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Dive into the research topics where Nazar Najib Amso is active.

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Featured researches published by Nazar Najib Amso.


The Lancet | 2016

Ovarian cancer screening and mortality in the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS): a randomised controlled trial

Ian Jacobs; Usha Menon; Andy Ryan; Aleksandra Gentry-Maharaj; Matthew Burnell; Jatinderpal Kalsi; Nazar Najib Amso; Sophia Apostolidou; Elizabeth Benjamin; Derek Cruickshank; Danielle N Crump; Susan K Davies; Anne Dawnay; Stephen Dobbs; Gwendolen Fletcher; Jeremy Ford; Keith M. Godfrey; Richard Gunu; Mariam Habib; Rachel Hallett; Jonathan Herod; Howard Jenkins; Chloe Karpinskyj; Simon Leeson; Sara Lewis; William R Liston; Alberto Lopes; Tim Mould; John Murdoch; David H. Oram

Summary Background Ovarian cancer has a poor prognosis, with just 40% of patients surviving 5 years. We designed this trial to establish the effect of early detection by screening on ovarian cancer mortality. Methods In this randomised controlled trial, we recruited postmenopausal women aged 50–74 years from 13 centres in National Health Service Trusts in England, Wales, and Northern Ireland. Exclusion criteria were previous bilateral oophorectomy or ovarian malignancy, increased risk of familial ovarian cancer, and active non-ovarian malignancy. The trial management system confirmed eligibility and randomly allocated participants in blocks of 32 using computer-generated random numbers to annual multimodal screening (MMS) with serum CA125 interpreted with use of the risk of ovarian cancer algorithm, annual transvaginal ultrasound screening (USS), or no screening, in a 1:1:2 ratio. The primary outcome was death due to ovarian cancer by Dec 31, 2014, comparing MMS and USS separately with no screening, ascertained by an outcomes committee masked to randomisation group. All analyses were by modified intention to screen, excluding the small number of women we discovered after randomisation to have a bilateral oophorectomy, have ovarian cancer, or had exited the registry before recruitment. Investigators and participants were aware of screening type. This trial is registered with ClinicalTrials.gov, number NCT00058032. Findings Between June 1, 2001, and Oct 21, 2005, we randomly allocated 202 638 women: 50 640 (25·0%) to MMS, 50 639 (25·0%) to USS, and 101 359 (50·0%) to no screening. 202 546 (>99·9%) women were eligible for analysis: 50 624 (>99·9%) women in the MMS group, 50 623 (>99·9%) in the USS group, and 101 299 (>99·9%) in the no screening group. Screening ended on Dec 31, 2011, and included 345 570 MMS and 327 775 USS annual screening episodes. At a median follow-up of 11·1 years (IQR 10·0–12·0), we diagnosed ovarian cancer in 1282 (0·6%) women: 338 (0·7%) in the MMS group, 314 (0·6%) in the USS group, and 630 (0·6%) in the no screening group. Of these women, 148 (0·29%) women in the MMS group, 154 (0·30%) in the USS group, and 347 (0·34%) in the no screening group had died of ovarian cancer. The primary analysis using a Cox proportional hazards model gave a mortality reduction over years 0–14 of 15% (95% CI −3 to 30; p=0·10) with MMS and 11% (−7 to 27; p=0·21) with USS. The Royston-Parmar flexible parametric model showed that in the MMS group, this mortality effect was made up of 8% (−20 to 31) in years 0–7 and 23% (1–46) in years 7–14, and in the USS group, of 2% (−27 to 26) in years 0–7 and 21% (−2 to 42) in years 7–14. A prespecified analysis of death from ovarian cancer of MMS versus no screening with exclusion of prevalent cases showed significantly different death rates (p=0·021), with an overall average mortality reduction of 20% (−2 to 40) and a reduction of 8% (−27 to 43) in years 0–7 and 28% (−3 to 49) in years 7–14 in favour of MMS. Interpretation Although the mortality reduction was not significant in the primary analysis, we noted a significant mortality reduction with MMS when prevalent cases were excluded. We noted encouraging evidence of a mortality reduction in years 7–14, but further follow-up is needed before firm conclusions can be reached on the efficacy and cost-effectiveness of ovarian cancer screening. Funding Medical Research Council, Cancer Research UK, Department of Health, The Eve Appeal.


