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A Coune

Publications and source records attributed to A Coune.

At least 19 recordsLinked to original sources
PubMed1994

Influence of divalent cations on androgen and estrogen binding in human prostatic tissue.

The influence of divalent cations on estrogen and androgen binding in human benign prostatic hypertrophy (BPH) was investigated. Two tissue types were detected. In type I, important estradiol binding increase in the presence of Mg++ and good evidence of the androgen receptors were noticed. Type II tissues were characterized by weak or inhibitory effect of Mg++ and, poor detection of the androgen receptors in some of the buffers used. Zn++ inhibited estradiol binding. Effects of chelators leaving some endogenous divalent cations in the medium were investigated. For both binding activities no difference could be established between type I and type II tissues. One exception was a somewhat increased androgen binding for type II when endogenous Mg++ was present. Strong inhibition of estradiol binding in the presence of EDTA + Mg++ always occurred. Influence of divalent cations on steroid binding measurements in BPH tissues is discussed.

Androgens↗
PubMed1993

Analysis of the low affinity high capacity estrogenic binding in human benign prostatic hypertrophy.

The binding of estradiol in extracts of human benign prostatic hypertrophy (BPH) tissue was studied using the agar gel electrophoretic method. Two distinct binding peaks were observed having the same high specificity for natural estrogens and very poor affinity for the other classes of steroids as well as for diethylstilbestrol (DES). Therefore, it is highly probable that these peaks are two different forms of the low affinity binding protein present in human prostate. Cytosols were shown to contain smaller amounts of the binding proteins than the tissular extracts. This difference probably resulted from protein degradation occurring during the time required to prepare the cytosol. The concentrations of the extract and of the radiolabeled ligand, the composition of the buffer, the addition of sodium molybdate, sodium tartrate or proteolytic inhibitors, were evaluated in order to delineate optimal binding conditions. The possible function of these low-affinity high-capacity binding proteins is discussed.

Binding, Competitive↗
PubMed1992

Estradiol- and estriol-binding in human benign prostatic hyperplasia.

Binding of the natural estrogens, estradiol and estriol, was investigated, in 34 samples of human benign prostatic hypertrophy (BPH) tissue, using Scatchard analysis and agar gel electrophoresis. Saturation binding analysis using a wide range of concentrations of both ligands resulted in curvilinear Scatchard plots. This confirmed the presence of two binding forms for estradiol: a true estrogen receptor, and a protein with lower affinity and higher capacity. Both binding species were also demonstrated and quantified with estriol. The electrophoretic process, after incubation at low and high ligand concentrations also resulted in separation, for both estrogens, of two binding peaks. They are probably two distinct forms of the low affinity, high capacity binding measured by Scatchard. The procedure used in our laboratory was not able to provide accurate determination of the concentrations of these binding forms. Possible modifications to alleviate these drawbacks are discussed.

Electrophoresis, Agar Gel↗
PubMed1991

Tissue distribution and bioactivity of amphotericin B administered in liposomes to cancer patients.

Amphotericin B concentration was measured by high-pressure liquid chromatography (HPLC) and by bioassay in tissues of 11 cancer patients who died from infection and/or their underlying disease after having received amphotericin B entrapped into sonicated liposomes (ampholiposomes). These concentrations were compared to those measured in 28 patients who had only received the commercially available preparation of amphotericin B-Na deoxycholate complex (Fungizone). The fungistatic and fungicidal titres of the tissue homogenates were also evaluated using two strains of Candida spp. and one strain of Cryptococcus neoformans to determine the bioactivity of amphotericin B incorporated in our liposomes. Tissue concentrations varied with the tested tissues and were correlated with the total dose of amphotericin B administered whether given as amphotericin B-Na deoxycholate or ampholiposomes. Amphotericin B concentrations measured by bioassay in tissue methanolic extracts reached 58-81% of concentrations measured by HPLC, whereas only 15-41% was recovered from the unextracted homogenates. Fungicidal titres were seldom measured in tissues, but fungistatic titres were observed and were linearly correlated with amphotericin B concentration measured by HPLC. These results were similar for the patients who received only amphotericin B-Na deoxycholate and for those who received both preparations (amphotericin B-Na deoxycholate and ampholiposomes). Our results suggest that the tissue distribution of amphotericin B is not significantly modified by the type of preparation (deoxycholate complex or liposomes) and that most of the tissue-bound amphotericin B is not bioactive. However, higher daily doses of amphotericin B can be administered safely when incorporated in liposomes and therefore high tissue concentrations may be obtained more rapidly with ampholiposomes than with amphotericin B-Na deoxycholate.

