117 research outputs found

    Protein Releasing Kinetics of Bakers’ Yeast Cells by Ultrasound

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    The protein releasing kinetics of Saccharomyces cerevisiae cells were investigated by using the ultrasonication method. The effects of acoustic power, duty cycle % of a sonicator, medium pH and cell concentration on protein release were examined. An attempt was also made to enhance cell disruption further by adding glass beads to the solution. An increase with protein release was observed with increasing acoustic power, duty cycle and glass beads loading %. The protein release was found almost independent of cell concentration and optimum pH was obtained as 7. The relationship between protein release and processing time at various process conditions were studied; and the data were fit to a first order kinetic expression. By using the kinetic data, energy calculations with respect to protein release % were made; and found that using high acoustic power is not feasible for disruption process. By increasing the duty cycle %, no significant energy alteration was observed to achieve the same protein release %. However, disruption time decreased considerably. The effect of ultrasonic energy which is a function of both acoustic power and duty cycle % on the kinetic coefficients was also investigated using an exponential expression based on Arrhenius equation; and the activation energy of protein release was found as 0.44 kJ L-1

    Research capacity and training needs for non-communicable diseases in the public health arena in Turkey

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    Background The aim of this study is to define the research capacity and training needs for professionals working on non-communicable diseases (NCDs) in the public health arena in Turkey. Methods This study was part of a comparative cross-national research capacity-building project taking place across Turkey and the Mediterranean Middle East (RESCAP-Med, funded by the EU). Identification of research capacity and training needs took place in three stages. The first stage involved mapping health institutions engaged in NCD research, based on a comprehensive literature review. The second stage entailed in-depth interviews with key informants (KIs) with an overview of research capacity in public health and the training needs of their staff. The third stage required interviewing junior researchers, identified by KIs in stage two, to evaluate their perceptions of their own training needs. The approach we have taken was based upon a method devised by Hennessy&#38;Hicks. In total, 55 junior researchers identified by 10 KIs were invited to participate, of whom 46 researchers agreed to take part (84%). The specific disciplines in public health identified in advance by RESCAP-MED for training were: advanced epidemiology, health economics, environmental health, medical sociology-anthropology, and health policy. Results The initial literature review showed considerable research on NCDs, but concentrated in a few areas of NCD research. The main problems listed by KIs were inadequate opportunities for specialization due to heavy teaching workloads, the lack of incentives to pursue research, a lack of financial resources even when interest existed, and insufficient institutional mechanisms for dialogue between policy makers and researchers over national research priorities. Among junior researchers, there was widespread competence in basic epidemiological skills, but an awareness of gaps in knowledge of more advanced epidemiological skills, and the opportunities to acquire these skills were lacking. Self-assessed competencies in each of the four other disciplines considered revealed greater training needs, especially regarding familiarity with the qualitative research skills for medical anthropology/sociology. Conclusions In Turkey there are considerable strengths to build upon. But a combination of institutional disincentives for research, and the lack of opportunities for the rising generation of researchers to acquire advanced training skills.</p

    Persistent Left Superior Vena Cava and Partial Anomalous Pulmonary Venous Return in an Old Asymptomatic Female Patient

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    Persistent left superior vena cava is a rare congenital venous anomaly. It results from failure of closure of the left anterior cardinal vein during cardiac development. It is usually asymptomatic but can be associated with other congenital cardiac defects including atrial septal defects, ventricular septal defects, endocardial cushion defects, tetralogy of Fallot and rhythm disturbances. PLSVC should be considered in the presence of a dilated coronary sinus on transthoracic echocardiography. The diagnosis can be made when injection of contrast in left antecubital vein results in enhancement of the dilated coronary sinus before right atrium. MRI, CT-scan and catheterisation can be used to confirm the diagnosis

    Direct interaction of the Usher syndrome 1G protein SANS and myomegalin in the retina

