Submicroscopical observations on the differentiation of chick gonads

Development ◽  
1966 ◽  
Vol 16 (1) ◽  
pp. 41-47
Author(s):  
Roberto Narbaitz ◽  
Ruben Adler
Keyword(s):  
Morphological Changes ◽  
Morphological Differentiation ◽  
Sex Identification ◽  
The Other ◽  
Gonadal Differentiation ◽  
Steroid Production ◽  
Steroid Synthesis ◽  
Estrogen Synthesis ◽  
Exact Moment

The role of hormones in gonadal differentiation has not been fully elucidated. One of the main problems consists in determining the exact moment in which steroid synthesis begins. If, as has been claimed, sex hormones act as organizers and are responsible for the morphological changes which characterize gonadal differentiation, then they should appear before these changes take place. Although the morphological differentiation of chick gonads is evident only after the eighth day of incubation small differences in epithelium height permit sex identification on the seventh day. Biological (Wolff, 1946), biochemical (Gallien & Le Foulgoc, 1961) and histochemical (Scheib, 1959; Narbaitz & Sabatini, 1963; Narbaitz & Kolodny, 1964; Chieffi, Manelli, Botte & Mastrolia, 1964) evidence suggests that estrogen synthesis takes place in embryonic ovaries after the eighth day. On the other hand, steroid production by embryonic testes has not been proven.

Role of pro-opiomelanocortin-derived peptides in the regulation of steroid production by human fetal adrenal cells in culture

1983 ◽  
Vol 97 (3) ◽  
pp. 357-367 ◽  
Author(s):  
Andrew Baird ◽  
K. W. Kan ◽  
Samuel Solomon
Keyword(s):  
Peptide Hormones ◽  
The Other ◽  
Dehydroepiandrosterone Sulphate ◽  
Steroid Production ◽  
Adrenal Cells ◽  
The Third ◽  
Cells In Culture

Synthetic (1–39)ACTH, (1–24)ACTH, (18–39)ACTH, α-MSH, met-enkephalin and α-, βand γ-endorphin were tested for their ability to stimulate steroidogenesis by human fetal adrenal cells in culture. Adrenal cells were incubated with peptide hormones for two periods of 24 h. On the third day of the experiment the cells were incubated with progesterone (4 μg/2 ml) for 8 h. At the doses tested only (1–39)ACTH, (1–24)ACTH and α-MSH stimulated steroidogenesis. None of the other peptides had any corticotrophic effect on the formation of cortisol, corticosterone or dehydroepiandrosterone sulphate (DHAS). At the highest doses tested, α-MSH (100 μg/2 ml) had a corticotrophic effect that was not different from that obtained with 20 ng (1–39)ACTH or (1–24)ACTH. At the lower doses (0·2–2 μg/2 ml), α-MSH stimulated the formation of DHAS (P<0·01) without stimulating the formation of cortisol.

Membrane Potentials in Amoeba Proteus

1966 ◽  
Vol 45 (2) ◽  
pp. 251-267
Author(s):  
M. S. BINGLEY
Keyword(s):  
Plasma Membrane ◽  
Membrane Potential ◽  
Morphological Changes ◽  
Amoeba Proteus ◽  
Membrane Potentials ◽  
The Other ◽  
The Earth ◽  
Electrode Resistance ◽  
Alternating Voltage

1. Amoebae can be penetrated by microelectrodes at either end. One records voltage and the other supplies alternating current. 2. Step-like increases in alternating voltage superimposed on potentials recorded by the voltage electrode when in either the pseudopod or rear region demonstrate that low potentials recorded from a pseudopod and high ones from the rear region exist across a discrete impedance barrier. The only structure so far shown to fulfil this function is the plasma membrane. 3. A resistance inserted in the earth path monitors current flowing through the system and confirms observations made when recording with single electrodes that there is a reduction of electrode resistance when the cell is entered. 4. Pronounced depolarization in the rear region is shown when the current-carrying electrode penetrates the pseudopod, but not vice versa. 5. Morphological changes associated with membrane potential reversal are illustrated. 6. Consideration is given to the role of step-like potential changes in movement.

scholarly journals Aromatase expression in Xenopus oocytes: a three cell-type model for the ovarian estradiol synthesis

2011 ◽  
Vol 47 (2) ◽  
pp. 241-250 ◽  
Author(s):  
M Gohin ◽  
P Bodinier ◽  
A Fostier ◽  
J Bobe ◽  
F Chesnel
Keyword(s):  
Classical Model ◽  
Biological Significance ◽  
Type Model ◽  
Aromatase Activity ◽  
Steroid Synthesis ◽  
Aromatase Expression ◽  
Androgen Synthesis ◽  
Estrogen Synthesis ◽  
Estradiol Synthesis