Adult↗
PubMed1990

In-vitro evaluation of the antifungal activity of amphotericin B entrapped into liposomes during storage for one year.

The stability of the antifungal activity of amphotericin B entrapped in small sonicated liposomes (ampholiposomes) was studied in vitro over a one-year period. Preparations of ampholiposomes stored at -20 degrees C or at 4 degrees C were compared monthly with freshly-prepared ampholiposomes and a commercial preparation of amphotericin B-deoxycholate (Fungizone; Squibb) by a killing curve method with Candida albicans. The bioactivity of the four preparations, each containing 1.5 or 2 mg/l of amphotericin B, was measured as the initial rate of killing and the 'relative bioactivity'. Relative bioactivity was calculated as the percentage reduction of the area under the growth curve compared with control growth. Storage of ampholiposomes for one year did not decrease their antifungal activity. Storage of ampholiposomes containing 1.5 mg/l amphotericin B for one year at -20 degrees C, but not at 4 degrees C, gave a significant increase in relative bioactivity and killing rate in comparison with freshly-prepared ampholiposomes. This was probably due to modifications in the spatial configuration of phospholipids and amphotericin B. The persisting antifungal activity of ampholiposomes stored for one year should allow the preparation of large batches to perform comparative clinical studies.

Amphotericin B↗
PubMed1989

Successful treatment with liposomal amphotericin B in two patients with persisting fungemia.

Two granulocytopenic patients in whom fungemia persisted despite therapy with deoxycholate amphotericin B were subsequently successfully treated by daily intravenous administration of amphotericin B entrapped in sonicated liposomes made of egg yolk lecithin, cholesterol and stearylamine in a molar ratio of 4:3:1. High serum concentrations of amphotericin B could be maintained in both patients during therapy with liposomal amphotericin B and were associated with high in vitro antifungal activity. Liposomal amphotericin B was tolerated much better than the deoxycholate preparation. These findings suggest that the liposomal amphotericin B preparation is superior in the treatment of fungemia in granulocytopenic patients, and that randomized trials are warranted.

Agranulocytosis↗
PubMed1989

Analysis of the androgen binding in human benign prostatic hypertrophy.

In order to delineate optimal conditions for the determination of androgen specific binding in human benign prostatic hypertrophy tissues (BPH), extracts of these tissues were prepared using buffers of different compositions. The binding of 5 alpha-dihydrotestosterone (DHT) and of methyltrienolone (R 1881) was analyzed using agar gel electrophoresis. This method allowed the detection of 3 different high affinity tissular binding peaks with similar specificity. Moreover, the inhibition by each of the competitors was also the same for both ligands. It could be demonstrated that none of the observed peaks resulted from the binding of 1 of the ligands to sex hormone binding globulin (SHBG) or to a progesterone receptor. Hypotheses about the possible origin of these peaks are discussed.

Binding, Competitive↗
PubMed1988

Role of intensive care unit in a medical oncology department.

Over a 4-year period, 912 patients were admitted to the ICU of the medical oncology service at the Institut Jules Bordet: 574 (63%) were admitted for medical emergencies and 338 (37%) for intensive treatment and/or monitoring. In the first group, the main causes of admission were hypercalcemia, thromboembolic disease, cardiac arhythmias, encephalopathies and pneumopathies. Overall mortality during the ICU stay was 23% (133/574). In the second group, patients were admitted primarily in order to receive, under optimal surveillance, anticancer treatment, either because they were at high risk of complications or because the approach was mainly investigational; several investigations, in the fields of supportive care and anticancer treatment, were successfully conducted within the ICU environment.

Arrhythmias, Cardiac↗
PubMed1988

Pilot study of amphotericin B entrapped in sonicated liposomes in cancer patients with fungal infections.

