.131), MoCA (p = 0.539) and MMSE (p = 0.097)), while the difference of Qmci-TR total score was statistically significant (p = 0.027). While dementia was detected in only 6 (%22,2) of 27 patients with decompensated Mini-Cog test, dementia was detected in 3 (%12,5) of 24 patients with a normal Mini-Cog score. There was no statistically significant correlation between Mini-Cog test defect and dementia diagnosis (p = 0.363). Mini-Cog word repetition was significantly different between dementia and normal group (p = 0.010). As a result, Mini-Cog test could not be shown to be effective in dementia screening. Larger scale studies are needed to support and improve the results.Yaşlanan nüfusla beraber sık görülen demansı, etkin ve kolay bir testle taramak önemlidir. Bu saha çalışmasında, Mini-Cog’un tanı koymadaki başarısının sık kullanılan kognitif fonksiyon tarama testleriyle karşılaştırılması ve etkin bulunursa birinci basamakta kullanılmasının yaygınlaştırılması amaçlanmıştır. Çalışmada sosyokültürel düzeyleri farklı olan toplam 4 aile sağlığı merkezi belirlenmiş, 65 yaş ve üzeri unutkanlığı olan 115 hasta taranmış, kriterlere uyan 51 hasta ile çalışma tamamlanmıştır. Tüm hastalara detaylı hikaye sonrası Mini-Cog testi uygulanmış, Mini-Cog testinden tam puan alamayanlar Hacettepe Üniversitesi İç Hastalıkları Anabilim Dalı Geriatri Bilim Dalı Polikliniği’nde diğer kognitif tarama testlerinden MMSE, Qmci-TR, MoCA ile kognitif değerlendirmeleri ve kapsamlı geriatrik değerlendirmeleri ile gerekli rutin kan tetkikleri yapılmıştır. Değerlendirme sonucunda 51 hastanın 42’si hafif kognitif bozukluk olarak kabul edilirken, 9 hastaya DSM-V kriterlerine göre demans tanısı konmuştur. Sonuçlara göre Mini-Cog (p=0,131), MoCA (p=0,539) ve MMSE (p=0,097) total puanının demanslı hastalar ile normal hastalar arasındaki farkı, istatistiksel olarak anlamlı bulunmazken, Qmci-TR total puanının farkı istatistiksel olarak anlamlıydı (p=0,027). Mini-Cog testi bozuk olan 27 hastanın sadece 6’sında (%22,2) demans saptanmışken, Mini-Cog puanı normal olan 24 hastanın 3’ünde (%12,5) demans saptandı. Mini-Cog testinin bozuk olması ve hastaların demans tanısı alması arasındaki ilişki istatistiksel olarak anlamlı saptanmadı (p=0,363). Mini-Cog kelime tekrarı demans ve normal grup arasında anlamlı olarak farklıydı (p=0,010). Sonuç olarak Mini-Cog testinin demans taramasında etkin olduğu gösterilemedi. Sonuçların desteklenmesi ve geliştirilmesi için daha büyük ölçekli çalışmalara ihtiyaç duyulmaktadır

Design and Manufacturing of Usable Membrane for Polyvinyl Alcohol (Pva)/ Graphene Oxide (Go) Based Biosensor Application

