Comparison of Bayer Advia Centaur immunoassay results obtained on samples collected in four different Becton Dickinson Vacutainer tubes.

BACKGROUND: Medicines and Healthcare products Regulatory Agency's (MHRA's) Medical Device Alert MDA/2004/048 described bias in some endocrine test results obtained on a few immunoassay platforms, particularly the Bayer Advia Centaur instrument, when using blood specimens collected into Becton Dickinson (BD) Vacutainer SSTII Advance tubes. As users of BD tubes and the Advia Centaur instrument, we addressed our concerns about the quality of the results that we had previously reported by undertaking an independent study. METHOD: We compared the results of 15 immunoassays performed on Bayer Advia Centaur using blood specimens collected into four different BD Vacutainer tubes (plain, old and newly released BD SSTII Advance, and BD PSTII). RESULTS: Compared with plain tubes, old SSTII Advance tube results showed no bias for testosterone, CA15-3, follicle-stimulating hormone and folate assays, but gave a positive bias for cortisol and a negative bias for vitamin-B12. Compared with plain tubes, BD PSTII tubes gave no significant bias for thyroid function tests, prolactin, parathyroid hormone, and CA125, but gave a negative bias for steroid assays, and a positive bias for gonadotrophins. The results obtained using new BD SSTII Advance tubes were generally comparable with those on plain tubes. CONCLUSIONS: Only for cortisol did our findings support the bias described by MHRA. Based on our results, apart from vitamin-B12 and possibly cortisol, there may have been no significant influence on clinical decisions as a result of using the old BD SSTII Advance specimen tubes. New BD SSTII Advance tubes and plain tubes give generally comparable results. BD PSTII tubes should not be used for steroid hormone measurements on the Bayer Advia Centaur instrument.

Adrenomedullin and tumour angiogenesis.

The angiogenic activity of peptide adrenomedullin (AM) was first shown in 1998 . Since then, a number of reports have confirmed the ability of AM to induce the growth and migration of isolated vascular endothelial and smooth muscle cells in vitro and to promote angiogenesis in xenografted tumours in vivo. In addition, knockout murine models point to an essential role for AM in embryonic vasculogenesis and ischaemic revascularisation. AM expression is upregulated by hypoxia (a typical feature of solid tumours) and a potential role as a regulator of carcinogenesis and tumour progression has been proposed based on studies in vitro and in animal models. Nevertheless, translational research on AM, and in particular, confirmation of its importance in the vascularisation of human tumours has lagged behind. In this commentary, we review current progress and potential directions for future research into the role of AM in tumour angiogenesis.

Levonorgestrel intrauterine system (LNG-IUS) with conjugated oral equine estrogen: a successful regimen for HRT in perimenopausal women.

BACKGROUND: This study was designed to assess the long-term efficacy (5 years) of the levonorgestrel-releasing intrauterine system (LNG-IUS) in protecting the endometrium from hyperplasia during estrogen replacement therapy in perimenopausal women. METHODS: Prospective, open, outpatient clinical trial in London and Oxford. Eighty-two women received oral conjugated equine estrogen 1.25 mg daily and LNG-IUS releasing 20 mug levonorgestrel per 24 h. Endometrial biopsy and histological assessment were performed annually. Endometrial thickness was measured by vaginal ultrasonography. RESULTS: Non-proliferative endometrium was present at the end of cycles 12, 24, 36, 48 and 60 in 98.6, 98.6, 95.5, 96.8 and 95.2% of the participants respectively. No endometrial hyperplasias were confirmed throughout a period of 60 cycles. The proportion of amenorrhoeic women increased from 54.4% at 12 cycles to 92.7% at the end of the study. The continuation rate per 100 women at 60 cycles was 79.84 (95% CI 71.0-88.6). CONCLUSIONS: The LNG-IUS with estrogen supplementation in perimenopausal women suppresses endometrial proliferation resulting in amenorrhoea and relieves vasomotor symptoms. The treatment regimen is well tolerated and provides an alternative strategy for perimenopausal women with the likelihood of increasing compliance.

Endometrial safety and tolerability of triphasic sequential hormone replacement estradiol valerate/medroxyprogesterone acetate therapy regimen.

