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PubMed2005

Prospective, randomized trial comparing cetrorelix acetate and ganirelix acetate in a programmed, flexible protocol for premature luteinizing hormone surge prevention in assisted reproductive technologies.

OBJECTIVE: To compare the safety and efficacy of single-dose cetrorelix acetate (3 mg) and daily ganirelix acetate (0.25 mg) in the inhibition of premature LH surge in women undergoing cycle-programmed ovarian stimulation before Assisted Reproductive Technology (ART). DESIGN: Prospective, open-label, randomized, comparative study. SETTING: Sixteen ART centers in the United States. PATIENT(S): One hundred eighty-five infertile patients undergoing ART. INTERVENTION(S): Single injection of cetrorelix (3 mg SC) or daily dose of ganirelix (0.25 mg SC) was administered when the lead follicle was > or =14 mm. Daily cetrorelix (0.25 mg) was administered if the criteria for hCG administration were not met 4 days after receiving 3 mg of cetrorelix. MAIN OUTCOME MEASURE(S): Percentage of patients who did not have a premature LH surge, defined as LH <10 IU/L on the day of hCG administration. The IVF and embryo transfer (ET) outcomes were assessed. RESULT(S): No patient in either treatment group had a premature LH surge. There were no statistically significant differences between treatments for any IVF/intracytoplasmic sperm injection (ICSI) or ET outcomes, including pregnancy rate (PR). However, cetrorelix required significantly fewer injections than ganirelix. Similar safety profiles were observed. CONCLUSION(S): Cetrorelix and ganirelix effectively prevented LH surges in oral contraceptive (OC) pill-programmed, flexible protocols, with similar safety profiles and PRs; however, cetrorelix required significantly fewer injections, increasing patient convenience.

Adult↗
PubMed1999

Inhibition of DT-diaphorase (NAD(P)H:quinone oxidoreductase, EC 1.6.99.2) by 5,6-dimethylxanthenone-4-acetic acid (DMXAA) and flavone-8-acetic acid (FAA): implications for bioreductive drug development.

The tumour blood flow inhibitors 5,6-dimethylxanthenone-4-acetic acid (DMXAA) and flavone-8-acetic acid (FAA) have been shown to potentiate the antitumour activity of several bioreductive drugs in vivo. Whilst the induction of hypoxia as a result of blood flow inhibition is presumed to be responsible for enhancing the activity of bioreductive drugs, no studies have examined potential interactions between DMXAA or FAA and enzymes involved in bioreductive drug activation. Both FAA and DMXAA are competitive inhibitors of the enzyme DT-diaphorase (NAD(P)H:Quinone oxidoreductase EC 1.6.99.2) with respect to NADH, with Ki values of 75 and 20 microM, respectively. Cytochromes P450 reductase and b5 reductase activities are not significantly inhibited by FAA, whereas DMXAA partially inhibits cytochrome b5 reductase activity. The cytotoxicity of the indoloquinone EO9 (3-hydroxymethyl-5-aziridinyl-1-methyl-2-[1H-indole-4,7-dione] prop-beta-en-alpha-ol) against DLD-1 (IC50 = 0.32+/-0.08 microM) was significantly reduced when combinations of EO9 and FAA (IC50 = 12.26+/-5.43 microM) or DMXAA (IC50 > 40 microM) were used. In the case of menadione (which is detoxified by DT-diaphorase), combinations of menadione with FAA or DMXAA were more toxic (IC50 = 7.46+/-2.22 and 9.46+/-1.70 microM, respectively) than menadione alone (IC50 = 22.02+/-1.59 microM). Neither DMXAA nor FAA potentiated the activity of tirapazamine in vitro. These results suggest that the use of DMXAA and FAA to potentiate the activity of bioreductive drugs where DT-diaphorase plays a central role in either activation or detoxification may be inappropriate. The fact that FAA in particular does not inhibit other key enzymes involved in bioreductive activation suggests that it may be useful in terms of identifying DT-diaphorase-activated prodrugs.

Antineoplastic Agents↗
PubMed1999

Induction of STAT and NFkappaB activation by the antitumor agents 5,6-dimethylxanthenone-4-acetic acid and flavone acetic acid in a murine macrophage cell line.

