Production of a growth factor(s) by fibroblasts from the lungs of ventilated premature baboons and oxygen-exposed adult hamsters

Among the pathologic findings in infants succumbing to bronchopulmonary dysplasia are peribronchiolar and alveolar fibrosis. We examined the possibility that endogenously produced growth factors might contribute to these fibrotic changes through stimulation of fibroblast replication, with a resulting increase in collagen synthesis. We cultured fibroblasts from the lungs of prematurely delivered baboons and adult hamsters exposed to 100% oxygen and tested the media from these cells to see if they produced a factor(s) that was mitogenic to normal fibroblasts. We found that lung fibroblasts from baboons delivered prematurely at 140 days of gestation and ventilated for 6 days with 100% oxygen produced a factor(s) that supported fibroblast growth. A similar factor was also secreted by fibroblasts from normal term newborn baboon lungs and from the lungs of adult hamsters exposed to 100% oxygen for 4 to 8 days. Growth factor was not secreted by lung fibroblasts from 140-day non-breathing or 24-h-ventilated premature baboons, adult baboons, or hamsters not exposed oxygen. The growth-promoting substance is apparently a progression factor that is heat labile and inactivated by exposure to trypsin. These findings indicate that exposure of both the premature and adult lung to high concentrations of oxygen causes the elaboration of a growth factor that may induce fibroblast hyperplasia. This action may result in an increased production of connective tissue proteins and thereby contribute to the development of the fibrosis seen in bronchopulmonary dysplasia.

Metabolism of platelet-activating factor (alkylacetylphosphocholine) by type-II epithelial cells and fibroblasts from rat lungs

The uptake and metabolism of 3H-labeled platelet-activating factor by interstitial and epithelial cells from rat lungs was investigated. The uptake of 1-O-[3H]octadecyl-2-acetyl-sn-glycero-3-phosphocholine (3H-AGEPC) by alveolar type-II cells was linear with time from 5 to 60 min, with an average rate of 660 and 450 fmol/10(6) cells for cells in primary culture for 48 to 72 h, respectively. AGEPC was rapidly metabolized and by 10 min 60% of AGEPC was converted into long-chain acylphosphatidylcholine (PC) (50%) and 1-O-alkyl-2-lyso-sn-glycero-3-phosphocholine (lyso-GEPC) (10%). By 60 min radioactivity in AGEPC was less than 10% of the total intracellular activity. Lyso-GEPC remained at about 10% throughout the incubation period. The uptake of 3H-AGEPC by fibroblasts was very similar to type II cells, but the rate of metabolism was slower. AGEPC in fibroblasts constituted 85% of the cellular counts after 10 min of incubation, and 50% by 60 min. After 60 min only 30% of the AGEPC was converted to alkylacyl-PC. Characterization of the fatty acids in the alkylacyl-PC of both the type-II cells and lung fibroblasts indicated that arachidonic acid was preferentially (more than 90%) inserted at the 2-position.

Characterization and biological relevance of a 29-kDa, oestrogen receptor-related protein

The properties of a monoclonal antibody (D5) that can immunoprecipitate human oestradiol receptor (ER) under some but not all conditions are described. The antibody recognises a 29-kDa serine phosphoprotein that is qualitatively and quantitatively related to ER but not other steroid receptors or binding proteins. p29 will not complex with untreated cytosol ER but, after ammonium sulphate, KCl, heat or phosphatase treatments, interaction occurs that can be detected by immunoprecipitation with D5; molybdate and GTP inhibit complex formation. In human endometrium, p29 is increased by oestrogen and decreased by progestins. IRMA and histochemical assays for p29 have been developed and applied to a large series of human breast tumours. Most, but not all ER+ tumours are p29+, whilst ER-tumours are rarely p29+ unless they are also PR+. p29 predicts for clinical response to hormone therapy. ER+ p29+ tumours have a higher response rate than the ER+ p29-tumours. We do not know if p29 is a previously undetected component of the oestradiol receptor machinery or whether it is a product of oestrogen action.

