Multicenter evaluation of TDx test for assessing fetal lung maturity

"TDx Fetal Lung Maturity," an automated assay that measures the relative concentrations of surfactant and albumin in amniotic fluid, was compared with the lecithin/sphingomyelin (L/S) ratio and phosphatidylglycerol determination at five clinical sites. A total of 695 amniotic fluid samples were analyzed, of which 312 were followed by delivery of the infant within three days of sample collection. Of these 312, 24 developed respiratory distress syndrome and seven developed transient tachypnea. With the cutoff for maturity set at a surfactant/albumin value of 50 mg/g, the assay showed a sensitivity of 0.96 and a specificity of 0.88 for all samples, compared with a sensitivity of 0.96 and a specificity of 0.83 for the L/S ratio. The combination of rapid assay (30 min), accurate results, and uniformity among testing centers makes the TDx assay a very promising method.

Multicenter evaluation of TDx test for assessing fetal lung maturity

"TDx Fetal Lung Maturity," an automated assay that measures the relative concentrations of surfactant and albumin in amniotic fluid, was compared with the lecithin/sphingomyelin (L/S) ratio and phosphatidylglycerol determination at five clinical sites. A total of 695 amniotic fluid samples were analyzed, of which 312 were followed by delivery of the infant within three days of sample collection. Of these 312, 24 developed respiratory distress syndrome and seven developed transient tachypnea. With the cutoff for maturity set at a surfactant/albumin value of 50 mg/g, the assay showed a sensitivity of 0.96 and a specificity of 0.88 for all samples, compared with a sensitivity of 0.96 and a specificity of 0.83 for the L/S ratio. The combination of rapid assay (30 min), accurate results, and uniformity among testing centers makes the TDx assay a very promising method.

Studies of the HER-2/neu proto-oncogene in human breast and ovarian cancer

Carcinoma of the breast and ovary account for one-third of all cancers occurring in women and together are responsible for approximately one-quarter of cancer-related deaths in females. The HER-2/neu proto-oncogene is amplified in 25 to 30 percent of human primary breast cancers and this alteration is associated with disease behavior. In this report, several similarities were found in the biology of HER-2/neu in breast and ovarian cancer, including a similar incidence of amplification, a direct correlation between amplification and over-expression, evidence of tumors in which overexpression occurs without amplification, and the association between gene alteration and clinical outcome. A comprehensive study of the gene and its products (RNA and protein) was simultaneously performed on a large number of both tumor types. This analysis identified several potential shortcomings of the various methods used to evaluate HER-2/neu in these diseases (Southern, Northern, and Western blots, and immunohistochemistry) and provided information regarding considerations that should be addressed when studying a gene or gene product in human tissue. The data presented further support the concept that the HER-2/neu gene may be involved in the pathogenesis of some human cancers.

IgG and IgA content of vaginal fluid during the menstrual cycle

Immunoglobulin levels in cervicovaginal secretions during the menstrual cycle have not been well characterized biochemically. We determined the IgG and IgA concentrations in vaginal fluid obtained by patient self-sampling with an Ovu-Trac aspirator. Vaginal fluid IgG levels were less than 1-270 mg/dL. On the average the levels of IgG were relatively high after menstruation, declined during the ovulatory phase and remained relatively low during most of the luteal phase. The IgA levels were less than 10 mg/dL, and many samples contained IgA at our assay's lower limits of detection (microradial immunodiffusion). The preovulatory and luteal phase levels of IgG and IgA in vaginal fluid were generally lower than those reported for cervical mucus, but the ovulatory phase IgG and IgA composition was comparable between vaginal fluid and cervical mucus.

