Publications by authors named "Heba Sidahmed"

5 Publications

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Paracrine Mechanisms of Mesenchymal Stromal Cells in Angiogenesis.

Stem Cells Int 2020 9;2020:4356359. Epub 2020 Mar 9.

Advanced Cell Therapy Core, Sidra Medicine, Doha 26999, Qatar.

The role of the mesenchymal stromal cell- (MSC-) derived secretome is becoming increasingly intriguing from a clinical perspective due to its ability to stimulate endogenous tissue repair processes as well as its effective regulation of the immune system, mimicking the therapeutic effects produced by the MSCs. The secretome is a composite product secreted by MSC (in conditioned medium) and (in the extracellular milieu), consisting of a protein soluble fraction (mostly growth factors and cytokines) and a vesicular component, extracellular vesicles (EVs), which transfer proteins, lipids, and genetic material. MSC-derived secretome differs based on the tissue from which the MSCs are isolated and under specific conditions (e.g., preconditioning or priming) suggesting that clinical applications should be tailored by choosing the tissue of origin and a priming regimen to specifically correct a given pathology. MSC-derived secretome mediates beneficial angiogenic effects in a variety of tissue injury-related diseases. This supports the current effort to develop cell-free therapeutic products that bring both clinical benefits (reduced immunogenicity, persistence , and no genotoxicity associated with long-term cell cultures) and manufacturing advantages (reduced costs, availability of large quantities of off-the-shelf products, and lower regulatory burden). In the present review, we aim to give a comprehensive picture of the numerous components of the secretome produced by MSCs derived from the most common tissue sources for clinical use (e.g., AT, BM, and CB). We focus on the factors involved in the complex regulation of angiogenic processes.
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http://dx.doi.org/10.1155/2020/4356359DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7085399PMC
March 2020

Enhancing Mesenchymal Stromal Cell Immunomodulation for Treating Conditions Influenced by the Immune System.

Stem Cells Int 2019 5;2019:7219297. Epub 2019 Aug 5.

Sidra Medicine, Member of Qatar Foundation, Doha, Qatar.

Mesenchymal stromal cells (MSCs), formerly known as mesenchymal stem cells, are nonhematopoietic multipotent cells and are emerging worldwide as the most clinically used and promising source for allogeneic cell therapy. MSCs, initially obtained from bone marrow, can be derived from several other tissues, such as adipose tissue, placenta, and umbilical cord. Diversity in tissue sourcing and manufacturing procedures has significant effects on MSC products. However, in 2006, a minimal set of standard criteria has been issued by the International Society of Cellular Therapy for defining derived MSCs. These include adherence to plastic in conventional culture conditions, particular phenotype, and multilineage differentiation capacity . Moreover, MSCs have trophic capabilities, a high self-renewal ability, and immunomodulatory characteristics. Thus, immunosuppressive treatment with MSCs has been proposed as a potential therapeutic alternative for conditions in which the immune system cells influence outcomes, such as inflammatory and autoimmune diseases. The precise mechanism by which MSCs affect functions of most immune effector cells is not completely understood but involves direct contact with immune cells, soluble mediators, and local microenvironmental factors. Recently, it has been shown that their homeostatic resting state requires activation, which can be achieved with various cytokines, including interferon-. In the present review, we focus on the suppressive effect that MSCs exert on the immune system and highlight the significance of preconditioning and its use in preclinical studies. We discuss the clinical aspects of using MSCs as an immunomodulatory treatment. Finally, we comment on the risk of interfering with the immune system in regard to cancer formation and development.
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http://dx.doi.org/10.1155/2019/7219297DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6701346PMC
August 2019

Tailoring cells for clinical needs: Meeting report from the Advanced Therapy in Healthcare symposium (October 28-29 2017, Doha, Qatar).

J Transl Med 2018 10 10;16(1):276. Epub 2018 Oct 10.

Research Department, Clinical Research Center, Sidra Medicine, Doha, Qatar.