A pilot study with amphotericin B incorporated in sonicated liposomes (ampholiposomes) made of egg phosphatidylcholine, cholesterol and stearylamine in a molar ratio 4:3:1 was performed in cancer patients with fungal infections. Fifteen patients received a total of 117 intravenous infusions of ampholiposomes. The total dose of amphotericin B administered per patient ranged from 20 to 1004 mg (mean 472 mg). The number of infusions per patient varied from 1 to 20 (mean 8) and the duration of treatment from 1 to 29 days (mean 10 days). Infusion of doses up to 1.8 mg/kg was well tolerated. None of the common side-effects of Fungizone, the colloidal suspension of amphotericin B, occurred; it was noteworthy that patients had no renal function impairment. Serum amphotericin B concentrations given as ampholiposomes were much higher than those obtained with Fungizone. With a daily treatment schedule, peak and trough serum amphotericin B concentrations, as measured by HPLC, were 10 to 20 micrograms/ml and 5 to 10 micrograms/ml respectively; while they did not exceed 2 micrograms/ml and 1 microgram/ml with Fungizone. Amphotericin B given as ampholiposomes had a prolonged serum beta half-life (25.3 +/- 16.0 h). Higher serum antifungal activity was observed with ampholiposomes as compared to Fungizone. We concluded that ampholiposomes have a better therapeutic index than Fungizone.

Adult↗
PubMed1987

Endocrine effects of Trilostane: in vitro and in vivo studies.

Trilostane (4-alpha-5-epoxy-17 beta-hydroxy-3-oxo-5-alpha-androstan-2-carbonitrile) is a modified steroidal molecule. In vitro and in vivo studies in rats have shown that it inhibits adrenal, ovarian and placental steroid synthesis. It seems to act by exerting a selective blockade on 3 beta-hydroxysteroid dehydrogenase. In this study, we investigated whether this molecule interacts with hormone receptors for estrogen, androgen or progesterone. We also tried to demonstrate the effect which Trilostane may have on cellular cultures of human mammary carcinoma (MCF-7 Evsa-T). We also studied hormonal modifications in a series of 12 patients treated with different doses of Trilostane, since this drug is supposed to inhibit the production by the adrenal glands of mineralocorticoids, of glucocorticoids and of the precursors of estrogens. Our results indicate that Trilostane does not react with any of the main hormonal sex steroid receptors, nor does it interfere with cultures of human mammary cancer cells either containing estrogen receptors and therefore allegedly hormone-dependent (MCF-7 line), or estrogen receptor-negative cells, presumably independent of hormonal manipulations (Evsa-T cell line). Finally, endocrine studies on postmenopausal women with advanced breast cancer show that Trilostane significantly reduces the plasma levels of estrone and of its major androgen precursor (androstenedione). However, the latter inhibition is no different from that exerted by hydrocortisone acetate administered alone at a dose of 40 mg/day. The results of clinical trials comparing hydrocortisone alone with hydrocortisone plus Trilostane are awaited.

Antineoplastic Agents↗
PubMed1987

Intracardiac thrombosis associated with an acute consumption coagulopathy.

A 53-year-old man with a prior history of myocardial infarcts and small cell lung cancer presented with lower limb ischemia. Laboratory tests revealed acute consumption coagulopathy and echocardiography showed massive intracavitary thrombi in the right atrium and both ventricles. Despite the administration of heparin, the patient died 3 weeks later of ventricular fibrillation. Autopsy demonstrated no relapse of lung cancer but large old myocardial infarcts.

Disseminated Intravascular Coagulation↗
PubMed1986

Intravenous infusion of high doses of liposomes containing NSC 251635, a water-insoluble cytostatic agent. A pilot study with pharmacokinetic data.

In patients with resistant malignant tumors, we performed a pilot trial of intravenous infusion of a water-insoluble cytostatic agent, NSC 251635, entrapped in large volumes of liposomes made of egg yolk lecithin, cholesterol, and stearylamine (4:3:1). Forty liposome infusions were given to 14 patients in 38 courses. The volume of liposomes (20 mg of lipids/mL) varied from 205 to 1,000 mL or 124 to 617 mL/m2 of body surface, and amounts of NSC 251635 varied from 82 to 456 mg/m2. Three patients received repeated single courses. Liposomal therapy was very well tolerated. Side effects observed during some infusions were mild sedation, fever, chills, lumbar pain, urticarial rash, and bronchospasm. In all patients investigated, an important activation of the complement system was observed. No objective regression of the tumors was observed. The limiting factor in the phase I study was not toxicity but the volume of liposomes that could be prepared at once because of the long time required for its preparation. Pharmacokinetic data showed that maximal serum phospholipid and NSC 251635 concentrations were obtained at the end of the liposome infusion. The drug's peak was followed by a decreasing phase leading to a kind of plateau and a prolonged presence of the drug in the blood until 120 hours after its administration. Comparison of the pharmacokinetics of phospholipids and NSC 251635 suggests a rather rapid dissociation of the drug from the liposome.

Adult↗