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    AbstractThe human Usher syndrome (USH) is the most frequent cause of combined hereditary deaf-blindness. USH is genetically heterogeneous with at least 11 chromosomal loci assigned to 3 clinical types, USH1-3. We have previously demonstrated that all USH1 and 2 proteins in the eye and the inner ear are organized into protein networks by scaffold proteins. This has contributed essentially to our current understanding of the function of USH proteins and explains why defects in proteins of different families cause very similar phenotypes. We have previously shown that the USH1G protein SANS (scaffold protein containing ankyrin repeats and SAM domain) contributes to the periciliary protein network in retinal photoreceptor cells. This study aimed to further elucidate the role of SANS by identifying novel interaction partners. In yeast two-hybrid screens of retinal cDNA libraries we identified 30 novel putative interacting proteins binding to the central domain of SANS (CENT). We confirmed the direct binding of the phosphodiesterase 4D interacting protein (PDE4DIP), a Golgi associated protein synonymously named myomegalin, to the CENT domain of SANS by independent assays. Correlative immunohistochemical and electron microscopic analyses showed a co-localization of SANS and myomegalin in mammalian photoreceptor cells in close association with microtubules. Based on the present results we propose a role of the SANS-myomegalin complex in microtubule-dependent inner segment cargo transport towards the ciliary base of photoreceptor cells

    Prenatal ethanol intoxication and maternal intubation stress alter cell survival and apoptosis in the postnatal development of rat hippocampus

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    It is well known that the fetal ethanol exposure and prenatal stress may have adverse effects on brain development. Interestingly, some morphological and functional recovery from their teratogenic effects that take place during brain maturation. However, mechanisms that underlie this recovery are not fully elucidated. The aim of this study was to examine whether the postnatal attenuation of fetal alcohol - and maternal stress-induced morphological and functional deficits correlates with compensatory changes in the expression/activation of the brain proteins involved in inflammation, cell survival and apoptosis. In this project, we investigated the hippocampus which belongs to the brain regions most susceptible to the adverse effects of prenatal ethanol exposure. Pregnant rat dams were administered ethanol (A) or isocaloric glucose solution (IC) by a gastric intubation during gestational days 7-20. The pure control group received ad libitum laboratory chow and water with no other treatment. The hippocampi of fetal-ethanol and control pups were examined at the postnatal day (PD)1, PD10, PD30 and PD60. Moderate fetal-ethanol exposure and prenatal intubation stress caused a significant increase in molecular factors relating to inflammation (iNOS) and cell survival/apoptosis pathways (PTEN, GSK-3 and ERK) at birth, with a rapid compensation from these developmental deficits upon removal of alcohol at PD10. Indeed, an increase in ERK1/2 and JNK1/2 activation at PD30 was observed with ethanol consumption. It indicates that the recovery process in A and IC brains started soon after the birth upon the ethanol and stressor withdrawal and continued until the adulthood

    Importance of ectopic thyroid tissue detected in the midline of the neck: single center experience

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    ABSTRACT Objective: Ectopic thyroid tissue (ETT) is a rare abnormality of the thyroid gland and the true prevalence and importance is not known. The aim of this study was to evaluate ultrasonography (US) guided fine needle aspiration biposy (FNAB) results, sonographic features, and frequency of ETT detected in the midline of the neck. Subjects and methods: Five thousand five hundred and twenty outpatients who were referred to our thyroid clinic between September 2010 and April 2012 and underwent thyroid US, were retrospectively analyzed. Patients with ETT, detected in the midline of the neck in US were included in the study. Thyroid functions, sonographic features, and US guided FNAB results were evaluated. Results: There were 81 (81.8%) female and 18 (18.2%) male patients with a mean age of 50.9 ± 11.7. The ETT in the midline was present in 1.79% (99/5,520) of the patients. In the majority of the patients, benign sonographic features (isoechoic, regular margin, type 1 vascularization) were detected. There were 92 (92.9%) patients with a previous history of thyroidectomy and all were histopathologically benign. In 7 (7.1%) patients, there was no history of thyroid operation. FNAB results of ETT were benign. Conclusion: This study evaluated the importance of ETT detected incidentally in the midline of the neck. Especially in patients with a history of thyroidectomy, the thyroid masses in the midline of the neck can be found as incidental with imaging methods. Our results suggests that the incidence of malignancy in this group is much lower than orthotopic thyroid nodules and they are often benign. Arch Endocrinol Metab. 2016;60(3):231-

