1,720,958 research outputs found
Differential expression of miRNAs in the seminal plasma and serum of testicular cancer patients
No full textVarious microRNAs from the miR-371-3 and miR-302a–d clusters have recently been proposed as markers for testicular germ cell tumours. Upregulation of these miRNAs has been found in both the tissue and serum of testicular cancer patients, but they have never been studied in human seminal plasma. The aim of this study was, therefore, to assess the differences in the expression of miR-371-3 and miR-302a–d between the seminal plasma and serum of testicular cancer patients, and to identify new potential testicular cancer markers in seminal plasma. We investigated the serum and seminal plasma of 28 pre-orchiectomy patients subsequently diagnosed with testicular cancer, the seminal plasma of another 20 patients 30 days post-orchiectomy and a control group consisting of 28 cancer-free subjects attending our centre for an andrological check-up. Serum microRNA expression was analysed using RT-qPCR. TaqMan Array Card 3.0 platform was used for microRNA profiling in the seminal plasma of cancer patients. Results for both miR-371-3 and the miR-302 cluster in the serum of testicular cancer patients were in line with literature reports, while miR-371and miR-372 expression in seminal plasma showed the opposite trend to serum. On array analysis, 37 miRNAs were differentially expressed in the seminal plasma of cancer patients, and the upregulated miR-142 and the downregulated miR-34b were validated using RT-qPCR. Our study investigated the expression of miRNAs in the seminal plasma of patients with testicular cancer for the first time. Unlike in serum, miR-371-3 cannot be considered as markers in seminal plasma, whereas miR-142 levels in seminal plasma may be a potential marker for testicular cancer
Sperm glyceraldehyde 3-phosphate dehydrogenase gene expression in asthenozoospermic spermatozoa
Get PDFIt has been suggested that the energy required for sperm motility is produced by oxidative phosphorylation while glycolysis seems to be an important source for ATP transmission along the flagellum. Some studies have investigated the chemical and kinetic properties of the enzyme glyceraldehyde 3‐phosphate dehydrogenase to identify any changes in the regulation of glycolysis and sperm motility. In contrast, there are few studies analyzing the genetic basis of hypokinesis. For this reason, we investigated the glyceraldehyde 3‐phosphate dehydrogenase gene in human sperm to evaluate whether asthenozoospermia was correlated with any changes in its expression. Semen examination and glyceraldehyde 3‐phosphate dehydrogenase gene expression studies were carried out on 116 semen samples divided into two groups – Group A consisted of 58 normokinetic samples and Group B of 58 hypokinetic samples. Total RNA was extracted from spermatozoa, and real‐time PCR quantification of mRNA was carried out using specific primers and probes. The expression profiles for the Groups A and B were very similar. The mean delta Ct was as follows – Group A, 5.79 ± 1.04; Group B, 5.47 ± 1.27. Our study shows that in human sperm, there is no difference in glyceraldehyde 3‐phosphate dehydrogenase gene expression between samples with impaired motility and samples with normal kinetics. We believe that this study could help in the understanding of the molecular mechanisms of sperm kinetics, suggesting that hypomotility may be due to a possible posttranscriptional impairment of the control mechanism, such as mRNA splicing, or to posttranslational changes
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
Semen quality and fertility before and after therapy in patients affected by non Hodgkin Lymphoma
No full textNon hodgkin lymphoma represent phatology in men in fertile age and includes about 8% of all cancer diagnosis in men aver 15-45 years. In recent years overall survival of these patients has improved remarkably. Thus, new challenges regarding reproductive outcome have emerged as many antineoplastic regimens utilised as chemotherapy (CH) and radiotherapy (RT), stem cell transplantation (SCT), are known to alter semen qualit
Human sperm motility: a molecular study of mitochondrial DNA, mitochondrial transcription factor A gene and DNA fragmentation
No full textAlterations affecting the mitochondrial genome and chromatin integrity of spermatozoa impair male reproductive potential. This study aimed to evaluate the impact of mitochondrial DNA (mtDNA) copy number alterations on sperm motility and on the molecular mechanism regulating the number of mtDNA copies, through analysis of mitochondrial transcription factor A (TFAM) gene expression. It also investigated any correlation between mtDNA copy number and sperm DNA fragmentation (SDF). Sixty-three asthenozoospermic semen samples (Group A) and 63 normokinetic semen samples (Group N) were analysed according to WHO (WHO laboratory manual for the examination and processing of human semen, World Health Organization, Geneva, 2010). Sperm mtDNA copy number and TFAM gene expression were quantified by real time quantitative polymerase chain reaction. SDF was evaluated using the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) assay. The mtDNA copy number was higher in asthenozoospermic semen samples and was negatively correlated with sperm concentration, total sperm number and total motile spermatozoa. The caseload showed a global negative correlation of TFAM gene expression with total motile sperm and a positive correlation with abnormal forms, SDF and mtDNA copy number, but this was not confirmed within each subgroup. SDF was significantly increased in asthenozoospermic samples and correlated with abnormal forms. No correlation was found between SDF and mtDNA copy number. Our results suggest a potential role of mtDNA content as an indicator of semen quality and support the hypothesis that dysregulation of TFAM expression is accompanied by a qualitative impairment of spermatogenesis. Since mtDNA copy number alterations and impaired chromatin integrity could affect reproductive success, these aspects should be evaluated in relation to assisted reproductive techniques
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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