New technologies and therapies designed to facilitate development of personalized treatments are rapidly emerging in the field of biomedicine. Strikingly, the goal of personalized medicine refined the concept of therapy by developing cell-based therapies, the so-called "living drugs". Breakthrough advancements were achieved in this regard in the fields of gene therapy, cell therapy, tissue-engineered products and advanced therapeutic techniques. The Advanced Therapies in Healthcare symposium, organized by the Clinical Research Center Department of Sidra Medicine, in Doha, Qatar (October 2017), brought together world-renowned experts from the fields of oncology, hematology, immunology, inflammation, autoimmune disorders, and stem cells to offer a comprehensive picture of the status of worldwide advanced therapies in both pre-clinical and clinical development, providing insights to the research phase, clinical data and regulatory aspects of these therapies. Highlights of the meeting are provided in this meeting report.
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http://dx.doi.org/10.1186/s12967-018-1652-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6180452PMC
October 2018

Harnessing the immune system for the treatment of melanoma: current status and future prospects.

Expert Rev Clin Immunol 2016 Aug 3;12(8):879-93. Epub 2016 May 3.

b Tumor Biology, Immunology and Therapy Section, Division of Translational Medicine , Research Branch, Sidra Medical and Research Center , Doha , Qatar.

When malignant melanoma is diagnosed early, surgical resection is the intervention of choice and is often curative, but many patients present with unresectable disease at later stages. Due to its complex etiology paired with well-documented chemoresistance and high metastatic potential, patients with advanced melanoma had a poor prognosis, and the treatment of this disease remained unsatisfactory for many years. Recently, targeted therapy, immune checkpoint inhibition, or combinatory approaches have revolutionized the therapeutic options of melanoma allowing considerable improvement in disease control and survival. In this review we will summarize these novel therapeutic strategies with particular focus on combinatory immunotherapies and further discuss recent data derived from immunogenomic studies and potential options to improve the therapeutic efficacy of immune modulatory approaches.
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http://dx.doi.org/10.1080/1744666X.2016.1176529DOI Listing
August 2016

Risk factors contributing to road traffic crashes in a fast-developing country: the neglected health problem.

Ulus Travma Acil Cerrahi Derg 2010 Nov;16(6):497-502

Department of Public Health & Medical Education, Weill Cornell Medical College, Qatar.

Background: The main objective of this study was to explore the patterns of road traffic crashes (RTCs) among drivers in Qatar and to examine the contributing factors involved.

Methods: This study was a cross-sectional survey conducted from February to June 2009 at the Primary Health Care Centers in the State of Qatar. A random sample of 1675 Qatari drivers were approached, and 1228 of them responded and agreed to participate in this study, with a response rate of 74.6%. Face to face interview was conducted by well-trained research assistants based on a questionnaire covering sociodemographic information, driving history, type of vehicle, driver behavior, details of crashes, and accident pattern.

Results: The study revealed that 26.6% of the studied Qatari drivers were involved in RTCs. 69.4% of the drivers with a history of RTCs were male. Drivers in the age group 25-34 years showed a higher risk of having a crash (31.2%). Drivers of cars (45.6%) and 4WD/SUVs (23.5%) were more frequently involved in RTCs. 23.5% of drivers who had RTC did not always wear their seat belt while driving. 37.9% of the drivers with RTC were engaged in eating and drinking and 41.9% were using their mobile phones while driving. More than half of the drivers with RTCs had traffic violations (57.2%), with 25.7% exceeding the speed limit. A highly significant difference was observed between the two groups (drivers with and without RTC) in terms of presence of traffic violation (<0.001) and exceeding the speed limit (<0.001). Most of the crashes happened during sunny days (84.7%) with fewer crashes on holidays (5.5%) and weekends (12.5%). Overturn skid (17.7%), angle collision (14.3%) and rear-end hit (10.7%) were the most frequently reported patterns of RTCs.

Conclusion: The study findings revealed the high risk of RTCs among drivers in the State of Qatar. Among the sociodemographic factors, male drivers and young drivers aged 25-34 years were found to have a higher accident involvement. Human behavior was identified as the main contributing factor of all RTCs, especially presence of traffic violations.
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November 2010