The antitumor agents flavone-8-acetic acid (FAA) and its dose-potent analogue 5,6-dimethylxanthenone-4-acetic acid (DMXAA), currently in clinical trials, have a novel mechanism of action that is mediated through their ability to induce a spectrum of cytokines. Since NFkappaB and STAT transcription factors participate in the regulation of a number of genes involved in immune and cytokine responses, we investigated whether these transcription factors were activated in the ANA-1 murine macrophage cell line by DMXAA and FAA compared with lipopolysaccharide (LPS), a bacterial component that induces an overlapping spectrum of cytokines. Activation of STAT1 and STAT3 was observed distinctly 4 hr after DMXAA and FAA stimulation. DMXAA and FAA induced NFkappaB translocation with slower kinetics of activation compared with LPS. STAT activation by DMXAA and FAA was inhibited by cycloheximide, indicating a requirement for de novo protein synthesis. The ANA-1 cells produced high titres of interferons (IFNs) in the culture supernatant after stimulation with DMXAA and FAA, and the addition of antibodies to IFNalpha/beta inhibited STAT activation, indicating that IFNs mediated STAT activation. NFkappaB activation, on the other hand, was not inhibitable with cycloheximide or with antibodies to IFNalpha/beta. NFkappaB activation appeared to be a direct action of the anticancer agents, whereas activation of the STAT proteins was due, in part, to the high titres of IFNs induced. These results demonstrate the significance of the IFN response in initiating the cascade of secondary events that may contribute to the overall antitumor efficacy of DMXAA and FAA in murine models.

Animals↗
PubMed1981

Separation of 5-hydroxyindole-3-acetic acid and indole-3-acetic acid in urine by direct injection on a reversed-phase column containing a hydrogen-accepting stationary phase.

The separation of 5-hydroxyindole-3-acetic acid and indole-3-acetic acid from urine is demonstrated. The urine is injected directly on a liquid chromatographic column which is coupled to a flow-through fluorescence detector or a UV detector. A hydrogen-accepting stationary phase, tributyl phosphate (TBP), which retains carboxylic acid selectivity, was more selective than more common reversed-phase systems with alkyl-bonded stationary phases. The mobile phases were buffers, sometimes buffers containing methanol or acetonitrile. A simple method of removing late peaks in the chromatogram, in order to reduce analysis time, is also presented.

Chromatography, Liquid↗
PubMed1983

Hydrolyses of alpha-naphthyl acetate, beta-naphthyl acetate, and acetyl-DL-phenylalanine beta-naphthyl ester.

Using simultaneous coupling azo dye techniques kidney enzymes active against alpha-naphthyl acetate, beta-naphthyl acetate, and acetyl-DL-phenylalanine beta-naphthyl ester are characterized. The enzymes show identical distribution in the section. The banding patterns in zymograms are the same after incubation with the different substrates. The enzymes might, however, be separated by difference in pH optimum, initial velocity and sensitivity to inhibitors and activators.

Animals↗
PubMed1997

Disproportionation Kinetics of Hypoiodous Acid As Catalyzed and Suppressed by Acetic Acid-Acetate Buffer.

The kinetics of the disproportionation of hypoiodous acid to give iodine and iodate ion (5HOI right harpoon over left harpoon 2I(2) + IO(3)(-) + H(+) + 2H(2)O) are investigated in aqueous acetic acid-sodium acetate buffer. The rate of iodine formation is followed photometrically at -log [H(+)] = 3.50, 4.00, 4.50, and 5.00, &mgr; = 0.50 M (NaClO(4)), and 25.0 degrees C. Both catalytic and inhibitory buffer effects are observed. The first process is proposed to be a disproportionation of iodine(I) to give HOIO and I(-); the iodide then reacts with HOI to give I(2). The reactive species (acetato-O)iodine(I), CH(3)CO(2)I, is postulated to increase the rate by assisting in the formation of I(2)O, a steady-state species that hydrolyzes to give HOIO and I(2). Inhibition is postulated to result from the formation of the stable ion bis(acetato-O)iodate(I), (CH(3)CO(2))(2)I(-), as buffer concentration is increased. This species is observed spectrophotometrically with a UV absorption shoulder (lambda = 266 nm; epsilon = 530 M(-)(1) cm(-)(1)). The second process is proposed to be a disproportionation of HOIO to give IO(3)(-) and I(2). Above 1 M total buffer, the reaction becomes reversible with less than 90% I(2) formation. Rate and equilibrium constants are resolved and reported for the proposed mechanism.

Journal Article↗
PubMed2005

Conformation of acetate derivatives of sugars and other cyclic alcohols. Crystal structures, NMR studies, and molecular mechanics calculations of acetates. When is the exocyclic C-O bond eclipsed?

