PLACENTAL TRANSFER OF OESTRIOL GLUCOSIDURONATES

1968 ◽  
Vol 59 (3) ◽  
pp. 426-432 ◽  
Author(s):  
U. Goebelsmann ◽  
N. Wiqvist ◽  
E. Diczfalusy
Keyword(s):  
Placental Transfer ◽  
Conclusive Evidence ◽  
Radioactive Material ◽  
Experimental Conditions ◽  
Unchanged Form ◽  
Urine Specimens

ABSTRACT Two human placentas were perfused in situ at midpregnancy with a combination of oestriol-15-3H-3-glucosiduronate (OE3-3Gl) and oestriol-16-14C-16-glucosiduronate (OE3-16Gl) and the radioactive material recovered from the placentas, perfusates and urine specimens was analysed. Only 1 to 2 per cent of the tracers administered was recovered from the urine; the bulk of the administered material was found in the perfusates and placentas. Under the experimental conditions used, no evidence for the metabolism of the two conjugates was found. The OE33Gl isolated from the three sources contained only 3H-label, and the OE3-16Gl only 14C-label. Whereas the evidence indicating the placental transfer of OE3-16Gl in an unchanged form is circumstantial, conclusive evidence is presented that OE3-3Gl is transferred across the placenta without hydrolysis.

PLACENTAL TRANSFER OF 3H-OESTRIOL-3-SULPHATE-16-GLUCOSIDURONATE AND 3H-OESTRIOL-16-GLUCOSIDURONATE-14C

1972 ◽  
Vol 70 (1) ◽  
pp. 132-142 ◽  
Author(s):  
U. Goebelsmann ◽  
J. M. Roberts ◽  
R. B. Jaffe
Keyword(s):  
Placental Transfer ◽  
Conclusive Evidence ◽  
Radioactive Material ◽  
Maternal Urine ◽  
Urine Specimens

ABSTRACT Four human placentas were perfused in situ at midpregnancy, two with biosynthetically prepared 3H-oestriol-16-glucosiduronate-14C (OE3-16Gl) and two with 3H-oestriol-3-sulphate-16-glucosiduronate (OE3-3S,16Gl). The radioactive material recovered from the placentas, perfusates and maternal urine was quantitated and identified. Only 0.8 to 3.7% of the labelled material administered was recovered from urine specimens; the bulk of the labelled material perfused was found in the extracts of placentas and perfusates. The double-labelled material isolated from the three sources following perfusion with 3H-OE3-16Gl-14C was identified as OE3-16Gl. The 3H/14C ratios measured in these fractions were virtually identical with those of the tracers perfused. Following perfusion with 3H-OE3-3S,16Gl, three-fourths of the 3H-labelled material recovered from the urine was identified as OE3-3S,16Gl and a small but significant portion of the tritiated material extracted from the placentas and perfusates was shown to be 3H-OE3-16Gl. No significant quantities of unconjugated labelled material could be detected in any of the four placental perfusions. The data presented provide conclusive evidence that both OE3-16Gl and OE3-3S,16Gl are transferred across the placenta in situ without previous hydrolysis. The placenta in vivo is capable of converting some OE3-3S,16Gl to OE3-16Gl. The latter conjugate remains unhydrolysed.

METABOLISM OF DEHYDROEPIANDROSTERONE SULPHATE AND OESTRONE SULPHATE FOLLOWING IN SITU PLACENTAL PERFUSION AT MIDPREGNANCY

1971 ◽  
Vol 66 (4) ◽  
pp. 637-647 ◽  
Author(s):  
J. Schwers ◽  
T. Vancrombreucq ◽  
M. Govaerts ◽  
G. Eriksson ◽  
E. Diczfalusy
Keyword(s):  
Radioactive Material ◽  
Dehydroepiandrosterone Sulphate ◽  
Placental Perfusion ◽  
Carbon 14 ◽  
Maternal Urine ◽  
Oestrone Sulphate ◽  
Unchanged Form ◽  
Urine Specimens

