Is fibromyalgia a cause of failure in the treatment of a painful shoulder?

PURPOSE: This study aims to review the incidence of fibromyalgia in a cohort of patients who were treated for shoulder pain and address whether a concomitant fibromyalgia could have had detrimental effect on outcomes. METHODS: The treatment of 286 consecutive patients for shoulder pain was reviewed. RESULTS: Eighteen patients (6.3 %) were diagnosed as having fibromyalgia, but in 13 of them (72 %), the diagnosis was initially missed. Five patients received a total of 11 surgeries for treatment of the shoulder. At an average follow-up of 15 months (range 12-27), the average new Oxford shoulder score (OS score) was 49 % (range 6-87 %). The average physical component of the Short-Form-12 Healthy Survey (SF-12) was 36 (range 21-55), and the mental component 30 (range 15-46). The Summary Outcome Determination score (SOD score) was 1.3 (range-3 to 6). CONCLUSIONS: Fibromyalgia occurs relatively frequently in patients who complain of shoulder pain and it can be a cause of failure in the treatment of concomitant painful shoulder conditions.

Estradiol induction of cAMP in breast cancer cells is mediated by foetal calf serum (FCS) and sex hormone-binding globulin (SHBG).

Plasma sex hormone-binding globulin (SHBG or SBP), the specific carrier for estradiol and androgens, after binding to its membrane receptor (SHBG-R), causes a significant increase of cAMP in the presence of estradiol, in both breast (MCF-7) and prostate (LNCaP) cancer cells maintained in serum-free medium. On the other hand, it has been proposed that estrogens, in addition to the well-known nuclear receptor pathway, exert their biological effect inducing cAMP, as a consequence of a direct membrane action, in breast cancer and uterine cells. The aim of the present study was to clarify this controversial issue by verifying if the cAMP increase in MCF-7 cells was a direct effect of estradiol, or if it was mediated by FCS proteins, such as bovine sex hormone-binding globulin; and to reevaluate the effect of human SHBG on cAMP induction in the presence of FCS. MCF-7 cells were maintained in DCC-FCS (treated with DCC to remove steroids), in SHBG-FREE/DCC-FCS (treated with DCC and with a specific affinity chromatography to remove bovine sex hormone-binding globulin), or in serum-free medium (SFM). It was observed that estradiol determined a significant time-dependent increase of cAMP only in MCF-7 cells maintained in 10% DCC-FCS. When cells were maintained in 10% SHBG-FREE/DCC-FCS, estradiol had no detectable effect. However, its ability to increase cAMP was observed again after the addition of human SHBG, in doses ranging from 5 to 50 nM. Moreover, in the presence of 10% SHBG-FREE/DCC-FCS, SHBG, even in the absence of estradiol, caused a significant increase of cAMP. In conclusion, the data reported in the present study suggest that the ability of estradiol to induce cAMP in MCF-7 cells is not due to a direct membrane effect of the hormone, but rather it is mediated by FCS. SHBG is one of the serum factors mediating estradiol action. Lastly, it was proven that SHBG triggers the cAMP pathway in MCF-7 cells in a physiologic culture condition and at physiologic concentrations.

Sex steroid binding protein exerts a negative control on estradiol action in MCF-7 cells (human breast cancer) through cyclic adenosine 3',5'-monophosphate and protein kinase A.

Estradiol is considered to be a critical factor in the growth induction of some breast cancer cells, like MCF-7 cell line. Among other compounds involved in the control of neoplastic mammary cell growth, cAMP has been suggested, on the other hand, to exert an antiproliferative effect. Sex steroid binding protein (SBP) sex hormone binding globulin (SHBG), the plasma carrier for both androgens and estradiol, recognizes a specific receptor located on membranes of estrogen- and androgen-sensitive tissue and cultured cells (e.g. MCF-7 cell). The interaction of estradiol with the receptor-bound SBP has been reported to induce a significant accumulation of cAMP in MCF-7 cells; in addition, a negative modulation of estradiol induced proliferation of these cells has been described after treatment with SBP. We report here a more detailed observation about the effect of SBP on MCF-7 cell estradiol-induced growth as well as the possible linkage between SBP and its membrane receptor and protein kinase A activity. MCF-7 cell growth was induced by estradiol, but the effect of estradiol was completely abolished by cell treatment with both SBP and estradiol. The inhibitory effect of SBP was highly specific. Because it was suggested that SBP might act through cAMP, we investigated the effect of SBP and estradiol in cells treated with protein kinase A inhibitor peptide (6-22) amide, a specific inhibitor of the cAMP target protein kinase A. The blockade of PKA had no effect on estradiol action on cell growth but masked completely the effect of SBP because MCF-7 increased growth sustained by estradiol was fully detectable also in the presence of SBP. We also observed that MCF-7 cells treated with increasing doses of 8Br-cAMP, cAMP analog and PKA activator, showed a progressive reduction of their growth. 8Br-cAMP was also able to inhibit estradiol promotion of MCF-7 cell growth. The inhibitory effect of 8Br-cAMP on estradiol-induced proliferation was already detectable at analog concentration of 100 nM, which has been reported to be the level reached by cAMP in MCF-7 cells treated with SBP and estradiol. In conclusion, the present study strongly confirms our previous observation that SBP inhibits the estradiol induction of MCF-7 cell growth, appropriately suggesting that this SBP action, a consequence of the interaction with the receptor, is likely to be mediated by cAMP and PKA. In addition, the study implies a significant role of cAMP in the control of breast cancer cell growth.