OBJECTIVE: Two randomized comparative multicenter studies were conducted to establish the endometrial safety and tolerability of a triphasic sequential hormone replacement estradiol valerate/medroxyprogesterone acetate (E2V/MPA) therapy regimen. METHODS: Study 1 was a randomized, double-blind, clinical phase III study in 399 postmenopausal women, following parallel-group design with two groups. The duration of study treatment was 12 or 13 cycles of 28 days. A double-dummy technique was used to ensure blinding in the study. The investigational drugs were E2V/MPA triphasic and E2V/MPA biphasic (Diviseq and Divina, respectively; Orion Pharma). In study 2, a total of 341 subjects were randomly allocated by computer into two parallel groups receiving either E2V/MPA or estradiol/norethisterone acetate triphasic (E2/NETA, Trisequens; Novo Nordisk A/S) for 12-13 cycles. The study was an open, clinical phase III trial with a randomized, parallel-group design. Endometrial biopsies combined with transvaginal ultrasound were undertaken before and at the end of treatment during the progestogen phase. Bleeding patterns and symptom control were assessed throughout both studies. RESULTS: E2V/MPA triphasic was found to have similar endometrial effects and bleeding patterns to those with E2V/MPA biphasic and E2/NETA triphasic. Climacteric symptoms were relieved as quickly and effectively as with the two comparator treatments. No adverse drug reactions specific to E2V/MPA triphasic were observed. At the end of the study, the proportions of secretory samples were 67.1% for the combined E2V/MPA triphasic groups, 65.6% for the E2V/MPA biphasic group and 71.6% for the E2/NETA triphasic group. One case of hyperplasia occurred in the E2V/MPA triphasic group. Thus the incidence of hyperplasia for the combined groups was 0.33%. CONCLUSIONS: The triphasic E2V/MPA regimen was well tolerated and produced endometrial effects similar to those of the two comparators. Extending estrogen during the so-called treatment-free week with a lower dose of estradiol was effective in controlling vasomotor symptoms.

Tissue and plasma expression of the angiogenic peptide adrenomedullin in breast cancer.

Adrenomedullin (ADM) is an angiogenic factor that has also been shown to be a mitogen and a hypoxia survival factor for tumour cells. These properties point to ADM as a potential promoter of human malignancies, but little data are available concerning the expression of ADM in human breast cancer. In the present work, we have examined ADM peptide expression in a series of malignant breast tumours by immunohistochemistry using a newly developed anti-ADM monoclonal antibody. In addition, ADM plasma concentrations in breast cancer patients and healthy controls were determined by radioimmunoassay. Of the examined breast cancer samples, 27/33 (82%) showed a moderate to strong staining intensity. ADM-peptide expression in breast tumours was significantly correlated with axillary lymph node metastasis (P=0.030). Analysis of ADM plasma concentrations showed no significant difference between the circulating ADM levels of breast cancer patients and healthy controls. However, a significant positive correlation was found between tumour size and plasma ADM levels (r=0.641, P=0.017). Moreover, ADM levels in breast cancer patients correlated with the presence of lymph node metastasis (P=0.002). In conclusion, we have shown for the first time that ADM peptide is widely expressed in breast cancer and that the degree of expression is associated with lymph node metastasis. ADM peptide in plasma of breast cancer patients reflects the size of the primary tumour, but is unlikely to be a useful tumour marker for the detection of breast cancer. Plasma ADM might represent an independent predictor of lymph node metastasis. The clinical implications of these findings remain to be evaluated.

Menorrhagia: an update.

Menorrhagia is defined as a 'complaint of heavy cyclical menstrual bleeding occurring over several consecutive cycles'. Objectively it is a total menstrual blood loss equal to or greater than 80 ml per menstruation. It is estimated that approximately 30% of women complain of menorrhagia. Excessive bleeding is the main presenting complaint in women referred to gynecologists and it accounts for two-thirds of all hysterectomies, and most of endoscopic endometrial destructive surgery. Thus, menorrhagia is an important healthcare problem. Its etiology, investigation, medical and surgical management are described. In approximately 50% of cases of menorrhagia no pathology is found at hysterectomy. Abnormal levels of prostaglandins or the fibrinolytic system in the endometrium have been implicated. Effective medical treatments suitable for long-term use include intrauterine progestogens, antifibrinolytic agents (tranexamic acid) and nonsteroidal anti-inflammatory agents (mefenamic acid). Over the past decade there has been increasing use of endometrial destructive techniques as an alternative to hysterectomy. Their further refinement and the advent of fibroid embolization has increased the options available to women.

Wnt-7a is upregulated by norethisterone in human endometrial epithelial cells: a possible mechanism by which progestogens reduce the risk of estrogen-induced endometrial neoplasia.

