bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical Carbon-Skeleton Rearrangements as Catalyzed by Cyano-Coordinated Hydrophobic Vitamin B12
Authors: Murakami Yukito , Hisaeda Yoshio , Ozaki Toshiaki , Matsuda Yoshihisa 
Published: July 2006

Abstract
Electrochemical carbon-skeleton rearrangements catalyzed by heptamethyl cobyrinate perchlorate proceeded more efficiently upon coordination of the cyanide ion to the central cobalt atom, and such enhanced catalysis was originated from facilitated formation of an anionic intermediate.
Bis(η5-cyclopentadienyl)diphenyltitanium-catalyzed Hydrosilylation of Ketones
Authors: Nakano Taichi , Nagai Yoichiro 
Published: July 2006

Abstract
Bis(η5-cyclopentadienyl)diphenyltitanium activated a Si–H bond of diphenylsilane, methylphenylsilane, and phenylsilane effectively to bring about the reaction with ketones giving hydrosilylation products, alkoxysilanes, in good yields with good selectivity.
Optical Resolution of 2-Methylpiperazine by Complex Formation with Optically Active 1-Phenyl-1-(o-chlorophenyl)prop-2-yn-1-ol and 1,6-Diphenyl-1,6-di(o-chlorophenyl)hexa-2,4-diyne-1,6-diol
Authors: Toda Fumio , Tanaka Koichi , Kido Masaru 
Published: July 2006

Abstract
An efficient optical resolution of 2-methylpiperazine was achieved by complex formation with the title host compounds. X-Ray crystal structure of a 1:2 complex of (S)-(+)-piperazine and (R)-(−)-1-phenyl-1-(o-chlorophenyl)prop-2-yn-1-ol was studied.
A New Ambient Pressure Organic Superconductor Based on BEDT-TTF with TC Higher than 10 K (TC=10.4 K)
Authors: Urayama Hatsumi , Yamochi Hideki , Saito Gunzi , Nozawa Kiyokazu , Sugano Tadashi , Kinoshita Minoru , Sato Shoichi , Oshima Kokichi , Kawamoto Atsushi , Tanaka Jiro 
Published: July 2006

Abstract
An ambient pressure superconductivity of (BEDT-TTF)2Cu(SCN)2 was observed by d.c. magnetic susceptibility and electrical conductivity measurements. The superconducting critical temperature is the highest (TC=10.4 K) among the organic superconductors so far obtained, even though the anion has a positional disorder in the crystal.
Elevations of Nematic–Isotropic Transition Temperature and Dichroic Ratio of Nonmesomorphic Guest–Nematic Host System with Increasing Guest Concentration
Authors: Kobayashi Michio , Maeda Akihiko , Tanizaki Yoshie , Okubo Jun , Hoshi Toshihiko 
Published: July 2006

Abstract
The nematic-isotropic transition temperature of 4-cyano-4′-pentylbiphenyl (host) has been elevated by admixture of 1,5-di-(p-n-butylanilino)-anthraquinone (guest), the elevation being as much as 2.1 °C for 1 mol% guest concentration (β=−0.689). This phenomenon has been considered to be attributable to the guest-host interaction which must be at least attractive and, in addition, of “many-body” type.
Reversible Change in the Structure of Cerium Oxide in Alumina-Supported Catalyst
Authors: Miki Takeshi , Ogawa Takao , Ueno Akifumi , Matsuura Shinji , Sato Masayasu 
Published: July 2006

Abstract
Ceria in the alumina-supported catalyst was found to react with the alumina to produce CeAlO3 when heated in flowing H2 and to return reversibly to the original ceria particles when calcined in flowing O2 at 1173 K, while lanthana was proved to react irreversibly with the alumina to from LaAlO3.
Colloidal Noble Metal Catalysts Protected by Surfactant Micelles. Regio-Selectivity in the Hydrogenation of Unsaturated Fatty Acids in Organized Media
Authors: Toshima Naoki , Takahashi Tadahito 
Published: July 2006

Abstract
Colloidal dispersions of platinum and palladium protected by nonionic surfactants were prepared by photo-irradiation. They work as active catalysts for the hydrogenation of unsaturated fatty acids and their sodium salts. The regio-selectivity was observed in the hydrogenation in the organized media which surround the colloidal particles. Thus, 10-undecenoic acid was more rapidly hydrogenated than 2-undecenoic acid.
Remarkable Activity Enhancement of Rh/Al2O3 Prepared from RhCl3 for CO–H2 Reaction by the Pretreatment of High Temperature Evacuation
Authors: Fujitsu Hiroshi , Ishibashi Hideo , Ikeyama Nobuhide , Mochida Isao 
Published: July 2006