    Out-of-pocket health care expenditure in Turkey: Analysis of the 2003-2008 Household Budget Surveys

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    This paper analyses the prevalence of ‘catastrophic’ out-of-pocket health expenditure in Turkey and identifies the factors which are associated with its risk using the Turkish Household Budget Surveys from 2003 to 2008. A sample selection approach based on Sartori (2003) is adopted to allow for the potential selection problem which may arise if poor households choose not to seek health care due to concerns regarding its affordability. The results suggest that poor households are less likely to seek health care as compared to non-poor households and that a negative relationship between poverty and experiencing catastrophic health expenditure remains even after allowing for such selection bias. Our findings, which may assist policy-makers concerned with health care system reforms, also highlight factors such as insurance coverage, which may protect households from the risk of incurring catastrophic health expenditure

    Interleukin-4 Alters Early Phagosome Phenotype by Modulating Class I PI3K Dependent Lipid Remodeling and Protein Recruitment

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    Phagocytosis is a complex process that involves membranelipid remodeling and the attraction and retention of key effector proteins. Phagosome phenotype depends on the type of receptor engaged and can be influenced by extracellular signals. Interleukin 4 (IL-4) is a cytokine that induces the alternative activation of macrophages (MΊs) upon prolonged exposure, triggering a different cell phenotype that has an altered phagocytic capacity. In contrast, the direct effects of IL-4 during phagocytosis remain unknown. Here, we investigate the impact of short-term IL-4 exposure (1 hour) during phagocytosis of IgG-opsonized yeast particles by MΊs. By time-lapse confocal microscopy of GFP-tagged lipid-sensing probes, we show that IL-4 increases the negative charge of the phagosomal membrane by prolonging the presence of the negatively charged second messenger PI(3,4,5)P3. Biochemical assays reveal an enhanced PI3K/Akt activity upon phagocytosis in the presence of IL-4. Blocking the specific class I PI3K after the onset of phagocytosis completely abrogates the IL-4-induced changes in lipid remodeling and concomitant membrane charge. Finally, we show that IL-4 direct signaling leads to a significantly prolonged retention profile of the signaling molecules Rac1 and Rab5 to the phagosomal membrane in a PI3K-dependent manner. This protracted early phagosome phenotype suggests an altered maturation, which is supported by the delayed phagosome acidification measured in the presence of IL-4. Our findings reveal that molecular differences in IL-4 levels, in the extracellular microenvironment, influence the coordination of lipid remodeling and protein recruitment, which determine phagosome phenotype and, eventually, fate. Endosomal and phagosomal membranes provide topological constraints to signaling molecules. Therefore, changes in the phagosome phenotype modulated by extracellular factors may represent an additional mechanism that regulates the outcome of phagocytosis and could have significant impact on the net biochemical output of a cell

    Empirical Analysis of Health and Educational Attainment in Turkey

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    The overall aim of this thesis is to examine and analyse three separate yet related issues in health and education that have been attracting increasing attention on the policy agenda in Turkey, especially over the recent decade. Public policy attention has particularly been devoted to issues such as financial protection against health care costs, decreasing the smoking prevalence rate and closing the gender gap in educational attainment. One of the main reasons behind the interest of policy makers in these areas may be attributed to need of the country to enhance human capital as well as to its aim to fulfill the requirements for EU membership. This provides the motivation for the empirical analyses presented in this thesis which investigate these issues in depth and, where relevant, provide policy implications. The first empirical study presented in Chapter 2 investigates the prevalence of ‘catastrophic’ out-of-pocket health care expenditure in Turkey and identifies the factors which are associated with its risk. The results indicate that poverty is an important barrier to seeking health care and that poverty is inversely associated with the risk of incurring catastrophic health expenditure. Chapter 3 examines the determinants of adult smoking propensity and intensity from a gender perspective. The findings of this chapter are twofold. First, the factors associated with smoking participation differ from the factors associated with the level of cigarette consumption. Second, the determinants of smoking behaviour are found to be different across males and females. The third empirical study is presented in Chapter 4 and aims to examine the educational attainment of girls and boys at the primary and secondary education levels. The findings indicate that the determinants of educational attainment and the potential factors that are associated with gender inequality differ by the level of education
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