[reaction: see text] A study of published crystal structures (of O-acetylated sugars for the most part) suggests that the exocyclic C-O bond in acetate esters of cyclic alcohols intrinsically prefers a staggered conformation, although the eclipsed conformation is only slightly less stable. When the acetate is flanked by two equatorial substituents the preferred conformation is close to eclipsed. Over 1500 C-OAc bonds have been analyzed. Diagnostic NMR criteria for torsion angles and MM3 calculations are reported and confirm these conclusions.

Journal Article↗
PubMed1999

Four Enantiomerization Routes of 1,2,2-Trimesitylvinyl Acetate. Enantioselective Liquid Chromatography of (E)- and (Z)-2-m-Methoxymesityl-1,2-dimesitylvinyl Acetates.

The vinyl propellers (E)- and (Z)-2-m-methoxymesityl-1,2-dimesitylvinyl acetates (3c and 3d) were prepared and their geometries assigned. The stereoisomerization barriers of the trimesityl vinyl acetate system were determined by DNMR and by enantioselective LC resolution and polarimetric monitoring of the behavior of the two diastereomeric racemates of 3c and 3d. Combined with data for trimesitylvinyl-OAc 3a and its 1-m-methoxymesityl analogue 3b, the following order of barriers DeltaG() is obtained: alphabeta-2-ring flip > alphabeta'-2-ring flip > betabeta'-2-ring flip > alphabetabeta'-3-ring flip (the threshold enantiomerization barrier). This order which differs from the previously found orders for trimesitylvinyl-X, X = H, OPr-i was rationalized and discussed.

Journal Article↗
PubMed2004

Thermal and palladium-catalyzed [3 + 2] synthesis of cyclopentadienone acetals from cyclopropenone acetals and acetylenes.

[reaction: see text] Substituted cyclopentadienone acetals (CPDAs) were synthesized by a thermal or palladium-catalyzed [3 + 2] cycloaddition reaction of a substituted cyclopropenone acetal to an electron-deficient acetylene. The synthesis afforded di-, tri-, and tetra-substituted CPDAs of considerable structural varieties that undergo Diels-Alder reaction to produce bicyclo[2.2.1]heptenes.

Journal Article↗
PubMed2002

Effect of vinyl acetate content on the sintering behavior of hydroxyapatite-ethylene vinyl acetate copolymer composites.

Ethylene vinyl acetate copolymer (EVA) alone could be used as a binder material for the fabrication of hydroxyapatite (HAP) into intricate shapes for various bone substitute applications. It was observed that as the vinyl acetate content in the polymer was increased from 12 to 28 wt % an increase in the sintered density of the HAP was observed. Retention of the shapes of HAP in the molded form was also observed.

Journal Article↗
PubMed1984

Simultaneous measurement of renal clearance and plasma clearance of 99mTc-labelled diethylenetriaminepenta-acetate, 51Cr-labelled ethylenediaminetetra-acetate and inulin in man.

The present investigation was undertaken to study the kinetics of 99mTc-labelled diethylenetriaminepenta-acetate (DTPA) as compared with inulin and 51Cr-labelled ethylenediaminetetra-acetate (EDTA). Twenty patients with various degrees of decreased renal function were studied. The renal clearance, plasma clearance and volume of distribution of all three tracers were measured after a simultaneous single injection. The average renal clearance ratio 99mTc-DTPA to inulin was 0.97; the average renal clearance ratio 99mTc-DTPA to 51Cr-EDTA was 1.02. In all patients the plasma clearance of inulin exceeded that of 99mTc-DTPA. No difference was seen between the plasma clearance of 99mTc-DTPA and 51Cr-EDTA. The plasma clearance of all three tracers overestimated the simultaneously measured renal clearance; on average this was, for 99mTc-DTPA 5.7 ml/min, for 51Cr-EDTA 6.0 ml/min and for inulin 8.1 ml/min. The plasma clearance of 99mTc-DTPA correlated well with the renal clearance of inulin, but overestimated this by 3.5 ml/min on average. The volume of distribution of inulin was less than that of 99mTc-DTPA and 51Cr-EDTA. No difference was seen between the volume of distribution of 99mTc-DTPA and 51Cr-EDTA. It is concluded that the difference in the kinetics of 99mTc-DTPA and 51Cr-EDTA in patients with decreased renal function was small and without clinical relevance.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

The morphological effects of the anti-tumor agents flavone acetic acid and 5,6-dimethyl xanthenone acetic acid on the colon 38 mouse tumor.

