Publications by authors named "Ahmad El-Sheikhah"

7 Publications

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Genetic Counseling in Primary Immunodeficiency Disorders: An Emerging Experience in Egypt.

Mol Diagn Ther 2017 12;21(6):677-684

Department of Pediatrics, Faculty of Medicine, Cairo University, Cairo, Egypt.

Background: Primary immunodeficiency disorders (PIDs) are a heterogeneous group of diseases of the immune system leading to life-threatening infections, and, unless urgently treated with immune reconstitution, patients do not usually survive. With the continuing progress in molecular diagnosis, many mutations have been described in more than 300 genes. Genetic counseling has recently been considered an essential part of the management of PIDs. This study presents the experience of genetic counseling services in the largest PID center in Egypt, and reports on our management plan and the impact of prenatal diagnosis (PND) on families.

Methods: Based on the biochemical and molecular diagnosis of index cases, PND was offered for 10 families in 12 subsequent pregnancies. Five different genes were sequenced by Sanger sequencing in fetal samples.

Results: Seven fetuses were either normal or were carriers, while five fetuses were affected and human leukocyte antigen typing was performed, seeking a suitably related donor for stem cell transplantation.

Conclusion: In spite of the genetic heterogeneity behind PIDs, genetic counseling should play a critical role in the management and future decisions of affected families.
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http://dx.doi.org/10.1007/s40291-017-0297-5DOI Listing
December 2017

Immunomodulatory effects of umbilical cord-derived mesenchymal stem cells.

Microbiol Immunol 2015 Jun;59(6):348-56

Department of Clinical Pathology and.

Umbilical cord blood (UCB) is of great interest as a source of stem cells for use in cellular therapies. The immunomodulatory effect of mesenchymal stem cells (MSCs) originating from bone marrow, adipose tissue and amniotic membrane has previously been reported. In this study, MSCs were isolated from UCB with the aim of evaluating their immunomodulatory effects on proliferation of PB lymphocytes by two different techniques; namely, 5-bromo-2-deoxyuridine ELISA and a carboxy fluorescein diacetate succinimidyl ester flow cytometric technique. MSCs were isolated from UCB, propagated until Passage four, and then characterized for cell surface markers by flow cytometry and ability to differentiate towards osteocytes and adipocytes. Immunosuppressive effects on PB lymphocytes were examined by co-culturing mitomycin C-treated UCB MSCs with mitogen-stimulated lymphocytes for 72 hr. Thereafter, proliferation of lymphocytes was detected by CFSE flow cytometry and colorimetric ELISA. The titers of cytokines in cell culture supernatant were also assayed to clarify possible mechanisms of immunomodulation. UCB MSCs suppressed mitogen-stimulated lymphocyte proliferation, which occurs via both cell-cell contact and cytokine secretion. Titers of transforming growth factor beta and IL 10 increased, whereas that of IFN-γ decreased in the supernatants of co-cultures. Thus, UCB MSCs suppress the proliferation of mitogen-stimulated lymphocytes. However further in vivo studies are required to fully evaluate the immunomodulatory effects of UCB MSCs.
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http://dx.doi.org/10.1111/1348-0421.12259DOI Listing
June 2015

Would gestational age and presence of brain anomalies affect interobserver reliability of fetal head biometry? Using off-line analysis of 3-D dataset.

Ultrasound Med Biol 2012 Jan 21;38(1):69-74. Epub 2011 Nov 21.

Fetal and Maternal Medicine Department, Nottingham University Hospitals NHS Trust, Nottingham, UK.

The objective was to assess interobserver reliability of fetal head biometry using archived three-dimensional (3-D) volumes and the impact of gestational age and presence of brain anomalies on examiners' performance. Seventy nine 3-D volume datasets of fetal head were examined: 27 were normal and 52 had brain abnormalities. Off-line analysis was done by three fetal medicine experts (E1, E2 and E2), all were blinded to history and patient details. Measurements of the biparietal diameter (BPD), head circumference (HC), lateral ventricle (Vp) and transcerebellar diameter (TCD) were compared between examiners and to two-dimensional (2-D) measurements. Comparisons were made at two gestational age groups (≤22 and >22 weeks) and in presence and absence of brain anomalies. The intraclass coefficient showed a significantly high level of measurement agreement between 3-D examiners and 2-D, with values >0.9 throughout (p < 0.001). Bias was evident between 3-D examiners. E2 produced smaller measurements. The mean percentage difference between this examiner and the other two in BPD, HC, Vp and TCD measurements was significant, of 1.6%, 1%, 4.9% and 1.8%, respectively. E1 measured statistically larger for HC and TCD. E3 measured significantly larger for only BPD. The presence of anomalies was of no influence on the 3-D examiners' performance except for E3 who showed bias in BPD measurements only in cases with brain anomalies. Unlike other examiners, bias of E2 was only seen at gestational age group ≤22 weeks. Limits of agreement in measurements between observers were narrow for all parameters but were widest for the Vp measurements, being ±23% of the mean difference. Despite the above bias, the actual mean difference between examiners was small and unlikely to be of any clinical significance. Off-line measurement of fetal head biometry using 3-D volumes is reliable. In our study, presence of brain anomalies was unlikely to influence the reproducibility of measurements. Gestational age seemed to be of an impact on examiners' bias. Among experts this bias may be of no clinical significance.
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http://dx.doi.org/10.1016/j.ultrasmedbio.2011.10.016DOI Listing
January 2012

Detection of trisomy 21 by quantitative mass spectrometric analysis of single-nucleotide polymorphisms.

Clin Chem 2005 Dec;51(12):2358-62

Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Special Administrative Region, China.

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http://dx.doi.org/10.1373/clinchem.2005.056978DOI Listing
December 2005

Optimized real-time quantitative PCR measurement of male fetal DNA in maternal plasma.

Clin Chem 2005 Sep 14;51(9):1598-604. Epub 2005 Jul 14.

University Women's Hospital/Department of Research, University Hospital Basel, Basel, Switzerland.

Background: Circulating fetal DNA (cfDNA) in maternal plasma has been measured to investigate its possible relationship with pregnancy-related disorders, including fetal trisomy 21 and preeclampsia. The circulating concentrations of single-copy fetal genes, however, are close to the detection limits of PCR methods.

Methods: We optimized a protocol for the real-time quantitative PCR amplification of the multicopy sequence DYS14 on the Y-chromosome. This was compared with an established real-time PCR assay for the single-copy SRY gene.

Results: By probit regression analysis, the measurements of male DNA by the DYS14 assay had a 10-fold lower detection limit (0.4 genome equivalents) than did measurements of SRY. For plasma samples from women in the first trimester of pregnancy, imprecision (CV) was 2%-22% when amplifying DYS14 compared with 26%-140% for SRY.

Conclusions: The low copy numbers of fetal DNA in plasma of women in the first trimester of pregnancy cannot be measured precisely when targeting single-copy sequences. Better results are obtained by amplifying a sequence that is present in multiple copies per male genome.
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http://dx.doi.org/10.1373/clinchem.2005.051235DOI Listing
September 2005

Evaluation of human chorionic gonadotropin beta-subunit mRNA concentrations in maternal serum in aneuploid pregnancies: a feasibility study.

Clin Chem 2004 Jun;50(6):1055-7

Departments of Chemical Pathology and Obstetrics & Gynaecology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong SAR.

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http://dx.doi.org/10.1373/clinchem.2004.031260DOI Listing
June 2004