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Biomedical subjects

A Pousette

Publications and source records attributed to A Pousette.

At least 91 records · Page 5Linked to original sources
PubMed1987

Steroid-sensitive proteins, growth hormone and somatomedin C in prostatic cancer: effects of parenteral and oral estrogen therapy.

The effects of parenteral and parenteral plus oral estrogen therapy on the serum levels of sex hormone binding globulin (SHBG), pregnancy-associated alpha 2-macroglobulin (alpha 2-PAG), growth hormone (GH), and somatomedin C (SmC) were studied in 26 patients with prostatic cancer. Intramuscular polyestradiol phosphate treatment, yielding a mean serum level of estradiol-17 beta of 1,446 pM and a mean testosterone level of 4.5 nM, had no significant effects on alpha 2-PAG, GH, and SmC and increased SHBG levels only marginally. Combined treatment with intramuscular polyestradiol phosphate and oral ethinyl estradiol greatly increased SHBG and alpha 2-PAG levels and caused elevated GH and decreased SmC levels. The route of estrogen administration is probably of major importance for the hormonal effects on hepatic activity as reflected by SHBG and alpha 2-PAG levels. Bypassing the portal circulation might be advantageous with respect to liver-related side effects of estrogen therapy. GH and SmC might act as mediators of estrogen effects on the human liver.

Administration, Oral↗
PubMed1987

Hormonal regulation of an estramustine-binding protein in the submaxillary gland of the rat.

An estramustine binding protein, in many aspects similar to the prostatic secretion protein (PSP), has partly been characterized in the submaxillary gland of the male rat. The [3H]estramustine-macromolecule complex is found in the void volume of a Sephadex G 200 column, indicating a Stokes radius larger than 52 A. The estramustine binding protein is bound to Concanavalin-A, indicating a glycoprotein structure. Like PSP, the macromolecule complex that is bound to Concanavalin-A inhibits the binding of the androgen-receptor complex to DNA-cellulose. The concentration of the protein is decreased following testectomy or estrogen treatment but can be restored to normal values following testosterone administration. These results strongly indicate that the estramustine binding macromolecule in the submaxillary gland belongs to the same group of proteins as PSP. We have earlier proposed a role for PSP as an intracellular regulator of androgen activity. Based on these new results it is tempting to speculate that androgen sensitive glycoproteins may act in the same way in all androgen sensitive tissues.

Animals↗
PubMed1987

Analysis of an estrogen binding macromolecule in human pancreas by radioimmunoassay.

A radioimmunoassay for quantitation of the human pancreatic estrogen binding protein (hEBP) was developed using polyclonal rabbit hEBP antiserum and iodinated purified hEBP. Parallel dose-response curves were obtained when serial dilutions of human serum and of cytosols obtained from human pancreas, prostate and colon were analyzed simultaneously with serial dilutions of purified hEBP standard. Very high levels of hEBP (500-1000 mg/kg wet weight) were found in normal pancreas. High as well as medium levels were found in pancreatic carcinoma tissue and medium values (0.1-1 mg/kg wet weight) in prostate, colon and ovarian tissue. Other tissues and serum from healthy volunteers showed low values, usually below 0.1 mg/kg. When serial dilutions of rat pancreatic cytosol were analyzed in the hEBP assay, [125I]hEBP was displaced by the rat preparation, but the dose-response curves were not parallel to the standard curves, indicating similarity but non-identity between the estrogen binding proteins in human and in rat pancreas.

Animals↗
PubMed1987

Mouse monoclonal antibodies against rat estramustine binding protein.

Hybridomas producing antibodies against rat prostatic estramustine binding protein (rEMBP) have been obtained by fusion of spleen lymphocytes from Balb/c mice, immunized with rEMBP, and SP2/0 Ag 14 mouse myeloma cells. Anti-rEMBP IgG producing cultures were identified in a solid phase ELISA using alkaline phosphatase conjugated sheep antimouse IgG. Cultures producing specific antibodies were subcloned and expanded. The produced immunoglobulins were characterized according to interaction with subunits of rEMBP. No interaction was found with [3H]estramustine-human estramustine binding protein. Following development of a radioimmunoassay, tissue distribution of rEMBP in the rat was studied. Despite high specificity, shown by selective interaction with rEMBP (F and S subunits), macromolecules interacting with anti-rEMBP were found in high concentrations in the prostrate and also in low concentrations, in other tissues of the male genital tract, and further in the adrenals, pancreas and submaxillary gland. The high specificity also makes it possible to study the F and S subunit selectively. These results show that macromolecules very similar to rEMBP are present in hormone-sensitive tissues in the rat.