Progestogens are added to oestrogen in hormone replacement therapy regimens to reduce the risk of endometrial cancer. We have performed in vitro studies analysing gene expression of isolated normal endometrial epithelia cells (NEE) treated with estradiol and the progestogen norethisterone acetate (NETA). We report here for the first time upregulation of the Wnt-7a gene by NETA in estrogen treated NEE. Wnt genes are a large family of developmental genes associated with cellular responses such as oncogenesis. We therefore suggest that upregulation of Wnt-7a may be associated with the antineoplastic effects of progestogens on the endometrium.

Tamoxifen induction of angiogenic factor expression in endometrium.

Tamoxifen is the current therapy of choice for patients with oestrogen receptor positive breast cancer, and it is currently under evaluation as a prophylactic for women at high risk of developing the disease. However, tamoxifen is also known to induce proliferative changes in the endometrium increasing the risk of developing endometrial hyperplasia, polyps and carcinoma. Angiogenesis is an intimate part of this process. For this reason, we have examined the expression of several well characterized angiogenic factors, namely, acidic and basic fibroblast growth factor, thymidine phosphorylase, vascular endothelial growth factor and adrenomedullin in both normal and tamoxifen exposed pre- and postmenopausal endometrium. Vascular density and endothelial proliferation index were also quantified. We found increased expression of acidic and basic fibroblast growth factor and adrenomedullin after treatment with tamoxifen mainly in premenopausal tissue. Vascular density was significantly increased in pre- but not post-menopausal endometrium (P=0.0018) following tamoxifen treatment. These results support the notion that angiogenesis is integral to the response to tamoxifen exposure, and is a potential target with which to block these side effects of tamoxifen.

Protease activated receptor-1 is down regulated by levonorgestrel in endometrial stromal cells.

Progestogens are used clinically for contraception, to control excessive menstrual bleeding and to oppose oestrogen in hormone replacement therapy. The use of intrauterine levonorgestrel (LNG) is however, associated with endometrial atrophy and decidualisation of the stroma. In this study, we aimed to identify genes whose expression is modulated by LNG either alone or in combination with progesterone. Thus endometrial stromal cells were stimulated with progesterone, LNG or LNG and progesterone. Poly-A RNA was isolated and used to probe expression arrays. The expression of a number of genes was altered on exposure to LNG or LNG and progesterone. Alteration of expression patterns was confirmed using semi-quantitative RT-PCR and western blot analysis. In particular, the protease activated receptor-1 (PAR-1) gene that encodes a receptor for thrombin was down regulated. This is the first demonstration that PAR-1 is down regulated by the progestogen LNG in human endometrium. Alteration in the expression levels of this receptor may affect both growth and haemostatic activity within the endometrium and may account for the observed morphological effects seen in users of intrauterine LNG delivery devices.

Differential and cell-specific expression of calcitonin receptor-like receptor and receptor activity modifying proteins in the human uterus.

The calcitonin receptor-like receptor (CRLR) can function as a receptor for either calcitonin gene-related peptide (CGRP) or adrenomedullin (AM), depending upon co-expression with members of a novel family of receptor activity-modifying proteins (RAMP). RAMP1 presents the CRLR at the cell surface as a CGRP/AM receptor. RAMP2- and RAMP3-transported CRLR receptors act as AM-specific receptors. However, it is still unknown if this signalling system operates in vivo. Of particular interest is the uterus, where both peptides and their binding sites are known to be present and where both mitogenic and vasodilatory responses to AM and CGRP have been demonstrated. In this study, we examined whether CRLR and RAMP are co-expressed in the same populations of cells in human uterine tissue. Analysis by in-situ hybridization and immunocytochemistry revealed a heterogeneous and cell type-specific distribution of components of this AM/CGRP signalling system. Adrenomedullin mRNA was expressed and evenly distributed across all cell types. CRLR mRNA was predominantly found in blood vessels. RAMP1 expression was specific to myometrial myocytes and vascular smooth muscle cells in uterine arteries. RAMP2 and RAMP3 mRNA were not detectable by in-situ hybridization. The pattern of differential and cell-specific expression of CRLR and RAMP suggests the involvement of CRLR/RAMP1 in the processes of vasodilation, smooth muscle relaxation and angiogenesis in response to AM and CGRP in the human uterus, but also indicates that other receptors may be implicated.

Adrenomedullin inhibits hypoxic cell death by upregulation of Bcl-2 in endometrial cancer cells: a possible promotion mechanism for tumour growth.

