The Dynamics of Histone Modifications during Mammalian Zygotic Genome Activation.

Mammalian fertilization initiates the reprogramming of oocytes and sperm, forming a totipotent zygote. During this intricate process, the zygotic genome undergoes a maternal-to-zygotic transition (MZT) and subsequent zygotic genome activation (ZGA), marking the initiation of transcriptional control and gene expression post-fertilization. Histone modifications are pivotal in shaping cellular identity and gene expression in many mammals. Recent advances in chromatin analysis have enabled detailed explorations of histone modifications during ZGA. This review delves into conserved and unique regulatory strategies, providing essential insights into the dynamic changes in histone modifications and their variants during ZGA in mammals. The objective is to explore recent advancements in leading mechanisms related to histone modifications governing this embryonic development phase in depth. These considerations will be useful for informing future therapeutic approaches that target epigenetic regulation in diverse biological contexts. It will also contribute to the extensive areas of evolutionary and developmental biology and possibly lay the foundation for future research and discussion on this seminal topic.

Effects of Ramadan Fasting on Extracorporeal Photopheresis Outcomes.

Although there are many studies on the impact of Ramadan fasting on health in the medical literature, the effects have not been explored in Muslim patients undergoing extracorporeal photopheresis (ECP). This report aimed to describe the potential effects of Ramadan fasting on ECP treatment outcomes. Patients undergoing ECP were prospectively evaluated before and during the month of Ramadan 1443 AH (2022 AD) at the Abu Dhabi Stem Cells Center (ADSCC), United Arab Emirates. The following ECP outcomes were assessed: treatment completion, adverse events reported, body mass index (BMI), and laboratory test results, including complete blood count (CBC), C-reactive protein (CRP), and other systemic immune-inflammatory biomarkers (SIIBs). No statistically significant differences were found in most of the variables analyzed in the three patients who underwent ECP before and during the holy month. Two non-fasting patients were not able to complete the Ramadan ECP schedule, and one fasting patient experienced a vascular access event during his first procedure in Ramadan. These findings suggest that fasting during Ramadan could add further risk factors and develop serious complications related to the ECP treatment. Therefore, we suggest that fasting should be avoided during photopheresis treatment, and we provided recommendations to achieve the best possible clinical outcomes.

Collection efficiency in apheresis.

Significant advances in procedural information displayed by current apheresis machines have been made, but analyses of cell collection efficiency (CE) still rely on calculations done by apheresis professionals. Accordingly, understanding CE equations can support the optimization of apheresis techniques and identification of incidents that could impact the procedure's effectiveness. This report summarizes classical and novel CE analyses applied to apheresis exemplified by an actual case of hematopoietic progenitor cell collection. In addition to the apheresis yield and most common CE1 and CE2 formulas, we present the instantaneous and corrected CE, fold enrichment, collection throughput, collection rate and its variants, average inlet rate, classical and adjusted captured cells, recruitment pool, recruitment factor, recruitment coefficient, blood component loss, predictive apheresis yield, and performance ratio calculations. Moreover, the mathematical relationship between these CE equations is also shown, which can be helpful in many apheresis procedures.

Treatment of sickle cell disease - options and perspective.

Sickle Cell Disease (SCD) is one of the most inherited hematologic diseases affecting humans. Clinically, there is a progressive multiorgan failure and increased mortality in severe cases. The highest prevalence is in West Africa, India, the Mediterranean region, and Middle East countries. Hydroxyurea was the primary drug available for SCD and remains first-line therapy for patients with SCD. Three additional drug therapies, L-glutamine, Voxelotor, and Crizanlizumab, have been approved as adjunctive agents. However, none of these treatments are curative. Effective cell-based therapies are available, such as red blood cell (RBC) exchange and the only curative therapy is hematopoietic stem cell transplantation (HSCT). Gene-editing now shows promise in treating SCD and the ß-thalassemias. Recent clinical trials have proven that this therapeutic strategy is effective, however costly. Despite the availability of safe and effective drug treatments, questions focusing on the overall value of these drugs exist in light of rising healthcare costs including hospitalizations and medical interventions. Herein, we report a cost-effective evaluation that can guide future efforts in making decisions towards HSCT as cell therapy treatment in SCD patients.

Application of mass cytometry to characterize hematopoietic stem cells in apheresis products of patients with hematological malignancies.