British Journal of Obstetrics and Gynaecology | 1998

Uterine thermal balloon therapy for the treatment of menorrhagia: the first 300 patients from a multi-centre study

Nazar Najib Amso; Seth A. Stabinsky; P. McFaul; Bernard Blanc; Laura Pendley; Robert S. Neuwirth

Objective To evaluate the safety and efficacy of thermal balloon therapy for menorrhagia.


Lancet Oncology | 2011

Sensitivity of transvaginal ultrasound screening for endometrial cancer in postmenopausal women: a case-control study within the UKCTOCS cohort

Ian Jacobs; Aleksandra Gentry-Maharaj; Matthew Burnell; Ranjit Manchanda; Naveena Singh; Aarti Sharma; Andrew M. Ryan; Mourad W. Seif; Nazar Najib Amso; Gillian Turner; Carol Brunell; Gwendolen Fletcher; Rani Rangar; Kathy Ford; Keith M. Godfrey; Alberto Lopes; David H. Oram; Jonathan Herod; Karin Williamson; Ian A. Scott; Howard Jenkins; Tim Mould; Robert Woolas; John Murdoch; Stephen Dobbs; Simon Leeson; Derek Cruickshank; Steven J. Skates; Lesley Fallowfield; Mahesh Parmar

BACKGROUND The increase in the worldwide incidence of endometrial cancer relates to rising obesity, falling fertility, and the ageing of the population. Transvaginal ultrasound (TVS) is a possible screening test, but there have been no large-scale studies. We report the performance of TVS screening in a large cohort. METHODS We did a nested case-control study of postmenopausal women who underwent TVS in the United Kingdom Collaborative Trial of Ovarian Cancer Screening (UKCTOCS) following recruitment between April 17, 2001, and Sept 29, 2005. Endometrial thickness and endometrial abnormalities were recorded, and follow-up, through national registries and a postal questionnaire, documented the diagnosis of endometrial cancer. Our primary outcome measure was endometrial cancer and atypical endometrial hyperplasia (AEH). Performance characteristics of endometrial thickness and abnormalities for detection of endometrial cancer within 1 year of TVS were calculated. Epidemiological variables were used to develop a logistic regression model and assess a screening strategy for women at higher risk. Our study is registered with ClinicalTrials.gov, number NCT00058032, and with the International Standard Randomised Controlled Trial register, number ISRCTN22488978. FINDINGS 48,230 women underwent TVS in the UKCTOCS prevalence screen. 9078 women were ineligible because they had undergone a hysterectomy and 2271 because their endometrial thickness had not been recorded; however, 157 of these women had an endometrial abnormality on TVS and were included in the analysis. Median follow-up was 5·11 years (IQR 4·05-5·95). 136 women with endometrial cancer or AEH within 1 year of TVS were included in our primary analysis. The optimum endometrial thickness cutoff for endometrial cancer or AEH was 5·15 mm, with sensitivity of 80·5% (95% CI 72·7-86·8) and specificity of 86·2% (85·8-86·6). Sensitivity and specificity at a 5 mm or greater cutoff were 80·5% (72·7-86·8) and 85·7% (85·4-86·2); for women with a 5 mm or greater cutoff plus endometrial abnormalities, the sensitivity and specificity were 85·3% (78·2-90·8) and 80·4% (80·0-80·8), respectively. For a cutoff of 10 mm or greater, sensitivity and specificity were 54·1% (45·3-62·8) and 97·2% (97·0-97·4). When our analysis was restricted to the 96 women with endometrial cancer or AEH who reported no symptoms of postmenopausal bleeding at the UKCTOCS scan before diagnosis and had an endometrial thickness measurement available, a cutoff of 5 mm achieved a sensitivity of 77·1% (67·8-84·3) and specificity of 85·8% (85·7-85·9). The logistic regression model identified 25% of the population as at high risk and 39·5% of endometrial cancer or AEH cases were identified within this high risk group. In this high-risk population, a cutoff at 6·75 mm achieved sensitivity of 84·3% (71·4-93·0) and specificity of 89·9% (89·3-90·5). INTERPRETATION Our findings show that TVS screening for endometrial cancer has good sensitivity in postmenopausal women. The burden of diagnostic procedures and false-positive results can be reduced by limiting screening to a higher-risk group. The role of population screening for endometrial cancer remains uncertain, but our findings are of immediate value in the management of increased endometrial thickness in postmenopausal women undergoing pelvic scans for reasons other than vaginal bleeding.