Flavone acetic acid and 5,6-dimethyl xanthenone acetic acid have a broad spectrum of anti-tumor activity in mice, and act by stimulating immune cells and inhibiting tumor blood flow, resulting in hemorrhagic necrosis within 24 hrs. To study the evolution of hemorrhagic necrosis, subcutaneous Colon 38 tumors were examined by light and electron microscopy from 30 min to 24 hrs after treatment with these agents, and measurements of tumor energy metabolites made. The results show that both agents cause apoptosis beginning at 30 min, and that by 4 hrs necrosis supervenes, accompanied by rupture of tumor blood vessels. The absence of early endothelial cell damage or thrombosis suggests that vessel rupture, and consequent loss of blood flow and energy metabolite depletion, is caused by loss of extravascular mechanical support by the tumor parenchyma.

Adenocarcinoma↗
PubMed2006

Treatment of dysfunctional uterine bleeding in the perimenopause: the effects of adding combined estradiol/norethisterone acetate therapy to goserelin acetate treatment--a randomized, placebo-controlled, double-blind trial.

OBJECTIVE: To assess the effects of adding combined estradiol/norethisterone acetate therapy (CENT) to goserelin acetate treatment (GA) of dysfunctional uterine bleeding (DUB) in perimenopausal women. METHODS: In a randomized, placebo-controlled, double-blind trial followed by an open follow-up study, 31 perimenopausal women with DUB were recruited from gynecological outpatient departments of two Dutch hospitals and randomized for treatment with either GA/placebo or GA/CENT for 6 months followed by 18 months of GA/CENT for all. The main outcome measures were abdominal pain, number of bleeding days, double-layer endometrial thickness (DET), Greene climacteric score (GCS), visual analog scale for well-being, bone mineral density (BMD) and mammographic density (BI-RAD score). RESULTS: Abdominal pain, number of bleeding days and DET decreased in both groups, the between-group difference in decrease not being statistically significant. GCS initially showed significant improvement in the GA/CENT group. BMD decreased significantly in the GA/placebo group (-4.1%) compared with the GA/CENT group (-0.3%). Another 18 months of GA/CENT did not result in a lasting difference in BMD between groups. BI-RAD scores did not differ significantly between or within the two groups. CONCLUSIONS: Adding CENT to GA treatment for DUB in perimenopausal women initially prevented BMD loss and improved climacteric complaints, while having no negative impact on vaginal bleeding, abdominal pain or BI-RAD scores. However, prolonged treatment did not result in a lasting prevention of bone loss.

Antineoplastic Agents, Hormonal↗
PubMed2006

Ganirelix acetate causes a rapid reduction in estradiol levels without adversely affecting oocyte maturation in women pretreated with leuprolide acetate who are at risk of ovarian hyperstimulation syndrome.

BACKGROUND: Elevated estradiol (E(2)) levels predispose to development of ovarian hyperstimulation syndrome (OHSS). Since GnRH antagonist is associated with a reduction in E(2) levels, we hypothesized that GnRH-antagonist treatment of women down-regulated with GnRH agonist who are at risk of OHSS might reduce E(2) levels and avoid cycle cancellation. METHODS: Retrospective study in a university-based assisted reproduction technology (ART) programme in 87 patients treated with long luteal (LL) or microdose flare (MDF) with ovarian hyperresponse and 87 control patients without ovarian hyperresponse. GnRH-antagonist (ganirelix acetate) treatment was started and leuprolide acetate discontinued in women who failed to respond to a reduction in gonadotrophin dosage. RESULTS: In the treatment group, there was a significant, reproducible reduction in serum E(2) levels. Mean E(2) at the start of ganirelix treatment was 4219.8 pg/ml and decreased in 24 h to 2613.7 pg/ml (36.7%; P < 0.001). An average of 24.9 +/- 8.8 oocytes were obtained at retrieval and an average of 19.1 +/- 8.0 were metaphase II (79.2%). Fertilization occurred in 13.9 +/- 8.1 embryos (72.8%). In this high risk group, two cases of severe OHSS (2.3%) occurred. The ongoing pregnancy rate was 51.8%. Compared with the control group, there were no statistically significant differences in the rate of oocyte recovery, oocyte maturity, 2PN rate, fertilization, cancellation, OHSS or pregnancy. CONCLUSIONS: GnRH-antagonist treatment of women pretreated with GnRH agonist rapidly reduced circulating serum E(2) without adversely affecting oocyte maturation, fertilization rates or embryo quality and resulted in a high pregnancy rate in this subgroup of patients at risk of OHSS.