Assessment of the potency of orally administered progestins in women

The effects of at least three doses of each of five orally administered progestins on estrogen-primed, postmenopausal endometrial biochemistry and morphologic features were analyzed. The progestins tested were norethindrone, medroxyprogesterone acetate (MPA), norgestrel, dydrogesterone, and progesterone. The dose required to elicit responses similar to those seen in premenopausal, secretory endometria was assessed for each of the parameters measured, and the relative potencies were calculated. Potencies, relative to a value of 1 for norethindrone, are L norgestrel 8 (D/L norgestrel 4), MPA 0.1, dydrogesterone 0.02, and progesterone 0.002. The dose of norethindrone required to elicit secretory phase activity was about 0.35 mg/day. These values agree with published data obtained with the use of different methods (delay of menstruation in premenopausal women, endometrial histologic features of estrogen-primed, ovariectomized women).

Histochemical studies with an estrogen receptor-related protein in human breast tumors

The histochemical characteristics of a Mr 29,000 phosphoprotein related to estradiol receptor are described in a large series of human breast tumors. The antigen was detected with a monoclonal antibody (D5) raised against partially purified human myometrial estradiol receptor. An indirect immunoperoxidase method was used with methacarn-fixed, wax-embedded sections. Quantitation of staining and its reproducibility are described. Results with trucut biopsies agree with those obtained with larger tumor sections. Normal breast is infrequently positive. Histochemical staining is higher in invasive carcinoma than in normal breast with ductal carcinoma in situ adjacent to infiltrating tumors exhibiting intermediate values. Furthermore, most in situ carcinomas have a heterogeneous staining pattern. About 20% of invasive tumors also exhibit heterogeneity. No simple correlation is seen between staining and histological grade. There are more low-staining tumors in young (less than 50 yr old) patients than in older women. Staining correlates with levels of cytosol estradiol receptor but not cytosol progesterone receptor. However, cytosol estradiol receptor-negative, cytosol progesterone receptor-positive tumors tend to have positive Mr 29,000 phosphoprotein levels. Positive staining is associated with a higher response rate to hormone therapy (50%). None of the negative tumors responded to hormone treatment. With these patients, comparison of histochemical assay for Mr 29,000 phosphoprotein and [3H]estradiol binding assays indicated that the former was at least as good as the latter assay in predicting hormone response. About 20% of cytosol estradiol receptor-positive tumors have low Mr 29,000 phosphoprotein, and such tumors have poor response to hormone treatment.

CSF dopamine levels correlate with extraversion in depressed patients

Cerebrospinal fluid (CSF) dopamine levels were studied in 16 male patients who also were tested for self-reported extraversion using the Eysenck Personality Inventory. Log CSF dopamine was significantly correlated with extraversion as predicted by recent theoretical work integrating mesolimbic dopamine function and active responding to external incentives as psychobiological traits. CSF dopamine levels were uncorrelated with the total score on the Hamilton Rating Scale for Depression, self-reported neuroticism, and age. The results are discussed in relation to other biological models of extraversion such as the construct of sensation-seeking behavior.

Evidence for an ordered reaction mechanism for bile salt: 3'phosphoadenosine-5'-phosphosulfate: sulfotransferase from rhesus monkey liver that catalyzes the sulfation of the hepatotoxin glycolithocholate

The in vivo formation of the sulfate ester of glycolithocholate is a critical step in the elimination of this hepatotoxic bile salt. Rhesus monkeys fed chenodeoxycholate or ursodeoxycholate, the precursors of lithocholate, develop frank cirrhosis in association with accumulation of nonsulfated glycolithocholate in bile. An enzyme catalyzing the formation of glycolithocholate-3-sulfate has been isolated from hepatic cytosol of adult female rhesus monkeys and has been purified 146-fold. When reduced it appears as a 30 kD band on an SDS-polyacrylamide gradient gel. It has a pH optimum of 7.0 and is stimulated by low concentrations of Mg2+ (up to 2 mM), but does not have an absolute requirement for this metal ion. The kinetics of this enzyme have been investigated to ascertain whether its reaction mechanism can account for the poor in vivo rate of glycolithocholate sulfation. Inhibitor studies with an oxidized metabolite of lithocholate, 3-keto-5 beta-cholanoate, showed that the latter is a competitive inhibitor of glycolithocholate and is noncompetitive with the active form of sulfate, 3'phosphoadenosine-5'-phosphosulfate. The monophosphonucleotide 3'-AMP is a competitive inhibitor of 3'phosphoadenosine-5'-phosphosulfate, and is noncompetitive with glycolithocholate. These observations are consistent with a sequentially ordered Bi Bi reaction mechanism in which the bile salt is the first substrate to bind to the enzyme. Such a reaction mechanism for bile salt:3'phosphoadenosine-5'-phosphosulfate:sulfotransferase would be, therefore, the first time in which the sulfate acceptor (the bile salt) is the initial substrate to bind to a sulfotransferase. These studies have shown that although rhesus monkeys have a liver enzyme capable of forming the sulfate ester of glycolithocholate, its reaction mechanism and the potent inhibition caused by simple metabolites, such as 3-keto-5 beta-cholanoate, may serve to under-express the activity of the enzyme in vivo.