Abstract
Catalytic activity of Rh/Al2O3 prepared from RhCl3 for the CO–H2 reaction at 473 and 523 K was found to be remarkably enhanced by the evacuation after the reduction of catalyst. Evacuation at 773 K after the reduction with hydrogen at 673 K exhibited the maximum activity of 1200 mmol CO/g-Rh h, which is comparable to that of Rh/TiO2. Significant increases in H2 and CO adsorption, especially the irreversible adsorption of CO, as well as the enhanced reactivity of the adsorbed CO by the evacuation treatment may cause the activity enhancement.
Active Transport of Formaldehyde through an Anion-Exchange Membrane via the Formation of Bisulfite Adduct
Authors: Igawa Manabu , Hoffmann Michael R 
Published: July 2006

Abstract
Formaldehyde reacts with bisulfite to form hydroxymethanesulfonate, which is a conjugate base of a strong acid, and is able to be transported actively by the coupled countertransport of hydroxide ion through an anion-exchange membrane. The permeation rate is controlled by pH and formaldehyde can be separated readily from other types of organic solutes via this method.
Preparation of Size-Controlled CdS Colloids in Water and Their Optical Properties
Authors: Nosaka Yoshio , Yamaguchi Katsuhiko , Miyama Hajime , Hayashi Hisaharu 
Published: July 2006

Abstract
Size of colloidal CdS particles in aqueous medium was controlled by adding thiols in the procedure of the preparation. The change in optical absorption spectra and the quantum yield of photoinduced electron transfer were measured for these size-controlled CdS colloids.
Photochemical Rearrangement of 16β,17β-Epoxydigitoxigenin 3-Acetate. The Formation of Cyclopropyl Ketones
Authors: Ishii Keitaro , Hashimoto Toshihiro , Sakamoto Masanori , Taira Zenei , Asakawa Yoshinori 
Published: July 2006

Abstract
The first photochemical transformation of a cardenolide derivative was studied. The photolysis of 16β,17β-epoxydigitoxigenin 3-acetate prepared from gitoxigenin leads to cyclopropyl ketones, which are formed by oxa-di-π-methane rearrangement of the primary photoproduct, 16-oxodigitoxigenin 3-acetate.
Lipophilic Calix[4]arene Ester and Amide Derivatives as Neutral Carriers for Sodium Ion-Selective Electrodes
Authors: Kimura Keiichi , Matsuo Mitsunori , Shono Toshiyuki 
Published: July 2006

Abstract
Lipophilic calix[4]arenes bearing ester and amide linkages were synthesized and tested for their usefulness as neutral carriers of Na+-selective electrodes. The resulted poly(vinyl chloride) (PVC) membrane electrodes based on the calixarene derivatives were found to be highly selective for Na+.
Meissner Effect in an Organic Superconductor (BEDT-TTF)2[Cu(NCS)2]
Authors: Nozawa Kiyokazu , Sugano Tadashi , Urayama Hatsumi , Yamochi Hideki , Saito Gunzi , Kinoshita Minoru 
Published: July 2006

Abstract
A quite large diamagnetic susceptibility corresponding to 83% of the perfect diamagnetism is observed for (BEDT-TTF)2[Cu(NCS)2] at 2 K. The critical temperature is determined to be 9.8±0.3 K at 30 G. The magnetization shows a hysteresis loop with sharp maxima near 35 G, thereby indicating the type II superconducting nature. The lower critical field and the critical current density are estimated from the analysis of the hysteresis loop.
Ring-Expansion Reactions Catalyzed by Hydrophobic Vitamin B12 in Synthetic Bilayer Membrane
Authors: Murakami Yukito , Hisaeda Yoshio , Ohno Teruhisa , Matsuda Yoshihisa 
Published: July 2006

Abstract
Heptapropyl cobyrinate perchlorate catalyzed the ring-expansion reactions, which convert 2-methyl-1,3-cyclopentanedione and 3-methyl-2-pyrrolidinone into 1,4-cyclohexanedione and 2-piperidinone, respectively, in single-compartment bilayer vesicles.
Photochemical Epoxidation of Olefins with Molecular Oxygen Activated by Oxo(tetra-p-tolylporphinato)molybdenum(V)
Authors: Matsuda Yoshihisa , Koshima Hiroaki , Nakamura Koichiro , Murakami Yukito 
Published: July 2006