Regulation of progesterone production in the rabbit corpus luteum

Substantial evidence accumulated over six decades has established that estradiol exerts a dominant stimulatory influence on the production of progesterone by luteal tissue in pseudopregnant or pregnant rabbits, beginning approximately five days after ovulation. The direct steroidogenic action of estradiol on the luteal cell is mediated by the estrogen-receptor protein complex at the nuclear level. Major effects of estradiol lie distal to cholesterol ester and the formation of lipid droplets, and proximal to cholesterol availability for translocation into cytochrome P-450 cholesterol side-chain cleavage enzyme (P-450scc). Structure-function studies corroborate this as an estrogen-sensitive segment of the steroidogenic pathway in the rabbit corpus luteum. Estradiol increases the amount of precursor available for pregnenolone production in rabbit luteal mitochondria. Whether this is because of enhanced precursor storage in the mitochondria or because of effects on intramitochondrial movement of precursor, or both, is unclear. There is a void in knowledge between events at the nuclear level in response to the estrogen stimulus and known post-translational effects at the level of cellular and subcellular organelles. Studies to determine estrogen-sensitive transcriptional and translational events associated with steroidogenesis in the rabbit luteal cell model offer a novel perspective for an improved understanding of the regulatory processes governing steroidogenesis.

Estrogen increases precursor for pregnenolone synthesis with temperature-sensitive occupancy of P-450scc in mitochondria of rabbit corpus luteum

To examine the mechanism of estrogen's direct stimulation of steroidogenesis in the rabbit corpus luteum, we tested the hypothesis that the effect of estrogen on progestin production occurs at the site of processing of the precursor for pregnenolone (i.e. cholesterol) in the mitochondrion. For this purpose, we manipulated a model of estrogen stimulation by 1) removing sc estradiol-filled polydimethylsiloxane capsules from superovulated rabbits on day 9 of pseudopregnancy or 2) leaving the capsules in place to preserve a chronic estrogen stimulus. In the estrogen-deprived rabbits, the serum progesterone level fell precipitously in vivo within 24 h, but in rabbits with chronic estrogen stimulation, serum progesterone levels remained high. Our results show that the loss in progestin production caused by estrogen deprivation could not be attributed to loss of the mitochondrial cytochrome P-450 side-chain cleavage enzyme (P-450scc), a common rate-limiting step in progestin synthesis in many steroidogenic tissues. In addition, we confirmed that there was no loss in the catalytic activity of this enzyme. Treatment with aminoglutethimide in vivo followed by electron paramagnetic resonance spectroscopic analysis of mitochondria (prepared in aminoglutethimide-free buffers) showed that incubation of isolated mitochondria at 37 C and pH 6.2 caused an increased high spin state (g = 8.2 signal) and a concomitant decreased low spin state. This shift from low to high spin states, which is indicative of cholesterol-P-450scc complex formation, occurred in the luteal mitochondria from both estrogen-deprived and estrogen-stimulated rabbits. In further studies to localize estrogen's regulatory point, we determined that the initial (first minute) rate of production of pregnenolone (per mg protein or per U P-450scc) from endogenous precursor proceeded equally fast in mitochondria from estrogen-deprived and those from estrogen-stimulated rabbits. However, the rapid pregnenolone production in the estrogen-deprived group lasted for a shorter time and, after 30 min, yielded less pregnenolone per mg protein or per U P-450scc than did mitochondria from estrogen-stimulated rabbits. Addition of 25-hydroxycholesterol did not increase the initial rate of pregnenolone formation, indicating that precursor availability is not limiting during the initial period. In aggregate, these observations suggest that the effect of estrogen on progestin production in the rabbit corpus luteum is not regulation of the movement of cholesterol to the catalytic site on the inner mitochondrial membrane, even though this is a step in the regulation of protein hormone-stimulated steroidogenesis.(ABSTRACT TRUNCATED AT 400 WORDS)

Serum CA 125 and survival of mice inoculated with ovarian carcinoma and treated with antiestrogen, estrogen, or progestin

