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Biomedical subjects

G L Adessi

Publications and source records attributed to G L Adessi.

At least 55 records · Page 3Linked to original sources
PubMed1991

In vitro effect of synthetic progestogens on estrone sulfatase activity in human breast carcinoma.

The effect of progesterone and nine synthetic progestogens on the activity rate of microsome estrone sulfatase obtained from human breast carcinoma tissues was studied. The progestogens were classified into three groups: group I with a strict inhibitor effect: demegestone and chlormadinone acetate; group II with a strict activator effect: medroxyprogesterone acetate, quingestanol acetate, lynestrenol and progesterone and group III with a nonsignificant effect: dydrogesterone, promegestone, norgestrel and danazol. Demegestone was the most potent inhibitor and medroxyprogesterone acetate and quingestanol acetate had the highest activator effect. The effect of Triton X-100, a nonionic detergent, was also tested. This detergent consistently increased the microsome estrone sulfatase activity. A comparison was made between the effects of demegestone, medroxyprogesterone acetate and danazol on estrone sulfatase activity measured with or without Triton X-100 in the incubation medium. The presence of the detergent modified the progestogen action. Our results suggest that synthetic progestogens can influence the estrone sulfatase activity measured in human breast carcinoma tissues. However, the effect of progestogens was dependent on experimental conditions. Progestogens such as demegestone and chlormadinone acetate which inhibited estrone sulfatase activity in intact preparations, can reduce the intracellular production of biological active estrogen via the sulfatase pathway.

Breast Neoplasms↗
PubMed1991

Additive effect of oestradiol-17 beta and serum on synthesis of deoxyribonucleic acid in guinea-pig endometrial cells in culture.

Normal guinea-pig endometrial cells, grown in primary culture, were made quiescent by serum depletion. Quiescent cells cultured in the control medium (containing 1% fetal calf serum treated with dextran-coated charcoal, DCC-FCS) showed a steady and weak rate of [3H]thymidine incorporation, but the addition of 15% fetal calf serum (FCS) or 10% DCC-FCS to the control medium induced a significant increase of DNA synthesis, demonstrating the responsiveness of the quiescent cells to stimulation. A lower but significant increase in [3H]thymidine incorporation was elicited by epidermal growth factor (EGF, 100 ng/ml) or insulin (10 micrograms/ml) added to the basal medium. Oestradiol-17 beta added to the control medium at concentrations ranging from 10(-10) to 10(-5) mol/l not only failed to increase but even inhibited [3H]thymidine incorporation at the highest concentrations tested. An additive effect was noticed when quiescent cells were incubated with oestradiol-17 beta (10(-9) mol/l) in the presence of 10% DCC-FCS, but no synergistic effect occurred when 2 x 10(-9) mol oestradiol-17 beta/l was combined with either EGF (100 ng/ml) or insulin (10 micrograms/ml). Oestradiol-17 beta appears unable alone to stimulate DNA synthesis in normal endometrial cells, but requires factor(s) present in fetal calf serum.

Animals↗
PubMed1990

Effects of 17 beta-estradiol and growth factors on c-fos gene expression in endometrial epithelial cells in primary culture.

Primary culture of guinea-pig endometrial cells was made quiescent by serum depletion. When added to quiescent cells, 17 beta-estradiol (E2) alone affected neither c-fos and c-myc gene expression, nor DNA synthesis and cell proliferation. Insulin or epidermal growth factor (EGF) only induced DNA synthesis. An association of both growth factors allowed significant cell proliferation without inducing c-fos or c-myc expression. A response including c-fos induction (maximal expression at 75 min), but not c-myc expression, DNA synthesis and a marked cell proliferation was only obtained when 17 beta-estradiol was associated with insulin plus EGF. In this case, cycloheximide raised the c-fos gene expression. These data suggest that in endometrial epithelial cells, E2 is mitogenic only when it acts in association with EGF plus insulin and the c-fos gene expression may not be correlated with cell proliferation.

Animals↗
PubMed1990

Regulation of c-fos expression in primary culture of guinea pig glandular epithelial cells stimulated by growth factors and estradiol.

The c-fos expression was investigated in primary culture of guinea pig glandular epithelial cells. These cells were made quiescent by serum deprivation and stimulated with fetal calf serum (FCS, 15%), 17 beta-estradiol (E2 10(-8) mol/l) alone or in combination with epidermal growth factor (EGF, 100 ng/ml) and insulin (I, 10 micrograms/ml). Low levels of c-fos mRNA were detectable in quiescent cells and were not increased in cells stimulated with either E2, EGF, I, or EGF plus I. On the contrary, the c-fos mRNA were early and transiently increased by FCS or E2 plus EGF plus I (4.5 and 9.5 fold induction, respectively). This effect was independent of de novo protein synthesis since it was not abolished in the presence of cycloheximide. It appears that E2 acts in a multiple step process including the stimulation by EGF plus insulin.