Journal of Clinical Oncology | 2015

Risk Algorithm Using Serial Biomarker Measurements Doubles the Number of Screen-Detected Cancers Compared With a Single-Threshold Rule in the United Kingdom Collaborative Trial of Ovarian Cancer Screening

Usha Menon; Andrew M. Ryan; Jatinderpal Kalsi; Aleksandra Gentry-Maharaj; Anne Dawnay; Mariam Habib; Sophia Apostolidou; Naveena Singh; Elizabeth Benjamin; Matthew Burnell; Susan Davies; Aarti Sharma; Richard Gunu; Keith M. Godfrey; Alberto Lopes; David Oram; Jonathan Herod; Karin Williamson; Mourad W. Seif; Howard Jenkins; Tim Mould; Robert Woolas; John Murdoch; Stephen Dobbs; Nazar Najib Amso; Simon Leeson; Derek Cruickshank; Ian A. Scott; Lesley Fallowfield; Martin Widschwendter

Purpose Cancer screening strategies have commonly adopted single-biomarker thresholds to identify abnormality. We investigated the impact of serial biomarker change interpreted through a risk algorithm on cancer detection rates. Patients and Methods In the United Kingdom Collaborative Trial of Ovarian Cancer Screening, 46,237 women, age 50 years or older underwent incidence screening by using the multimodal strategy (MMS) in which annual serum cancer antigen 125 (CA-125) was interpreted with the risk of ovarian cancer algorithm (ROCA). Women were triaged by the ROCA: normal risk, returned to annual screening; intermediate risk, repeat CA-125; and elevated risk, repeat CA-125 and transvaginal ultrasound. Women with persistently increased risk were clinically evaluated. All participants were followed through national cancer and/or death registries. Performance characteristics of a single-threshold rule and the ROCA were compared by using receiver operating characteristic curves. Results After 296,911 women-years of annual incidence screening, 640 women underwent surgery. Of those, 133 had primary invasive epithelial ovarian or tubal cancers (iEOCs). In all, 22 interval iEOCs occurred within 1 year of screening, of which one was detected by ROCA but was managed conservatively after clinical assessment. The sensitivity and specificity of MMS for detection of iEOCs were 85.8% (95% CI, 79.3% to 90.9%) and 99.8% (95% CI, 99.8% to 99.8%), respectively, with 4.8 surgeries per iEOC. ROCA alone detected 87.1% (135 of 155) of the iEOCs. Using fixed CA-125 cutoffs at the last annual screen of more than 35, more than 30, and more than 22 U/mL would have identified 41.3% (64 of 155), 48.4% (75 of 155), and 66.5% (103 of 155), respectively. The area under the curve for ROCA (0.915) was significantly (P = .0027) higher than that for a single-threshold rule (0.869). Conclusion Screening by using ROCA doubled the number of screen-detected iEOCs compared with a fixed cutoff. In the context of cancer screening, reliance on predefined single-threshold rules may result in biomarkers of value being discarded.


