Jean Couture

Determination of Nonconjugated and Conjugated Steroid Levels in Plasma and Prostate after Separation on C‐18 Columns

An accurate method is described for analysis of C-21, C-19, and C-18 steroids as well as steroid conjugates, namely, androstane-3 alpha,17 beta-diol glucuronide, androsterone glucuronide, estradiol glucuronide, and estrone glucuronide as well as dehydroepiandrosterone sulfate and androst-5-ene-3 beta,17 beta-diol sulfate. This technique involves an extraction step, aimed at solubilizing the nonconjugated steroids as well as the steroid sulfates and glucuronides, C-18 column chromatography, permitting the separation of nonconjugated steroids and the conjugated group followed by specific hydrolysis of the glucuronide and, finally, solvolysis of the steroid sulfates. Our data indicated that using 1 ml of plasma or 1 g of prostate, good recovery of the three groups of steroids was obtained. Moreover, an accurate determination of steroids could be achieved. The plasma levels of steroids in normal adult women and men found using our technique were within the range of those previously reported by us and other authors.

Diverticulitis of the appendix: Report of sixty-one cases

Abstract Analysis of ninety cases of diverticulum of the appendix makes it possible for us to classify this lesion into five main groups, thus recognizing this disease as a definite pathologic entity. A comparative clinical study of sixty-one cases of acute diverticulitis of the appendix and sixty-one cases of acute appendicitis has revealed some differences between both lesions, namely those concerning the age of the patient, the type of abdominal pains, and the operative findings. It then appears possible in certain cases to make a preoperative diagnosis of diverticulitis of the appendix: our observations seem to indicate that acute diverticulitis of the appendix is a clinical entity different in some respect from acute appendicitis.

Modulation transfer function measurements for thin layers of azo dyes in PVA matrix used as an optical recording material

Diffraction efficiencies and characteristic erasure times were measured for two recording materials suitable for real-time holography and four-wave mixing. A study of real-time transmission volume grating formation was done in conjunction with polarization states of the writing beams for 30-microm thick layers. Modulation transfer function curves presented were obtained using a versatile device for which the spatial frequency domain was 500-4000 cycles/mm.

Collagen coatings as biological sealants for textile arterial prostheses

Two collagen-coated grafts were studied: Hemashield (bovine collagen cross-linked with formaldehyde vapours and softened by exposure to glycerol) and Tascon (collagen fibres cross-linked with glutaraldehyde solution). The weight of the coating was 310 +/- 5 mg/g for Hemashield and 45 +/- 2.5 mg/g for Tascon. However, notwithstanding these differences, both coatings were efficient in making the walls of the grafts impervious to blood. The water permeabilities for the Hemashield and the Tascon were 8.7 and 5.9 ml.min-1.cm-2 at 120 mmHg respectively. The Hemashield collagen coating was rapidly eroded in vitro (4 h) after exposure to buffer, trypsin or pancreatin solutions, whereas the Tascon collagen coating remained well preserved after 7 d incubation. Both coatings were safe and did not interfere with the physical properties of the graft which was used as a skeleton. The healing properties of the Hemashield were similar to that observed with preclotted polyester prostheses, except in the early hours following graft implantation. On the other hand, the absence of erosion in the coating of the Tascon seemed to contribute to early antithrombogenicity. It also induced marked inflammatory reactions in the surrounding tissues and thus the healing appeared to be delayed.

Steroid glucuronides: Human circulatory levels and formation by LNCaP cells

We studied the relationship between circulating androsterone glucuronide, androstane-3 alpha, 17 beta-diol glucuronide and androstane-3 beta, 17 beta-diol glucuronide concentrations and adrenal as well as testicular C-19 steroids in men. Among the three 5 alpha-reduced steroid glucuronides, androsterone glucuronide is the predominant C-19 steroid glucuronide measured in plasma and its levels are markedly elevated compared to those of the non-conjugated steroid. The marked rise in testosterone during puberty was strongly correlated with the increase in both androsterone glucuronide and androstane-3 alpha, 17 beta-diol glucuronide, thus suggesting that testicular C-19 steroids are the main precursors of the steroid glucuronides. We also found that the presence of testicular androgen in plasma contributes to approx. 70% of plasma androsterone glucuronide and androstane-3 alpha, 17 beta-diol glucuronide. Our data suggest that the adrenal C-19 steroids remaining in circulation after castration in men are converted into potent androgen which are then glucuronidated by UDP-glucuronyltransferase. We also demonstrated that the human prostate cell line LNCaP is capable of converting to a large extent androstenedione into androsterone glucuronide. Our data further confirm that glucuronidation is a major pathway of steroid metabolism in steroid target tissues.