The human ovarian carcinoma cell line NIH-OVCAR-3 grown in immunodeficient mice has been reported to be sensitive to estrogen medications and to express progestin receptor. To assess the effects of sex steroids on CA 125 production and survival times in these mice, we administered Tamoxifen, estrogen, and progestin. During the first 28 days after inoculation of mice with 2.3 million tumor cells ip, serum CA 125 rose exponentially, reaching 4308 +/- 776 and 3905 +/- 1013 units/ml (mean +/- SEM, P greater than 0.1) in placebo- and Tamoxifen-treated mice, respectively; median survival times were 41 and 39 days, respectively (P greater than 0.1). Uninoculated mice had nondetectable CA 125, and all outlived the inoculated mice. In tumor-inoculated mice, serum CA 125 levels and survival were similar when estrogen or progestin was injected alone and when both were given in combination. We detected no significant differences in production of CA 125 in vitro by tumor cells harvested from ascites fluid when the mice were treated with placebo, estrogen, or progestin. We conclude that, for our model, serial measurements of serum CA 125 provide excellent estimates of the relationship between tumor burden and survival, and that CA 125 production appears unaffected by estrogen, progestin, or Tamoxifen.

Enzyme-linked immunochemical measurement of estrogen receptor in gynecologic tumors, and an overview of steroid receptors in ovarian carcinoma

We tested whether a newly available enzyme-linked immunoassay (EIA) validly measures estrogen receptor (ER) in gynecologic tumors. We first documented that ER so measured agreed with results by established radioligand-based assays [dextran-coated charcoal (DCC) and hydroxylapatite (HAP)] for in-house breast carcinomas and for proficiency testing specimens. Then, for gynecologic tumors, we found strong correlations between results for ER as measured by the two methods; e.g., for 27 ovarian carcinomas, r greater than or equal to 0.86. The same was true for ER measured in nine specimens of ovarian carcinoma from women who had undergone chemotherapy: r greater than or equal to 0.94. Radioinert estradiol or serum had no discernible effect on EIA measurements of ER, whereas our DCC assay was rendered uninterpretable. Evidently the EIA validly measures ER in steroidogenic tissues, including ovarian, and also in breast and uterine carcinomas. Clinical management of the latter is now based in part on results of steroid receptor assays. For ovarian carcinomas, ER assay can be helpful for determining the probable primary site of adenocarcinomas of unknown origin, and it is providing a rational basis for development of new diagnostic and therapeutic strategies.

Enzyme-linked immunochemical measurement of estrogen receptor in gynecologic tumors, and an overview of steroid receptors in ovarian carcinoma

We tested whether a newly available enzyme-linked immunoassay (EIA) validly measures estrogen receptor (ER) in gynecologic tumors. We first documented that ER so measured agreed with results by established radioligand-based assays [dextran-coated charcoal (DCC) and hydroxylapatite (HAP)] for in-house breast carcinomas and for proficiency testing specimens. Then, for gynecologic tumors, we found strong correlations between results for ER as measured by the two methods; e.g., for 27 ovarian carcinomas, r greater than or equal to 0.86. The same was true for ER measured in nine specimens of ovarian carcinoma from women who had undergone chemotherapy: r greater than or equal to 0.94. Radioinert estradiol or serum had no discernible effect on EIA measurements of ER, whereas our DCC assay was rendered uninterpretable. Evidently the EIA validly measures ER in steroidogenic tissues, including ovarian, and also in breast and uterine carcinomas. Clinical management of the latter is now based in part on results of steroid receptor assays. For ovarian carcinomas, ER assay can be helpful for determining the probable primary site of adenocarcinomas of unknown origin, and it is providing a rational basis for development of new diagnostic and therapeutic strategies.

Cholesterol metabolism in estrogen-sensitive progestin synthesis by rabbit corpus luteum

To learn whether either reduced de novo cholesterol synthesis and/or altered cholesteryl ester metabolism is responsible for the deficient progestin production induced by estrogen withdrawal from pseudopregnant rabbits, we measured the luteal activity of three enzymes: 1) 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase (the rate-limiting step in de novo cholesterol synthesis), 2) cholesteryl ester hydrolase, and 3) acyl coenzyme A:cholesterol acyltransferase (ACAT) in estrogen-stimulated and estrogen-deprived rabbits. The only change in the activity of these enzymes and of the enzyme NADPH-cytochrome c reductase (a microsomal marker enzyme) after estrogen capsule removal for 12 or 24 h was a 30% decrease in HMG-CoA reductase activity after 24 h. The decrease in HMG-CoA reductase activity was not accompanied by a detectable change in either the content or localization of cellular free cholesterol. Previous data from our laboratory have demonstrated that 24 h of estrogen deprivation has no effect on inner mitochondrial membrane P-450 side-chain cleavage activity (a rate-limiting step in the conversion of cholesterol to steroid hormones). These data, and our earlier finding that estrogen deprivation leads to accumulation of cholesteryl ester in the luteal cells, indicate that estrogen maintains rabbit luteal progestin production by stimulating the transfer of cytoplasmic cholesterol to the active site of P-450 side-chain cleavage on the inner mitochondrial membrane.