Animals↗
PubMed1987

Comparison between a swim-up and a Percoll gradient technique for the separation of human spermatozoa.

Two methods of separating human sperm were compared using twenty-two semen samples. The sperm were separated by a swim-up technique or by self-migration on a Percoll gradient followed by medium change. After separation, the sperm obtained were assessed for progressive motility, ATP content, energy charge index ([ATP + 0.5 ADP]/[ATP + ADP + AMP]) and morphology. In general, and especially for semen samples containing less than 20 X 10(6) sperm/ml, separation by Percoll gradient selected sperm that were superior to those separated by the swim-up technique. The relatively high energy charge index (greater than 0.8) showed that the sperm tolerated the separation conditions well. It is suggested that self-migration on a Percoll gradient should prove useful for obtaining sperm of high quality.

Adenosine Triphosphate↗
PubMed1987

Serum prolactin assays have no prognostic value in treatment of prostatic cancer by orchidectomy or estrogens.

Eighty patients (54-75 years) with cytologically and/or histologically confirmed cancer of the prostate (CAP) were randomly allocated to either orchidectomy (ORX, n = 41) or combined intramuscular and oral estrogen treatment (ESTR, n = 39). Serum levels of prolactin (PRL) were determined prior to treatment and 6, 12 and 24 months after initiation of the treatment. In the ORX group, 32 patients responded to the treatment and 9 did not. In the ESTR group, 27 patients responded and 12 did not. Serum PRL levels were significantly increased by ESTR treatment in responders as well as in nonresponders, but were not affected by ORX. There were no differences in PRL values between responders and nonresponders at any time in any of the two treatment groups. It is concluded that serum PRL assays have no prognostic value in the employed endocrine treatment of CAP.

Aged↗
PubMed1987

Serum sex hormone binding globulin (SHBG), testosterone/SHBG index, endometrial pathology and bone mineral density in postmenopausal women.

Serum levels of sex hormone binding globulin (SHBG) and testosterone (T) and bone mineral density (BMC) in the non-dominant forearm were determined in 28 postmenopausal women aged 44-62 years. Significant correlations (Spearman's rank correlation test) were found between BMC and SHBG (negative) and between BMC and the T/SHBG index on biologically active androgen (positive). Significant correlations were also found between endometrial pathology (Kruskal-Wallis test; 0 = atrophic, 1 = hyperplasia, 2 = cancer) and SHBG (negative) and the T/SHBG index (positive). It is suggested that SHBG may act as one common denominator in the pathogenesis of postmenopausal osteoporosis and endometrial disease by regulating the levels of unbound, biologically active androgens and estrogens.

Adult↗
PubMed1987

Metabolism of estrone sulfate by normal human pancreatic tissue in vitro.

Homogenates of normal pancreatic tissue obtained from five female and nine male subjects transformed (3H)estrone sulfate into (3H)estrone and (3H)estradiol-17 beta in vitro. No other unconjugated (3H)metabolites were found. The rates of transformation were comparable to those previously demonstrated in mammary carcinoma and greatly exceeded those found in endocrinologically unrelated pectoralis and abdominal muscle. The results may provide additional indications for a possible association between estrogens and pancreatic function.

Estradiol↗
PubMed1986

Increase in progressive motility and improved morphology of human spermatozoa following their migration through Percoll gradients.

Human spermatozoa were separated on the basis of their motility in a discontinuous Percoll-gradient made up in tissue culture medium containing 10% (v/v) human serum (TCMS). Portions of ejaculates were placed on top of the gradients. After 3 h at 37 degrees C the bottom 1.5 ml was collected and the sperm washed free of the Percoll solution by centrifugation at 240 X g after dilution in TCMS. In this way the spermatozoa were separated from seminal fluid by means of the swimming rate of the sperm. When semen samples from normal men were used, total recovery of sperm after separated on a Percoll gradient was 21 +/- 2.3%. The progressive motility index increased by a factor of 15 +/- 1 when comparing separated samples with the same unseparated ejaculate, and the frequency of sperm with normal morphology increased from 60 to 85%. The improvements in these semen samples was attributable to the Percoll separation as the washing procedure itself was without effect. Using this method sperm of relatively unifirm motility and morphology can be collected. These may then be used for further biochemical and physiological studies. Improved sperm quality was also obtained when samples from patients with abnormal semen profiles were separated in this way, although the degree of improvement was much more variable than that obtained with semen from normal fertile men. This indicates that this method can be used in clinical practice in selected cases for the preparation of sperm for insemination or for in-vitro fertilization.