INTRODUCTION: Hematopoietic stem cell transplantation (HSCT) is a widely used therapy, but its success largely depends on the number and quality of stem cells collected. Current evidence shows the complexity of the hematopoietic system, which implies that, in the quality assurance of the apheresis product, the hematopoietic stem cells are adequately characterized and quantified, in which mass cytometry (MC) can provide its advantages in high-dimensional analysis. OBJECTIVE: This research aimed to characterize and enumerate CD45dim/CD34+ stem cells using the MC in apheresis product yields from patients with chronic lymphoid malignant diseases undergoing autologous transplantation at the Abu Dhabi Stem Cells Center. METHODS: An analytical and cross-sectional study was performed on 31 apheresis products from 15 patients diagnosed with multiple myeloma (n = 9) and non-Hodgkin lymphomas (n = 6) eligible for HSCT. The MC was employed using the MaxPar Kit for stem cell immunophenotyping. The analysis was performed manually in the Kaluza and unsupervised by machine learning in Cytobank Premium. RESULTS: An excellent agreement was found between mass and flow cytometry for the relative and absolute counts of CD45dim/CD34+ cells (Bland-Altman bias: -0.029 and -64, respectively), seven subpopulations were phenotyped and no lineage bias was detected for any of the methods used in the pool of collected cells. A CD34+/CD38+/CD138+ population was seen in the analyses performed on four patients with multiple myeloma. CONCLUSIONS: The MC helps to characterize subpopulations of stem cells in apheresis products. It also allows cell quantification by double platform. Unsupervised analysis allows results completion and validation of the manual strategy. The proposed methodology can be extended to apheresis products for purposes other than HSCT.

"Original Antigenic Sin" in SARS-CoV-2 Vaccination Followed by Infection.

Although the "original antigenic sin" (OAS) effects have been predicted against new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), only a few pieces of evidence are available regarding its impact on the safety and effectiveness of coronavirus disease 2019 (COVID-19) vaccines. This article aims to provide an immunological explanation for the delayed side effects of a SARS-CoV-2 vaccine during an episode of natural infection. We reported a case of a 39-year-old male healthcare worker who complained about pruritus and discomfort around the injection site of an inactivated SARS-CoV-2 vaccine administrated 18, 17, and 13 months earlier. Those symptoms resembled the side effects previously experienced with one of the booster doses, and a sole erythematous papule was also documented. The patient was diagnosed with COVID-19 one or two days after noticing these local signs and symptoms, and high serum titers of immunoglobulin M (IgM) and immunoglobulin E (IgE) were found five weeks after the onset, along with SARS-CoV-2-specific immunoglobulin G (IgG) antibodies. Therefore, the OAS might be a plausible phenomenon to consider in individuals immunized with inactivated vaccines and exposed secondarily to a wild virus with antigenic variations.

Tele-ECP: A feasible telemedicine-based approach to extracorporeal photopheresis.

The acquisition of telecommunication technologies in clinical practices is transforming medical care capabilities, whereas applying telemedicine in apheresis medicine has resulted in the revolutionary concept of "telapheresis." This manuscript aims to describe the regulatory landscape of telapheresis by presenting the first "tele-ECP" (telemedicine-based approach to extracorporeal photopheresis) reported in the United Arab Emirates. The tele-ECP procedure was done successfully in a patient with chronic graft-versus-host disease, who, despite having one vascular access-related adverse event, it was solved promptly without further complications. Therefore, this telemedicine-based approach arose as a feasible practice, but required direct physical contact with other trained and privileged/credentialed staff.

Refractory pemphigus vulgaris and high-intensity extracorporeal photopheresis: A case report.

A 41-year-old man with oral pemphigus vulgaris (PV) presented to our clinic with a history of no response to numerous immunosuppressant agents and was referred for extracorporeal photopheresis (ECP) therapy. Although the patient underwent a high-intensity ECP regimen for five months, which included two different photopheresis systems, his oral dysesthesia continued to interfere with oral intake, leading to continued weight loss and other adverse events. The intervention was associated with changes in several immune cell subpopulations without modifying the anti-epidermal antibody titers, aligned with his poor clinical outcome. To the best of the authors' knowledge, this is the first report to examine immunophenotyping of a PV patient who was refractory to previous immunosuppression and recalcitrant to high-intensity ECP therapy.

Wide Range Applications of Spirulina: From Earth to Space Missions.