Estrogen regulation of steroidogenesis in rabbit luteal cells

Estradiol is a potent modifier of gonadotropin-stimulated steroidogenesis. By the seventh day after ovulation, estradiol is the only agent required for the stimulation of progesterone synthesis by corpora lutea of superovulated pseudo-pregnant rabbits. To learn which control points in steroidogenesis are susceptible to regulation by estradiol alone, we have studied the production of pregnenolone, progesterone, and 20 alpha-hydroxy-4-pregnen-3-one by corpora lutea of estradiol-stimulated and estradiol-deprived pseudopregnant rabbits. In previous investigations, we learned that estradiol deprivation in vivo, on day 9 of pseudopregnancy, causes an abrupt cessation of progesterone and 20 alpha-hydroxy-4-pregnen-3-one production, which is associated with accumulation of cholesterol and cholesteryl ester in the luteal tissue. We now report that production of pregnenolone, measured as its concentration in serum, also decreases abruptly by 84% within 48 h when the estradiol stimulus is removed on day 9 of pseudopregnancy. In addition, short term incubations of luteal tissue demonstrate that corpora lutea from estradiol-deprived rabbits do not use stores of luteal intracellular cholesterol for production of pregnenolone and progestin. These findings suggest that upon estradiol deprivation, rabbit luteal cells lose their capacity for using stored cholesteryl ester, or cholesterol synthesized de novo, for the production of pregnenolone and progestins. We, therefore, tested the hypothesis that a blockade of steroidogenesis caused by estrogen deprivation occurs at the point of cytochrome P-450 cholesterol side-chain cleavage (P-450scc), a principal rate-limiting step in the conversion of cholesterol to hormonal steroid products. To this end, we assayed the P-450scc activity in mitochondria-rich fractions of corpora lutea from rabbits that were deprived of estradiol for 24 and 48 h beginning on day 9 after induction of superovulation. Surprisingly, withdrawal of the estradiol stimulus did not cause loss of luteal P-450scc activity, measured as the amount of aminoglutethimide-inhibitable conversion of 25-hydroxycholesterol to pregnenolone by mitochondria-rich preparations. From these results, we infer that the luteotropic action of estradiol is probably not effected at P-450scc in the rabbit corpus luteum, but, presumably, occurs at control points that regulate the availability of stored cholesterol and/or its movement to or within the mitochondria for conversion to pregnenolone.

Immunocytochemical identification of estrogen receptor in ovarian carcinomas. Localization with monoclonal estrophilin antibodies compared with biochemical assays

Estrogen receptor (estrophilin) has been identified in ovarian carcinomas by a variety of physicochemical methods. Since these methods require disruption of the tissue, they do not provide any anatomic information about the cellular distribution and location of receptor. The authors have used monoclonal estrophilin antibodies and an indirect immunoperoxidase technique to study the immunocytochemical localization of estrogen receptor in 43 tissue samples of ovarian carcinoma from 27 patients. The immunocytochemical findings were compared with the results of conventional estrogen receptor assays of cytosolic and nuclear extracts prepared from adjacent pieces of ovarian carcinoma. Exclusively nuclear localization of estrogen receptor was observed with the immunocytochemical technique in all of the 25 tumor samples which had a cytosolic estrogen receptor content, determined by either the dextran-coated charcoal or hydroxylapatite techniques, greater than 700 fmoles/gm wet weight of tissue. Only 3 of 16 tumor samples with cytosolic estrophilin concentrations of less than 700 fmoles/gm wet weight displayed nuclear staining for estrogen receptor; two of these three were metastases from receptor-rich primaries. Specific cytoplasmic staining for estrogen receptor was not observed. These results indicate that many ovarian carcinomas have estrogen receptor, predominantly localized in the nucleus, which is similar to tissues of the female genital tract (vagina, cervix, endometrium, fallopian tube) and breast carcinoma.