Adult↗
PubMed1986

On the use of adenosine triphosphate for estimation of motility and energy status in human spermatozoa.

Following the development of a reliable technique for analysis of total ATP in semen, the ATP concentration of untreated human ejaculates was compared with progressive sperm motility during 3 continuous days following ejaculation. As correlation was poor between these variables, spermatozoa were separated by self-migration on Percoll gradients and washed free of Percoll solution. ATP concentration and sperm motility was then assessed. Aliquots of separated sperms were transferred to separate tubes, and increasing concentrations of sera were added prior to incubation at 37 degrees C for 4 days. Under these conditions a good correlation between specific progressive motility and specific ATP content was found (r = 0.88). A high concentration of human blood serum (10% v/v) was found to be necessary for maintainance of motility, but neither the addition of bovine serum albumin nor an increase in the glucose concentration had any effect on sperm motility or on the ATP concentration. Addition of different fractions of human blood serum indicated that the components mainly responsible for maintaining sperm motility are greater than 10,000 daltons. Our findings strongly indicate that ATP assessment can be used to estimate the energetic condition of a human sperm population after its separation from seminal plasma. It is suggested that this in vitro system can be used to define optimal conditions for sperm function.

Adenosine Triphosphate↗
PubMed1986

Peripheral hormone levels in healthy subjects during controlled fasting.

The effect of one week of controlled fasting (31 of fluid containing 50 g of carbohydrate/day) upon the serum levels of hormones, sex hormone binding globulin, and albumin was studied in healthy subjects. Fasting caused decreased levels of prolactin and T3, no changes in the levels of TSH, FSH, LH, dehydroepiandrosterone, 4-androstene-3, 17-dione, total oestrone, and total testosterone, and increased levels of cortisol, dehydroepiandrosterone sulphate and albumin. A significant positive correlation was found between albumin and dehydroepiandrosterone sulphate. Fasting rapidly increased the levels of sex hormone binding globulin and decreased the percentage of free testosterone and the calculated free testosterone level in both sexes. A decreased metabolic clearance of certain steroids (cortisol, dehydroepiandrosterone sulphate) owing to an increased protein binding may be one of the endocrine consequences of fasting. An increased protein binding of testosterone may be outweighed by a decreased gonadal production, thus resulting in an unchanged total testosterone level. The increased sex hormone binding globulin level could not be explained by changes in gonadal and thyroid hormones.

Adult↗
PubMed1986

High affinity protein-binding and enzyme-inducing activity of methyltrienolone in Pseudomonas testosteroni.

The synthetic androgen methyltrienolone (R 1881) was shown to increase steroid delta 1 dehydrogenase activity when added to cultures of Pseudomonas testosteroni at concentrations of 10(-10)-10(-8)M. Incubation with a soluble extract of P. testosteroni showed that (3H)-R 1881 was bound to a macromolecule with high affinity (Kd 0.6 X 10(-9)M) and low capacity (number of binding sites 120 X 10(-15) mol/mg of protein). The (3H)-R 1881-macromolecule complex was partially destroyed following treatment with protease, was precipitated by addition of ammonium sulfate at 20% of saturation, sedimented at 6.3 S both in 0.01 and 0.4 M KCl solutions, and had an isoelectric point of pH 6.3. The complex was partially bound to DNA-cellulose. Analysis by sucrose gradient centrifugation indicated that neither (3H)-testosterone and (3H)-estradiol-17 beta nor (3H)-corticosterone were bound with high affinity to the (3H)-R 1881-binding macromolecule. It is suggested that the partially characterized R 1881-binding macromolecule, which at least in certain respects resembles androgen receptors described in mammalian cells, is involved in the inductive effect of R 1881 on the delta 1 dehydrogenase activity in P. testosteroni.