Sex steroid-binding protein and its membrane receptor in estrogen-dependent breast cancer: biological and pathophysiological impact.

Data obtained in our laboratory about the membrane receptor for sex steroid-binding protein (SBP-R) in human breast cancer are reported. SBP-R was detected in MCF-7 cells (estrogen receptor positive, ER+), while MDA-MB 231 cells (ER-) did not bind SBP. MCF-7 cells treated with SBP and E2 showed a marked increase of intracellular cAMP, and a significant reduction of both E2 induced cell proliferation and E2-mediated increase of progesterone receptor (PGR). The inhibition of E2 effects in MCF-7 cells was shown to be highly specific for SBP and mediated by protein kinase A, the target of cAMP. Membrane SBP-R was also evaluated in primary breast cancers. SBP-R was detectable only on ER+/PR+ samples and SBP-R+ samples presented a lower proliferation rate than negative samples. Our data, thus suggest that SBP-R and ER could be functionally related and also that SBP could modulate estrogen action at target cell site.

The receptor-mediated action of sex steroid binding protein (SBP, SHBG): accumulation of cAMP in MCF-7 cells under SBP and estradiol treatment.

The interaction of sex steroid binding protein (SBP) with its specific receptor in MCF-7 cell (estrogen-sensitive human breast cancer cells), followed by the binding of estradiol (E2) to the complex SBP-receptor, induced a significant accumulation of intracellular cAMP. SBP alone as well as E2 alone did not elicit any modification of the nucleotide. The maximal increase in cAMP was observed with 1 nM SBP + 1 nM E2. Increasing doses of both SBP and E2, even raising cAMP levels with respect to basal, did not give any higher response. Both testosterone and dihydrotestosterone, used instead of E2, were not able to induce any significant modification of cAMP. E2-induced MCF-7 cell proliferation was significantly reduced by 8Br-cAMP. MDA-MB 231 cells (estrogen-insensitive breast cancer cells) were not shown to bind SBP, or to respond to SBP + E2 as far as both their proliferation and cAMP content are concerned. In summary, the present study provides evidence that the SBP receptor is part of the G-protein receptor family, and that SBP can act as modulator of E2 action at cell site through the second messenger cAMP.

The hepatic receptor for sex steroid-binding protein: study on a non-malignant cell line (Chang liver).

The binding of human sex steroid-binding protein (SBP), labelled with 125I, was studied on whole cultured liver cells (Chang liver cells). SBP was shown to bind to a receptor site on normal hepatocytes. The binding was time- and temperature-dependent, highly specific and of high affinity. The liver receptor recognizing SBP was demonstrated to be different from the asialoglycoprotein receptor; in addition, laminin, which is structurally related to SBP, could not bind to the receptor. SBP was shown to recognize two binding sites with different affinities; the low affinity site was shown to possess a remarkably high capacity. This characteristic, which until now has been described only for hepatocytes, could be related to the unique role of the liver with regard to both SBP and sex steroids.

Biological relevance of the interaction between sex steroid binding protein and its specific receptor of MCF-7 cells: effect on the estradiol-induced cell proliferation.

The human breast cancer cells MCF-7 were shown to bind sex steroid binding protein (SBP) at a receptor site. The binding to whole cells was specific, time-dependent, saturable, and at high affinity. Estradiol, bound to SBP, induced a significant inhibition of SBP-cell binding at a dose of 10(-9) M. The presence of SBP, bound either to estradiol, or to cells, did not alter the amount of estradiol entering cells, but it "captured" an additional quantity of the hormone at the outer surface of cells. Furthermore, the effect of SBP on estradiol-induced MCF-7 cell proliferation was evaluated. While estradiol is an effective proliferating agent on MCF-7 cells, SBP itself did not produce any significant cell proliferation; the growth of MCF-7 cells in the presence of the complex SBP-estradiol was not different from the growth in the presence of estradiol alone; SBP bound to its receptor produced a significant reduction of the estradiol-induced cell proliferation. In summary, the present study provides evidence that the interaction of SBP with its receptor on MCF-7 cells is not involved in the uptake of estradiol, but it can modify the effect of estradiol at target site by a mechanism which is not likely to be a simple sequestration of the hormone at the outer surface of cells.

The membrane receptor for sex steroid binding protein is not ubiquitous.

The tissue distribution of the membrane receptor for the Sex Steroid Binding Protein (SBP) has been studied, either in estrogen/androgen dependent tissues and in tissues not strictly sex steroid dependent. A specific interaction of SBP with cell membranes has been observed to occur only in estrogen/androgen dependent tissues, some of them had been previously shown by our laboratory and by other authors to possess a specific receptor for the protein. Thus, the sex steroid dependence of the tissue is likely to be determinant for the expression of the membrane receptor for Sex Steroid Binding Protein.