Monoclonal antibody recognition of multiple forms of estrogen receptor tagged with [125I]methoxy-iodovinyl estradiol in ovarian carcinomas

Based on previous studies of the properties of moxestrol, we hypothesized that a radiohalogenated analog of moxestrol, [125I]11 beta-methoxy-17 alpha-iodovinyl-estradiol [( 125I] MIVE2), should bind to the estrogen receptor (ER) in some ovarian adenocarcinomas (OVCA), thereby offering the potential for imaging and/or treatment of these cancers. We used monoclonal antibodies (H222, H226, and D547) against human breast cancer ER to identify the [125I]MIVE2-binding moiety in OVCA cytosols that is found on high salt sucrose gradients. After gel electrophoresis and western blotting, exposure of OVCA extracts to the ER antibodies, followed by exposure to goat antirat serum and then rat peroxidase antiperoxidase, demonstrated a moiety in OVCA that migrated indistinguishably from the ER in MCF-7 human breast cancer cells and from that in specimens of breast cancer tissue. Because few studies have demonstrated efficacy of hormone management for OVCA, we also wanted to learn whether ER exists in multiple forms in OVCA, in view of the possibility that some forms may be inactive in regulating growth-dependent cell functions while retaining estrogen-binding capacity. By incubating the monoclonal antibodies H222, H226, and D547, each of which recognizes a different region on the ER protein, with OVCA cytosol fractions, we demonstrated that ER in OVCA can exist in multiple forms, some of which fail to express an H226-recognized site and some of which fail to express a D547-recognized site. This observation indicates that a relationship may exist between the presence or absence of certain forms of ER in ovarian epithelial cancer and a patient's response to hormone therapy.

Persistence and distribution of estrogen receptor in advanced epithelial ovarian carcinoma after chemotherapy

Estrogen receptor in tumor cytosol extracts from primary ovarian adenocarcinomas and/or from their metastatic foci was measured for determination of whether or not estrogen receptor content is preserved after chemotherapy. Tumor tissue was analyzed from 36 patients who had not received chemotherapy and from 16 patients after varying periods of chemotherapy. The percentages of relatively estrogen receptor-rich tumors (with more than 35 fmol estrogen receptor per milligram soluble protein, or with more than 1200 fmol estrogen receptor per gram tissue wet weight) were similar in the two groups (31 and 37%). In three of four patients who had specimens analyzed both before and after chemotherapy, there was little difference between the levels of estrogen receptor in the initial sample and in samples taken after ten to 32 months of chemotherapy. In one patient, a decrease in the amount of receptor after chemotherapy appeared to be related to the sampling technique used. There was no discernible effect of treatment on the prevalence or amount of estrogen receptor in metastases. No correlation was observed between estrogen receptor levels and the histologic type or grade of the tumor or the patients' survival. The data suggest that chemotherapy has little effect on measurable receptor levels in ovarian epithelial carcinomas. When present in one tumor site, receptor can be expected to be present in a majority of other sites in the same patient.

Estradiol-induced changes in progesterone secretion by rabbit corpora lutea are associated with quantitative ultrastructural changes in luteal cells