Interaction between the 35 kDa apolipoprotein of pulmonary surfactant and saturated phosphatidylcholines. Effects of temperature

We studied the interaction between the 35 kDa apolipoprotein of canine pulmonary surfactant (SP 35) and five saturated phosphatidylcholines: distearoyl (DSPC), diheptadecanoyl (DHPC), dipalmitoyl (DPPC), dimyristoyl (DMPC), and dilauroyl (DLPC); and two monoenoic unsaturated phosphatidylcholines: dioleoyl (DOPC) and dielaidyl (DEPC), using temperatures at which all of the phospholipids except DOPC were in both the gel and liquid-crystalline states. The experiments were carried out in a buffer without Ca2+. The amount of apolipoprotein which was bound by both small unilamellar and multilayered vesicles of these lipids decreased as the temperature was increased. Moreover, near the temperatures of the phase transitions of all lipids except DLPC, there was an abrupt and marked reduction in binding of protein, in that over a 3-4 degree change in temperature there was an abrupt decrease in bound apolipoprotein. A similar change in binding occurred using DLPC, although the relatively large changes in bound protein occurred at about 10 and 20 degrees C, temperatures which are above the phase transition temperature of this lipid. Experiments using DOPC were limited to temperatures above the phase transition, and apolipoprotein binding was low. Experiments monitoring the intrinsic fluorescence of the protein, and the fluorescence of bis-1-anilino-8-naphthalene sulfonic acid bound to the protein, revealed a possible conformational change at about 40 degrees C. Measurement of intrinsic fluorescence provided the same result whether or not the protein was associated with lipid. DSC of the apolipoprotein indicated that this change was not associated with a measurable thermogenic process. We found that the interaction with DPPC was reversible at 42 degrees C, and we measured the thermodynamic parameters of the interaction at this temperature. These were: delta G0 = -8.0 kcal/mol apolipoprotein; delta H0 = -88 kcal/mol; delta S0 = -254 cal/Cdeg per mol. We conclude that the interaction between SP 35 and saturated phosphatidylcholines is temperature sensitive, and this probably reflects differences in the ability of gel and liquid-crystalline phospholipids to bind this protein. Both the delta H0 and delta S0 of the interaction are negative, and may reflect an immobilization of phospholipid around the apolipoprotein to form a boundary layer. This hypothesis is consistent with the findings obtained by DSC, in which the enthalpy of the phase transition of DMPC in lipid-apolipoprotein recombinants was found to be about 60% of that expected for a pure and unperturbed multilamellar dispersion.

Effect of the method of biopsy on the prognosis of and reliability of receptor assays in patients with operable breast cancer

A comparison has been made of the survival of contemporary patients treated by mastectomy in whom the original diagnosis was made by either Tru-cut biopsy or by excision biopsy. After a minimum of 5 years of follow-up there was no difference in survival between those biopsied by either method. When subdivided by tumour size again no differences emerged. Among those patients in whom the original Tru-cut biopsy was false negative there was no difference in survival compared with those treated by excision biopsy. This suggests that Tru-cut biopsy is a safe method for obtaining a histological diagnosis in operable breast cancer. Furthermore, when the receptor status of the tumours from the two groups was determined, there was no difference in the percentage of oestrogen receptor positive tumours, nor in the mean receptor value. However, there were more progesterone receptor positive tumours among the Tru-cut group, suggesting that a better tumour sample could have been submitted for analysis. This may be yet another advantage for the use of Tru-cut biopsy for the diagnosis of breast cancer.

