Biliary strictures and liver transplantation : clinical and biomedical aspects

The current thesis describes short and long term results of orthotopic liver transplantation (OLT) performed with livers from donation after brain death (DBD) and livers from donation after cardiac death (DCD) with an emphasis on biliary complications, especially nonanastomotic biliary strictures (NAS). In a 20-year single center study we have shown that long term survival has improved significantly with current 1-, 5- and 10-years survival rates of 91%, 83% en 77%, respectively. However, DCD-OLT leads to more development of NAS probably due to more ischemia/reperfusion damage as indicated by higher peaks of alanine aminotransferas (ALT) after OLT. We have shown that peak ALT level of >1300 IU/L was associated with a higher incidence of NAS and can thus be used as a clinical tool. Furthermore, the role of genetic polymorphisms of matrix metalloproteinases (MMPs), as proteolytic enzymes involved in tissue remod eling, was investigated in the relation to the development of biliary stricture formation before, i.e. in primary sclerosing cholangitis (PSC), and after OLT. We have found that MMP-2 C/T polymorphism was related to more severe progression of PSC resulting in earlier OLT or death. In addition, MMP-2 C/T polymorphism was clearly associated with the development of NAS after OLTDr. Falk B.V.UBL - phd migration 201

Quasi-free Compton Scattering from the Deuteron and Nucleon Polarizabilities

Cross sections for quasi-free Compton scattering from the deuteron were measured for incident energies of 236--260 MeV at the laboratory angle -135 degrees. The recoil nucleons were detected in a liquid-scintillator array situated at 20 degrees. The measured differential cross sections were used, with the calculations of Levchuk et al., to determine the polarizabilities of the bound nucleons. For the bound proton, the extracted values were consistent with the accepted value for the free proton. Combining our results for the bound neutron with those from Rose et al., we obtain one-sigma constraints of alpha_n = 7.6-14.0 and beta_n = 1.2-7.6.Comment: 4 pages, 3 figures, accepted in PR

Acute and delayed sulfur mustard toxicity; novel mechanisms and future studies

Sulfur mustard (SM), also known as mustard gas, has been the most widely used chemical weapon. The toxicity of SM as an incapacitating agent is of much greater importance than its ability to cause lethality. Acute toxicity of SM is related to reactive oxygen and nitrogen species, DNA damage, poly(ADP-ribose) polymerase activation and energy depletion within the affected cell. Therefore melatonin shows beneficial effects against acute SM toxicity in a variety of manner. It scavenges most of the oxygen- and nitrogen-based reactants, inhibits inducible nitric oxide synthase, repairs DNA damage and restores cellular energy depletion. The delayed toxicity of SM however, currently has no mechanistic explanation. We propose that epigenetic aberrations may be responsible for delayed detrimental effects of mustard poisoning. Epigenetic refers to the study of changes that influence the phenotype without causing alteration of the genotype. It involves changes in the properties of a cell that are inherited but do not involve a change in DNA sequence. It is now known that in addition to genetic mutations, epimutations can also involve in the pathogenesis of a variety of human diseases. Several actions of melatonin are now delineated by epigenetic actions including modulation of histone acetylation and DNA methylation. Future studies are warranted to clarify whether epigenetic mechanisms are involved in pathogenesis of delayed sulfur mustard toxicity and melatonin alleviates delayed toxicity of this warfare agent

Analytical study of quality-biased competition dynamics for memes in social media

The spreading of news, memes and other pieces of information occurring via online social platforms has a strong and growing impact on our modern societies, with enormous consequences, that may be beneficial but also catastrophic. In this work we consider a recently introduced model for information diffusion in social media taking explicitly into account the competition of a large number of items of diverse quality. We map the meme dynamics onto a one-dimensional diffusion process that we solve analytically, deriving the lifetime and popularity distributions of individual memes. We also present a mean-field type of approach that reproduces the average stationary properties of the dynamics. In this way we understand and control the role of the different ingredients of the model, opening the path for the inclusion of additional, more realistic, features.Comment: 6 pages + 9 pages of Supplementary Materia

Spor Yapan Çocukların Spor Tercihleri Ve Bunu Etkileyen Bazı Faktörlerin İncelenmesi,

Araştırmanın amacı spor yapan öğrencilerin spor yapma tercihlerini belirleyen faktörlerin belirlenmesi ve bazı faktörler arasındaki ilişkinin incelenmesidir. Araştırma uygulamalı bir çalışma olup, ölçekli bir anket formu kullanılmıştır. Uygulamada kullanılan anket daha önce kullanılmış ve güvenirliliği sağlanmış bir anket olup, anket üzerinde bazı değişiklikler gerçekleştirilmiştir. Araştırmanın örneklemini rast gele yöntemle seçilmiş olan 3562 katılımcı oluşturmaktadır. Katılımcılara (N= 3562) uygulanan anketin güvenirlik katsayısı (Cronbach’s Alpha) hesaplanarak 0.950 değeri elde edilmiştir. Bireyden elde edilen veriler SPSS Pasw 18.0 istatistik programı ile analiz edilmiştir. Araştırma 19 ay sürmüştür. Araştırmada kullanılan teknik basit rassal yöntemdir. Araştırmada betimleyici istatistikler, faktör analizi, KMO ve Barlett’s testi, eşleştirilmiş iki grup t-testi, bağımsız t- testi, Crosstabs testi ve Anova testlerinden yararlanılmıştır. Araştırma sonunda anne-baba eğitim durumu, gelir durumu, spor yapılan mekanın spor tercihine etki ettiği bulunmuştur. Aynı zamanda ebeveyn eğitimi, çalışma durumu ve Tv ve görsel araçların çocuğun beslenme alışkanlıklarında, beslenme alışkanlığının ise psikolojik durum ve spor yaralanmalarında etken faktör olduğu saptanmıştır

