Reactivation of human placental 17 beta, 20 alpha-hydroxysteroid dehydrogenase: affirmation of affinity labeling principles.

abstract：:A mechanistic study on the nucleophilic substitution of a strictly geometric 21-bromo-3alpha-hydroxyl-3beta-methoxymethyl-5alpha-pregnan-20-one was described. Reaction of the alpha-bromoketone with excess lithium imidazole followed by the addition of extra bases including n-butyllithium, methyllithium, lithium piperid...

journal_title：Steroids

authors： Chen CY,Wong FF,Lee YH,Chou SY,Huang JJ,Yeh MY

更新日期：2006-11-01 00:00:00

abstract：:Mouse models of cystic fibrosis (CF) display increased sulfotransferase 1E1 (SULT1E1) activity in hepatocytes of cystic fibrosis transmembrane receptor (CFTR)-deficient animals. SULT1E1 is responsible for the sulfation and inactivation of beta-estradiol (E2) at physiological concentrations. IGF-1 message levels in CFT...

journal_title：Steroids

authors： Li L,He D,Wilborn TW,Falany JL,Falany CN

更新日期：2009-01-01 00:00:00

abstract：:2,2,6,6-Tetramethyl piperidine-N-oxyl nitroxyls are known to partition between aqueous and lipid phases, thus serving as probes to study membrane dynamics. The synthesis of a novel steroidal spin label, 3alpha-hydroxycholan-24-yl-(2",2",6",6"-tetramethyl-N-oxyl)p iperidyl butan-1',4'-dioate, containing 2,2,6,6-tetrame...

journal_title：Steroids

authors： Katoch R,Trivedi GK,Phadke RS

更新日期：1999-12-01 00:00:00

abstract：:Although aldosterone production declines with age, so does the aldosterone metabolic clearance rate (MCR), and the net effect of age on the circulating level of aldosterone may be less than can be predicted from production rates alone. The effect of age on aldosterone production and plasma levels was studied in a grou...

journal_title：Steroids

authors： Pratt JH,Hawthorne JJ,Debono DJ

更新日期：1988-01-01 00:00:00

abstract：:Testosterone (17 beta -hydroxy-4-androsten-3-one ; T) and dihydrotestosterone (17 beta -hydroxy-5 alpha -androstan-3-one ; DHT) concentrations were determined by radioimmunoassay in different fetal tissues taken from male guinea-pigs. Androgen concentrations were maximal in the components of the Wolffian duct (vas def...

journal_title：Steroids

authors： Rigaudière N

更新日期：1981-08-01 00:00:00

abstract：OBJECTIVE:To evaluate the role of physiologic levels of androgens and their precursors in the regulation of body composition, energy and substrate metabolism and aerobic capacity in healthy, cycling, premenopausal women. EXPERIMENTAL:We evaluated 30 young (27±1 year) premenopausal, non-obese (23±0.5 kg/m(2)), normally...

journal_title：Steroids

authors： Keller JL,Casson PR,Toth MJ

更新日期：2011-11-01 00:00:00

abstract：:The leaky heme mutants G204, G216, and G214 are shown to accumulate exogenous sterols. Unlike hem mutants which have complete blocks in the heme pathway, these strains do not require ergosterol, methionine, or unsaturated fatty acids for growth. The addition of aminolevulinic acid to the growth medium inhibited sterol...

journal_title：Steroids

authors： Shinabarger DL,Keesler GA,Parks LW

更新日期：1989-03-01 00:00:00

abstract：:5 alpha-(17R,20R)-14,15-Secocholestane (12) was synthesized from cholesterol (1) in 12 steps. The key intermediate, 5 alpha-cholest-14-en-3 beta-yl acetate (4), underwent ozonization, reduction, hydrolysis, and oxidation to provide 5 alpha-14,15-secocholesta-3,14,15-trione (8). One of the Clemmensen reduction products...

journal_title：Steroids

authors： Li TS,Li YL,Liang XT

更新日期：1990-06-01 00:00:00

abstract：:The influence of daily injections, for 7 days, of 17-hydroxyprogesterone caproate (8 mg/100 g body weight pro die), of estradiol-17 beta 17-undecylate (1.2 mg/100 g body weight pro die) of testosterone enanthate (2 mg/100 g body weight pro die) and of ACTH (4 IU/100 g body weight pro die) to male Wistar rats, weighing...

journal_title：Steroids

authors： Bukhari AR,Guessab A,Nicol ML

更新日期：1981-07-01 00:00:00

abstract：:The mechanistic aspects of the alkali-catalyzed rearrangement of 16alpha-hydroxy-17-keto steroid 1 to 17beta-hydroxy-16-keto steroid 2 are elucidated by use of (18)O- and deuterium-labeling experiments. The (18)O-labeling experiments refute the gem-hydration-quasi-diaxial dehydration mechanism for the rearrangement pr...

