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Dive into the research topics where Dharani Hapangama is active.

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Featured researches published by Dharani Hapangama.


Contraception | 2001

The effects of peri-ovulatory administration of levonorgestrel on the menstrual cycle.

Dharani Hapangama; Anna Glasier; D. T. Baird

Levonorgestrel (LNG) 0.75 mg administered 12 h apart within 72 h of unprotected coitus, is an established method of emergency contraception (EC). The mechanism of action of LNG used in this manner is unknown. We administered LNG 0.75 mg twice immediately before ovulation, to test the hypothesis that LNG acts as an emergency contraceptive by abolishing the pre-ovulatory lutenizing hormone (LH) surge and thereby delaying ovulation. Twelve women took LNG on or before the day of the first significant rise in urinary LH in 12 cycles. In four women, the LH peak and the onset of next menses were significantly delayed (delay of 16.8 days (SD +/- 8.7) from the day of mean LH peak in placebo cycles). One woman did not ovulate at all, despite a normal LH peak and cycle length. In the remaining eight women, LNG did not affect ovulation or the cycle length, but the length of the luteal phase and the total luteal phase LH concentrations were significantly reduced. We suggest that LNG acts as an emergency contraceptive by other mechanisms as well as delaying the LH surge and interfering with ovulation.


The Journal of Clinical Endocrinology and Metabolism | 2008

Effects of the selective progesterone receptor modulator asoprisnil on uterine artery blood flow, ovarian activity, and clinical symptoms in patients with uterine leiomyomata scheduled for hysterectomy

Julia Wilkens; Kristof Chwalisz; Cong Han; Jane Walker; Iain T. Cameron; Susan Ingamells; Alexandra C. Lawrence; Mary Ann Lumsden; Dharani Hapangama; Alistair Williams; Hilary O. D. Critchley

INTRODUCTION Asoprisnil, a novel orally active selective progesterone receptor modulator, is being studied for the management of symptomatic uterine leiomyomata. The exact mechanism of action is not yet discerned. The primary objectives of this double-blind, randomized, placebo-controlled study included evaluation of the effect of asoprisnil on uterine artery blood flow. Furthermore, we assessed effects of asoprisnil on leiomyoma symptoms. PATIENTS AND METHODS Thirty-three premenopausal patients scheduled for hysterectomy due to symptomatic uterine leiomyomata were recruited in four centers and treated with 10 or 25 mg asoprisnil or placebo for 12 wk before surgery. At baseline and before hysterectomy, all patients underwent sonographic assessment to measure impedance to uterine artery blood flow, determined by resistance index and pulsatility index, as well as volumes of largest leiomyoma and uterus. In addition, patients recorded intensity and frequency of menstrual bleeding on a menstrual pictogram. Each asoprisnil treatment was compared with placebo. RESULTS The increased pulsatility index in both asoprisnil groups and the statistically significantly increased resistance index within the 25-mg asoprisnil group suggest a moderately decreased uterine artery blood flow. Analysis of menstrual pictogram scores showed a statistically significant larger decrease in frequency and intensity of bleeding for both asoprisnil groups compared with placebo. Bleeding was suppressed by asoprisnil 25mg in 91% of patients. Asoprisnil treatment was well tolerated when administered daily for a 12-wk period, and no serious adverse events occurred. CONCLUSION Asoprisnil moderately reduced uterine artery blood flow. This effect may contribute in part to the clinical effects of asoprisnil.


International Journal of Reproductive Medicine | 2014

Theories on the Pathogenesis of Endometriosis

Samer Sourial; Nicola Tempest; Dharani Hapangama

Endometriosis is a common, chronic inflammatory disease defined by the presence of extrauterine endometrial tissue. The aetiology of endometriosis is complex and multifactorial, where several not fully confirmed theories describe its pathogenesis. This review examines existing theories on the initiation and propagation of different types of endometriotic lesions, as well as critically appraises the myriad of biologically relevant evidence that support or oppose each of the proposed theories. The current literature suggests that stem cells, dysfunctional immune response, genetic predisposition, and aberrant peritoneal environment may all be involved in the establishment and propagation of endometriotic lesions. An orchestrated scientific and clinical effort is needed to consider all factors involved in the pathogenesis of this multifaceted disease and to propose novel therapeutic targets to reach effective treatments for this distressing condition.