Abstract
Photochemical epoxidation of olefins was catalyzed by a molybdenum porphyrin in benzene under aerobic conditions. The catalytic reaction rate was somewhat lower than that observed for the similar reaction catalyzed by the corresponding niobium complex. A reaction mechanism, involving cooperative interaction of an olefin and dioxygen with the molybdenum(IV) species, was postulated.
Spin-Trapped Alkyl Radicals in Dehydrogenation of Alkenes with 4-t-Butyl-o-benzoquinone
Authors: Takada Masayuki , Oshima Ryuichi , Tsuchiya Jun-ichi , Miyakoshi Tetsuo , Seno Manabu 
Published: July 2006

Abstract
By the spin-trapping technique using 2-methyl-2-nitrosopropane as a spin trap conjugated hydrocarbon radicals have been detected in dehydrogenation of methyl linoleate and (2E,4E,7Z)-tetradecatriene with 4-t-butyl-o-benzoquinone.
Syntheses of Nickel(II) Dinuclear Complexes with Tetraketone and the Effect of Anions on Coordination Geometries
Authors: Fukuda Yutaka , Mafune Kumiko 
Published: July 2006

Abstract
Three nickel(II) mixed ligand dinuclear complexes were prepared, Ni2(tae)(tmen)2X2·nH2O where tae = tetraketonate; tmen = N-alkylethylenediamine; X− = B(C6H5)4−, ClO4−, or NO3−; n = 0 or 3. Each complex assumes the unique combination of square planar and octahedral coordination geometries in the dinuclear entity.
Boron Trifluoride-Assisted Reaction of Perfluoroalkyllithiums with Imines. A Novel Route to Perfluoroalkylated Amines
Authors: Uno Hidemitsu , Shiraishi Yasukazu , Shimokawa Kazuhiro , Suzuki Hitomi 
Published: July 2006

Abstract
In the presence of BF3, perfluoroalkyllithiums were found to react with imines to give perfluoroalkylated amines in moderate to good yields.
Spectroelectrochemical Properties of Phenolphthalein Incorporated within a Poly(Hydroquinone/p-Benzoquinone) Film
Authors: Arai Gorou , Enomoto Katsuyoshi , Yasumori Iwao 
Published: July 2006

Abstract
Electrochemical oxidation-reduction of poly(mercaptohydroquinone/mercapto-p-benzoquinone) causes a rapid and large pH change in the polymer film in an aqueous solution. Phenolphthalein, a typical pH indicator, incorporated within the polymer film on a SnO2 electrode showed a rapid reversible color change from red to colorless when the electrode potential is repetitively stepped between −0.6 (reduction) and +0.4 V vs. SCE (oxidation).
Thin Film Formation of 2-Methyl-4-nitroaniline by Ionized Cluster Beam Technique
Authors: Aratani Sukekazu , Isogai Masato , Kakuta Atsushi 
Published: July 2006

Abstract
Thin films of 2-methyl-4-nitroaniline were prepared by an ionized cluster beam (ICB) technique. Their SEM photographs suggested that the ICB-deposited films are much denser than vacuum-deposited films. X-Ray diffraction patterns suggested that the control of a preferential orientation is possible by changing the substrate temperature.
Mixed Organocuprates Derived from ortho-Heterosubstituted ArCu Species. Reactions with Simple α,β-Unsaturated Ketones
Authors: Arevalo F , Castedo L , Fernandez B R , Mouriño A , Sarandeses L 
Published: July 2006

Abstract
We describe the reaction of new organocuprates of the form ArRTCuLi (Ar an ortho-heterosubstituted non-transferable ligand), and their reactions with simple α,β-unsaturated ketones.
Synthesis of Optically Active myo-Inositol 1,3,4-Trisphosphate
Authors: Ozaki Shoichiro , Kohno Masayasu , Nakahira Hiroyuki , Bunya Motonobu , Watanabe Yutaka 
Published: July 2006

Abstract
Synthesis of optically active myo-inositol 1,3,4-trisphosphate has been accomplished. Efficiency of a chiral HPLC column for optical resolution of myo-inositols is shown.
Aggregated Structures of Azobenzene-linked Amphiphiles at the Air–Water Interface
Authors: Xu Xinfei , Era Masanao , Tsutsui Tetsuo , Saito Shogo 
Published: July 2006