ABSTRACT Two midgestation placentas were perfused in situ with a combination of [7α-3H] dehydroepiandrosterone sulphate and [4-14C] oestrone sulphate and metabolites were isolated from the placentas, perfusates and maternal urine specimens. Approximately 70 per cent of the perfused radioactive material was recovered from these three sources. The bulk of the administered radioactive material was recovered in an unchanged form from the perfusates; some 2–4 per cent was excreted in the urine and less than 0.5% was found in the placentas. The tritium to carbon-14 ratio of the unconjugated material isolated from the perfusates and placentas was higher, and that of the conjugated material recovered from the same sources was lower than the ratio of the administered material. In addition, more tritium than carbon-14 labelled material was present in the urine. Approximately 2 per cent of the perfused dehydroepiandrosterone sulphate was recovered in the form of phenolic steroids, mostly from the urine. From this source double labelled oestrone, oestriol, 16α-hydroxy-oestrone and 16-epioestriol were isolated. The tritium to carbon-14 ratio of all oestrogens isolated from the urine was higher than that of the perfused material. From the urine specimens 10 to 15 times more double labelled oestriol than oestrone was isolated.

LACK OF AROMATISATION OF CIRCULATING DEHYDROEPIANDROSTERONE AND DEHYDROEPIANDROSTERONE SULPHATE IN AMENORRHOEIC WOMEN STIMULATED WITH HUMAN GONADOTROPHINS

1965 ◽  
Vol 49 (2) ◽  
pp. 248-261 ◽  
Author(s):  
S. Mancuso ◽  
Francesca P. Mancuso ◽  
K.-G. Tillinger ◽  
E. Diczfalusy
Keyword(s):  
Pregnant Women ◽  
Ovarian Stimulation ◽  
Interstitial Cell ◽  
Follicular Phase ◽  
Radioactive Material ◽  
Dehydroepiandrosterone Sulphate ◽  
Experimental Conditions ◽  
Human Menopausal Gonadotrophin ◽  
Urine Specimens ◽  
Stimulating Hormone

ABSTRACT Two amenorrhoeic women were given a course of 10 injections of human menopausal gonadotrophin (HMG) in daily doses corresponding to 260 IU of follicle stimulating hormone (FSH) activity and 165 IU of interstitial cell stimulating hormone (ICSH) activity. In both patients an extensive ovarian stimulation was observed as indicated by the greatly increased urinary excretion of oestrone, 17β-oestradiol and oestriol. When HMG-treatment was followed subsequently by the administration of human chorionic gonadotrophin (HCG) for 5 days in a total dose of 18 000 and 30 000 IU, respectively, functional corpus luteum tissue was formed in both patients as evidenced by a huge rise in urinary pregnane-3α,20α-diol excretion and by the secretory transformation of a previously atrophic endometrium. At the approximate height of the follicular phase tracer doses of 3H-labelled dehydroepiandrosterone sulphate (DHAS) and 14C-labelled dehydroepiandrosterone (DHA) were administered to both patients in the form of a continuous intravenous infusion of 10 hours' duration. Infusion of the same dose was repeated under identical experimental conditions at the approximate height of the luteal phase. In both patients, very little radioactive material was associated with oestrone and 17β-oestradiol and none with oestriol isolated from 96-hours' urine specimens obtained at both phases of ovarian stimulation. It is concluded that — in contradistinction to the situation in pregnant women — circulating DHAS is not a significant precursor of urinary oestrogens in non-pregnant women.