Animals↗
PubMed1990

Uterine epithelial cells in primary culture: a model system to study cell proliferation.

Guinea-pig uterine glandular epithelial cells were grown in primary culture. During the 4-day initial culture period, a 6.7 fold increase in DNA synthesis and a doubling time of approximately 30 hours were observed. Then the cells were submitted to serum depletion (60 hours) and the quiescent cells were stimulated with 15% fetal calf serum (FCS). The control cells were submitted to 1% heated and dextran-coated charcoal stripped FCS. In stimulated cells, the DNA synthesis increased and peaked between the 12th and 24th hour. In these cells, c-fos mRNAs increased rapidly, within 30 min., peaked at 75 min. (ratio to the control = 2.5), and returned to basal level within 90 min. These results prove that uterine epithelial cells in primary culture are able to respond to unspecific mitogen by both rapid expression of c-fos gene and DNA synthesis, suggesting that this cell culture system will be useful in studying the growth regulation in endometrium.

Animals↗
PubMed1989

Effect of progesterone on protein synthesis and secretion by cultured epithelial cells from guinea-pig endometrium.

The pattern of proteins synthesized and secreted in response to progesterone by guinea-pig endometrial epithelial cell cultured with estradiol-17 beta was investigated. Glandular epithelial cells were maintained in culture for 3 days on growth medium, then washed three times with a steroid-free medium. After this period, 2 x 10(-8) M estradiol-17 beta or 2 x 10(-8) M estradiol-17 beta plus 5 x 10(-7) M progesterone were added to the medium for 48 h. To study biochemical changes, the proteins in medium and in cells were analyzed by one- and two-dimensional polyacrylamide gel electrophoresis, followed by fluorography. The addition of progesterone to estradiol-17 beta in the culture medium caused a change in the patterns of cellular and secreted proteins: one-dimensional gel electrophoresis showed that variation of 8 cellular proteins and 12 secreted proteins was caused by progesterone. Induction of individual proteins by progesterone treatment was observed by two-dimensional gel electrophoresis: one cellular protein (Mr 49,000; pI 5.90) and one secreted protein (Mr 14,300; pI 4.80) were specifically induced and might serve as markers of progesterone action.

Animals↗
PubMed1989

Effects of oestrone sulphate, oestradiol and progesterone on protein sulphation in the guinea-pig uterus.

Ovariectomized guinea-pigs were treated with oestradiol-17 beta (ES), oestrone sulphate (E1S) and progesterone (P) and the in-vitro incorporation of 35SO4 was studied in uterine fragments. The net uptake of 35O4 into tissue was only increased by oestradiol-17 beta plus progesterone. The incorporation of 35SO4 in the tissue-associated proteins was increased after treatment with E2 and E1S compared with untreated controls (3.1- and 2.5-fold, respectively). For secreted proteins, all hormone treatments induced an increase in protein sulphation, the highest increase occurring when progesterone was administered after oestrogens. Tyrosine 35SO4 was identified in protein extracts from tissues and media and values were greater after hormone treatments. The biggest increase in tyrosine 35SO4 was observed in secreted proteins in the E1S + P treatment group. The patterns of 35S-sulphate-labelled proteins were examined by SDS-polyacrylamide gel electrophoresis. In tissue extracts, the most striking differences related to the hormone treatments were observed in the Mr 94,000-190,000 region. A sulphated protein band of Mr 102,000 was specifically found in the E2 + P group and a band of Mr 125,000 only in the E1S + P group. The Mr 125,000 band was also found in tissue proteins from the E1S + P-treated animals after the incorporation of 35SO4 in vivo. This protein band may be a marker of the action of oestrone sulphate plus progesterone. For secreted proteins, those with a molecular weight greater than 100,000 were more abundant in the oestrogen plus progesterone-treated groups than in the oestrogen-treated groups. The content of tyrosine sulphate in each protein band ranged from 8 to 25% of the total radioactivity. No protein sulphated exclusively on the tyrosine residues was found. These studies provide the first description of the effects of steroid hormones on sulphated proteins in the guinea-pig uterus and suggest that oestrone sulphate is a potent biologically active hormone in the uterus.

Animals↗
PubMed1989

Ultrastructural changes induced by oestradiol-17 beta, progesterone and oestrone-3-sulphate in guinea-pig endometrial glandular cells grown in primary culture.

