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2. Is maternal progesterone actually independent of the fetal steroids?
- Creator:
- Martin Hill, Antonín Pařízek, Jan Evangelista Jirásek, Marie Jirkovská, Velíková, M., Michaela Dušková, Klímková, M., Andrea Pašková, Zdeněk Žižka, Alexandra Moravská, Michal Koucký, Marta Kalousová, and Luboslav Stárka
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, steroidy, progesteron, práce, steroids, progesterone, labor, 20α-dihydroprogesterone, plasma, metabolome, GC-MS, 14, and 612
- Language:
- English
- Description:
- a1_Progesterone and estradiol are the foremost steroid hormones in human pregnancy. However, the origin of maternal progesterone has still not been satisfactorily explained, despite the generally accepted opinion that maternal LDL-cholesterol is a single substrate for placental synthesis of maternal progesterone. The question remains why the levels of progesterone are substantially higher in fetal as opposed to maternal blood. Hence, the role of the fetal zone of fetal adrenal (FZFA) in the synthesis of progesterone precursors was addressed. The FZFA may be directly regulated by placental CRH inducing an excessive production of sulfated 3β-hydroxy-5-ene steroids such as sulfates of dehydroepiandrosterone (DHEAS) and pregnenolone (PregS). Due to their excellent solubility in plasma these conjugates are easily transported in excessive amounts to the placenta for further conversion to the sex hormones. While the significance of C19 3β-hydroxy-5-ene steroid sulfates originating in FZFA for placental estrogen formation is mostly recognized, the question “Which maternal and/or fetal functions may be served by excessive production of PregS in the FZFA?“ - still remains open. Our hypothesis is that, besides the necessity to synthesize de novo all the maternal progesterone from cholesterol, it may be more convenient to utilize the fetal PregS. The activities of sulfatase and 3β-hydroxysteroid dehydrogenase (3β-HSD) are substantially higher than the activity of cytochrome P450scc, which is rate-limiting for the placental progesterone synthesis from LDL-cholesterol. However, as in the case of progesterone synthesis from maternal LDL-cholesterol, the relative independence of progesterone levels on FZFA activity may be a consequence of substrate saturation of enzymes converting PregS to progesterone., a2_Some of the literature along with our current data (showing no correlation between fetal and maternal progesterone but significant partial correlations between fetal and maternal 20α-dihydroprogesterone (Prog20α) and between Prog20α and progesterone within the maternal blood) indicate that the localization of individual types of 17β-hydroxysteroid dehydrogenase is responsible for a higher proportion of estrone and progesterone in the fetus, but also a higher proportion of estradiol and Prog20α in maternal blood. Type 2 17β-hydroxysteroid dehydrogenase (17HSD2), which oxidizes estradiol to estrone and Prog20α to progesterone, is highly expressed in placental endothelial cells lining the fetal compartment. Alternatively, syncytium, which is directly in contact with maternal blood, produces high amounts of estradiol and Prog20α due to the effects of type 1, 5 and 7 17β-hydroxysteroid dehydrogenases (17HSD1, 17HSD5, and 17HSD7, respectively). The proposed mechanisms may serve the following functions: 1) providing substances which may influence the placental production of progesterone and synthesis of neuroprotective steroids in the fetus; and 2) creating hormonal milieu enabling control of the onset of labor., M. Hill ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
3. Jak pracovat?: Přednášky z roku 1898
- Creator:
- Masaryk, Tomáš Garrigue and Valenta, Jan
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- práce, labor, 6, and 53
- Language:
- Czech
- Description:
- Tomáš Garrigue Masaryk. Úryvky vybral J. Valenta.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4. Konference Community, work and family 2009
- Creator:
- Alena Křížková
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- rodina, práce, zaměstnání, komunity (sociologie), gender, mezinárodní konference, family, labor, employment, communities (sociology), international conferences, 18, and 316.33
- Language:
- Czech
- Description:
- Alena Křížková.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
5. Labour in the era of fictional capital
- Creator:
- Trenkle, Norbert
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- labor, fictitious capital, and value theory
- Language:
- Czech
- Description:
- Th is essay discusses the consequences of the changed relationship between capital and labour after the end of the Fordist post-war boom. As a result of these changes, capital accumulation is no longer predominantly based on the exploitation of labour in the production of commodities like cars, hamburgers, and smartphones but on the massive emission of property titles like shares, bonds, and fi nancial derivatives that represent claims to future value. Th ese changes irreversibly weakened labour power, giving capital a freer hand than ever before. But making large numbers of workers redundant also had consequences for capital. Th e Th ird Industrial Revolution thus marked the onset of a fundamental crisis. Th e production of value through the exploitation of labour has been replaced with the systematic anticipation of future value in the form of fi ctitious capital. However, this form of expansion is reaching its limits and is linked with signifi cant costs to society. Albeit sobering and chilling, this analysis suggests removing the political response of the left from the retrospective romanticising of the Fordist era capitalism and pursue the abolition of labour as a form of social mediation. In other words: pursue liberation from labour and from its dependence on capital accumulation rather than the liberation of labour.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
6. Nejistá budoucnost lidské práce
- Creator:
- Božena Buchtová
- Format:
- Type:
- article, zprávy, model:article, and TEXT
- Subject:
- Psychologie, práce, nezaměstnanost, konference, labor, unemployment, conferences, Brno (Česko), Brno (Czechia), 17, and 159.9
- Language:
- Czech
- Description:
- B. Buchtová.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
7. Obhajoba sociologie se stala obhajobou společnosti: rozhovor Zuzany Uhde s Michaelem Burawoyem
- Creator:
- Zuzana Uhde and Burawoy, Michael
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- sociologové, etnografové, práce, globalizace, sociologists, ethnographers, labor, globalization, 18, and 316
- Language:
- Czech
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
8. Steroid metabolome in the umbilical cord: is it necessary to differentiate between arterial and venous blood?
- Creator:
- Andrea Pašková, Antonín Pařízek, Martin Hill, Velíková, M., Kubátová, J., Martina Dušková, Adamcová, K., Michal Koucký, Šimjak, P., Černý, A., and Luboslav Stárka
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, steroidy, práce, krev, steroids, labor, blood, metabolome, GC-MS, 14, and 612
- Language:
- English
- Description:
- Steroids are important marker s in pregnancy. Although estimating their levels separately in umbilical arterial (UA) and venous blood (UV) enable more precise insights into the functioning fetoplacental unit compared to using mixed umbilical blood (UM), selective aspiration of UA and UV is technically more demanding than collecting UM. We measured the levels of 67 unconjugated steroids and steroid polar conjugates in UA and UV using GC-MS in 80 women giving birth within weeks 28 to 42 of gestation. The samples were sorted into three groups: women entering labor within weeks 28- 32 (group A, n=19), weeks 33-37 (group B, n=19), and weeks 38-42 (group C, n=42) of gestation, respectively. The preterm labo rs were due to pathologies unrelated to steroid status. Most unconjugated steroids exhibited pronounced arteriovenous differences (AVD). The AVD were less distinct in more stable steroid conjugates. Most steroids positively correlate with gestational age, but unconjugated 5 β -reduced pregnanes show negative correlations, as do testosterone and androstenediol, substrates for the placental synthesis of estrogens. Tight correlations be tween steroids in UA and UV indicate that steroid measurements in UA, UV and UM can be accurately derived from each other, which is important for the diagnostics of steroid related diseases in newborns., A. Pašková ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
9. The search for compensating differentials: is there a pot of gold after all?
- Creator:
- Randall Keith Filer and CERGE-EI
- Publisher:
- CERGE-EI, Center of Excellence
- Format:
- print, svazek, and 26, 13 stran.
- Type:
- model:monograph and TEXT
- Subject:
- Práce, mzdy, práce, vědecký výzkum, wages, labor, scientific research, kompenzační rozdíly, 331.2, 331, 001.891, (048.8), and 4
- Language:
- English and Czech
- Description:
- Randall K. Filer., Obsahuje bibliografii a bibliografické odkazy., and Abstrakt v angličtině a češtině
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
10. Za plnohodnotné občanství žen: Hašková, H., Uhde, Z. (eds.). Women and social citizenship in Czech society: continuity and change
- Creator:
- Hřešanová, Ema
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- ženy, gender, občanství, multikulturalismus, rodina, práce, feminismus, women, citizenship, multiculturalism, family, feminism, labor, 18, and 316.4/.7
- Language:
- Czech
- Description:
- [autor recenze] Ema Hřešanová.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public