Enzyme Induction↗
PubMed1986

Abbott monoclonal enzyme immunoassay measurement of estrogen receptors in human breast cancer: a European multicenter study.

A new enzyme immunoassay (Abbott ER-EIA Monoclonal) for the determination of estrogen receptor in cytosols from breast tumor specimens has been developed by Abbott Laboratories. To establish the correlation of the results from this new technique with currently existing steroid binding methods, a multicenter study was conducted in eight European laboratories. All participants followed the same protocol consisting of a familiarization phase, a proficiency evaluation, and a comparison of existing steroid binding methods with the new immunoassay using panel samples and clinical specimens. ER-EIA was compared with the multipoint dextran coated charcoal assay in six laboratories, four of which followed the EORTC protocol; of the remaining two laboratories, one used a single saturating dose assay, the other an isoelectric focusing assay. The results show no significant difference between reducing agents when used in the ER-EIA. Reproducibility for the immunoassay (interassay coefficient of variation, 6%, interlaboratory coefficient of variation, 11-19%) was somewhat better than that for the steroid binding methods (interlaboratory coefficient of variation, 12-32%). The correlation between the methods was dependent on the origin of the lyophilized specimens. In breast tumor samples, an excellent correlation, (not statistically different from 1) was found between the ER-EIA and the steroid binding method in six laboratories. One laboratory showed a slope of 1.1 for the correlation line; the laboratory using isoelectric focusing showed a slope of 1.9. The mean value determined by the enzyme immunoassay in premenopausal women was 74 fmol/mg cytosol protein, and in postmenopausal women it was 187 fmol/mg cytosol protein with no significant difference in the slope of the correlation line. Results suggest the usefulness of the new standardized enzyme immunoassay for routine use in the clinical laboratory.

Antibodies, Monoclonal↗
PubMed1986

Quantitation of estrogen receptor in seventy-five specimens of breast cancer: comparison between an immunoassay (Abbott ER-EIA monoclonal) and a [3H]estradiol binding assay based on isoelectric focusing in polyacrylamide gel.

Quantitation of estrogen receptor has been performed in cytosol prepared from 75 specimens of breast cancer tissue from patients who had not received hormonal therapy. The study was performed in order to compare an immunoassay (Abbott Laboratories, North Chicago, IL) with our currently used method for estrogen receptor analysis based on isoelectric focusing of [3H]estradiol-receptor complex in polyacrylamide gels. Using linear regression analysis, a regression coefficient (slope) of 1.30 and a correlation coefficient of 0.75 were calculated. The differences in results between the two methods are probably partly explained by the fact that the ligand-based method only measures unoccupied receptor, whereas the immunoassay detects the total amount of receptor, resulting in generally slightly higher concentrations with the latter method. However, in five of 75 specimens the ligand-based method gave a considerably higher concentration of estrogen receptor. This was most probably explained by partial proteolysis resulting in the formation of receptor fragment(s), which was undetectable with the immunoassay but detectable with the ligand-based method. These observations underline the importance of careful handling of specimens during the whole immunoassay procedure.

Acrylic Resins↗
PubMed1985

Effect of hormones on growth and ATP content of a human prostatic carcinoma cell line, LNCaP-r.

The use of ATP content as a measurement for cell growth was evaluated in the LNCaP prostatic cancer cell line. ATP content was found to correlate well with cell counts and was an easy and reliable method for following the effect of substances on cell growth. During cultivation for 9 days no effect on cell counts or ATP content could be seen when testosterone (10(-10) to 10(-6) M), estradiol-17 beta (10(-10) to 10(-5) M), 5 alpha-DHT (10(-9) to 10(-6) M), prolactin, vitamin A, or antiandrogen was added to the cell medium in different combinations. However, a weak positive effect was seen on the mitotic index when 10 or 100 nM 5 alpha-DHT was added to the cells, whereas 1 microM 5 alpha-DHT inhibited cell growth. Thus despite the fact that this LNCaP line contained 16 fmol androgen receptor/mg protein (Kd 0.6 nM), it is unresponsive to hormones and should be designated LNCaP-r (resistant). Chromosome analysis revealed that a shift in the modal chromosome number had occurred from the original LNCaP line, which could account for the lack of hormonal sensitivity.

Adenosine Triphosphate↗