Fertility and Sterility | 2013

Phospholipase Cζ rescues failed oocyte activation in a prototype of male factor infertility.

Michail Nomikos; Khalil Elgmati; Maria Theodoridou; Karen Campbell; Vyronia Vassilakopoulou; Christos Zikos; Evangelia Livaniou; Nazar Najib Amso; George Nounesis; Karl Swann; F. Anthony Lai

Objective To determine the effect of infertility-linked sperm phospholipase Cζ (PLCζ) mutations on their ability to trigger oocyte Ca2+ oscillations and development, and also to evaluate the potential therapeutic utility of wild-type, recombinant PLCζ protein for rescuing failed oocyte activation and embryo development. Design Test of a novel therapeutic approach to male factor infertility. Setting University medical school research laboratory. Patient(s) Donated unfertilized human oocytes from follicle reduction. Intervention(s) Microinjection of oocytes with recombinant human PLCζ protein or PLCζ cRNA and a Ca2+-sensitive fluorescent dye. Main Outcome Measure(s) Measurement of the efficacy of mutant and wild-type PLCζ-mediated enzyme activity, oocyte Ca2+ oscillations, activation, and early embryo development. Result(s) In contrast to the wild-type protein, mutant forms of human sperm PLCζ display aberrant enzyme activity and a total failure to activate unfertilized oocytes. Subsequent microinjection of recombinant human PLCζ protein reliably triggers the characteristic pattern of cytoplasmic Ca2+ oscillations at fertilization, which are required for normal oocyte activation and successful embryo development to the blastocyst stage. Conclusion(s) Dysfunctional sperm PLCζ cannot trigger oocyte activation and results in male factor infertility, so a potential therapeutic approach is oocyte microinjection of active, wild-type PLCζ protein. We have demonstrated that recombinant human PLCζ can phenotypically rescue failed activation in oocytes that express dysfunctional PLCζ, and that this intervention culminates in efficient blastocyst formation.


Nature Methods | 2009

Neonatal desensitization allows long-term survival of neural xenotransplants without immunosuppression

Claire Kelly; Sophie Victoria Precious; Caroline Scherf; Richard Penketh; Nazar Najib Amso; Alysia Battersby; Nicholas Denby Allen; Stephen B. Dunnett; Anne Elizabeth Rosser

Preclinical development of human cells for potential therapeutic application in neurodegenerative diseases requires that their long-term survival, stability and functional efficacy be studied in animal models of human disease. Here we describe a strategy for long-term immune protection of human fetal and stem cell–derived neural cells transplanted into the adult rat brain, by desensitizing the host rat to similar cells in the neonatal period, without the need for additional immunosuppression.


Ultrasound in Obstetrics & Gynecology | 2012

Risk of epithelial ovarian cancer in asymptomatic women with ultrasound-detected ovarian masses: a prospective cohort study within the UK collaborative trial of ovarian cancer screening (UKCTOCS)

Aarti Sharma; Sophia Apostolidou; Matthew Burnell; Stewart Campbell; Mariam Habib; A Gentry-Maharaj; Nazar Najib Amso; Mourad W. Seif; Gwendolen Fletcher; N. Singh; Elizabeth Benjamin; Carol Brunell; Gill Turner; Rani Rangar; Keith M. Godfrey; David H. Oram; Jonathan Herod; Karin Williamson; Howard Jenkins; Tim Mould; Robert Woolas; John Murdoch; Stephen Dobbs; Simon Leeson; Derek Cruickshank; Evangelia-Ourania Fourkala; Andrew M. Ryan; M. Parmar; Ian Jacobs; Usha Menon

To estimate the risk of primary epithelial ovarian cancer (EOC) and slow growing borderline or Type I and aggressive Type II EOC in postmenopausal women with adnexal abnormalities on ultrasound.


