1,720,995 research outputs found
Invasive and Noninvasive Approaches in Prenatal Diagnosis of Thalassemias
No full textThalassemia is a significant health problem worldwide. There are two main classifications, α- and β-thalassemias, which are usually caused by the defective synthesis of the α-globin, and which are commonly caused by different mutations of the β-globin chain. Different hemoglobin mutations have been identified to date. Thalassemias can result in profound anemia from early life and, if not treated with regular blood transfusions, can lead to death in the first year. Prenatal diagnosis of thalassemia is the essential part of preventive medicine and is currently dependent on the use of invasive diagnostic tests within the first 2 months of pregnancy. These diagnostic techniques carry a small but significant risk of fetal loss up to 1%. Molecular diagnostic methods have been developed for genotyping thalassemias based on PCR techniques and high-throughput technologies. Noninvasive tests using cell-free DNA (cfDNA) from a maternal blood sample is also an alternative method, thus eliminating the risk of miscarriage. This chapter summarizes the current invasive approaches and the noninvasive methods using cell-free fetal DNA as new molecular diagnostic methods for genotypic diagnosis of thalassemia in clinical practice. Prevention strategies that encompass carrier screening, genetic counseling, and prenatal diagnosis are discussed
Laboratory Approach to Anemia
No full textAnemia is a major cause of morbidity and mortality worldwide and can be defined as a decreased quantity of circulating red blood cells (RBCs). The epidemiological studies suggested that one-third of the world’s population is affected with anemia. Anemia is not a disease, but it is instead the sign of an underlying basic pathological process. However, the sign may function as a compass in the search for the cause. Therefore, the prediagnosis revealed by thorough investigation of this sign should be supported by laboratory parameters according to the underlying pathological process. We expect that this review will provide guidance to clinicians with findings and laboratory tests that can be followed from the initial stage in the anemia search
Investigation of the effects of vitamin D treatment on the uterine structural changes in the experimental model with polycystic ovary syndrome: an ultrastructural and immunohistochemical study
No full textIn this study, we aimed to investigate the structural changes seen in the endometrium in experimental PCOS rat model and the effects of vitamin D treatment on these changes at immunohistochemical and electron microscopic levels. 24 prepubertal female rats were divided into three groups. Two groups were injected with dehydroepiandrosterone and one of them was treated with 1,25(OH)2 D3 at the same time. The control group was injected with sesame oil. At the end of the 28th day, the blood samples were collected. Uterus tissues were prepared for light and electron microscopic examinations. Epithelial, stromal and endometrial thickness measurements were investigated. Immunohistochemical staining was applied against caspase-3 and Ki-67. Serum AMH and estradiol levels were higher in PCOS group compared to the control group. Serum progesterone levels were similar in all groups. Endometrial, epithelial and stromal thickness measurements were increased in PCOS group compared to the control group, and decreased in the vitamin D treatment group compared to the PCOS group. Light and electron microscopic results of PCOS group showed an increase in apoptosis and proliferation. In the PCOS group, immunohistochemical staining of caspase-3 and Ki-67 were found to be higher than in the control group, but stainings were decreased with vitamin D treatment compared to PCOS group. Structural changes observed in endometrium may be related to implantation problems seen in patients with PCOS. Our studies suggest that vitamin D therapy may be beneficial in these patients
A New Alternative Approach for RhD Incompatibility; Determination Fetal RhD Status via Biosensor Technology
No full textPrenatal detection of the fetal RHD status in early stage of pregnancy is observed to be useful in the management of RhD incompatibility to identify fetuses at risk of hemolytic disease. The routine use of antenatal and postnatal anti-D prophylaxis reduces the incidence of hemolytic disease of the fetus and newborn. Cell-free fetal DNA in maternal plasma is in use today for routine genotyping fetal RHD status. Fetal RhD antigens can be detected in the blood of RhD-negative pregnant women using a nanopolymer-coated biosensor and could be an alternative method for medical diagnosis. We detected RhD-positive fetal antibodies with biosensor in maternal blood of RhD-negative mothers. The electrochemical measurements were performed on a PalmSens potentiostat and corundum ceramic-based screen-printed gold electrode. The demonstrated method has a different view for the detection of fetal RhD status in early pregnancy. The biosensor technology is useful and can be carried out rapidly in clinical diagnosis. Biosensors are also reproducible methods which give results quickly compared to noninvasive fetal RHD genotyping with real-time PCR-based techniques. We suggest that this method could become an alternative part of fetal RHD genotyping from maternal plasma as a prenatal screening in the management of RhD incompatibility
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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