Androgen regulation by the long terminal repeat of mouse mammary tumor virus

Mouse mammary tumor virus (MMTV) has long been implicated in mouse mammary carcinogenesis, and it is now well established that the long terminal repeat (LTR) contains regulatory sequences responsible for glucocorticoid-mediated induction of viral RNA. However, we have demonstrated previously that androgens as well as glucocorticoids can regulate MMTV RNA in the S115 mouse mammary tumor cell line. To determine if androgens act directly on the LTR in these cells, plasmids were constructed with the MMTV LTR joined to the coding sequences of genes not normally expressed in the cells. Following transfection of these chimeric genes into S115 cells, we show that the expression of the genes is regulated by both androgens and glucocorticoids. Furthermore, hormonal regulation is also conferred by the LTR on the neighboring guanine phosphoribosyltransferase (gpt) gene. Thus, androgens can act on the LTR of MMTV when the appropriate receptors are present in the cells, and this interaction can influence the expression of additional adjacent genes.

Serum prolactin levels in women with breast cancer and their relationship to survival

Serum prolactin (HPr) has been measured in 459 patients 1 day before (HPr-1) and in 433 patients 10 days after (HPr-2) treatment. These came from an unselected sequence of 739 patients with operable breast cancer who had been referred to Guy's Hospital over a period of 5 yr. In addition HPr was measured in 100, or more, women at 3, 6 or 12 months after mastectomy. The median levels of either HPr-1 or HPr-2 were higher in pre-menopausal compared with postmenopausal patients (P = 0.03 and 0.06, respectively). Mastectomy was associated with increased serum HPr in both pre- and post-menopausal patients (P less than 0.001 in both cases). Average levels at 3 months, or after, were similar to those found before treatment. Nulliparous women had a higher median amount of HPr-1 than parous which was significant in premenopausal patients (P less than 0.008) whilst HPr-2 levels were not related to parity. Thus the rise in HPr associated with surgery was greater in parous than nulliparous women. Prolactin levels were not related to nodal status or tumour size. However, the amounts of HPR-2 were significantly greater in women with histological grade 3 tumours than those with grade 1 or 2. Standardising for either nodal status, tumour size or histological grade seven situations were found in which HPr-1 or HPr-2 levels were of prognostic significance. Although some of these significant associations could be fortuitous all shared a common feature that the least favourable prognosis was associated with the highest HPr levels.

Monoamine interactions in narcolepsy and hypersomnia: a preliminary report

Principal component analysis was performed on data obtained for the concentrations of 3,4-dihydroxyphenylacetic acid, 3-methoxy-4-hydroxyphenylethylene glycol, homovanillic acid, and 5-hydroxyindoleacetic acid in lumbar cerebrospinal fluid from a group of normal volunteers (n = 40), hypersomniac patients (n = 13), and narcoleptic patients (n = 8). All four compounds were shown to be highly intercorrelated in the normal volunteers. In the hypersomniac patients, 3-methoxy-4-hydroxyphenylethylene glycol did not appear to be correlated with the other three compounds. In the narcoleptic patients, homovanillic acid and 3,4-dihydroxyphenylacetic acid appeared not to be correlated with the other two metabolites. The results provide tentative support for a neurochemical distinction between narcolepsy and hypersomnia and suggest that attention should be given to a possible malfunction of the dopamine system in narcolepsy and norepinephrine in hypersomnia.

Analysis of proteins in rabbit pulmonary surfactant using monoclonal antibodies

We have used monoclonal antibodies developed against the apolipoproteins associated with pulmonary surfactant purified from rabbit lavage fluid to study the expression of epitopes common to these proteins. The pulmonary surfactant contained nearly 20 proteins, of which at least 10 were not derived from serum. Electrophoresis, with sulfhydryl reduction of these proteins indicated apparent molecular weights of approximately 155, 135, 125, and 115 X 10(3) (high-molecular-weight group); 80, 70, and 60 X 10(3) (intermediate group); and 18 through 10 X 10(3) (low-molecular-weight group). Two-dimensional polyacrylamide gel electrophoresis, in which the proteins were electrophoresed without reduction in the first dimension, but with sulfhydryl reduction in the second dimension, revealed that the 80, 70, and 60 X 10(3) proteins dissociated into proteins of nominal molecular weights of 40, 35, and 30 X 10(3), respectively. In contrast, the 125 and 115 X 10(3) proteins of the high-molecular-weight group contained a protein which could only be reduced to a minimum molecular weight of 55 to 60 X 10(3). Monoclonal antibodies generally were of three types: those that reacted strongly with the high-molecular-weight group and weakly with the intermediate group; those that reacted conversely; and those that reacted only with the low-molecular-weight group. Our results indicate that at least two different surfactant apolipoproteins, with differing minimum molecular weights in SDS-polyacrylamide gel electrophoresis, have common epitopes. Although these results cannot certify a physiological relationship between these proteins, they suggest that the intracellular synthesis or extracellular processing of surfactant apolipoproteins may be more complicated than predicted by the findings of previous experiments, perhaps involving the posttranslational assembly of one surfactant protein into oligomers which resist dissociation under the conditions used for the analyses.