Spirulina is the most studied cyanobacterium species for both pharmacological applications and the food industry. The aim of the present review is to summarize the potential benefits of the use of Spirulina for improving healthcare both in space and on Earth. Regarding the first field of application, Spirulina could represent a new technology for the sustainment of long-duration manned missions to planets beyond the Lower Earth Orbit (e.g., Mars); furthermore, it could help astronauts stay healthy while exposed to a variety of stress factors that can have negative consequences even after years. As far as the second field of application, Spirulina could have an active role in various aspects of medicine, such as metabolism, oncology, ophthalmology, central and peripheral nervous systems, and nephrology. The recent findings of the capacity of Spirulina to improve stem cells mobility and to increase immune response have opened new intriguing scenarios in oncological and infectious diseases, respectively.

Viability assessment of human peripheral blood-derived stem cells after three methods of nebulization.

BACKGROUND AND OBJECTIVES: Drug delivery by nebulization has become a crucial strategy for treating different respiratory and lung diseases. Emerging evidence implicates stem cell therapy as a promising tool in treating such conditions, not only by alleviating the related symptoms but by improving the prognosis. However, delivery of human peripheral blood-derived stem cells (hPBSCs) to the respiratory airways remains an innovative approach yet to be realized. This study is an analytic, translational, and in vitro research to assess the viability and morphological changes of identified cell populations in hPBSCs cocktail derived from COVID-19 patients. METHODS AND RESULTS: Peripheral blood (PB) samples were obtained from patients enrolled in the SENTAD-COVID Study (ClinicalTrials.gov Reference: NCT04473170). hPBSCs cocktails (n=15) were provided by the Cells Processing Laboratory of Abu Dhabi Stem Cells Center, and were nebulized by three different methods of nebulization: compressor (jet), ultrasonic, and mesh. Our results reported that nucleated CD45dim cell count was significantly lower after the three nebulization methods, but nucleated CD45- cells show a significant decrease only after mesh nebulization. Mesh-nebulized samples had a significant reduction in viability of both CD45dim and CD45- cells. CONCLUSIONS: This study provides evidence that stem cells derived from PB of COVID-19 patients can be nebulized without substantial loss of cell viability, cell count, and morphological changes using the compressor nebulization. Therefore, we recommend compressor nebulizers as the preferable procedure for hPBSCs delivery to the respiratory airways in further clinical settings.

Safety and efficacy of autologous non-hematopoietic enriched stem cell nebulization in COVID-19 patients: a randomized clinical trial, Abu Dhabi 2020.

BACKGROUND: The novel SARS-CoV-2 has caused the coronavirus disease 2019 (COVID-19) pandemic. Currently, with insufficient worldwide vaccination rates, identifying treatment solutions to reduce the impact of the virus is urgently needed. METHOD: An adaptive, multicentric, open-label, and randomized controlled phase I/II clinical trial entitled the "SENTAD-COVID Study" was conducted by the Abu Dhabi Stem Cells Center under exceptional conditional approval by the Emirates Institutional Review Board (IRB) for COVID-19 Research Committee from April 4th to July 31st, 2020, using an autologous peripheral blood non-hematopoietic enriched stem cell cocktail (PB-NHESC-C) administered by compressor (jet) nebulization as a complement to standard care therapy. The primary endpoints include safety and efficacy assessments, adverse events, the mortality rate within 28 days, and the time to clinical improvement as measured by a 2-point reduction on a seven-category ordinal scale or discharge from the hospital whichever occurred first. RESULTS: The study included a total of 139 randomized COVID-19 patients, with 69 in the experimental group and 70 in the control group (standard care). Overall survival was 94.20% for the cocktail-treated group vs. 90.27% for the control group. Adverse events were reported in 50 (72.46%) patients receiving PB-NHESC-C and 51 (72.85%) in the control group (p = 0.9590), with signs and symptoms commonly found in COVID-19. After the first 9 days of the intervention, 67.3% of cocktail-treated patients recovered and were released from hospitals compared to 53.1% (RR = 0.84; 95% CI, 0.56-1.28) in the control group. Improvement, i.e., at least a 2-point reduction in the severity scale, was more frequently observed in cocktail-treated patients (42.0%) than in controls (17.0%) (RR = 0.69; 95% CI, 0.56-0.88). CONCLUSIONS: Cocktail treatment improved clinical outcomes without increasing adverse events. Thus, the nebulization of PB-NHESC-C was safe and effective for treatment in most of these patients. TRIAL REGISTRATION: ClinicalTrials.gov. NCT04473170. It was retrospectively registered on July 16th, 2020.