1,722,158 research outputs found
Synthesis of the allylic regulatory steroid, 3α-hydroxy-4-pregnen-20- one, by rat granulosa cells and its regulation by gonadotropins
No full textThe production of the allylic regulatory steroid 3α-hydroxy-4-pregnen- 20-one (3αHP) in the rat ovary was examined and compared to progesterone levels through use of specific RIAs that had been validated by capillary gas chromatography-mass spectrometry (GC/MS). Results showed that serum levels of 3αHP are comparable to levels of progesterone at all ages examined. In the 4-day cycling rat, serum levels of 3αHP were highest during diestrus and lowest during proestrus and estrus, while serum FSH levels were highest during proestrus/estrus and lowest during diestrus. Hypophysectomy resulted in decreases in ovarian and serum 3αHP. Treatment of hypophysectomized rats with eCG, but not hCG, increased ovarian and serum 3αHP, while serum progesterone was elevated by treatment with hCG. Ovariectomy resulted in a 55-60% reduction in serum 3αHP, indicating that ovaries are a substantial, but not exclusive, source of 3αHP in serum. As further evidence, cultures of preparations consisting primarily of either granulosa cells or granulosa/theca 'shells' produced 3αHP in time-dependent amounts comparable to those of progesterone. Granulosa cells in culture showed a significant increase in accumulation of 3αHP (and progesterone) due to treatment with FSH, but not LH. In contrast to the granulosa-only cell cultures, follicle shells consisting of theca and granulosa cells responded to either LH or FSH treatment with marked increases in 3αHP; increases resulting from combined treatment (FSH + LH) were significantly greater than those due to each hormone alone, but the increases were not additive. Studies of the metabolism of [14C]progesterone by cultured granulosa cells indicated not only that 3αHP is a direct product of progesterone but also that it can serve as a precursor for 4-ene steroids (such as 4-pregnen-20α-ol-3-one) as well as for the 5α-reduced steroid, 5α-pregnan-3α-ol-20-one. A 4-ene 21-carbon steroid cycle is proposed for ovarian steroidogenesis that includes 3αHP as a pivotal member and suggests an additional new pathway for steroid interconversion in the ovary. Since there is rapid interconversion between progesterone and 3αHP, it is possible that some of the actions (intraovarian and otherwise) previously ascribed to progesterone may be due, wholly or in part, to the actions of 3αHP
"Aspetti radiografici e implicazioni chirurgiche nei tumori del sacro"
No full textAspetti radiografici e implicazioni chirurgiche nei tumori del sacr
Letter to the Editor: Restructuring the Gut Microbiota of Patients with Cirrhosis After HCV Eradication: A Matter of Time?
No full textN/
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Gaspare Tagliacozzi, pioneer of plastic surgery and the spread of his technique throughout Europe in "De Curtorum Chirurgia per Insitionem"
No full textGaspare Tagliacozzi's innovative surgical technique, which consisted of reconstructing parts of the face by grafting, was masterfully described in the work that made him famous, "De Curtorum Chirurgia per Insitionem." It was published by Gaspare Bindoni the Younger in 1597 in Venice, who was granted the exclusive right to print it by the Senate. However, in the same year in Venice Roberto Meietti published an unauthorized edition; nevertheless, this edition was soon discovered. The great demand for the text even abroad was soon testified by a 3rd edition published in Frankfurt in 1598, similar to the Bindoni edition but in another format and with a different title. This has caused confusion among bibliographers and Authors. Two centuries later, in 1831 in Berlin, a 4th edition was printed, thus suggesting renewed interest in rhinoplasty procedures, which surgeons Van Graefe and Dieffenbach promoted in Germany. However, few people know that the integral text of Tagliacozzi's De Curtorum was also published by Jacques Manget in his "Bibliotheca Chirurgica," printed in Venice in 1721. The name of the illustrator of the three fourteenth-century editions, whose illustrations in the text are compared, is not known. Instead the name of the artist, Tiburzio Passerotti, who painted Tagliacozzi's portrait holding his De Curtorum open at the ninth woodcut shortly before it was printed, is well known. The impact of Tagliacozzi's technique on modern surgery is supported by experience of the last century as well as recent years, mostly in musculoskeletal oncology reconstruction
Atlas of craniocervical Junction and cervical spine surgery
No full textAtlas of craniocervical Junction and cervical spine surger
Variations on the Author
Full text link“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
Onset of Berger disease after Staphylococcus aureus infection: septic arthritis after anterior cruciate ligament reconstruction.
No full textSeptic arthritis is rare in patients undergoing knee arthroscopic surgery. If the infection is due to Staphylococcus aureus, patients might experience fever, severe clinical syndromes, and extra-articular manifestations, including vasculitis and glomerulonephritis. We describe a case of onset of immunoglobulin A nephropathy (Berger disease) after S aureus septic arthritis complicating an anterior cruciate ligament surgical reconstruction. The patient had no previous history of renal disease, and renal function returned to normal after resolution of the knee infection. S aureus infection has been associated with several glomerular diseases, but this is the first report of the infection causing immunoglobulin A nephropathy. In addition, this is the first description of Berger disease after arthroscopic treatment, providing evidence that this disease might complicate the clinical course of orthopedic surgery
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
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