In this study, we examined changes in luteal cell structure that accompany estradiol-altered progesterone production by the rabbit corpus luteum. To stimulate progesterone production, polydimethylsiloxane (Silastic) capsules containing 17 beta-estradiol were inserted sc into superovulated New Zealand White rabbits. Luteal progesterone production, assessed by measurement of progesterone in peripheral serum, was high after the estradiol-filled capsules were inserted, declined within 24 h after the capsules were removed, and increased within 32 h after reinsertion of the capsules. Stereological analyses at the light microscopic level revealed that the number of luteal cells and the volume of an average luteal cell did not differ significantly between estradiol-stimulated and estradiol-deprived rabbits over the time period employed. In contrast, stereological analyses at the electron microscopic level demonstrated that the surface areas of smooth endoplasmic reticulum and inner mitochondrial membrane declined with estradiol deprivation, but were restored by reimposition of estradiol stimulation. These changes in the surface area per cell of smooth endoplasmic reticulum and inner mitochondrial membrane were strongly correlated (r = 0.94 and r = 0.88, respectively) with changes in progesterone concentrations in peripheral serum. Changes in the surface area of lipid droplets per luteal cell also occurred, but were inversely correlated (r = -0.87) with progesterone levels. No significant changes were seen in the surface areas per cell of outer mitochondrial membrane or rough endoplasmic reticulum. These results demonstrate that estradiol stimulation and deprivation cause reversible quantitative changes in the rabbit luteal cell organelles known to be directly involved in progesterone biosynthesis. This leads to the conclusion that the steroidogenic activity of the luteal cell is tightly coupled to its subcellular structure.

Limitations of qualitative serum beta-HCG assays in the diagnosis of ectopic pregnancy

Seventy-four patients had ectopic pregnancies proven by surgery. Three of them had a serum beta-HCG test for pregnancy that was reported as negative (less than 25-35 mIU/ml). We sought a threshold for positive in the serum beta-HCG test that would maximize its usefulness in diagnosing ectopic pregnancy. Sera from 52 of the patients were available for reanalysis. Quantitative values of beta-HCG were determined. Lowering the threshold for positive from 25-35 to 10 mIU/ml might increase the test's sensitivity without sacrificing specificity but would still not ensure detection of all ectopic pregnancies. Of 445 cases of ectopic pregnancy described in the literature, 6 had serum beta-HCG values reported as negative. In the published reports and in our own cases, clinical histories and histologies indicated that a nonviable ectopic pregnancy can be expected to have an associated serum concentration of beta-HCG that may be below the sensitivity of detection even with current, commercially available quantitative tests.

The fundamental chemistry of life. An attempt to define and identify the basic reaction responsible for life's creation and evolution

All natural growth follows exponential characteristics which vary from a simple exponential equation (non-solid cancer, bacteria) to complex Gompertzian functions describing solid cancer and multicellular organisms. Like all chemical processes the reagents (energy sources of food) react during life to produce vital energy, but in addition also create the next generation of life. This latter reaction is unique in that a simple proportional increase in the reagents creates an exponential increase in products: it is the sole invariable criterion of all life. The target of combined ionising and non-ionising radiations in cancer cells appears to be identical with this fundamental exponential chemical reaction. Identification of this target as a system of anaerobic glycolysis suggests that life's first reaction is a unique one whereby a simple proportional increase in available glucose causes an exponential proportional increase in energy which is available solely for reproduction.

Antibody-recognized [125I]estradiol-receptor complex in ovarian epithelial carcinoma

Monoclonal antibody against human breast cancer estrogen receptor was used to demonstrate binding of a gamma- and Auger electron-emitting estrogen to the estrogen receptor in ovarian epithelial carcinomas. When cytosols of estrogen receptor-rich ovarian adenocarcinomas were analyzed on sucrose gradients containing 0.4 M KCl, the presence of monoclonal antibody against breast cancer estrogen receptor caused a binding peak for [125I]- and [3H]estradiol to shift from the 4S to the 8-9S region, indicating antibody complex formation with ovarian adenocarcinoma estrogen receptor. The antibody-shifted peak of 8-9S [125I]- and [3H]estradiol binding was totally inhibited by a 100-fold molar excess of diethylstilbestrol (DES), but not by testosterone or progesterone, indicating a preference for estrogen binding by the antibody-shifted estrogen receptor. When estrogen receptor from the nuclear fraction of ovarian adenocarcinomas was incubated with [125I]estradiol at 1C, in the presence of 0.4 M NaSCN to facilitate exchange with endogenous ligand, binding occurred that was inhibitable by DES and restricted to the 4S region. Under these conditions the nuclear estrogen receptor was also shifted to the 8-9S region by the presence of the monoclonal antibody against estrogen receptor.