Abstract
With three azobenzene-linked amphiphiles containing designed alkyl and methylene groups, spectroscopic studies on monolayer at the air–water interface were performed. The effects of the alkyl and methylene groups on the molecular orientation and aggregate states in the monolayers were shown.
Complete Mixing of Two Amphiphilic Compounds at Air–Water Interface
Authors: Niino Hiroyuki , Takehara Kenji , Isomura Kazuaki , Taniguchi Hiroshi , Era Masanao , Tsutsui Tetsuo , Saito Shogo 
Published: July 2006

Abstract
Two amphiphilic compounds, 5-(p-hexadecylphenyl)pyrazin-2-oxyacetic acid (1) and p-(5-hexadecylpyrazin-2-yl)phenoxyacetic acid (2), were newly synthesized. The mixture of 1 and 2 formed more closely packed monolayer than pure 1 or 2 did. This phenomenon was revealed to be caused by complete mixing due to the attractive interaction between reversely oriented chromophores of 1 and 2.
Low Temperature Synthesis of TiO2 by Vapor-Phase Hydrolysis of Titanium Isopropoxide
Authors: Kirkbir Fikret , Komiyama Hiroshi 
Published: July 2006

Abstract
At sufficiently high H2O concentration, titanium isopropoxide vapor could almost completely be hydrolyzed to form submicron-size TiO2 powder at a reaction temperature as low as 380 K with little deposition inside a tubular-flow reactor, indicating a highly efficient method for preparation of powders.
Two Bromopyrroles from a Marine Sponge Agelas sp.
Authors: Tada Haruhiko , Tozyo Takehiko 
Published: July 2006

Abstract
Extremely unstable bromopyrrole metabolites were isolated from a sponge Agelas sp. and characterized as 2,3-dibromopyrrole and 2,3-dibromo-5-methoxymethylpyrrole.
(E)-(2-Bromoethenyl)diisopropoxyborane. A New Building Block for (E)-Olefins
Authors: Hyuga Satoshi , Yamashina Naoko , Hara Shoji , Suzuki Akira 
Published: July 2006

Abstract
(E)-(2-Bromoethenyl)diisopropoxyborane is a useful precursor for the synthesis of (E)-olefins by the stepwise cross-coupling reaction with organozinc chlorides and then with organic halides in the presence of a base, both catalyzed by Pd complex.
Ring Transformation Reaction of 1,2,4,5-Tetrazines to 1,2,4-Triazin-5-ols and -5-thiols by Isocyanato- and Isothiocyanatotrimethylsilane
Authors: Takahashi Masahiko , Kikuchi Hiroyasu 
Published: July 2006

Abstract
A new ring transformation reaction of 1,2,4,5-tetrazines to 1,2,4-triazin-5-ols and -5-thiols on treatment with isocyanato- and isothiocyanatotrimethylsilane, respectively, is described.
Triphenylbismuthonio-4,4-dimethyl-2,6-dioxocyclohexane-1-ide and Triphenylbismuthonio-4,4-dimethyl-2,6-dioxo-3,5-dioxan-1-ide. Preparation and Properties of the Stable Bismuthonium Ylides
Authors: Suzuki Hitomi , Murafuji Toshihiro , Ogawa Takuji 
Published: July 2006

Abstract
The title two bismuthonium ylides were obtained in pure form and their reactions with some electrophiles were studied. In contrast with stable ylides of arsenic and antimony, these bismuthonium ylides readily react with aldehydes and isothiocyanates but they are inert towards ketones.
Triphenylmethanesulfenyl Group. A New Protecting Group for the Uracil Residue in Oligoribonucleotide Synthesis
Authors: Takaku Hiroshi , Imai Kazuaki , Nagai Masato 
Published: July 2006

Abstract
The selective protection of the N3-imido group of uridine with triphenymethanesulfenyl group is described. This group could be introduced selectively onto the N3-position of the uracil moiety of 3′,5′-O-(tetraisopropyldisiloxane-1,3-diyl)uridine in a good yield and removed very easily by treatment with aqueous iodine.
Oxidation of Cyclopentene with Hydrogen Peroxide Catalyzed by 12-Heteropoly Acids
Authors: Furukawa Hiroshi , Nakamura Teiji , Inagaki Hiroyuki , Nishikawa Eiichiro , Imai Chihiro , Misono Makoto 
Published: July 2006