Is Provera the ideal progestogen for addition to postmenopausal estrogen therapy?

In a dose-ranging study, medroxyprogesterone acetate, 2.5, 5, or 10 mg daily, was given for 12 days of each calendar month to postmenopausal women also receiving conjugated estrogens, 0.625 mg daily, continuously. Endometrial biopsy specimens were taken on the sixth day of combined therapy for histologic, ultrastructural and biochemical evaluation. Medroxyprogesterone acetate induced secretory and ultrastructural changes within the endometrium, but the responses were variable and inconsistent. Suppression of epithelial deoxyribonucleic acid synthesis appeared dose-dependent. The levels of nuclear estradiol receptor, although reduced to within the secretory phase range, were not significantly lower than the values observed during the estrogen-only phase of treatment. Induction of both estradiol and isocitrate dehydrogenase activities was to within the secretory phase ranges, but the magnitude of these responses appeared less than those observed previously with other progestogens. Both morphologically and biochemically, medroxyprogesterone acetate, even at high dosage, produced suboptimal responses. Further studies are required to establish whether this is a dose-related effect.

Colloidal gold immunoultrastructural localization of rat surfactant

Using a polyclonal antiserum against the nonserum proteins in purified rat surfactant, we have localized protein antigen within the lamellar bodies of rat alveolar Type II cells perfusion-fixed with 2% cacodylate-buffered paraformaldehyde and postfixed with 0.5% osmium. A postembedment indirect immunogold ultrastructural localization was used and 20 nm gold particles were localized over the lamellae in Type II cell lamellar bodies, in tubular myelin, and in some of the secondary lysosomes of alveolar macrophages. Occasional labeling was seen in the rough endoplasmic reticulum and multivesicular bodies in some Type II cells, but the amount of this staining was not different from nonspecific background. There was, however, an invariant lack of labeling over all other lung cell types. These results demonstrate the presence of surfactant proteins within the lamellar body secretory product and support the idea that the surfactant lipoprotein complex is formed within intracellular sites prior to its secretion into the alveolar space.

Effects of dydrogesterone on the oestrogenized postmenopausal endometrium

Postmenopausal women receiving conjugated oestrogens 1.25 mg daily continuously were also given dydrogesterone either 5, 10 or 20 mg daily for the first 12 days of each calendar month. Endometrial tissue obtained on the sixth day of combined therapy in the third or subsequent treatment cycle was subjected to histological, ultrastructural and biochemical assessments. Dydrogesterone provoked secretory histological and ultrastructural changes within the endometrium in a dose-dependent manner. A daily dose of 5 mg produced sub-optimal responses but 10 and 20 mg daily produced effects similar to those observed in the secretory phase of the ovulatory cycle. Dydrogesterone 10 mg and 20 mg daily reduced epithelial DNA synthesis and nuclear oestradiol receptor levels to values within the secretory phase range. A dose-response relation was seen in the induction of oestradiol-17 beta and isocitrate dehydrogenase activities; hyperphysiological values were observed with 20 mg of dydrogesterone daily. This study has demonstrated that dydrogesterone exerts potent anti-oestrogenic and progestational effects on the human endometrium which are dose-related. The 10 and 20 mg doses induced responses equal to or greater than those observed in the secretory phase of the ovulatory cycle and both dosages can be recommended for use in combination with exogenous oestrogens in postmenopausal women: and they may also have a role in the management of anovulatory dysfunctional uterine bleeding.

