Introduction: The understanding of blood group phenotypes in Saudi Arabia is limited to the ABO and Rh blood groups. Data for the other major blood group phenotypes in different populations have been widely studied and used as a reference for identifying antigen-negative blood in hospital blood banks. Such information is crucial for facilitating the challenging task of providing antigen-negative blood for patients with multiple antibodies. Objective: The aim of this study was to determine the frequency of the major blood group phenotypes in the Eastern region of Saudi Arabia and compare them to phenotypes in other populations. Methods: A total of 100 volunteer Saudi donors were included in this study. Red blood cells from the donors were subjected to antigen typing of the major blood group systems (Rh, Kell, Kidd, Duffy, MNS, Lewis, Lutheran, and P) using the gel microtube technique. Results: From the Rh blood group system, the e antigen was found in 97% of donors, followed by c at 86%. The Cellano (k) antigen of the Kell system was found in all donors, whereas the Kell (K) antigen was only found in 8 % of donors. The K+k- phenotype was not detected in our study. Unexpectedly, for the Duffy blood group system, the null phenotype Fy(a-b-) was found in 61% of donors. In the MNS blood group system, M+N-S+s+ was the most common phenotype at 24%. Conclusion: The frequency of blood group phenotypes in the Eastern region of Saudi Arabia differs from that in other populations because of the diverse ethnic backgrounds of those living in that region. The findings of this study can be used to establish a local donor registry to help provide antigen-negative blood for patients with unexpected antibodies or to create an in-house antibody identification panel to add to the commercial panel that would be useful for confirming antibody identification results.

Osteoarthritis (OA) is a long-term, persistent joint disorder characterized by bone and cartilage degradation, resulting in tightness, pain, and restricted movement. Current attempts in cartilage regeneration are cell-based therapies using stem cells. Multipotent stem cells, such as mesenchymal stem cells (MSCs), and pluripotent stem cells, such as embryonic stem cells (ESCs), have been used to regenerate cartilage. However, since the discovery of human-induced pluripotent stem cells (hiPSCs) in 2007, it was seen as a potential source for regenerative chondrogenic therapy as it overcomes the ethical issues surrounding the use of ESCs and the immunological and differentiation limitations of MSCs. This literature review focuses on chondrogenic differentiation and 3D bioprinting technologies using hiPSCS, suggesting them as a viable source for successful tissue engineering. Methods: A literature search was conducted using scientific search engines, PubMed, MEDLINE, and Google Scholar databases with the terms ‘Cartilage tissue engineering’ and ‘stem cells’ to retrieve published literature on chondrogenic differentiation and tissue engineering using MSCs, ESCs, and hiPSCs. Results: hiPSCs may provide an effective and autologous treatment for focal chondral lesions, though further research is needed to explore the potential of such technologies. Conclusions: This review has provided a comprehensive overview of these technologies and the potential applications for hiPSCs in regenerative medicine.

Background. The coronavirus disease‐19 (COVID‐19) pandemic caused a major impact on blood donation process and supply globally. A lockdown management procedure was launched nationally in Saudi Arabia to manage this global health crisis. The main aim of this study was to determine the effect of COVID‐19 lockdown on blood donation services and supply in different regions of Saudi Arabia. Study Design and Methods. A retrospective cross‐sectional study was conducted in the blood bank centers of 5 major cities including Riyadh, Jeddah, Dammam, Hail, and Jizan in Saudi Arabia. Demographic and blood characteristics were retrieved from the first 6 months of 2019 (January–June) and compared to the same period of 2020. Results. Our findings showed variation in the characteristics of blood donation and supply among the centers surveyed, as some of these centers were adversely affected, while others showed an increase in the availability of blood products during the pandemic. For example, Jeddah’s center was significantly affected by COVID‐19 lockdown whereas Hail’s center showed a significant increase in the analyzed characteristics of blood donation services in 2020 compared to 2019. Overall, there was no major difference among the surveyed centers between 2020 and 2019, and this might be due to the effective management of blood supply and transfusion. Discussion. Although blood supply and transfusion practice was slightly affected at various degree among the surveyed centers, the whole process did not show a significant effect on the overall outcome. This is in fact due to the proper preparedness, management of blood requirements and supplies, and efficient response of the surveyed centers in Saudi Arabia.

Hematopoietic stem cells (HPSCs) are multipotent stem cells that can differentiate into lymphoid and myeloid progenitors, giving rise to white blood cells

Background: Animal models of blood cancer are important tools to study these malignancies and also screen for novel therapeutic agents. Evidence from past research on the carcinogenic properties of 7,12-dimethylbenz[a]-anthracene (DMBA) was provided by a handful of studies. However, recent literature on DMBA carcinogenic activity and the underlying mechanisms is scarce. Objective: The aim of this study was to develop a chemical model of leukemia using DMBA. Male Wistar rats (6 weeks old) were administered 1.5 mg of DMBA dissolved in sesame oil in biweekly doses using oral intragastric intubation. Materials and Methods: Frequent complete blood counts and blood smear morphology assessment were used to assess the development of leukemia, while gross pathology and histopathology staining were used to evaluate malignancy development. Results: The results showed that only 4% of rats developed acute lymphocytic leukemia. Interestingly, 36% of the rats developed tumors (parotid tumors [24%] and fibrosarcomas [12%]). Conclusion: These results suggest the pleiotropic potential of DMBA in the induction of multiple types of malignancies, including leukemia. This could be used as a model to validate therapeutic targets for leukemia and other induced malignancies.