The effects of oestradiol-17 beta, progesterone and oestrone-3-sulphate were studied in primary cultures of guinea-pig endometrial glandular epithelial cells. Comparative ultrastructural studies were performed by means of transmission electron microscopy on cells grown either without hormones or with oestradiol-17 beta (2 nmol/l), oestradiol-17 beta (2 nmol/l) plus progesterone (50 nmol/l), or oestrone sulphate (0.1 mumol/l). In the control medium, without steroid hormones, the majority of epithelial cells were poorly differentiated, although numerous small mitochondria were present and abundant lipid droplets could be observed. Oestradiol-17 beta stimulated metabolic activity in the cells. Progesterone added to oestradiol-17 beta-primed cells stimulated the development of the endoplasmic reticulum-Golgi system. Oestrone sulphate induced a higher level of differentiation characterized by large clear mitochondria, well-developed Golgi complexes, and active nuclei, suggesting secretory activity. In all cases, the cultured cells displayed deep invaginations of the nuclear membrane associated with nuclear pores, known as nucleolar channels. After treatment with oestrone sulphate these channels were associated with a characteristic reticular nucleolus. We conclude that cultured endometrial epithelial cells display secretory activity in response to treatment with oestradiol-17 beta plus progesterone, or with oestrone sulphate.

Animals↗
PubMed1989

Specific effect of oestrone sulphate on protein synthesis and secretion by cultured epithelial cells from guinea-pig endometrium.

Patterns of induced protein synthesis and secretion in guinea-pig endometrial epithelial cell cultures in response to oestrone sulphate alone and oestrone sulphate plus progesterone were investigated. Epithelial cells were cultured for 3 days in growth medium, then washed three times in a steroid-free medium. For each experiment, anticytokeratin immunostaining was used to discriminate the epithelial cells from the stromal cells. Only experiments in which the control dishes displayed more than 80% of anticytokeratin-immunostained cells were further processed. After this period oestradiol-17 beta (20 nmol/l; control), oestradiol-17 beta (20 nmol/l) plus progesterone (0.5 mumol/l), oestrone sulphate (1 mumol/l) or oestrone sulphate (1 mumol/l) plus progesterone (0.5 mumol/l) were added to the medium for 48 h. An immunocytochemical progesterone receptor assay showed that oestradiol-17 beta increased the progesterone receptor content of cells, and progesterone added to cultured cells in the presence of oestradiol-17 beta induced a significant increase in oestrogen sulphotransferase activity assessing the hormone responsiveness of the cultured cells. In these culture conditions and after 16 h of incubation, oestradiol-17 beta induced a 1.7-fold increase in [3H]thymidine incorporation into DNA, and [35S]methionine incorporation into cellular proteins was linearly increased up to 8 h. Biochemical changes induced by the different hormone treatments were studied by labelling the proteins with a 6-h pulse of [35S]methionine. The proteins present in the medium and in cells were analysed by two-dimensional polyacrylamide gel electrophoresis, followed by fluorography.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Action of estradiol-17 beta, estrone sulfate and progesterone on the growth and differentiation of endometrial epithelial cells of the guinea pig in primary culture].

Endometrial guinea-pig glandular epithelial cells grown in primary culture incorporated [3H] thymidine. After three washings with a steroid-free medium, they were made quiescent and arrested in the G0/G1 phase. However, they remained hormone-responsive and resumed the cellular cycle after stimulation by 10(-6) M oestrone sulphate but not by oestradiol-17 beta.

Animals↗
PubMed1989

Protein tyrosine sulfation in guinea-pig uterus: estradiol and progesterone effects.

Tyrosine sulfation was studied in guinea-pig uterus by in vitro labelling with [35S]sulfate, after estradiol-17 beta (E2) and E2 plus progesterone (P) treatment. [35S]Sulfated tyrosine was identified in tissue and secreted proteins, ranged from 9.3 to 21.0% of total protein sulfation and was higher in secreted proteins than in tissue proteins. Sulfate incorporation into tyrosine increased with hormone treatments. The highest level was found in secreted proteins under the combined effect of E2 plus P. The effect of P may be related to both the increase of cellular uptake of sulfate and the increase of tyrosine sulfation of secreted proteins. These results are consistent with the effect of P on endometrium secretions.

Animals↗
PubMed1988

A sulfone group-labeled TEM-DNA probe: comparison with a 32P-labeled probe in dot-hybridization.

A non-radioactive DNA probe for the TEM-type beta-lactamase gene was obtained by using the 'Chemiprobe' system. It was used along with a 32P-labeled TEM probe to screen for TEM beta-lactamase gene in 107 bacterial isolates representing 7 Gram-negative genera and previously classified as TEM-positive or negative. The DNA to be tested was extracted from these bacterial isolates by the Birnboim-Doly method and, after blotting into charged nylon membranes, it was submitted to hybridization with either the TEM 'Chemiprobe' or the 32P-TEM probe. The TEM 'Chemiprobe' could detect as few as 25 pg specific DNA if it was used at a concentration of 5 ng per cm2 of membrane. The results obtained by both probes were concordant in 93.5% of the entire sample. The TEM 'Chemiprobe' was specific since only one false positive was observed. Furthermore, it appeared at least as sensitive as the 32P-labeled TEM probe. As the dot-hybridization with the sulfone-labeled probe was sensitive, simple and easy to perform, it will be useful for large-scale screening in clinical laboratory.

