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Studio sull’espressione e distribuzione della P450 aromatasi nell’ipotalamo ovino a differenti stadi di sviluppo fetale
Get PDFThe main goal of this study was to evaluate expression and distribution of
P450arom in the hypothalamus of sheep at different stages of fetal
development (E30, E40, E50, E80, E100, E115). Fetal heads were removed
and hypothalami dissected and fixed with ice-cold 4% paraformaldehyde for
3-4 hrs and then cryoprotected with 30% sucrose. Coronal cryotome sections
of the head at the hypothalamic level, 10μm thick, were obtained and
underwent immunoperoxidase technique (streptavidin biotin complex)
employing two polyclonal antibody: anti-P450arom and anti-androgen
receptor (AR), and a monoclonal antibody, anti-βIII. With the aim of
evaluating P450arom gene expression, samples from E30 and E50 the
earliest stage among those examined, to be processed within situhybridization technique using a biotinylated cDNA probe. Finally, blot
analyses were performed in order to verify the antibody specificity, as well as
quantify possible differences in P450arom amounts between sexes. For
sexing, fetal samples at E35 and E55 underwent DNA extraction and PCR
amplification of the sex determining region of the Y chromosome using
primers (SRYA) specific to the sheep. Moreover double immunofluorescences
were carried out using four antibody: a polyclonal antibody: anti-P450arom
and three monoclonal antibody: anti-GFAP, anti-PCNA and anti-βIII tubuline
Setting Up of Primary Cultures from Fetal Dog Brain: An Alternative Method in Line with the 3Rs Principles
No full textIn the last years, alternatives to animal testing were applied, aimed at reduce
the laboratory use of animals, in agreement with the 3Rs principles (Reduction,
Refinement and Replacement). In the approach to the study of neurological
disorders, several in vitro models and alternative animal species like mammals
with a more complex nervous system have been proposed as translational
model for human. Lately, canines have been considered an excellent model
for study on neurodegenerative disorders since they may develop central
nervous system disease close to those observed in humans. In the present
report, we describes a method to obtaining primary cultures from dog fetuses
brain collected accidentally and cryopreserved until the use. The brain tissues
were dissociated through a mild enzymatic papain system and cultured, and the
development, morphology and the amount of neuronal cells were assessed. We
appreciated the capability of cryopreserved brain tissues to provide a vital and
proliferating neuronal primary culture. Moreover, we noticed which explants from
early gestation days fetuses (25 days) yielded the higher number of neurons
in comparison with those obtained from older fetuses (45days). Our data may
suggest a good alternative experimental approach to obtain a primary neuronal
culture, without necessarily having to use experimental animals
Morphological and morphometrical features of Sardinian wild cat (Felis silvestris lybica var. sarda)
No full textWildcats (Felis silvestris) spread over Europe ranging from Spanish to Eastern woodlands. In Northern Africa, the wildcat belongs to a different subspecies (Felis silvestris libyca) which diffused in Sardinia giving rise to a novel taxon there (Felis silvestris libyca sarda). The morphological features of the Sardinian wildcat taxon are not well-know yet. In our work its morphological and morphometrical features have been studied on 19 stuffed models. Numerous morphometrical parameters were taken, and the distribution of spots and stripes of the coat was studied. A low variability in the morphometrical parameters was detected, confirming that the Sardinian wildcat can be considered a well-defined taxon. Since one of the most severe problems in the safeguard of pure Sardian wildcats in their crossbreeding with domestic cats, the comprehensive knowledge of the anatomical features of these animals could be useful in making a distinction between these two taxa
Expression and distribution of P450-aromatase in the ovine hypothalamus at different stages of fetal development
No full textOBJECTIVES:
An important step of sexual differentiation is the conversion of testosterone to estrogen by aromatase leading to masculinization and defeminization of the fetal brain areas crucial for normal sexual behavior and reproduction. Brain sexual differentiation occurs throughout a critical period starting from different prenatal stages depending on the species. Such period goes on from gestation day (GD) 30 to 100GD in the sheep. The fetal sheep brain is reported to aromatize androgens to estrogens at 64GD. The main goal of this work was to evaluate aromatase expression in sheep hypothalami during the whole period of sexual differentiation (35GD, 55GD, 80GD, 115GD) and whether differences may be observed depending on gestational stage and sex.
METHODS:
Sections at the hypothalamic level underwent immunoperoxidase technique employing anti-aromatase and anti-androgen receptor antibodies. Samples from 35GD and 55GD were also processed with in situ hybridization using aromatase cDNA probe. Blot analyses were performed to quantify possible aromatase immunoexpression differences between sexes. For sexing, samples at 35GD and 55GD underwent DNA extraction and SRY amplification.
RESULTS:
Our results revealed aromatase and androgen receptor immunoreactivity along the whole period of sexual differentiation. Both molecules were detected in many brain regions and markedly in the periventricular area. The highest aromatase and androgen receptor amounts were observed at 35GD and 55GD, when aromatase was more abundant in females than in males.
CONCLUSIONS:
In conclusion, the sheep can be included among the species where aromatase is highly expressed in the hypothalamus during the whole period of sexual differentiation
Studio sull’espressione e distribuzione della P450 aromatasi nell’ipotalamo ovino a differenti stadi di sviluppo fetale
No full textThe main goal of this study was to evaluate expression and distribution of
P450arom in the hypothalamus of sheep at different stages of fetal
development (E30, E40, E50, E80, E100, E115). Fetal heads were removed
and hypothalami dissected and fixed with ice-cold 4% paraformaldehyde for
3-4 hrs and then cryoprotected with 30% sucrose. Coronal cryotome sections
of the head at the hypothalamic level, 10μm thick, were obtained and
underwent immunoperoxidase technique (streptavidin biotin complex)
employing two polyclonal antibody: anti-P450arom and anti-androgen
receptor (AR), and a monoclonal antibody, anti-βIII. With the aim of
evaluating P450arom gene expression, samples from E30 and E50 the
earliest stage among those examined, to be processed with in situ
hybridization technique using a biotinylated cDNA probe. Finally, blot
analyses were performed in order to verify the antibody specificity, as well as
quantify possible differences in P450arom amounts between sexes. For
sexing, fetal samples at E35 and E55 underwent DNA extraction and PCR
amplification of the sex determining region of the Y chromosome using
primers (SRYA) specific to the sheep. Moreover double immunofluorescences
were carried out using four antibody: a polyclonal antibody: anti-P450arom
and three monoclonal antibody: anti-GFAP, anti-PCNA and anti-βIII tubuline
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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