journal_title：Steroids

authors： Numazawa M,Nagaoka M,Matsuzaki H,Yamashita K,Komatsu S,Osawa Y

更新日期：2008-09-01 00:00:00

abstract：:Studies were carried out on the effect of oxygen tension on progesterone (P) accumulation in rat granulosa cell cultures. At 1-2% oxygen, basal, luteinizing hormone (LH)-stimulated, and follicle stimulating hormone (FSH)-stimulated P accumulations were 20, 18, and 11%, respectively, of P levels at 20% oxygen. Basal P ...

journal_title：Steroids

authors： Koos RD,Feiertag MA

更新日期：1989-11-01 00:00:00

abstract：:Periodontitis is a complication of diabetes mellitus, and the two diseases are highly associated with the dysfunction of inflammatory mediators. 25-hydroxyvitamin D(3) (25(OH)D(3)) plays a pivotal role in inflammatory modulation, but little is known about its effects on the progression of diabetic periodontitis and th...

journal_title：Steroids

authors： Li H,Xie H,Fu M,Li W,Guo B,Ding Y,Wang Q

更新日期：2013-02-01 00:00:00

abstract：:Thyroid hormone receptors (TRs) are nuclear receptors that are activated by thyroid hormone ligands and co-regulator proteins. Two receptor subtypes, TRalpha and TRbeta, have been suggested to play a role in numerous physiological functions. However, specificity of receptor subtype function and co-regulator interactio...

journal_title：Steroids

authors： Koury EJ,Pawlyk AC,Berrodin TJ,Smolenski CL,Nagpal S,Deecher DC

更新日期：2009-02-01 00:00:00

abstract：:The concentration of estrogens in the body fluids of women is highly variable, due to the menstrual cycle, circadian oscillations, and other physiological and pathological causes. To date, only the cyclic fluctuations of the principal estrogens (estradiol and estrone) have been studied, with limited outcome of general...

journal_title：Steroids

authors： Bozzolino C,Vaglio S,Amante E,Alladio E,Gerace E,Salomone A,Vincenti M

更新日期：2019-10-01 00:00:00

abstract：:Phytochemical characterization of a commercial herb sample supplied as Smilax ornata Lem. (sarsaparilla) led to the isolation of five steroidal saponins, including two new furostanol saponins sarsaparilloside B (1) and sarsaparilloside C (2), whose structures were elucidated via a combination of multistage mass spectr...

journal_title：Steroids

authors： Challinor VL,Parsons PG,Chap S,White EF,Blanchfield JT,Lehmann RP,De Voss JJ

更新日期：2012-04-01 00:00:00

abstract：:To determine the sensitivity of the overnight 1-mg dexamethasone suppression test in diagnosing Cushing's syndrome, we evaluated the cortisol responses of 55 subjects (25 non-obese individuals with body mass index less than 25 kg/m2, 20 obese individuals with body mass index greater than 30 kg/m2, and 10 patients with...

journal_title：Steroids

authors： Fok AC,Tan KT,Jacob E,Sum CF

更新日期：1991-11-01 00:00:00

abstract：:CGS 16949A inhibited the conversion of [4-14C]androstenedione (A) to [4-14C]estrone by human placental microsomes in a competitive manner (Ki = 1.6 nM). Aminoglutethimide, also a competitive inhibitor, had a Ki = 0.7 microM in this assay system. The Km for the aromatization of A was 0.11 microM. Using ovarian microsom...

journal_title：Steroids

authors： Steele RE,Mellor LB,Sawyer WK,Wasvary JM,Browne LJ

更新日期：1987-07-01 00:00:00

abstract：:11 beta-hydroxysteroid dehydrogenase (11 beta-HSD), the enzyme that catalyzes the conversion of biologically active glucocorticoids to their inactive metabolites, was shown to be located exclusively in Leydig cells of the rat testis, and its appearance was associated with the developmental rise in testosterone. Thus, ...

journal_title：Steroids

authors： Nacharaju VL,Muneyyirci-Delale O,Khan N

更新日期：1997-03-01 00:00:00

abstract：:To investigate the effects of conjugated bile acid on bacterial growth and cholylglycine hydrolase activity, Clostridium perfringens from human feces was exposed to varying concentrations of taurine- or glycine-conjugated chenodeoxycholic acid. Extracellular enzyme activity was determined by deconjugation of radiolabe...

journal_title：Steroids

authors： Kishinaka M,Umeda A,Kuroki S

更新日期：1994-08-01 00:00:00

abstract：:A radioimmunoassay for plasma 3 beta, 7 alpha-dihydroxy-5-androsten-17-one (7 alpha-hydroxy DHA) has been developed using anti-sera raised against 3 beta, 7 alpha-dihydroxy-5-androstene-17 beta-carboxyl-bovine serum albumin conjugate and [1, 2 (n) - 3H] 7 alpha-hydroxy DHA as the radioligand. Significant cross reactiv...