Human Reproduction | 2008

Endometriosis is associated with aberrant endometrial expression of telomerase and increased telomere length

Dharani Hapangama; Mark A. Turner; Josephine A. Drury; Siobhan Quenby; Gabriele Saretzki; Carmen Martin-Ruiz; T. von Zglinicki

BACKGROUND In order to test our hypothesis that endometriosis is associated with abnormal expression of telomerase and telomere lengthening in endometrium, we assessed endometrial expression of the human telomerase enzyme and telomere length (TL). METHODS This prospective pilot study, included 29 women with symptomatic, surgically diagnosed endometriosis (Group 1) and 27 healthy, fertile, symptom-free women without endometriosis (Group 2, confirmed by laparoscopy). Seventeen women in Group 1 and 15 women in Group 2 had endometrial biopsies taken on Day 21 +/- 2 of the cycle. A further 12 women in each group were biopsied on Day 26 +/- 2. Telomerase and estrogen receptor beta (ERbeta) expression was evaluated by immunohistochemistry. Mean TL was determined by quantitative PCR. RESULTS The endometria of fertile healthy women showed either weak or no telomerase immunoreactivity throughout the luteal phase. Immunostaining for telomerase was significantly increased during the implantation window and the premenstrual endometria of women with endometriosis (P < 0.0001). This was associated with a loss of stromal and vascular ERbeta immunostaining (P < 0.05). The mean TL were significantly longer in endometria of women with endometriosis during the implantation window (P = 0.005), indicating the biological relevance of our novel finding of telomerase in benign endometrium. There was positive correlation of the circulating estradiol with peripheral blood TL in women. CONCLUSIONS We speculate that aberrant endometrial expression of telomerase mediates alterations in cell fate that enhance proliferation, contributing to the pathogenesis of endometriosis.


British Journal of Obstetrics and Gynaecology | 2013

A re-evaluation of the role of rotational forceps: retrospective comparison of maternal and perinatal outcomes following different methods of birth for malposition in the second stage of labour.

Nicola Tempest; Anna Hart; Stephen Walkinshaw; Dharani Hapangama

To compare the outcomes of operative cephalic births by Kielland forceps (KF), rotational ventouse (RV), or primary emergency caesarean section (pEMCS) for malposition in the second stage of labour in modern practise.


Human Reproduction | 2013

SSEA-1 isolates human endometrial basal glandular epithelial cells: phenotypic and functional characterization and implications in the pathogenesis of endometriosis

A.J. Valentijn; K. Palial; H. Al-lamee; Nicola Tempest; Josephine A. Drury; T. von Zglinicki; Gabriele Saretzki; Patricia Murray; Caroline E. Gargett; Dharani Hapangama