Immunological probes for oestradiol receptors in human breast tumours

Monoclonal antibodies have been prepared against a soluble oestradiol receptor (REC) preparation partially purified from human myometrium by oestradiol affinity chromatography. The antibodies were detected by their ability to immunoprecipitate receptor bound [125I] oestradiol. One of the antibodies (D5) has been studied in detail. It will only precipitate REC after activation by salt, heat, low pH or KCNS and will not react with nuclear RE. It will not react with androgen, progesterone or glucocorticoid receptors nor with sex hormone binding globulin; it will only combine with REC from human sources. D5 recognizes a cytoplasmic 29 kdalton protein (p29) that can be separated from both type I and II soluble oestradiol binding proteins. p29 can react with activated REC and is qualitatively and quantitatively related to REC. IRMA and histochemical methods have been developed for quantitating p29 and relating its amount to receptors in human breast tumours. With both methods, highly significant (P less than 0.001) correlations with REC but not RP have been obtained. Both methods indicate that many REC-RP+ tumours contain p29. The histochemical method detects marked cellular heterogeneity in some tumours. The function of p29 is not known. It is an REC-related antigen that may be a previously undetected component of the oestradiol receptor machinery.

Steroid regulation of transfected genes in mouse mammary tumour cells

The regulation of mouse mammary tumour virus (MMTV) RNA by glucocorticoid hormones is well-established and has provided much information on how steroid hormones work. However, we have shown that androgens can also control MMTV RNA accumulation in S115 mouse mammary tumour cells. This novel androgen action could be explained on the basis that the MMTV long terminal repeat (LTR) can respond to several classes of steroid if appropriate receptors are present in the cells. We have used transfection experiments to demonstrate that androgens can act directly on the LTR in S115 cells. Hormonal regulation of transfected chimaeric genes into these cells was effected by androgen and glucocorticoid but not by oestrogen or progesterone, corresponding to the receptor status of the cells. Furthermore, hormonal control was also conferred by the LTR on expression of an independent cotransfected adjacent gene under its own separate promoter, suggesting that effects of an LTR can stretch to neighbouring genes in a type of hormone-enhancer insertion mechanism.

Histochemical studies with a monoclonal antibody raised against a partially purified soluble estradiol receptor preparation from human myometrium

A monoclonal antibody (D5) raised against affinity-purified cytosol estradiol receptor (REC) from human myometrium has been used to stain human tissues by means of an indirect immunoperoxidase method. Good staining was obtained with ethanol-, glutaraldehyde-, or Carnoy's-fixed material but not with formalin or Bouin's fixation. Cytoplasmic staining of human breast tumors exhibited a highly significant correlation (P less than 0.001) with REC assayed by conventional estradiol-binding assay provided that allowance was made for both staining intensity and cellularity of the tumor; no correlation existed with soluble progesterone receptor content. Both patient age and tumor differentiation influenced staining patterns in the same way as did REC content. Cultured REC-positive human breast tumor cell lines (MCF-7, ZR-75-1, and CA-2) showed positive staining as did cultured epithelium from human milk. Epithelia in normal breast and fibroadenoma exhibited variable staining that rarely reached the intensity seen in REC-positive tumor cells. The staining patterns of human normal endometrium, myometrium, fallopian tube, ectocervix, endocervix, and ovary and neoplastic endometrium and ovary are described. In every situation thus far examined only cytoplasmic staining has been observed.

Androgen regulates MMTV RNA in the short-term in S115 mouse mammary tumour cells

This report demonstrates that androgens as well as glucocorticoids can regulate MMTV RNA production in the short term. In S115 mouse mammary tumour cells, MMTV RNA accumulation is regulated within hours by androgen, at a time before any increase in DNA synthesis can be detected, thus providing a marker of an early postreceptor molecular event in steroid action on these cells. Androgen acts via its own receptor and not by cross-binding to the glucocorticoid receptor. The effects are at transcription and not just on stabilisation of RNA because they are blocked by actinomycin D. However, the androgen action shows some partial dependence on simultaneous protein synthesis since cycloheximide is inhibitory. The androgen regulation of MMTV RNA is compared and contrasted with that by glucocorticoids in these cells.