Abstract
12-Heteropoly acids exhibited high performance for selective oxidation of cyclopentene to glutaraldehyde with hydrogen peroxide. Especially, heteropoly acids with mixed addenda atoms of Mo and W, H3PMo12−xWxO40(x=1–9), showed excellent results.
Regioselective Hydrostannation of Terminal Acetylenes under Transition Metal Catalysis
Authors: Kikukawa Kiyoshi , Umekawa Hideto , Wada Fumio , Matsuda Tsutomu 
Published: July 2006

Abstract
Rhodium complexes (RhClL3, RhCl(CO)L2, [RhCl(COD)]2; L=PPh3) catalyze hydrostannation of terminal acetylenes (RC≡CH; R=Ph, Me3Si, R1OC(R2)(R3), and R1OCH2CH2; R1=THP, OAc; R1, R2=H, Me) with Bu3SnH to produce R(Bu3Sn)C=CH2 selectively. Other transition metal complexes [MCl2L2(M=Ni, Pd, Pt, Co)] are also active for the hydrostannation, but with less selectivity.
Formation of Infrared Absorbing Dyes. Carbazole–Naphthoquinone Intermolecular Charge–Transfer Complexes
Authors: Matsuoka Masaru , Han Liyuan , Kitao Teijiro , Mochizuki Shinobu , Nakatsu Kazumi 
Published: July 2006

Abstract
Intermolecular charge–transfer (CT) complexes derived from carbazoles as donors and naphthoquinones as acceptors were evaluated as coloring matters. The PPP MO design, the relation between color and constitution, and the X-ray analysis of the CT complex dye were conducted.
Synthesis and Radical Cyclization of 2-(β-Haloacyl)-1,2-dihydroisoquinolines by Means of Tin Hydride. One-Pot Synthesis of Benzo[f]indolizidine Systems from Isoquinolines
Authors: Yamaguchi Ryohei , Hamasaki Takashi , Utimoto Kiitiro 
Published: July 2006

Abstract
Reactions of isoquinolines activated by 2-halopropionyl chlorides with tributyltin hydride afford selectively 2-(2-halopropionyl)-1,2-dihydroisoquinolines in good yields, the radical cyclizations of which furnish benzo[f]indolizidine systems. The above two reactions can be consecutively achieved in one-pot. Furthermore, the present procedures are extended to synthesis of 12,12a-dihydroisoindolo[2,3-b]isoquinolin-5(7H)-one.
Hydroxylation of Benzene with Dinitrogen Monoxide over H-ZSM-5 Zeolite
Authors: Suzuki Eiichi , Nakashiro Katsumi , Ono Yoshio 
Published: July 2006

Abstract
Phenol was obtained from benzene and dinitrogen monoxide over H-ZSM-5 zeolite at 603 K, a phenol yield on a benzene basis being 8.1% at partial pressures of benzene and dinitrogen monoxide of 6.9 kPa and 51 kPa, respectively. Neither CO nor CO2 was detected in the product.
13C CP-MAS NMR of Hofmann-type Clathrates
Authors: Yamasaki Akira , Nishikiori Shin-ichi , Iwamoto Toschitake 
Published: July 2006

Abstract
The 13C CP-MAS NMR spectra of two Hofmann-type clathrates, diamagnetic Cd(NH3)2Ni (CN)4·2C6H6 and paramagnetic Ni (NH3)2-Ni (CN)4·2C6H6, were analyzed. The guest benzene gives a singlet spectral line in the diamagnetic host and a doublet in the paramagnetic one. The doublet is due to the paramagnetic anisotropy at the crystallographically-independent two carbon atoms in the crystal structure.
Reactivities of Diastereoisomeric Carbanions in Dianions Generated from β-Hydroxysulfoxides
Authors: Tanikaga Rikuhei , Hamamura Kazumasa , Kaji Aritsune 
Published: July 2006

Abstract
Dianions generated from β-hydroxysulfoxides reacted with n-C8H17I, n-C9H19CHO, and D2O to give products in different threo/erythro ratios, but those ratios were found to be essentially same in the early stage. The configurational interconversion of the diastereoisomeric carbanions would play an important role.
Thiocyanate Solvent Polymeric Membrane Ion-selective Electrode Based on Cobalt(III) α, β, γ, δ-Tetraphenylporphyrin Anion Carrier
Authors: Hodinár Ales , Jyo Akinori 
Published: July 2006