STUDY QUESTION Can the basal epithelial compartment of the human endometrium be defined by specific markers? SUMMARY ANSWER Human endometrial epithelial cells from the basalis express nuclear SOX9 and the cell-surface marker SSEA-1, with some cells expressing nuclear β-catenin. In vitro, primary endometrial epithelial cells enriched for SSEA-1+ show some features expected of the basalis epithelium. WHAT IS KNOWN ALREADY The endometrial glands of the functionalis regenerate from the basalis gland stumps following menstruation. Endometriosis is thought to originate from abnormal dislocation of the basalis endometrium. In the highly regenerative intestinal epithelium, SOX9 and nuclear β-catenin are more highly expressed in the intestinal crypt, the stem/progenitor cell region. STUDY DESIGN, SIZE, DURATION A large prospective observational study analysing full-thickness human endometrial hysterectomy samples from 115 premenopausal women, 15 post-menopausal women and ectopic endometriotic lesions from 20 women with endometriosis. PARTICIPANTS/MATERIALS, SETTING, METHODS Full-thickness endometrium from hysterectomy tissues was analysed by immunohistochemistry for SSEA-1, SOX9 and β-catenin. Primary human endometrial epithelial cells from short-term cultures were sorted into SSEA1+/- fractions with a cell sorter or magnetic beads and analysed for markers of differentiation and pluripotency and telomere lengths (TLs) using qPCR, telomerase activity [telomere repeat amplification protocol (TRAP)] and growth in 3D culture. MAIN RESULTS AND THE ROLE OF CHANCE Similar to the intestinal crypt epithelium, human endometrial basal glandular epithelial cells expressed nuclear SOX9 and contained a rare subpopulation of cells with nuclear β-catenin suggestive of an activated Wnt pathway. The embryonic stem cell-surface marker, SSEA-1, also marked the human endometrial basal glandular epithelial cells, and isolated SSEA-1(+) epithelial cells grown in monolayer showed significantly higher expression of telomerase activity, longer mean TLs, lower expression of genes for steroid receptors and produced a significantly higher number of endometrial gland-like spheroids in 3D culture compared with SSEA-1(-) epithelial cells (P = 0.009). Cells in ectopic endometriosis lesions also expressed SSEA-1 and nuclear SOX9, suggesting that the basalis contributes to ectopic lesion formation in endometriosis following retrograde menstruation. LIMITATIONS, REASONS FOR CAUTION This is a descriptive study with only short-term culture of the primary human epithelial cells in vitro. WIDER IMPLICATIONS OF THE FINDINGS The surface marker SSEA1 enriches for an endometrial epithelial cell subpopulation from the basalis. Since the functional endometrium originates from these cells, it is now possible to study basalis epithelium for stem/progenitor cell activity to extend our current understanding of endometrial biology in health and diseases. STUDY FUNDING/COMPETING INTEREST(S) The work included in this manuscript was funded by Wellbeing of Women project grant RG1073 (D.K.H. and C.G.). We also acknowledge the support by National Health and Medical Research Council, RD Wright Career Development Award 465121 and Senior Research Fellowship 1042298, and the Victorian Governments Operation Infrastructure Support Program to C.G. and MRC G0601333 to T.V.Z. All authors have no conflict of interest to declare. TRIAL REGISTRATION NUMBER N/A.


Molecular Cancer | 2014

Molecular profiling of circulating tumor cells links plasticity to the metastatic process in endometrial cancer

Lorena Alonso-Alconada; Laura Muinelo-Romay; Kadri Madissoo; Antonio Díaz-López; Camilla Krakstad; Jone Trovik; Elisabeth Wik; Dharani Hapangama; Lieve Coenegrachts; Amparo Cano; Luis Chiva; Juan Cueva; María Vieito; Eugenia Ortega; Javier Mariscal; Eva Colas; Josep Castellví; Maite Cusido; Xavier Dolcet; Hans W. Nijman; Tjalling Bosse; John Green; Andrea Romano; Jaume Reventós; Rafael Lopez-Lopez; Helga B. Salvesen; Frédéric Amant; Xavier Matias-Guiu; Gema Moreno-Bueno; Miguel Abal