Occurrence of glyceryl ethers in the phosphatidylcholine fraction of surfactant from dog lungs

The molecular species of ether-linked lipids in the phosphatidylcholine (PC) fraction of the pulmonary surfactant obtained from the lavage fluid of dog were characterized. A combination of base-catalyzed methanolysis, phospholipase C treatment, gas-liquid chromatography, and mass spectrometry procedures were applied. The phospholipid composition of the surfactant, obtained by phosphorus assay of lipids separated by silica gel G thin-layer chromatography (TLC), was: PC (75%), phosphatidylglycerol (10%), phosphatidylethanolamine (7%), plus small amounts of sphingomyelin, phosphatidylinositol, and phosphatidylserine. The major components of the PC were 1,2-diacylPC (95%), and 1-O-alkyl-2-acylPC (5%). No detectable amounts of 1-O-alkyl-1'-enyl-2-acylPC or di-alkyl-1-enylPC were observed. The acyl groups present in the diacylPC were 14:0 (5%), 16:0 (68%), 16:1 (12%), 18:0 (6%), 18:1 (7%) and 18:2 (2%). The predominant alkyl ether chains located at the carbon 1 position of the 1-O-alkyl-2-acylPC were 16:0 (84%), 18:0 (5%) and 18:1 (14%). At the carbon 2 position only a 16:0 fatty acyl residue was detected. In three out of seven animals platelet-activating factor-like activity, as determined by a platelet aggregation assay, was isolated by TLC. This aggregating activity was lost upon base-catalyzed methanolysis, but was restored by functional levels after acetylation.

Monoclonal antibodies against a component related to soluble estrogen receptor

Mice were immunized with 1 to 3 micrograms of cytoplasmic estrogen receptor fragment purified from human myometrium by affinity chromatography. Two RE-antibody-secreting clones were detected from one fusion that were capable of precipitating cytosol RE. Monoclonal antibody D5 (subclass IgG1) reacts with an antigen that is related to RE from immunoprecipitation studies but which can be separated from the hormone binding unit. In the presence of anti-mouse serum, D5 precipitates labeled human cytoplasmic RE complexes from breast tumor, fibroid, myometrial, and endometrial preparations but does not react with nuclear RE from human endometrium or cytoplasmic RE from other species tested. Conversely, antibody C3 (Class IgM) precipitates human cytoplasmic RE and nuclear RE complexes as well as labeled cytoplasmic RE from rat and calf uterus and chick oviduct. Neither antibody reacts with progesterone receptor or androgen receptor from human breast tumor, SHBG from human plasma, or rat alpha-fetoprotein. With D5, steroid labeling of cytoplasmic RE at 25 degrees increased the RE immune complex precipitated. D5 precipitates molybdate-stabilized RE from myometrial cytosol when labeled at 25 degrees but not at 4 degrees. C5 precipitates molybdate-stabilized RE whether cytosol was steroid-labeled at 4 degrees or 25 degrees. For D5, optimal precipitation of RE from human breast tumor was observed when cytosol was steroid-labeled at 25 degrees in buffers of pH range 5 to 6. Immunochemical studies indicate that D5 is associated with a Mr 29,000 component in RE-positive cytosols. Electrofocusing and sucrose density gradient analysis confirmed that D5 antigen is a non-hormone-binding component related to cytosolic RE from breast tumor and myometrium.

Immunoradiometric studies with monoclonal antibody against a component related to human estrogen receptor

A human specific monoclonal antibody (D5) raised against a Mr 36,000 cytosolic estrogen receptor component (RE) partially purified from human myometrium was used to develop a simple, rapid, and sensitive solid-phase immunoradiometric assay (IRMA) for the reactive antigen in tissue cytosols from breast tumors, myometrium, endometrium, and endometrial carcinomas. The IRMA did not detect antigen in RE-negative cytosols from human breast tumors and endometrial carcinomas. RE-positive cytosols from chick oviduct and calf and rat uteri failed to produce an IRMA response. A pilot study indicated a significant correlation (P less than 0.001) between D5 IRMA value and RE sites in breast tumors assayed by [3H]estradiol binding sites. The presence of D5 antigen was dependent on the presence of cytosolic RE but not progesterone receptor. RE-positive patients age 50 years and over demonstrated significantly higher D5 assay values than did patients under 50 years. The data suggest that the D5 antigen is a component of the estrogen receptor or coordinately regulated with the receptor in human cells and that the assay method may have clinical use.