STUDIES ON THE METABOLISM OF C19 STEROIDS IN THE FOETO-PLACENTAL UNIT

1971 ◽  
Vol 66 (4) ◽  
pp. 653-665 ◽  
Author(s):  
G. Benagiano ◽  
M. Ermini ◽  
B. de la Torre ◽  
N. Wiqvist ◽  
E. Diczfalusy
Keyword(s):  
Sodium Salt ◽  
Human Placenta ◽  
Major Part ◽  
Isotopic Ratio ◽  
Water Soluble ◽  
Radioactive Material ◽  
Considerable Part ◽  
Maternal Urine ◽  
Unchanged Form ◽  
Urine Specimens

ABSTRACT Three midgestation placentas were perfused at laparotomy during fifteen minutes with tracer amounts of [1,2-3H] testosterone [35S] sulphate sodium salt, and metabolites present in the placentas, perfusates and maternal urine specimens were analyzed. Most of the radioactive material administered was present in the placentas and perfusates; approximately 2% of it was recovered from the urine. More than 99.5% of the radioactive material recovered from the placentas and the perfusates was in a water soluble (conjugated) form. No unconjugated testosterone was found in these sources. Radiochemically homogeneous [1,2-3H] testosterone [35S] sulphate was isolated from the placentas, perfusates and urine specimens collected during the first 24 hours of experiment. The isotopic ratio of the conjugate isolated from these sources was very similar to that of the perfused material. Seventy per cent of the double labelled radioactive material recovered from the Day 1 urine samples was radiochemically homogeneous testosterone sulphate. The relative amounts of testosterone sulphate present in the Day 2 and Day 3 urine specimens showed a gradual decrease. This decrease was associated with an increase in tritium to sulphur-35 ratio. From the pooled extracts of all urine specimens, small amounts of exclusively tritium labelled conjugated 5α-androsterone and 5β-androsterone were also isolated. No 17β-oestradiol 17-sulphate was detected in any of the sources studied. It is concluded that little, if any, testosterone sulphate is hydrolyzed by the midgestation human placenta, and that a considerable part of the testosterone sulphate secreted by the foetus is transferred across the placenta to the mother in an unchanged form. The major part of the transferred testosterone sulphate is excreted in the urine; a smaller part of it undergoes hydrolysis with a subsequent metabolism of the steroid moiety.

STUDIES ON THE AROMATISATION OF NEUTRAL STEROIDS IN PREGNANT WOMEN.

1967 ◽  
Vol 55 (3) ◽  
pp. 401-414 ◽  
Author(s):  
S. Dell'Acqua ◽  
S. Mancuso ◽  
G. Eriksson ◽  
J. L. Ruse ◽  
S. Solomon ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Placental Transfer ◽  
The Other ◽  
Radioactive Material ◽  
List Type ◽  
Low Degree

ABSTRACT 16α-Hydroxy-dehydroepiandrosterone-7α-3H (16αHO-DHA), 16α-hydroxy-androstenedione-4-14C (16αHO-A) and 16α-hydroxy-testosterone-4-14C (16αHO-T) were synthesized. Human placentas were perfused in situ at midpregnancy with these steroids and the radioactive material recovered from the placentas and perfusates was analysed. In order to compare the aromatisation of 16α-hydroxylated and 16-desoxy precursors, in a second series of perfusions 16αHO-DHA was combined with differently labelled dehydroepiandrosterone (DHA) and 16αHO-T with testosterone (T). Following the perfusion of 16αHO-DHA, both 16αHO-A and oestriol (OE3) were isolated from the placentas and perfusates. No labelled androst-5-ene-3β,16α,17β-triol (Δ5-TRIOL) or 16αHO-T was detected in these sources. When 16αHO-A or 16αHO-T was perfused, OE3 was isolated from the placenta and perfusates. However, there was no interconversion between 16αHO-A and 16αHO-T. No oestrogenic ring D ketols were found in the placentas and perfusates in any of the experiments. The extent of aromatisation (judged from the amount of oestrogen isolated from the placenta and perfusate) was approximately the same following the perfusion of 16αHO-DHA, 16αHO-A, DHA and T, but was much lower when 16αHO-T was perfused. The low degree of aromatisation of 16αHO-T was associated with the presence of large amounts of unchanged 16αHO-T in the placentas as well as in the perfusates. The transfer of 16αHO-T to the maternal compartment was also much lower than that of the other precursors studied. It is concluded that the placental transfer and aromatisation of 16αHO-T is much lower than those of other oestrogen precursors. This condition might lead to the accumulation of this compound in the placenta. The placental metabolism of Δ5-TRIOL and 16αHO-DHA follow separate pathways with no interconversion until the stage of aromatisation, or possibly 19-hydroxylation.