BackgroundAbout 20% of patients diagnosed with endometrial cancer (EC) are considered high-risk with unfavorable prognosis. In the framework of the European Network for Individualized Treatment in EC (ENITEC), we investigated the presence and phenotypic features of Circulating Tumor Cells (CTC) in high-risk EC patients.MethodsCTC isolation was carried out in peripheral blood samples from 34 patients, ranging from Grade 3 Stage IB to Stage IV carcinomas and recurrences, and 27 healthy controls using two methodologies. Samples were subjected to EpCAM-based immunoisolation using the CELLection™ Epithelial Enrich kit (Invitrogen, Dynal) followed by RTqPCR analysis. The phenotypic determinants of endometrial CTC in terms of pathogenesis, hormone receptor pathways, stem cell markers and epithelial to mesenchymal transition (EMT) drivers were asked. Kruskal-Wallis analysis followed by Dunn’s post-test was used for comparisons between groups. Statistical significance was set at p < 0.05.ResultsEpCAM-based immunoisolation positively detected CTC in high-risk endometrial cancer patients. CTC characterization indicated a remarkable plasticity phenotype defined by the expression of the EMT markers ETV5, NOTCH1, SNAI1, TGFB1, ZEB1 and ZEB2. In addition, the expression of ALDH and CD44 pointed to an association with stemness, while the expression of CTNNB1, STS, GDF15, RELA, RUNX1, BRAF and PIK3CA suggested potential therapeutic targets. We further recapitulated the EMT phenotype found in endometrial CTC through the up-regulation of ETV5 in an EC cell line, and validated in an animal model of systemic dissemination the propensity of these CTC in the accomplishment of metastasis.ConclusionsOur results associate the presence of CTC with high-risk EC. Gene-expression profiling characterized a CTC-plasticity phenotype with stemness and EMT features. We finally recapitulated this CTC-phenotype by over-expressing ETV5 in the EC cell line Hec1A and demonstrated an advantage in the promotion of metastasis in an in vivo mouse model of CTC dissemination and homing.


Human Reproduction | 2012

Aberrant expression of metastasis-inducing proteins in ectopic and matched eutopic endometrium of women with endometriosis: implications for the pathogenesis of endometriosis

Dharani Hapangama; R.S. Raju; A.J. Valentijn; Dong Liu Barraclough; Anna Hart; Mark A. Turner; Angela Platt-Higgins; Roger Barraclough; Philip S. Rudland

BACKGROUND Endometriosis is a metastatic disease without obvious tumorigenesis. Expression of S100P, S100A4, osteopontin (OPN) or anterior gradient homologue 2 (AGR2) proteins can induce metastasis but fail to induce tumorigenesis per se. We now explore whether this group of metastasis-inducing proteins (MIPs) are associated with the pathogenesis of endometriosis. METHODS Eutopic endometrial biopsies were taken from 73 women (35 fertile women without endometriosis and 38 women with surgically diagnosed endometriosis). Ectopic endometriotic lesions were collected from eight of the women with endometriosis. The expression of MIPs at the cellular level was evaluated by immunohistochemistry and the presence of these proteins in the endometrial tissues was verified by western blotting and their gene expression was confirmed by RT-PCR. RESULTS All four MIPs were immunolocated in the endometrium of control women and S100P, AGR2 and OPN showed a cyclical variation. Proliferative phase eutopic endometrium of both groups showed a similar staining pattern for all MIPs, whereas secretory phase endometrium showed a differential expression between controls and cases. The secretory phase endometrial immunostaining of controls showed weak stromal and perivascular AGR2, and decreased stromal and glandular S100P. In contrast, immunostaining for all MIPs was increased in the late secretory endometrial samples of women with endometriosis and intense immunostaining was seen for S100A4 in the stroma (P< 0.05) and for S100P (P< 0.001) and AGR2 (P< 0.0001) in both glands and stroma (P< 0.001). All active peritoneal endometriotic lesions showed strong immunostaining for each of the MIPs studied. CONCLUSIONS We propose that these MIPs enhance endometrial cell invasiveness and contribute to the establishment of ectopic endometriotic deposits after retrograde menstruation.