Regions of hypoxia are a common feature of solid tumours. When tumour cells are exposed to hypoxic stress, transcription of a battery of genes is initiated. The angiogenic factor adrenomedullin (ADM) is a hypoxia regulated gene. ADM is thought to act through the G protein-coupled receptor calcitonin receptor-like receptor (CRLR), with specificity being conferred by the receptor associated modifying protein 2 (RAMP2). Here we report for the first time that ADM treated or stably transfected Ishikawa cells overexpressing ADM show increased resistance to hypoxia induced apoptosis. These cells also show an upregulation of the oncoprotein Bcl-2, which is protective against hypoxic cell death when transiently transfected into Ishikawa cells. Since Ishikawa cells express the putative ADM-receptor CRLR-RAMP2 the production and secretion of ADM with the consecutive upregulation of Bcl-2 could establish an autocrine/paracrine mechanism rescuing malignant cells from hypoxic cell death. These results, taken together with our previous findings that ADM is an angiogenic factor which is upregulated by the nonsteroidal antiestrogen tamoxifen (TAM) in endometrial cells, implicate this peptide as a promoter of tumour growth and a possible target for anticancer strategies.

Adrenomedullin is an autocrine regulator of endothelial growth in human endometrium.

Human endometrium is a mucosa served by a microvascular blood supply that involves benign angiogenesis under the control of ovarian steroids throughout reproductive life. Adrenomedullin is a multifunctional 52-amino acid peptide involved in numerous physiological and pathological processes, including angiogenesis, growth regulation, differentiation, vasodilation and smooth muscle relaxation. We have previously shown that adrenomedullin is present in the human uterus. To investigate further the role of adrenomedullin in human endometrial angiogenesis, a method for the isolation and culture of non-pregnant endometrial endothelium was developed. Enzymatic dispersion and 'Percoll' gradient centrifugation, followed by positive selection using Ulex europaeus agglutinin-coated immunomagnetic beads, yielded pure isolates of endothelium. The cells formed a typical 'cobblestone' monolayer within 5-7 days and expressed the classic endothelial markers, CD31 and von Willebrand factor. The presence of adrenomedullin immunoreactivity in endometrial endothelial cells was shown by immunohistochemistry both in vitro and in vivo. Adrenomedullin promotes growth of endothelial cells as measured by [methyl-(3)H] thymidine uptake. Adrenomedullin also induced cyclic AMP in endometrial endothelial cells. These results demonstrate, for the first time, that adrenomedullin is an autocrine growth factor for human endometrial endothelial cells and is thus involved in endometrial angiogenesis.

Expression of the hypoxically regulated angiogenic factor adrenomedullin correlates with uterine leiomyoma vascular density.

Uterine leiomyomas are the most prevalent benign tumor type in women of reproductive age and are one of the most common indications for hysterectomy. The expression of five angiogenic factors, adrenomedullin (ADM), vascular endothelial growth factor (VEGF), acidic fibroblast growth factor, basic fibroblast growth factor, and platelet-derived endothelial cell growth factor/thymidine phosphorylase, were examined in 91 uteri collected throughout the menstrual cycle; 52 of which contained leiomyomata, and the remainder were normal controls. The microvascular density and endothelial proliferative indices were then determined for each of the uterine sections. ADM and VEGF were the most widely expressed angiogenic factors in the leiomyomas. Furthermore, the expression of ADM and VEGF in the endometrium and myometrium was up-regulated in leiomyoma-bearing uteri compared with controls. Although acidic fibroblast growth factor and basic fibroblast growth factor were expressed in leiomyomas and endometrium in all of the uterine samples examined, they were only expressed in the myometrium of leiomyomata-bearing uteri. Endothelial proliferation in leiomyomas was statistically greater than that of the myometrium and endometrium, both within and between uteri (P < 0.05). The vascular density in the myometrium but not the endometrium was significantly increased in leiomyoma-containing uteri (P < 0.05). Expression of ADM alone correlated directly with vascular density and endothelial cell proliferation index in leiomyomas and myometrium and may account for the high vascularity found in leiomyomas and the myometrium of leiomyoma-bearing uteri. As such, ADM is identified as a novel target for antiangiogenic therapy of these benign, clinically problematic uterine tumors.

Oestrogen and progestogen hormone replacement therapy for peri-menopausal and post-menopausal women: weight and body fat distribution.