In contrast to the classical model describing the synthesis of androgens and estrogens as restricted to somatic cells, a previous study demonstrated that Xenopus laevis oocytes participate in androgen synthesis. The objective of our study was to determine whether Xenopus oocytes are also involved in estrogen synthesis. More precisely, we analyzed aromatase expression by in situ hybridization and RT-QPCR and measured aromatase activity. Aromatase, the enzyme responsible for estrogen synthesis, appears to be expressed and active not only in the follicular cells but also in the vitellogenic oocytes. During late oogenesis, aromatase oocyte expression and activity decreased concomitantly with the trend observed in surrounding follicular layers. In order to investigate the role of estradiol-17β (E2), we studied its effect on oocyte meiotic resumption. It appears that, as in Rana pipiens, E2 inhibited the follicle-enclosed maturation of Xenopus oocytes, likely through inhibition of LH-induced maturation-inducing steroid synthesis. In addition, E2 exerted a slight enhancing action on denuded oocyte maturation whose biological significance remains unclear. Together, our results demonstrate that Xenopus oocyte significantly participates in ovarian E2 synthesis and this may be a common feature of vitellogenic vertebrates.

GIVING BIRTH TO CHILD OR IDEA: THE FEMININE DILEMMA

1983 ◽  
Vol 11 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Patricia Phillips ◽  
Fred Rozendal
Keyword(s):  
Sex Identification ◽  
The Other ◽  
Biological Role ◽  
Direct Production ◽  
The Feminine ◽  
Personal Conflict

Women today face a dilemma in creativity. Historically, women have been forced to create vicariously by supporting another person who creates (e.g., a child). More direct creativity, of music, painting, or ideas, has been reserved for men. In vicarious creativity, the woman fulfills her biological role of producing offspring. She gives birth to a child instead of an idea and projects her unfulfilled need to create directly to the child, who then has the task of creating. Direct creativity was repressed in women for centuries because of a belief that women were inferior. This concept evolved into the idea that if they were creative, then they must have qualities or abilities that only men possess. Previous research using the Mf scale of the MMPI suggests that creative individuals of either sex exhibit some cross-sex identification and implies that androgeny may be a useful component of creativity. Creativity has also been seen as a sign of psychopathology. Some (e.g., Bergler) believe creativity comes about to solve inner conflicts, while others (e.g., Rollo May) consider that creativity is a sign of courage. Women traditionally have not had direct creativity as an option in resolving personal conflict. Instead, they have been limited to vicarious creativity, while feeling resentment or fear that they do not live up to their role. The dilemma facing contemporary women is that by choosing one form of creativity (family or direct production), the need to do the other will be left unsatisfied. Should I have chosen a career? Should I have had children? If she chooses both, she feels guilt at doing an inadequate job with either form of creativity. Thus, with the advent of more options, women have discovered a new dilemma.

Gender, love and recognition in I Love Dick and The Other Woman

2021 ◽  
pp. 135050682199591
Author(s):  
Camilla Schwartz ◽  
Rita Felski
Keyword(s):  
Comparative Analysis ◽  
Women's Writing ◽  
Sex Identification ◽  
The Other ◽  
Same Sex ◽  
Literary Works ◽  
The World ◽  
Other Woman ◽  
Women’S Writing

How might the idea of recognition offer a fresh slant on contemporary women’s writing? In this essay, we bring theories of recognition into dialogue with two literary works: Chris Kraus’s widely reviewed memoir I Love Dick and The Other Woman by the well-regarded Swedish novelist Therese Bohman. Our analysis focuses on recognition within the texts as well as its relevance to relations between texts and readers. We seek to clarify how attitudes to heterosexual love, feminism and same-sex identification are entangled and the broader implications of such entanglements. We are interested in how the protagonists engage the world as readers and the role of literature in shaping their identifications and attachments. Yet, a comparative analysis can also bring to light how a feminist habitus is predicated on class and education, suggesting that these two texts may invite rather different experiences of recognition.

scholarly journals A role for calmodulin in the regulation of steroidogenesis

1981 ◽  
Vol 90 (2) ◽  
pp. 402-407 ◽  
Author(s):  
PF Hall ◽  
S Osawa ◽  
CL Thomasson
Keyword(s):  
Cyclic Amp ◽  
Adrenal Tumor ◽  
Side Chain ◽  
Dibutyryl Cyclic Amp ◽  
Steroid Production ◽  
Steroid Synthesis ◽  
Side Chain Cleavage ◽  
Cleavage Activity ◽  
Chain Cleavage

Two approaches were used to study the possible role of calmodulin in the regulation of steroid synthesis by mouse adrenal tumor cells: trifluoperazine was used as an inhibitor of calmodulin and liposomes were used to deliver calmodulin into the cells. Trifluoperazine inhibits three steroidogenic responses to both ACTH and dibutyryl cyclic AMP: (a) increase in steroid production, (b) increased transport of cholesterol to mitochondria, and (c) increased side-chain cleavage by mitochondria isolated from cells incubated with ACTH or dibutyryl cyclic AMP. When calmodulin is introduced into the cells via liposomes, steroid synthesis is slightly stimulated. When calmodulin extensively dialyzed against EGTA, this stimulation is abolished. Ca(2+) introduced via liposomes was also without effect. However, when both calmodulin and Ca(2+) are introduced via liposomes (either in separate liposomes or in the same liposomes), steroid synthesis is stimulated. This stimulation does not occur when either anticalmodulin antibodies or EGTA is also present in the liposomes or when trifluoperazine is present in the incubation medium. Calmodulin and Ca(2+) presented together in liposomes to the cells stimulate transport of cholesterol to mitochondria, and side-chain cleavage activity is greater in mitochondria isolated from cells previously fused with liposomes containing calmodulin and Ca(2+) than in mitochondria from cells fused with liposomes containing buffer only. These observations suggest that calmodulin may be involved in regulating the transport of cholesterol to mitochondria, a process which is stimulated by ACTH and dibutyryl cyclic AMP and which may account, at least in part, for the increase in steroid synthesis produced by these agents.