Abstract
A solvent polymeric membrane ion-selective electrode based on thiocyanato(α, β, γ, δ-tetraphenylporphynate)cobalt(III) was developed. The electrode membrane exhibits SCN−&gt;&gt;I−&gt;NO2−&gt;&gt;C1O4−&gt;HCO3−&gt;HPO42−&gt;Cl−≅Br−&gt;NO3−≅SO42− selectivity sequence with a preference for SCN− over ClO4− by 102.5–103.1. Response of the electrode is linear in the 10−5 to 10−1 M concentration range for SCN with a slope of −49±2 mV/log a.
Plasma 25-hydroxyvitamin D and not 1,25-dihydroxyvitamin D is associated with parathyroid adenoma secretion in primary hyperparathyroidism: a cross-sectional study
Authors: Moosgaard B , Vestergaard P , Heickendorff L , Melsen F , Christiansen P , Mosekilde L 
Published: July 2006

Background: Primary hyperparathyroidism (PHPT) is associated with reduced plasma 25-hydroxyvitamin D (P-25OHD) and usually increased plasma 1α,25-dihydroxyvitamin D (P-1,25(OH)2D). Parathyroid tissue expresses the vitamin D receptor and it is thought that circulating 1,25(OH)2D participate in the regulation of parathyroid cell proliferation, differentiation and secretion.
Aim: To investigate the relations between circulating levels of 1,25(OH)2D and 25OHD respectively and parathyroid adenoma weight (AW), plasma-parathyroid hormone (P-PTH) and PTH secretion expressed as P-PTH/AW.
Design: Cross-sectional study.
Material: One hundred and seventy-one consecutive hypercalcaemic caucasian patients aged 19–87 years (median 63, 84% females) with surgically proven parathyroid adenoma.
Results: A weak positive correlation was found between P-25OHD and P-1,25(OH)2D (r = 0.24, P < 0.005). AW depended on sex and body mass index. Following adjustment, it was correlated positively to P-PTH, calcium (Ca) and alkaline phosphatase (AP) and inversely to plasma phosphate in a multiple regression model. AW was not associated with vitamin D metabolites. Preoperative P-PTH correlated positively to plasma levels of Ca and AP, but inversely to phosphate and 25OHD (P < 0.001) levels. P-PTH was not associated with P-1,25(OH)2D (P = 0.65). The P-PTH:AW ratio correlated inversely to P-25OHD (P < 0.05), but showed no relations to plasma levels of Ca, phosphate or 1,25(OH)2D (P = 0.22).
Conclusion: In this material, low levels of 25OHD were related to higher levels of P-PTH and higher PTH:AW ratios in patients with PHPT suggesting that vitamin D deficiency increase PTH secretion activity. Neither PTH secretion nor AW was associated with circulating levels of 1,25(OH)2D.
The early luteal phase administration of estrogen and progesterone does not induce premature luteolysis in normo-ovulatory women
Authors: Beckers Nicole G M , Platteau Peter , Eijkemans Marinus J , Macklon Nicholas S , de Jong Frank H , Devroey Paul , Fauser Bart C J M 
Published: July 2006

Objective: The luteal phase after ovarian hyperstimulation for in vitro fertilization (IVF) is insufficient. Therefore, luteal phase supplementation is routinely applied in IVF. It may be postulated that premature luteolysis after ovarian hyperstimulation is due to supraphysiological steroid levels in the early luteal phase. In the present study, high doses of steroids are administered after the LH surge in normo-ovulatory volunteers in order to investigate whether this intervention gives rise to endocrine changes and a shortening of the luteal phase.
Design: Randomized controlled trial.
Methods: Forty non-smoking, normal weight women, between 18 and 37 years of age, with a regular menstrual cycle (24–35 days), received either high dosages of estradiol (E2), progesterone (P), E2+P or no medication. Blood sampling was performed every other day from the day of the LH surge until LH+14. Duration of the luteal phase and endocrine profiles were the main study outcomes.
Results: Early luteal phase steroid concentrations achieved by exogenous administration were comparable with levels observed following ovarian hyperstimulation for IVF. No difference in the luteal phase length was observed comparing all groups. However, a significant decrease in LH levels could be observed 6 days after the mid-cycle LH surge (P<0.001) in women receiving P, resulting in accelerated decrease of inhibin A production by the corpus luteum (P=0.001).
Conclusion: The present intervention of high-dose steroid administration shortly after the LH surge failed to induce a premature luteolysis regularly in cyclic women. It seems that the induced transient suppression in LH allowed for a timely recovery of corpus luteum function. Other additional factors may be held responsible for the distinct reduction in luteal phase length observed after ovarian hyperstimulation for IVF.