Bu çalışmada, elektro-eğirme yöntemi kullanılarak elde edilen polivinil alkol (PVA)/grafen oksit (GO) nanolifli yüzey özelliklerine çözelti parametrelerinin etkisi incelenmiş ve devamında, biyomedikal uygulamalarda biyosensör olarak kullanım potansiyeli yapılan testlere göre değerlendirilmiştir. Polivinil alkol çözeltileri elektro-eğirme yöntemi ile nanolif yüzey üretimi üzerinde çalışılmıştır. PVA derişimi değiştirilerek yapılan nanolifler gözlemlenmiştir. Oluşturulan PVA çözeltileri petri kaplarına dökülerek kurutulmuş, GO farklı konsantrasyonlardaki sulu çözeltileri oluşturulmuştur. Kurutulan PVA, elektro-eğirme cihazına yerleştirilerek GO çözeltisi ile atım yapılmıştır. Oluşturulan nanolifli yüzeyler Taramalı Elektron Mikroskobu (SEM) ile analiz edilerek lif çaplarının ortalamaları alınmıştır. Alınan sonuçlara göre nanolif yüzey özellikleri çapları ile ilişkilendirilmiştir. Biyosensör uygulamasında kullanılması için oluşturulan nanolif membranlara viskozite ve elektrik iletkenliği testleri yapılmıştır. Membran olması amacıyla üretilen nanolifli membranın antibakteriyel testleri ve dayanıklılığını değerlendirmek üzere mekanik testleri yapılarak sonuçları incelenmiştir. Isı karşısında ağırlık değişimi ve ısı akışının incelenmesi için termogravimetrik analizleri (TGA) yapılmıştır. Yapılan çalışmalar ve testler sonucunda, nanolif yüzey özellikleri ve çap değerleri üzerinde çözelti parametrelerinin önemli bir etkisi olduğu görülmüştür. İncelenen test sonuçları, biyosensör kullanımları değerlendirmelerine göre uygun olduğu öngörülmektedir.In this study, the effect of solution parameters on the surface properties of polyvinyl alcohol (PVA)/graphene oxide (GO) nanofibers obtained by using the electrospinning method was investigated, and then the potential for use as a biosensor in biomedical applications was evaluated according to the tests performed. Polyvinyl alcohol solutions were studied on nanofiber surface production by electro-spinning method. Nanofibers made by varying the PVA concentration were observed. The created PVA solutions are removed by pouring into petri dishes, the aqueous solutions of graphene oxide in different places are separated. The dried PVA was placed in the electrospinning device and pulsed with a graphene oxide casing. The averages of the fiber diameters were taken using the analyzes made with Scanning Electron Microscopy (SEM) on the nanofiber surfaces created. According to the results obtained, the nanofiber surface properties changed with their diameters. Viscosity and electrical conductivity experiments were carried out on nanofiber membranes produced for the use of biosensors. Protective effects against harmful organisms, cell testing and mechanical testing to maintain durability of the fabricated nanofibrous membrane intended to be a wound dressing. Thermogravimetric analyzes (TGA) were performed to examine the heat counterweight changes and heat tables. As a result of running and testing, measurement values have a significant influence on nanofiber surface properties and diameter values. Examined test results are predicted to be appropriate based on assessments of dressing use

Gözağrısı [Sesli Kitap]

Bu eser Fatih Sultan Mehmet Vakıf Üniversitesi Sağlık, Kültür ve Spor Daire Başkanlığı ve Kütüphane ve Dokümantasyon Daire Başkanlığı işbirliğinde oluşturulan Sesli Kitaplık Projesi için seslendirilmiştir. 5846 sayılı Fikir ve Sanat Eserleri Kanunu'nun Ek 11. Maddesi kapsamında görme engelliler dışında kullanımı, çoğaltımı, dağıtımı, satışı yasalara aykırıdır.Söz geçiyor belki ama mânâ bir başka şey olarak bizimle kalıyor. Edilmiş onca kelâm, kurulmuş onca cümle, buğulanmış onca cam... Mânâ taşıyan katarlar olarak dura kalka geçip gidiyor ömrümüzün uçsuz bucaksız düzlüklerinden. Uzun uzun yaşıyoruz ya bu dünyada, işte hep o mânâyı damıtmak için... Söylenmişlerden, söylenmemişlerden... Bir kâğıdın üstüne dökülmüşlerden, bir camın buğusuna yazılmışlardan, bir hâfızanın derinliklerine emanet edilmişlerden... İyi ki o mânâ var. İyi ki var da, ne zaman sendelesek yıkılıp gitmemek için tutunuyoruz köşe bucağına. Kimi sözler o mânâyı muhafaza etmek için daima bizimle kalıyor, kimi şöyle bir dokunup geçiyor. Nereden bildiğimizi artık hatırlamadığımız birçok şey, zamanın içinde unutulup giden bir sözün bize dokunuşunun eseri. Demek sözlerin de insanlar gibi bir kaderi var