Adult↗
PubMed1986

Boron and ectomycorrhizal influences on indole-3-acetic acid levels and indole-3-acetic acid oxidase and peroxidase activities of Pinus echinata Mill. roots.

The level of indole-3-acetic acid (IAA) in shortleaf pine (Pinus echinata Mill.) roots was increased by inoculation with the ectomycorrhizal fungus Pisolithus tinctorius (Pers.) Coker and Couch. Indole-3-acetic acid oxidase activity was also increased suggesting that the increased level of IAA was the result of increased synthesis. Boron fertilization reduced IAA levels in roots inoculated with P. tinctorius but not in noninoculated roots.

Journal Article↗
PubMed1991

A metabolic grid among versiconal hemiacetal acetate, versiconol acetate, versiconol and versiconal during aflatoxin biosynthesis.

Dichlorvos treatment of aflatoxigenic Aspergillus parasiticus SYS-4 (NRRL 2999) or a verscolorin A-accumulating mutant, NIAH-9, resulted in accumulation of versiconol acetate (VOAc) and versiconal hemiacetal acetate (VHA), whereas the production of aflatoxins, versicolorin A (VA), and versiconol (VOH) decreased. In feeding experiments using another non-aflatoxigenic mutant, NIAH-26, aflatoxins were newly produced from each of VHA, VOAc, VOH, versicolorin B (VB) and versicolorin C (VC). In these experiments, aflatoxin production from VHA or VOAc was inhibited by dichlorvos, whereas that from each of VOH, VB and VC was insensitive to dichlorvos. In cell-free experiments using the cytosol fraction of NIAH-26, VHA was converted to VC (or VB) and a substance tentatively identified as versiconal (VHOH). By further addition of NADH or NADPH to the same reaction mixture, VOAc and VOH were also formed together with VC (VB) and VHOH. VOH was produced from VOAc irrespective of nicotinamide adenine nucleotide. Also, the incubation of VOH in the presence of NAD or NADP led to the formation of VC (VB). The production of VC (VB) and VHOH from VHA, and that of VOH from VOAc was inhibited by dichlorvos, whereas the production of VOAc from VHA, and that of VC (VB) from VOH, was insensitive to dichlorvos. These results indicate that a metabolic grid catalysed by dehydrogenase and esterase among VHA, VOAc, VOH and VHOH, and a reaction from VHOH to VC (VB) are involved in aflatoxin biosynthesis. These enzyme activities were also detected when yeast extract peptone medium was used, or when A. oryzae SYS-2 was examined.

Aflatoxins↗
PubMed2004

The Aspergillus parasiticus estA-encoded esterase converts versiconal hemiacetal acetate to versiconal and versiconol acetate to versiconol in aflatoxin biosynthesis.

In aflatoxin biosynthesis, the pathway for the conversion of 1-hydroxyversicolorone to versiconal hemiacetal acetate (VHA) to versiconal (VHOH) is part of a metabolic grid. In the grid, the steps from VHA to VHOH and from versiconol acetate (VOAc) to versiconol (VOH) may be catalyzed by the same esterase. Several esterase activities are associated with the conversion of VHA to VHOH, but only one esterase gene (estA) is present in the complete aflatoxin gene cluster of Aspergillus parasiticus. We deleted the estA gene from A. parasiticus SRRC 2043, an O-methylsterigmatocystin (OMST)-accumulating strain. The estA-deleted mutants were pigmented and accumulated mainly VHA and versicolorin A (VA). A small amount of VOAc and other downstream aflatoxin intermediates, including VHOH, versicolorin B, and OMST, also were accumulated. In contrast, a VA-accumulating mutant, NIAH-9, accumulated VA exclusively and neither VHA nor VOAc were produced. Addition of the esterase inhibitor dichlorvos (dimethyl 2,2-dichlorovinylphosphate) to the transformation recipient strain RHN1, an estA-deleted mutant, or NIAH-9 resulted in the accumulation of only VHA and VOAc. In in vitro enzyme assays, the levels of the esterase activities catalyzing the conversion of VHA to VHOH in the cell extracts of two estA-deleted mutants were decreased to approximately 10% of that seen with RHN1. Similar decreases in the esterase activities catalyzing the conversion of VOAc to VOH were also obtained. Thus, the estA-encoded esterase catalyzes the conversion of both VHA to VHOH and VOAc to VOH during aflatoxin biosynthesis.

Aflatoxins↗