STUDIES ON THE AROMATISATION OF NEUTRAL STEROIDS IN PREGNANT WOMEN

1964 ◽  
Vol 45 (4) ◽  
pp. 535-559 ◽  
Author(s):  
E. Bolté ◽  
S. Mancuso ◽  
G. Eriksson ◽  
N. Wiqvist ◽  
E. Diczfalusy
Keyword(s):  
Pregnant Women ◽  
Comparative Studies ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Radioactive Material ◽  
Placental Barrier ◽  
Therapeutic Abortion ◽  
Limited Ability ◽  
Better Than

ABSTRACT In 15 cases of therapeutic abortion by laparotomy the placenta was disconnected from the foetus and perfused in situ with tracer amounts of radioactive dehydroepiandrosterone (DHA), dehydroepiandrosterone sulphate (DHAS), androst-4-ene-3,17-dione (A), testosterone (T) and 17β-oestradiol (OE2). Analysis of the placentas, perfusates and urine samples revealed an extensive aromatisation of DHA, A and T; more than 70% of the radioactive material recovered was phenolic, and at least 80 % of this phenolic material was identified as oestrone (OE1), 17β-oestradiol (OE2) and oestriol (OE3), the latter being detected only in the urine. Comparative studies indicated that A and T were aromatised somewhat better than DHA and that all three unconjugated steroids were aromatised to a much greater extent than DHAS. Radioactive OE1 and OE2 were isolated and identified in the placentas and perfusates, but no OE3, epimeric oestriols, or ring D ketols could be detected in these sources, not even when human chorionic gonadotrophin (HCG) was added to the blood prior to perfusion. Lack of placental 16-hydroxylation was also apparent when OE2 was perfused. Regardless of the precursor perfused, there was three times more OE2 than OE1 in the placenta and three times more OE1 than OE2 in the perfusate. This was also the case following perfusion with OE2. The results are interpreted as suggesting the existence in the pregnant human of a placental »barrier« limiting the passage of circulating androgen. The barrier consists of a) limited ability to transfer directly DHAS and b) an enzymic mechanism resulting in the rapid and extensive aromatisation of the important androgens DHA, A and T.

STUDIES ON THE AROMATISATION OF NEUTRAL STEROIDS IN PREGNANT WOMEN

1970 ◽  
Vol 65 (1) ◽  
pp. 69-83 ◽  
Author(s):  
H. Vokal ◽  
D. F. Archer ◽  
N. Wiqvist ◽  
E. Diczfalusy
Keyword(s):  
Pregnant Women ◽  
Placental Perfusion ◽  
Homogeneous Form ◽  
Urine Specimens

ABSTRACT The following steroids, [7α-3H]5-androstene-3β,16α,17β-triol and [4-14C] 5-androstene-3β,16β,17β-triol were biosynthesized and their metabolism was studied in two subjects at midgestation, following placental perfusion in situ. Among the metabolites isolated in a radiochemically homogeneous form, exclusively 3H-labelled 16α,17β-dihydroxy-4-androsten-3-one was isolated from the extracts of placentas and perfusates. Exclusively 14C-labelled 16β,17β-dihydroxy-4-androsten-3-one was isolated from the placentas and perfusates and 16-epioestriol (1,3,5(10)-oestratriene-3,16β,17β-triol) from the placentas, perfusates and urine specimens. The following compounds contained both 3H and 14C-label: oestriol (placentas and urine specimens) and 5β-androstane-3α,16α,17β-triol (urine specimens). The 3H/14C-ratio of oestriol isolated from the urine specimens was much lower than that of urinary 5β-androstane-3α,16α,17β-triol, or that of the oestriol isolated from the placentas. The 3H/14C-ratio of the oestriol isolated from the urine 2–4 days following the perfusion was lower than that of the perfused material. It is concluded that a considerable amount of the 16-epioestriol secreted by the placenta is gradually converted to oestriol by the maternal organism. A limited conversion occurs also in the placenta.