Fertility and Sterility | 2012

Phospholipase C-ζ-induced Ca2+ oscillations cause coincident cytoplasmic movements in human oocytes that failed to fertilize after intracytoplasmic sperm injection

Karl Swann; Shane P. Windsor; Karen Campbell; Khalil Elgmati; Michail Nomikos; Magdalena Zernicka-Goetz; Nazar Najib Amso; F. Anthony Lai; Adrian L. R. Thomas; Christopher F. Graham

Objective To evaluate the imaging of cytoplasmic movements in human oocytes as a potential method to monitor the pattern of Ca2+ oscillations during activation. Design Test of a laboratory technique. Setting University medical school research laboratory. Patient(s) Donated unfertilized human oocytes from intracytoplasmic sperm injection (ICSI) cycles. Intervention(s) Microinjection of oocytes with phospholipase C (PLC) zeta (ζ) cRNA and a Ca2+-sensitive fluorescent dye. Main Outcome Measure(s) Simultaneous detection of oocyte cytoplasmic movements using particle image velocimetry (PIV) and of Ca2+ oscillations using a Ca2+-sensitive fluorescent dye. Result(s) Microinjection of PLCζ cRNA into human oocytes that had failed to fertilize after ICSI resulted in the appearance of prolonged Ca2+ oscillations. Each transient Ca2+ concentration change was accompanied by a small coordinated movement of the cytoplasm that could be detected using PIV analysis. Conclusion(s) The occurrence and frequency of cytoplasmic Ca2+ oscillations, a critical parameter in activating human zygotes, can be monitored by PIV analysis of cytoplasmic movements. This simple method provides a novel, noninvasive approach to determine in real time the occurrence and frequency of Ca2+ oscillations in human zygotes.


international conference of the ieee engineering in medicine and biology society | 2008

Subjective and objective quality assessment in wireless teleultrasonography imaging

Robert S. H. Istepanian; Nada Philip; Maria G. Martini; Nazar Najib Amso; P. Shorvon

Mobile Robotic teleultrasonography is an emerging technology that can be applied in different clinical settings for remote ultrasound scanning without the need of the expert at the point of care. Guaranteed medical image quality for diagnostic purposes and their delivery in bandwidth limited wireless environments is a challenging issue. In this paper we present some of the subjective and objective image analysis acquired from a robotic teleultrasonography system operated remotely by the expert to provide an assessment of these medical imaging measures for such advanced wireless telemedical system.


Fertility and Sterility | 2001

Quantification of power Doppler energy and its future potential

Nazar Najib Amso; Sean R. Watermeyer; Neil D. Pugh; Sharon O’Brien; Arianna D’Angelo

OBJECTIVE To test a new software package (Color Quantifier, Kinetic Imaging, Liverpool, United Kingdom) that quantifies power Doppler energy and to determine its reproducibility. DESIGN Intraobserver and interobserver reproducibility study. SETTING University tertiary referral center. PATIENT(S) Transvaginal power Doppler ultrasound images were recorded from women taking part in a study evaluating the physiological vascular changes in the uterus and ovaries during the normal menstrual cycle. INTERVENTION(S) Nineteen consecutive frames of regions of interest in the uterus, ovary, and follicle, respectively, were analyzed by each of four observers on 10 occasions. MAIN OUTCOME MEASURE(S) Analysis of variance to determine the image and observer effect as well as the intraobserver and interobserver coefficients of variation. RESULT(S) Significant image and observer effects were found. However, the image effect was by far the largest component of the total variation. The large image-to-image variability was expected because the cardiac cycle was included within the 19 frames (images) analyzed. The combined intraobserver and interobserver variation, expressed as the coefficients of variation, was found to be small for the above indices (as low as 1.9%), particularly for total ovary and endometrium. CONCLUSION(S) The indices obtained with this color quantification software are reproducible in an in vitro setting using prerecorded images. Its applicability as a useful assay in the clinical setting requires further evaluation.

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Matthew Burnell

University College London

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Usha Menon

University College London

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Ian Jacobs

University of New South Wales

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Aarti Sharma

University College London

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Derek Cruickshank

James Cook University Hospital

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