Epigenetic perturbations in the pathogenesis of mustard toxicity; hypothesis and preliminary results

Among the most readily available chemical warfare agents, sulfur mustard (SM), also known as mustard gas, has been the most widely used chemical weapon. SM causes debilitating effects that can leave an exposed individual incapacitated for days to months; therefore delayed SM toxicity is of much greater importance than its ability to cause lethality. Although not fully understood, acute toxicity of SM is related to reactive oxygen and nitrogen species, oxidative stress, DNA damage, poly(ADP-ribose) polymerase (PARP) activation and energy depletion within the affected cell. Therefore several antioxidants and PARP inhibitors show beneficial effects against acute SM toxicity. The delayed toxicity of SM however, currently has no clear mechanistic explanation. One third of the 100,000 Iranian casualties are still suffering from the detrimental effects of SM in spite of the extensive treatment. We, therefore, made an attempt whether epigenetic aberrations may contribute to pathogenesis of mustard poisoning. Preliminary evidence reveals that mechlorethamine (a nitrogen mustard derivative) exposure may not only cause oxidative stress, DNA damage, but epigenetic perturbations as well. Epigenetic refers to the study of changes that influence the phenotype without causing alteration of the genotype. It involves changes in the properties of a cell that are inherited but do not involve a change in DNA sequence. It is now known that in addition to mutations, epimutations contribute to a variety of human diseases. Under light of preliminary results, the current hypothesis will focus on epigenetic regulations to clarify mustard toxicity and the use of drugs to correct possible epigenetic defects

Analysis of the Attitudes of Student-Atheletes Playing in the Universities Volleyball 2nd League in Turkey towards Sports,

The purpose of this research is to analyze the attitudes of student-athletes towards sports who played in Universities Volleyball Second League competitions held in Antalya on 16th-27th December 2014. Target population of the study is composed of the student-athletes studying in universities in Turkey and playing in the volleyball teams of universities at the same time, and the sample group of the study is composed of 23 studentathletes from different universities who participated in Universities Volleyball Second League held in Antalya on 16th-27th December 2014. With the purpose of determining the attitudes of student-athletes towards sports, the participants were applied a survey. SPSS (Statistical Package for Social Sciences) for Windows 21.0 program was used in the analysis of data. Descriptive statistics, t-test for determining the difference between two groups, One-way Anova test for comparisons of more than two groups were used in analysis of data. It has been found that attitude scores of all participants towards sports are high and attitude scores of female students towards sports are higher than those of male students. In conclusion, it has been determined that the attitudes of students playing in the volleyball teams of universities towards sports are positive. It has also been demonstrated that the attitude towards sports by the sex variable is higher in favor of female students; however, such variables as family educational background, income, age and grade point average don't create difference for the attitude towards sports

MIR376A is a regulator of starvation-induced autophagy

Background: Autophagy is a vesicular trafficking process responsible for the degradation of long-lived, misfolded or abnormal proteins, as well as damaged or surplus organelles. Abnormalities of the autophagic activity may result in the accumulation of protein aggregates, organelle dysfunction, and autophagy disorders were associated with various diseases. Hence, mechanisms of autophagy regulation are under exploration. Methods: Over-expression of hsa-miR-376a1 (shortly MIR376A) was performed to evaluate its effects on autophagy. Autophagy-related targets of the miRNA were predicted using Microcosm Targets and MIRanda bioinformatics tools and experimentally validated. Endogenous miRNA was blocked using antagomirs and the effects on target expression and autophagy were analyzed. Luciferase tests were performed to confirm that 3’ UTR sequences in target genes were functional. Differential expression of MIR376A and the related MIR376B was compared using TaqMan quantitative PCR. Results: Here, we demonstrated that, a microRNA (miRNA) from the DlkI/Gtl2 gene cluster, MIR376A, played an important role in autophagy regulation. We showed that, amino acid and serum starvation-induced autophagy was blocked by MIR376A overexpression in MCF-7 and Huh-7 cells. MIR376A shared the same seed sequence and had overlapping targets with MIR376B, and similarly blocked the expression of key autophagy proteins ATG4C and BECN1 (Beclin 1). Indeed, 3’ UTR sequences in the mRNA of these autophagy proteins were responsive to MIR376A in luciferase assays. Antagomir tests showed that, endogenous MIR376A was participating to the control of ATG4C and BECN1 transcript and protein levels. Moreover, blockage of endogenous MIR376A accelerated starvation-induced autophagic activity. Interestingly, MIR376A and MIR376B levels were increased with different kinetics in response to starvation stress and tissue-specific level differences were also observed, pointing out to an overlapping but miRNA-specific biological role. Conclusions: Our findings underline the importance of miRNAs encoded by the DlkI/Gtl2 gene cluster in stress-response control mechanisms, and introduce MIR376A as a new regulator of autophagy