In situ monitoring of isophorone diisocyanate-based flexible polyurethane foams formation

2016 ◽  
Vol 54 (1) ◽  
pp. 37-52 ◽  
Author(s):  
I Eceiza ◽  
L Irusta ◽  
A Barrio ◽  
MJ Fernández-Berridi
Keyword(s):  
Foam Height ◽  
Polyurethane Foams ◽  
In Situ Monitoring ◽  
Generation Process ◽  
Isophorone Diisocyanate ◽  
Experimental Conditions ◽  
Foaming Process ◽  
Foam Generation ◽  
Flexible Polyurethane

Novel isophorone diisocyanate-based flexible polyurethane foams were prepared by the one-step method in a computerized foam qualification system (FOAMAT). The experimental conditions to obtain this type of foams, in relation to the nature and concentration of catalysts as well as the reaction temperature, were established as no data were available in scientific literature. The chemical reactions occurring during the foam generation process were monitored in situ by attenuated total reflectance-FTIR spectroscopy. The kinetics of the foam generation was fitted to an nth order model and the data showed that the foaming process adjusted to a first-order kinetics. The physical changes as pressure, foam height, and dielectric polarization were monitored by the FOAM software (FOAMAT). According to these parameters, the foaming process was divided into four steps: bubble growth, bubble packing, cell opening, and final curing.

scholarly journals Application of an enzymatic cascade reaction for the synthesis of the emeraldine salt form of polyaniline

2021 ◽  
Author(s):  
Minoru Kurisu ◽  
Reinhard Kissner ◽  
Masayuki Imai ◽  
Peter Walde
Keyword(s):  
Cascade Reaction ◽  
Emeraldine Salt ◽  
Salt Form ◽  
Experimental Conditions ◽  
Peroxidase Isoenzyme ◽  
Large Unilamellar Vesicles ◽  
Dark Green ◽  
Catalyzed Oxidation ◽  
Reference Reaction

AbstractThe synthesis of the emeraldine salt form of polyaniline (PANI-ES) from aniline with Aspergillus sp. glucose oxidase (GOD), d-glucose, dissolved O2, and horseradish peroxidase isoenzyme C (HRPC) in the presence of large unilamellar vesicles of AOT (sodium bis-(2-ethylhexyl)sulfosuccinate) as templates at pH = 4.3 and T ~ 25 °C was investigated in a systematic way. In this cascade reaction mixture, the oxidation of aniline is catalyzed by HRPC with H2O2 that is formed in situ as byproduct of the GOD-catalyzed oxidation of d-glucose with O2. Under the elaborated experimental conditions which we considered ideal, the formation of PANI-ES products is evident, as judged by UV/Vis/NIR and EPR measurements. Comparison was made with a reference reaction, which was run under similar conditions with added H2O2 instead of GOD and d-glucose. Although the reference reaction was found to be superior, with the cascade reaction, PANI-ES products can still be obtained with high aniline conversion (> 90%) within 24 h as stable dark green PANI-ES/AOT vesicle dispersion. Our results show that the in situ formation of H2O2 does not prevent the inactivation of HRPC known to occur in the reference reaction. Moreover, the GOD used in the cascade reaction is inactivated as well by polymerization intermediates.

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