journal_title：Steroids

authors： Skinner SJ,Tobler CJ,Couch RA

更新日期：1977-09-01 00:00:00

abstract：:3 beta-Hydroxy-5-androsten-17-one is converted to 5-androstene-3, 17-dione by rat liver alcohol dehydrogenase (ADH). We have reported on the purity of the enzyme which is eluted with pyrazole as a single homogeneous protein using an AMP-agarose affinity column. Rat liver ADH can oxidize hydroxyl groups not only at 3 b...

journal_title：Steroids

authors： Knutson VP,Ungar F

更新日期：1982-11-01 00:00:00

abstract：:The synthesis of delta 7,9(11)-lanostadiene derivatives functionalized at C(32) starting from 3 beta-acetoxy-7 alpha,32-epoxylanostan-11-one has been presented. The delta 7,9(11) moiety was efficiently introduced in three steps in 71% yield by the regioselective abstraction of allylic 8 beta hydrogen. The formyl group...

journal_title：Steroids

authors： Solaja BA,Dermanović M,Lim DM,Paik YK,Tinant B,Declerq JP

更新日期：1997-11-01 00:00:00

abstract：:In each menstrual cycle only very few follicles in the mammalian ovary undergo maturation and ovulation while most of the follicles degenerate in the process of atresia. Moreover, in the absence of pregnancy, the newly formed corpora lutea will degenerate and disappear in the process of luteolysis. Recent studies sugg...

journal_title：Steroids

authors： Amsterdam A,Keren-Tal I,Aharoni D

更新日期：1996-04-01 00:00:00

abstract：:Smith-Lemli-Opitz syndrome (SLOS) is a malformation syndrome associated with 7-dehydrocholesterol (7DHC) 7-reductase deficiency. Although SLOS can be detected in an affected fetus before midpregnancy by measurement of 7DHC levels in amniotic fluid or chorionic villus cells, a noninvasive, more routine method is needed...

journal_title：Steroids

authors： Shackleton CH,Roitman E,Kratz LE,Kelley RI

更新日期：1999-07-01 00:00:00

abstract：:An efficient procedure for the chemical synthesis of 3 beta-hydroxy-5 alpha-cholest-8-en-7-one and 3 beta-hydroxy-5 alpha-cholest-8-en-11-one is described. These ketosterols have been shown to have possible significant hypocholesterolemic effects when fed to normal rats at a level of 0.15% in a laboratory chow diet. T...

journal_title：Steroids

authors： Parish EJ,Nanduri VB,Seikel JM,Kohl HH,Nusbaum KE

更新日期：1986-11-01 00:00:00

abstract：:Circulating levels (mean +/- SD) of estrone sulfate (E1S), estrone (E1) and estradiol-17 beta (E2) were measured in normal and cirrhotic postmenopausal women matched for body weight and age. In cirrhotic postmenopausal women, the E1S concentrations (201 +/- 46 pg/ml), while both E1 and E2 levels showed an increase (46...

journal_title：Steroids

authors： Jasonni VM,Bulletti C,Bolelli GF,Franceschetti F,Bonavia M,Ciotti P,Flamigni C

更新日期：1983-05-01 00:00:00

abstract：:The effect of a substituent in the 12-position of progestagens was studied. To this end, various approaches toward the preparation of 12 beta-alkyl- and 12-alkylidenenorpregnanes were investigated. Eventually, the desired compounds 17 beta-hydroxy-12 beta-methyl-18a-homo-19-nor-17 alpha-pregn-4-en-20-yn-3-one (37) and...

journal_title：Steroids

authors： Broess AI,van Vliet NP,Groen MB,Hamersma H

更新日期：1992-11-01 00:00:00

abstract：:Synthetic transformations of steroids for drug discovery and improvement of drug effectiveness have been an important part of modern medicinal chemistry and pharmaceutical sciences. Pentacyclic triterpenoids, being represented in the nature by various structures and biogenetically related to steroids, can largely expa...

journal_title：Steroids

authors： Tolmacheva IA,Nazarov AV,Eroshenko DV,Grishko VV

更新日期：2018-12-01 00:00:00

abstract：:Urinary steroid profile analysis requires enzymatic hydrolysis of glucuronide and sulfate conjugates and this is achieved simultaneously using Helix pomatia juice (HPJ), but steroids with 3beta-hydroxy-5-ene structure undergo transformation and yield of 5alpha-reduced corticosteroid glucuronides is poor. We describe t...

journal_title：Steroids

authors： Christakoudi S,Cowan DA,Taylor NF

更新日期：2008-03-01 00:00:00

abstract：:Steroidal nucleoside analogs were synthesized starting from testosterone. By reduction of the oxime of 17 beta-hydroxy-androst-4-en-3-one (testosterone), a mixture of the two amino epimers of C-3 were obtained. The 3 alpha-amino-androst-4-en-17 beta-ol was crystallized in 73% yield and coupled with 5-amino-4,6-dichlor...

journal_title：Steroids

authors： Gelpi ME,Cadenas RA,Mosettig J,Zuazo BN

更新日期：2002-03-01 00:00:00