1,720,976 research outputs found
Retention of heterozygosity at chromosome 7p22 and 11q13 in aldosterone-producing tumors of patients with familial hyperaldosteronism not remediable by glucocorticoids
No full textThe mechanisms involved in aldosterone overproduction and adrenal cell proliferation of FH-II remain unknown. The genetic basis of this disorder may involve heritable alterations of more than one gene and/or reflect an unrestrained stimulation of aldosterone synthesis and cell growth factors
Inhibin B levels in azoospermic subjects with cytologically characterized testicular pathology
No full textBACKGROUND AND OBJECTIVE:
Inhibin B, a heterodimeric glycoprotein of gonadal origin, is the most important circulating form of inhibin in human males and an inverse relationship between inhibin B and FSH plasma levels was been recently observed. Azoospermia represents the end-point of different kinds of testicular damage, ranging from a normal spermatogenic pattern (obstructive forms) to the complete absence of germ cells (Sertoli Cell Only Syndrome, SCOS). Furthermore, azoospermia may be related to maturational disturbances at different levels (spermatogonial, spermatocytic, spermatidic). To better define the relationship between testicular damage and inhibin levels and to evaluate the diagnostic value of this hormone in the management of subjects with azoospermia, we performed specific inhibin B assays in a group of azoospermic subjects affected by different kinds of testicular pathology.
PATIENTS:
Eighty-nine azoospermic men were studied by testicular ultrasound examination, fine needle aspiration of the testes and hormonal parameters (FSH, LH and testosterone, inhibin B). Thirty normozoospermic subjects were considered as controls for seminal and hormonal parameters.
DESIGN AND RESULTS:
On the basis of cytological analysis five different testicular appearences were identified in azoospermic patients: (i) Sertoli cell only syndrome (SCOS); (ii) Severe hypospermatogenesis; (iii) Spermatogonial and/or spermatocytic arrest; (iv) Spermatidic arrest; (v) Normal germ line (obstructive forms). No difference in LH and testosterone levels was found among the different groups. A significant negative correlation was present between inhibin B and FSH both in azoospermic men (r = - 0.503, P < 0.0001) and normozoospermic controls (r = -0.361, P < 0.05). Groups characterized by obstructive azoospermia and spermatidic arrest showed inhibin B concentrations similar to normozoospermic subjects (130.7 +/- 73.5, 160.3 +/- 35.1 and 148.5 +/- 46.8 ng/l, respectively), while groups characterized by SCOS, severe hypospermatogenesis and spermatogonial and/or spermatocytic arrest showed mean inhibin B concentrations significantly lower than controls (56.5 +/- 56.0, 57.9 +/- 31.2; 48.9 +/- 16.7 ng/l, respectively). In the group of SCOS, 8 out of 42 subjects (19.0%) showed inhibin B concentrations within the normal range despite high FSH levels.
CONCLUSIONS:
This study demonstrated that, in humans, spermatids play an important role in the mechanism regulating inhibin B secretion by Sertoli cells. The significance of this hormone as a diagnostic parameter in azoospermic patients does not seem to be specific because it does not permit discrimination between obstructive forms or spermatidic arrest. Furthermore, despite an evident clinical, cytological and hormonal pattern for SCOS, inhibin B levels are normal in some of these patients. The significance of this latter result remains to be elucidated
Case report: high fertilization rate in conventional in-vitro fertilization utilizing spermatozoa from an oligozoospermic subject presenting microdeletions of the Y chromosome long arm.
No full textEffect of captopril on aldosterone response to potassium infusion in primary aldosteronism
No full textHigh fertilization rate in conventional in-vitro fertilization utilizing spermatozoa from an oligozoospermic subject presenting microdeletions of the Y chromosome long arm
No full textAbnormality of aldosterone and cortisol pathways in Glucocorticoid-Remediable Aldosteronism.
No full text
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
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
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