Production and secretion of C-19 steroids by rat and guinea pig adrenals

The concentrations of C-19 steroids were measured in guinea pig and rat adrenals before and after castration as well as after stimulation with adrenocorticotropin hormone (ACTH). Characterization of adrenal C-19 steroids was also carried out by isolation with high-performance liquid chromatography and gas chromatography/mass spectrometry (GC/MS). From radioimmunoassay (RIA) data, androstenedione (4-DIONE) and 11 beta hydroxyandrostenedione (11 beta-DIONE) were the major C-19 steroids found in guinea pig adrenals, and castration induced a decrease of 4-DIONE levels only while all other C-19 steroids remained unchanged. In rat adrenals, the major C-19 steroids were 4-DIONE and testosterone, and they were also markedly inhibited after castration. With the exception of 11 beta-DIONE, all other C-19 steroids in circulation were eliminated after castration in both animals species. After ACTH administration in the guinea pig, adrenal 4-DIONE and 11 beta-DIONE levels were markedly stimulated, while an increase of only 11 beta-DIONE was observed in plasma. In the rat, ACTH had a small stimulatory effect on adrenal 52-androstane-3 alpha, 17 beta-diol (3 alpha-DIOL) and plasma 11 beta-DIONE levels. Analysis of guinea pig adrenal steroids by GC/MS confirmed the presence of C-19 steroids in adrenals (namely, 4-DIONE and 11 beta-DIONE) while, in the rat, this could not be confirmed. Our data indicate that production of C-19 steroids occurs in guinea pig adrenals, and 11 beta-DIONE is the major C-19 steroid as well as the only C-19 steroid secreted into the circulation. In the rat, the production of C-19 steroids detected by RIA is not supported by GC/MS data.

Dichromated polyvinyl alcohol films used as a novel polarization real time holographic recording material

Real time recording and reading of volume transmission holograms were performed with dichromated polyvinyl alcohol thin solid films (31 microm) that were easy to prepare and use. Real time holograms of high diffraction efficiency were produced without any chemical development, but these films were not erasable. The present holographic study of dichromated polyvinyl alcohol films permits the consideration of many engineering applications.

The low-mass stellar content of galaxies : constraints through hybrid population synthesis near 1 micron

We present high signal-to-noise observations obtained with the RC spectrograph at the CTIO 4 m telescope of six galaxies and of a variety of dwarfs and galactic bulge giants in the 9800-10200 A spectral range. This spectral region contains gravity-sensitive bands of the FeH molecule. The Wing-Ford band of FeH centered at 9916 A is clearly identified in all galaxies. A variety of modeling procedures employing the stellar library are used to reproduce the observed galactic spectra over this spectral range, and a method is described of scanning the solution space in search of secondary minima in the optimized synthesis procedure. We assume a power-law representation of the mass function with a slope x and a lower cutoff mass m low

Polarization holographic characterization of organic azo dyes/PVA films for real time applications.

Two azo dyes were introduced in polyvinyl alcohol matrices giving thin solid colored films on which they can record polarization volume holograms in real time. These new azo dye polymer photosensitive systems have been holographically studied. Holographic characterization was investigated to determine its optimal and dynamical recording application conditions. Under a light exposure of 300 mJ/cm(2), polarization volume real time holograms having 0.27% diffraction were produced. We present three simple uses based on the facts that these photosensitive films are erasable and reusable for many thousand write/read/erase cycles and that they may show a memory effect in specific conditions.

Wide spectrum of steroids serving as substrates for the formation of lipoidal derivatives in ZR-75-1 human breast cancer cells

Recently, several natural steroids have been found to be esterified to long-chain fatty acids (FAE) in various mammalian tissues. The purpose of the present study was to determine the ability of a series of 3H-labeled steroids to serve as substrates for the formation and accumulation of such non-polar derivatives in intact cells, using the hormone-responsive ZR-75-1 human breast cancer cell line as model. All 14 steroids tested were found to be converted, directly or following further metabolism, to lipoidal ester derivatives. The percentage of intracellular steroids recovered as FAE derivatives was usually substantial (14-90%), especially in the case of C-19 steroids (75-90%). The composition of the lipoidal steroid fractions recovered from the labeled cell extracts was characterized by chromatographic comparison with synthetic steroid FAEs and by saponification of the steroid FAEs and identification of the released steroidal moieties. Following metabolism, most steroid substrates were converted into multiple lipoidal esters. Furthermore, 5 alpha-androstane-3 alpha, 17 beta-diol, 5 alpha-androstane-3 beta, 17 beta-diol, as well as androst-5-ene-3 beta, 17 beta-diol formed lipoidal diesters in addition to the monoester form. The high level of intracellular steroid FAE accumulation reported in this study suggests that these yet poorly known steroid derivatives may play important functions in the regulation of steroid hormone metabolism and action.