Human Reproduction | 2008

Sustained replication in endometrium of women with endometriosis occurs without evoking a DNA damage response

Dharani Hapangama; Mark A. Turner; Josephine A. Drury; Siobhan Quenby; Anna Hart; Mandy Maddick; Carmen Martin-Ruiz; T. von Zglinicki

BACKGROUND To test our hypothesis that eutopic secretory phase endometrium from women with endometriosis is similar to proliferative phase endometrium from fertile women without endometriosis, we explored the expression of regulators of cell fate across the menstrual cycle. METHODS Endometrial biopsies were taken from 73 women, comprising 38 women with surgically diagnosed active peritoneal endometriosis (Group 1) and 35 fertile women without endometriosis (Group 2). Nucleolin, proliferating cell nuclear antigen (PCNA), telomerase and histone gamma-H2AX expression was evaluated by immunohistochemistry and mean telomere length (TL) by quantitative PCR. RESULTS We have immunolocalized nucleolin and gamma-H2AX in the benign premenopausal endometrium for the first time. All markers were present in the proliferative phase endometrium of all women. In Group 2, during the secretory phase, proliferative markers declined with a paradoxical increase in stromal gamma-H2AX. Women in Group 1, however, showed a persistent immunoreactivity for the proliferative markers, while the staining for gamma-H2AX decreased in secretory endometrium (P < 0.05). This difference between groups was significant in both stroma and glands for nucleolin (P < 0.0001), PCNA (P < 0.01) and gamma-H2AX (P < 0.05) in the secretory phase. We showed a positive correlation between mean TL and nucleolin expression (glandular r = 0.37, P = 0.002; stromal r = 0.4, P = 0.001), telomerase immunoreactivity (glandular r = 0.33, P = 0.009; stromal r = 0.4, P = 0.001) and glandular PCNA (r = 0.35, P = 0.004), whereas a negative correlation was seen between mean TL and gamma-H2AX (r = -0.28, P = 0.04). CONCLUSIONS These findings demonstrate that the state of replication seen in secretory phase endometrium from women with active peritoneal endometriosis is not a simple extension of the proliferative phase.


Human Reproduction | 2010

Aberrant expression of regulators of cell-fate found in eutopic endometrium is found in matched ectopic endometrium among women and in a baboon model of endometriosis

Dharani Hapangama; Mark A. Turner; Josephine A. Drury; L. Heathcote; Y. Afshar; P.A. Mavrogianis; Asgerally T. Fazleabas

BACKGROUND We have recently shown that women with endometriosis express an increased amount of telomerase and nucleolin, with concomitant loss of γ-H2AX in eutopic endometrium. To further examine these selected factors that regulate cell fate, in the pathogenesis of endometriosis, we studied the expression of telomerase, nucleolin, proliferating cell nuclear antigen and γ-H2AX in ectopic endometriotic deposits from women, and in matched eutopic and ectopic endometrial tissue from a baboon model of endometriosis. METHODS Ectopic active peritoneal endometriotic lesions were collected from seven symptomatic women. Endometriosis was induced in six baboons by intra-peritoneal autologous inoculation of menstrual endometrium. Eutopic and matched ectopic endometrial tissues were collected prior to and 6, 12 and 15 months after the induction of endometriosis as previously described. Eutopic endometrium was also obtained from eight healthy fertile control baboons. Immunohistochemistry was performed as previously described, and telomerase activity was confirmed using the telomeric repeat amplification protocol assay. RESULTS All active human endometriotic lesions expressed the proliferative markers but showed weak or absent staining for γ-H2AX. A similar expression pattern of these markers was seen in the ectopic lesions of the baboons with induced disease. In these baboons, the eutopic endometrium also showed intense immunoreactivity for all proliferative markers 6-12 months after induction with a parallel loss of γ-H2AX. The opposite staining pattern was seen in eutopic endometrium of healthy animals and in pre-induction endometrium of animals with induced disease. CONCLUSIONS Endometriotic lesions have excess proliferative potential; in baboons, these were present within 12 months of the initiation of the disease. In eutopic tissue, these changes appear to be induced by the development of endometriosis.

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Areege Kamal

University of Liverpool

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D. T. Baird

University of Edinburgh

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