Receptor for sex steroid-binding protein of endometrium membranes: solubilization, partial characterization, and role of estradiol in steroid-binding protein-soluble receptor interaction.

The sex steroid-binding protein (SBP) receptor was solubilized from the membranes of human premenopausal endometrium with the zwitterionic detergent CHAPS. The binding activity of the soluble receptor was studied, allowing it to interact with [125I]SBP and precipitating the complex with polyethylene glycol 8,000. The interaction of SBP with the soluble receptor was specific, saturable, and at high affinity. Indeed, the specific binding was definitely improved on the solubilized form of the receptor. The effect exerted by sex steroids on the interaction of SBP with receptor was also examined on both the soluble and membrane-bound forms. At physiologic doses (10(-8) M) estradiol inhibits the binding at a significant extent on the soluble receptor, but not on membrane-bound form. The dose of estradiol required to significantly inhibit the SBP-specific binding was dependent on the form of receptor. In membrane-bound receptor the inhibiting dose of estradiol was higher than its physiologic concentration. Thus, it is likely that, while soluble receptor cannot recognize the complex steroid-SBP, membrane-bound receptor can interact both with "unliganded" SBP and with the estradiol-SBP complex (but not with androgen-SBP complexes) in an estrogen-dependent tissue like human endometrium.

The receptor for human sex steroid binding protein (SBP) is expressed on membranes of neoplastic endometrium.

Sex steroid binding protein (SBP) receptor was detected on cell membranes obtained from human endometrium adenocarcinoma. The binding of SBP was proved to be highly specific, saturable, and at high affinity. It was, additionally, shown to occur at two sites at different affinities, as previously described for other human tissues. SBP was, therefore, demonstrated to recognized a specific receptor on endometrium adenocarcinoma membranes. The effect of steroid hormones on SBP-receptor interaction was also evaluated. Both dihydrotestosterone and estradiol were shown to inhibit the binding of SBP to its specific receptor on neoplastic membranes. Testosterone at a dose of 10(-9) M was shown not to interfere to a significant extent with SBP-receptor binding. The sensitivity for estradiol we had previously observed in normal premenopausal endometrium was completely lost in postmenopausal neoplastic tissue. These observations suggest that the SBP-membrane recognition system is still present in neoplastic postmenopausal endometrium, but it has been modified either by the postmenopausal endogenous milieu or by the neoplastic transformation.

Sex steroid-binding protein interacts with a specific receptor on human premenopausal endometrium membrane: modulating effect of estradiol.

Sex steroid-binding protein receptor was detected on membranes prepared from human premenopausal endometrium. The binding of sex steroid-binding protein to membranes was specific, saturable, and high affinity. Scatchard analysis showed the presence of two binding sites at different affinities. The addition of estradiol (10(-8) M) did not produce any inhibition of binding; indeed, it resulted in a modification of binding characteristics. The demonstration of sex steroid-binding protein receptor on membranes of human premenopausal endometrium indicates that the expression of receptor on membranes is not an effect of estrogen over stimulation on target tissues. Estradiol could act as a modulating factor of the binding, probably reflecting the sensitivity of tissues to different steroids.

Sex steroid binding protein (SBP) receptors in estrogen sensitive tissues.

Since the discovery of a specific membrane binding site for sex steroid binding protein (SBP) in human decidual endometrium and in hyperplastic prostate numerous speculations have been raised on the existence of an additional non-receptor-mediated system for steroid hormone action. In the present work SBP cell membrane binding was investigated in human estrogen target tissues other than those previously studied either in the absence of steroids or in the presence of varying amounts (10(-10)-10(-6) M) of estradiol, testosterone and dihydrotestosterone, respectively. Plasma membranes obtained by differential centrifugation from homogenized samples of pre-menopausal endometrium, endometrium adenocarcinoma, normal liver and post-menopausal breast showed a specific binding of highly purified [125I]SBP: a major displacement of labeled SBP was elicited by radioinert SBP, while no significant displacement occurred when other human plasma proteins were used as cold competitors (molar excess ranging 500-10,000-fold). A specific, time-dependent binding of [125I]SBP was also observed in MCF-7 and in Hep-G2 cell lines. The different patterns of specific binding, observed in membranes from different tissues when SBP was liganded with different sex steroid molecules, leads us to consider the tissue individuality of the receptor as a further entity in the membrane recognition system for SBP.

The collection of human skulls and postcranial skeletons at the department of human anatomy of the University of Torino (Italy).

The human osteological collection at the Department of Human Anatomy, University of Torino, Italy, has recently been rearranged and recatalogued, and is now available for study. It comprises 1,064 modern skulls of known sex (384 males and 680 females); the age is also recorded in 712 cases. Of these skulls, 162 are from persons aged less than or equal to 20 years of known sex. A few skulls also have the postcranial skeleton (35 males and 39 females). The collection includes microcephali and hydrocephali, and also some prehistoric, Etruscan, Phoenician, Egyptian, Greek, Roman, Ancient Jewish, and Lombard skulls. A brief catalogue is provided.