DNA Probes↗
PubMed1988

[Characterization, in the guinea pig, of a hepatic cytosol protein binding dehydroepiandrosterone sulfate and estrone sulfate].

A protein which binds dehydroepiandrosterone sulfate and estrone sulfate was detected in the cytosolic fraction of female Guinea-pig liver. It is characterized by a molecular mass of 14,400 Da, its affinity for DHEA sulfate (KD = 8.8 microM) and estrone sulfate (KD = 8.5 microM), and its lack of affinity for free steroids such as dehydroepiandrosterone or estrone. It is eluted by gel filtration on Sephadex G-50 simultaneously with the inhibitor of microsomal DHEA sulfatase recently described by some of us. This protein could be implicated in the intracellular transport or in the metabolism of sulfated steroids.

Animals↗
PubMed1987

In vitro metabolism of androstenedione and identification of endogenous steroids in Helix aspersa.

In vitro metabolism of androstenedione in gonads of juvenile and adult Helix aspersa has been investigated. The conversion of [3H]androstenedione into testosterone, 5 alpha-dihydrotestosterone, androsterone, and estriol was demonstrated. In juvenile animals testosterone (59.8%) is the major metabolite whereas in adult animals androsterone (18.8%) is. The following endogenous steroids have been identified by gas chromatography-mass spectrometry in adult gonads: androsterone, dehydroepiandrosterone, androstenedione, 3 alpha-androstanediol, estrone, estradiol-17 beta, and estriol. The levels of testosterone, 5 alpha-dihydrotestosterone, androstenedione, and progesterone have been measured by RIAs in gonads and hemolymph. Their levels vary with the physiological stage: the gonadal and circulating levels of testosterone decrease with the sexual maturation whereas the 5 alpha-dihydrotestosterone increases. These differences observed in metabolism and in level of steroids between the juvenile and the adult snails allow us to suppose that these steroids have a biological role.

Androstenedione↗
PubMed1987

Compared effects of oestrogens and oestrone sulphate on the epithelial cell surface of guinea-pig endometrium (in vivo and in vitro studies).

The comparative effect of oestradiol-17 beta, oestrone and oestrone-3-sulphate was examined on guinea-pig endometrium in primary culture. A parallel study was conducted in vivo to appreciate hormonal effects on the uterine luminal surface of ovariectomized guinea-pigs. Scanning electron microscopy studies showed that uterine epithelial cells were responsive to physiological concentrations of E2, E1 and E1S. Their plasma membrane was dramatically modified by 2.10(-9) M E2 and 10(-7) M E1S, but there are clear qualitative differences between the effect of E2 and of E1S. These effects were abolished by progesterone or 4-hydroxy-tamoxifen. Guinea-pig uterine epithelial cells in primary culture and in vivo are responsive to E2 and to E1S but their response to E1S appears to be more specific and can be distinguished by the cell surface morphology.

Animals↗
PubMed1987

Oestrone sulphate metabolism in normal human endometrium grown in organ culture.

Samples of human endometrium were maintained in organ culture for 6 days on growth medium. On Day 6, ultrastructural studies were performed on endometrial explants, demonstrating that human endometrium grown in organ culture preserved its normal structure. The effect of oestrone sulphate was studied on the endometrium explants. The endometrium was cultured on harvest medium for 4 days to ensure the complete removal of endogenous steroids, the tissues were then incubated with 10(-7) M oestrone sulphate for 24 h. The oestrone sulphatase known to interfere with oestrone sulphate metabolism was present in endometrial organ culture. By incubation with estrone sulphate for 24 h it was demonstrated that oestrone sulphate is hydrolysed to active oestrogens.

Endometrium↗
PubMed1987

Molecular hybridization versus isoelectric focusing to determine TEM-type beta-lactamases in gram-negative bacteria.

Isoelectric focusing and molecular hybridization with a TEM DNA probe were used to screen for TEM beta-lactamase in 328 bacterial isolates representing 11 gram-negative genera. The TEM enzyme was detected in 50% of isolates, and nine additional types of beta-lactamase could be identified in 36.9% of isolates. The TEM gene was detected in 53.6% of isolates. The results obtained by both methods were concordant in 92.7% of the entire sample. In situ colony hybridization with a specific probe therefore appears to be a convenient method to screen rapidly for the presence of homologous genetic sequences among a large number of isolates. Positive hybridization was observed for 16 isolates in which no TEM beta-lactamase was detected by isoelectric focusing. The significance of this hybridization remains to be determined.

DNA, Bacterial↗