Hematopoietic Recovery using Multi-Cytokine Therapy in 8 Patients Presenting Radiation-Induced Myelosuppression after Radiological Accidents

Radiation-induced gastrointestinal and cutaneous injuries: understanding models, pathologies, assessments, and clinically accepted practices

PURPOSE

A U. S. and European joint effort fostering the development of medical countermeasures (MCMs) operable in case of radiological or nuclear emergencies.

METHODS

Based on the joint engagement between the U.S. National Institute of Allergy and Infectious Diseases (NIAID) and the French Institut de Radioprotection et de Sûreté Nucléaire (IRSN), a Statement of Intent to Collaborate was signed in 2014 and a series of working group meeting were established. In December 2022, the NIAID and IRSN hosted a five-day, U.S./European meeting titled 'Radiation-Induced Cutaneous and Gastrointestinal Injuries: Advances in Understanding Pathologies, Assessment, and Clinically Accepted Practices' in Paris, France. The goals of the meeting were to bring together U.S. and European investigators to explore new research avenues for the medical management of skin and gastrointestinal injuries, including specific diagnostics for each organ system, animal models, and promising medical countermeasures (MCMs) to mitigate radiation damage. There was also an emphasis on exploring additional areas of medicine and response to understand best practices from other emergency scenarios, which could be leveraged to improve radiation preparedness, and the importance of accurate dosimetry in preclinical work.

RESULTS

Subsequent to the workshop, seven collaborative projects, funded by both organizations, were established on topics ranging from MCMs and predictive biomarkers, and using physical methods to assess cutaneous radiation injuries, to mechanistic studies to understand radiation-induced damage in multiple organ systems. The importance of accurate dosimetry in preclinical works was highlighted and two recently published U.S./European commentaries that focus on the need for dosimetry standardization in the reported literature had their origins in this meeting. This commentary summarizes the workshop and open discussions among academic investigators, industry researchers, and U.S. and IRSN program representatives.

CONCLUSIONS

Given the substantive progress made due to these interactions, both groups plan to expand out these meetings by incorporating high-level investigators from across the globe, while endeavoring to maintain the informal setting that was conducive to in-depth scientific discussion and enhanced the state of the science in radiation research.

Development of radiation countermeasure agents for acute radiation syndromes

The risk of internal and external exposure to ionizing radiation (IR) has increased alongside the development and implementation of nuclear technology. Therefore, serious security issues have emerged globally, and there has been an increase in the number of studies focusing on radiological prevention and medical countermeasures. Radioprotective drugs are particularly important components of emergency medical preparedness strategies for the clinical management of IR-induced injuries. However, a few drugs have been approved to date to treat such injuries, and the related mechanisms are not entirely understood. Thus, the aim of the present review was to provide a brief overview of the World Health Organization's updated list of essential medicines for 2023 for the proper management of national stockpiles and the treatment of radiological emergencies. This review also discusses the types of radiation-induced health injuries and the related mechanisms, as well as the development of various radioprotective agents, including Chinese herbal medicines, for which significant survival benefits have been demonstrated in animal models of acute radiation syndrome.

The effect of chronoradiotherapy on cervical cancer patients: A multicenter randomized controlled study

OBJECTIVES

To investigate the short-term efficacy and radiotoxicity 3.543of chronoradiotherapy in patients with cervical cancer. We also examined the overall symptom score and quality of life (QOL) of patients who underwent morning radiotherapy and evening radiotherapy.

METHODS

We conducted a multicenter randomized controlled trial to compare the effects of morning radiotherapy (9:00-11:00 AM) with evening radiotherapy (7:00-9:00 PM) in cervical cancer patients receiving radiotherapy. From November 2021 to June 2022, 114 cervical cancer patients admitted to eight cancer center hospitals in Tianjin, Chongqing, Hubei, Shanxi, Shandong, Shaanxi, Hebei, and Cangzhou were randomly divided into the morning radiotherapy group (MG; N = 61) and the evening radiotherapy group (EG; N = 53). The short-term efficacy of radiotherapy on cervical cancer patients at different time points and the occurrence of radiotoxicity were explored after patients had undergone radiotherapy.