BACKGROUND: Hormone replacement therapy (HRT) is commonly prescribed to treat menopausal symptoms and to prevent post-menopausal bone loss. However, many women are concerned about hormonal replacement therapy because they believe that such treatment will result in weight gain. The effect of HRT on weight and body fat distribution has not yet been examined in systematic reviews. It is an important topic since many women decline oestrogen therapy due to their concerns about resultant weight gain, and thus forego its potential therapeutic benefits. OBJECTIVES: To evaluate the effect of unopposed oestrogen or combined oestrogen and progestogen hormone replacement therapy (HRT) upon the weight and body fat distribution of perimenopausal and postmenopausal women. SEARCH STRATEGY: The search strategy of the Menstrual Disorders and Subfertility Group was used for the identification of randomised controlled trials (RCTs). Computerised searches of MEDLINE, EMBASE, Current Contents, Biological Abstracts and CINAHL were performed. Attempts were made to identify trials from citation lists of review articles and relevant papers already obtained. In most cases, first authors of each eligible trial were contacted for additional information. All those trials that had been located as at August 1998 were examined for eligibility. SELECTION CRITERIA: All randomised, placebo or no treatment controlled trials that detailed the effect of HRT on weight or body fat distribution, including studies where HRT was combined with other therapy such as diet, supplements or exercise. Studies were eligible for consideration even though the main focus of the trial may have been on another aspect of HRT. Previous HRT use should have ceased at least one month (in the case of patches, cream or gel) or three months (for oral preparations or subcutaneous pellets) before commencement of the study. DATA COLLECTION AND ANALYSIS: Twenty two RCTs were identified that fulfilled the inclusion criteria for this review. The results of one trial were not available in a form that allowed it to be included in the meta-analysis; however, it has been included in the text of the review for discussion. Twenty four RCTs are awaiting assessment pending additional information from first authors. Two reviewers extracted the data independently, and the weighted mean differences for continuous outcomes were estimated from the data. Results for unopposed oestrogen and combined oestrogen were analysed separately, and the effect of each treatment regimen on body weight, BMI, waist-hip ratio, fat mass and skinfold measurement was examined where available. The effect of differing dosage levels on these parameters was also examined. MAIN RESULTS: Outcomes were evaluated separately for unopposed oestrogen and oestrogen/progestogen regimens. Statistical analysis was performed using the weighted mean difference for continuous outcomes as recommended by the Cochrane Menstrual Disorders and Subfertility Group. No statistically significant difference was found in mean weight gain between those using unopposed oestrogen and non-HRT users (0.66 kg, 95% CI -0.62, 1.93). No significant difference was found in mean weight gain between those using oestrogen/progestogen therapy and non-HRT users (-0.47 kg, 95% CI -1.63, 0.69). Insufficient data exist to enable meta-analysis of the effect of unopposed oestrogen on BMI. The reviewers found no statistically significant difference in mean BMI increase between those using oestrogen/progestogen and non-HRT users (-0.50, 95% CI -1.06, 0.06). Insufficient data exist to enable meta-analysis of the effect of HRT on waist-hip ratio, fat mass or skinfold thickness. REVIEWER'S CONCLUSIONS: There is evidence of no effect of unopposed oestrogen or combined oestrogen on body weight, indicating that these regimens do not cause extra weight gain in addition to that normally gained at menopause. (ABSTRACT TRUNCATED)

Steroids and the endometrium.

Steroids are commonly employed in current clinical practice. The benefits of steroids in hormone replacement therapy, contraception and prevention or treatment of breast cancer are limited by their side effects arising from disorders in endometrial function. These side effects are complex and enclose bleeding problems and endometrial proliferation during hormone replacement therapy and antioestrogen treatment or menstrual disturbances during oral contraception. Numerous reports have identified gene targets influenced by steroids and have implicated these products as contributors to endometrial physiology or pathology. The expression of estrogen and progesterone receptors is regulated by steroids. The new estrogen receptor (ER) subtype ERbeta with different functional characteristics from ERalpha was recently described in endometrium. In addition, there is now increasing evidence that the functionally distinct progesterone receptor (PR) isoforms A and B are differentially expressed in this tissue. The relative proportions of these steroid receptors and their interaction determine the expression of specific genes upon steroidal stimulation. Steroids induce endometrial expression of various growth and angiogenic factors. Dysregulations of this steroid modulated expression is believed to be involved in the pathogenesis of many endometrial diseases. Irregular bleeding induced by steroidal contraception, for example, is thought to involve aberrant endometrial vascular development and expression of angiogenic growth factors. The antioestrogen tamoxifen induces growth factors like vascular endothelial growth factor and adrenomedullin which may be key mediators of endometrial neoplastic effects. This review describes recent advances regarding the mechanism of action of steroids on endometrium. The expression of oestrogen and progesterone receptors as well as steroid hormone dependent growth factors and angiogenic modulators are going to be discussed.