Plasma Levels of Protein S, Protein C, and Factor X: Effects of Sex, Hormonal State and Age

1995 ◽  
Vol 74 (05) ◽  
pp. 1271-1275 ◽  
Author(s):  
C M A Henkens ◽  
V J J Bom ◽  
W van der Schaaf ◽  
P M Pelsma ◽  
C Th Smit Sibinga ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Postmenopausal Women ◽  
Protein C ◽  
Blood Donors ◽  
Premenopausal Women ◽  
Protein S ◽  
The Other ◽  
Factor X ◽  
Normal Ranges

SummaryWe measured total and free protein S (PS), protein C (PC) and factor X (FX) in 393 healthy blood donors to assess differences in relation to sex, hormonal state and age. All measured proteins were lower in women as compared to men, as were levels in premenopausal women as compared to postmenopausal women. Multiple regression analysis showed that both age and subgroup (men, pre- and postmenopausal women) were of significance for the levels of total and free PS and PC, the subgroup effect being caused by the differences between the premenopausal women and the other groups. This indicates a role of sex-hormones, most likely estrogens, in the regulation of levels of pro- and anticoagulant factors under physiologic conditions. These differences should be taken into account in daily clinical practice and may necessitate different normal ranges for men, pre- and postmenopausal women.

On the role of the dispute between "non-possessors" and "Josephites" in the culture of Moscow's prediction

1998 ◽  
pp. 61-62
Author(s):  
N. S. Jurtueva
Keyword(s):  
The Other ◽  
Moral Transformation ◽  
15Th Century ◽  
The Future ◽  
Secular Power

In the XIV century. centripetal tendencies began to appear in the Moscow principality. Inside the Russian church, several areas were distinguished. Part of the clergy supported the specificobar form. The other understood the need for transformations in society. As a result, this led to a split in the Russian church in the 15th century for "non-possessors" and "Josephites". The former linked the fate of the future with the ideology of hesychasm and its moral transformation, while the latter sought support in alliance with a strong secular power.

From Container to Claustrum: Projective Identification in Couples

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
Tamara Feldman
Keyword(s):  
Psychological Health ◽  
Projective Identification ◽  
The Self ◽  
The Other ◽  
Intimate Partners ◽  
And Control ◽  
The Relationship ◽  
As If

This paper is a contribution to the growing literature on the role of projective identification in understanding couples' dynamics. Projective identification as a defence is well suited to couples, as intimate partners provide an ideal location to deposit unwanted parts of the self. This paper illustrates how projective identification functions differently depending on the psychological health of the couple. It elucidates how healthier couples use projective identification more as a form of communication, whereas disturbed couples are inclined to employ it to invade and control the other, as captured by Meltzer's concept of "intrusive identification". These different uses of projective identification affect couples' capacities to provide what Bion called "containment". In disturbed couples, partners serve as what Meltzer termed "claustrums" whereby projections are not contained, but imprisoned or entombed in the other. Applying the concept of claustrum helps illuminate common feelings these couples express, such as feeling suffocated, stifled, trapped, held hostage, or feeling as if the relationship is killing them. Finally, this paper presents treatment challenges in working with more disturbed couples.

Thomas More's “rule” of pleasure before, after, and inUtopia

Moreana ◽  
2017 ◽  
Vol 54 (Number 207) (1) ◽  
pp. 36-56
Author(s):  
Gerard Wegemer
Keyword(s):  
Human Nature ◽  
The Other ◽  
Biblical Allusions ◽  
De Officiis

After establishing a context of More's lifelong engagement with the “calculus” of pleasure, this essay shows how the section devoted to the Utopians' pleasure philosophy is structured around five formulations of a “rule” to calculate “true and honest [honesta]” pleasure in ways that playfully imitate and echo the “rule” Cicero formulates several times in De officiis to discern one's duty when there seems to be a conflict between honestas et utilitas. When followed, the Utopian pleasure calculus shows the necessary role of societas, officii, iustitia, caritas, and the other aspects of human nature, most importantly friendship, that Cicero stresses in his rule and that he argued Epicurus ignored. Much of the irony and humor of this section depends on seeing the predominance of Ciceronian vocabulary in Raphael's unusual defense [patrocinium] of pleasure, rather than a Ciceronian defense of duty rooted in honestas. Throughout, however, this essay also shows how More goes beyond Cicero by including Augustinian and biblical allusions to suggest ways that our final end is not as Epicurus or the Stoics or Cicero claim; the language and allusions of this section point to a level of good cheer and care for neighbors and for God in ways quite different from any classical thinker.

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