Validation of anti-vascular endothelial growth factor (anti-VEGF) antibodies for immunohistochemical localization of VEGF in tissue sections: expression of VEGF in the human endometrium.

Transient transfection of COS-1 cells followed by fixation, embedding in paraffin, and immunohistochemistry has identified anti-vascular endothelial growth factor (anti-VEGF) mouse monoclonal antibodies that efficiently immunostain VEGF in paraffin-embedded tissue sections. Immunohistochemical localization of VEGF in 34 specimens of normal human endometrium that had been collected at different stages of the menstrual cycle was then performed. VEGF was present at all stages of the cycle, but both the pattern and the intensity of staining varied. Thus, VEGF expression occurred predominantly in the endometrial epithelium and while weak in the proliferative phase, was strong in the secretory phase. VEGF expression in the stroma was weaker than in the proliferative phase glands and did not change throughout the cycle. These findings are in agreement with reports of VEGF mRNA expression in the endometrium, but disagree with previous immunohistochemical studies that employed an immunohistochemically unvalidated antiserum. This study has shown that the commercially available anti-VEGF monoclonal antibody M293 is excellent for the immunohistochemical localization of VEGF in paraffin sections.

PCR display identifies tamoxifen induction of the novel angiogenic factor adrenomedullin by a non estrogenic mechanism in the human endometrium.

Tamoxifen is currently the most widely used drug for the treatment of breast cancer, but there now exists considerable evidence that tamoxifen can also induce endometrial hyperplasia in pre menopausal women. We have used PCR differential display on primary human endometrial isolates in an attempt to identify genes induced by tamoxifen but not estrogen. Eight such differentially expressed bands were cloned and sequenced, one of which was found to be the peptide adrenomedullin. We have shown that adrenomedullin is a novel growth factor for endothelial cells and is angiogenic in vivo in the chick chorioallantoic membrane assay. Immunohistochemical analysis of endometrial sections have shown that while macrophages in the endometrium express adrenomedullin at a low level, endometrial macrophages of women receiving tamoxifen strongly express adrenomedullin (P=0.008). We postulate that endometrial induction of the angiogenic factor adrenomedullin by tamoxifen is part of the mechanism by which tamoxifen results in endometrial hyperplasia.

Angiogenesis in the endometrium.

Human endometrial vasculature has the unique property of undergoing benign angiogenesis during each menstrual cycle under the influence of the ovarian steroids estradiol and progesterone. However, neither has intrinsic angiogenic activity and endometrial angiogenesis involves stimulation by ovarian steroids of angiogenic factor release by the epithelium and stroma which then act on the endothelium. In vitro models using cultures of isolated endometrial epithelium, stroma and endothelium now allow mechanistic questions to be addressed. Vascular endothelial growth factor and platelet-derived endothelial cell growth factor/thymidine phosphorylase at present appear to be key players in endometrial angiogenesis.

Regulation of the expression of the angiogenic enzyme platelet-derived endothelial cell growth factor/thymidine phosphorylase in endometrial isolates by ovarian steroids and cytokines.

The angiogenic enzyme platelet-derived endothelial cell growth factor/thymidine phosphorylase (PD-ECGF/TP) was strongly expressed in the endometrial glands in the luteal and menstrual, but not the proliferative, phases of the cycle. The converse was seen in the stroma, where expression was strong in the proliferative, but not the luteal or menstrual, phases. Inflammatory cytokines induced PD-ECGF/TP expression in primary cultures of human normal endometrial epithelial (NEE) and normal endometrial stromal cells. The profile of cytokine induction of PD-ECGF/TP was cell dependent. Thus, in NEE cells, PD-ECGF/TP expression was strongly induced by the combination tumor necrosis factor-a and interferon-gamma. In contrast, in normal endometrial stromal cells, interferon-gamma gave, by far, the strongest induction of PD-ECGF/TP. Expression of the enzyme was not regulated by ovarian hormones alone. Although treatment of NEE cells with a physiological concentration of progesterone (5 X 10[-8] M) or transforming growth factor-beta1 (10 ng/ml) alone had no effect on PD-ECGF/TP expression, when delivered together at the same dose they induced a 48-fold increase in expression. This expression correlates with cyclic changes in progesterone and transforming growth factor-beta1 levels in the uterus.