RESULTS

The total effective response (partial remission [PR] + complete remission [CR]) rate was similar across the two groups (93.5% vs. 96.3%, p > 0.05). However, the incidence of bone marrow suppression and intestinal reaction in the two groups were significantly different (p < 0.05). The patients in the MG had significantly higher Anderson symptom scores than patients in the EG (21.64 ± 7.916 vs. 18.53 ± 4.098, p < 0.05). In terms of physical activity, functional status, and overall QOL, the MG had significantly lower scores than the EG (p < 0.05). No other measures showed a significant difference between the groups.

CONCLUSION

The radiotherapy effect of the MG was consistent with that of the EG. The incidence of radiation enteritis and radiation diarrhea in the MG was significantly higher than that in the EG; however, bone marrow suppression and blood toxicity in the EG were more serious than in the MG. Because of the small sample size of the study, we only examined the short-term efficacy of radiotherapy. Therefore, further clinical trials are needed to verify the efficacy and side effects of chronoradiotherapy.

CLINICAL TRIAL REGISTRATION

http://www.chictr.org.cn/searchproj.aspx, Registration Number: ChiCTR2100047140.

Medical countermeasures for the hematopoietic-subsyndrome of acute radiation syndrome in space

More than 50 years after the Apollo missions ended, the National Aeronautical and Space Administration (NASA) and other international space agencies are preparing a return to the moon as a step towards deep space exploration. At doses ranging from a fraction of a Gray (Gy) to a few Gy, crew will be at risk for developing bone marrow failure associated with the hematopoietic subsyndrome of acute radiation syndrome (H-ARS) requiring pharmacological intervention to reduce risk to life and mission completion. Four medical countermeasures (MCM) in the colony stimulating factor class of drugs are now approved for treatment of myelosuppression associated with ARS. When taken in conjunction with antibiotics, fluids, antidiarrheals, antiemetics, antipyretics, and other treatments for symptomatic illness, the likelihood for recovery and mission completion can be greatly improved. The current review describes the performance and health risks of deep space flight, ionizing radiation exposure during crewed missions to the moon and Mars, and U.S. Food and Drug Administration (FDA)-approved medical interventions to treat ARS. With an expansion of human exploration missions beyond low Earth orbit (LEO), including near-term Lunar and future Mars missions, inclusion of MCMs to counteract ARS in the spaceflight kit will be critical for preserving crew health and performance.

Model for Evaluating Antimicrobial Therapy To Prevent Life-Threatening Bacterial Infections following Exposure to a Medically Significant Radiation Dose

More evidence is needed to support recommendations for medical management of acute radiation syndrome (ARS) and associated infections resulting from a radiological/nuclear event. While current guidelines recommend the administration of antibiotics to chemotherapy patients with febrile neutropenia, the clinical benefit is unclear for acute radiation injury patients. A well-characterized nonhuman primate (NHP) model of hematopoietic ARS was developed that incorporates supportive care postirradiation. This model evaluated the efficacy of myeloid growth factors within 24 to 48 h after total body irradiation (TBI). However, in this model, NHPs continued to develop life-threatening bacterial infections, even when granulocyte colony-stimulating factor or granulocyte-macrophage colony-stimulating factor was administered in combination with antibiotic monotherapy. In this study, we evaluated the efficacy of combination antibiotic therapies administered to NHPs following 7.4-Gy TBI to understand the occurrence of bacterial infection in NHPs with hematopoietic ARS. We compared enrofloxacin-linezolid, enrofloxacin-cefepime, and enrofloxacin-ertapenem to enrofloxacin monotherapy. The primary endpoint was 60-day postirradiation mortality, with secondary endpoints of overall survival time, incidence of bacterial infection, and bacteriologic culture with antimicrobial susceptibility testing. We observed that enrofloxacin-ertapenem significantly increased survival compared to enrofloxacin monotherapy. Bacteria isolated from nonsurviving macaques with systemic bacterial infections exhibited uniform resistance to enrofloxacin and variable resistance to beta-lactam antibiotics, linezolid, gentamicin, and azithromycin. Multidrug antibiotic resistance was observed in Enterococcus spp. and Escherichia coli. We conclude that antibiotic combination therapies appear to be more effective than monotherapy alone but acknowledge that more work is needed to identify an optimal antimicrobial therapy.

Myelosuppression Alleviation and Hematopoietic Regeneration by Tetrahedral-Framework Nucleic-Acid Nanostructures Functionalized with Osteogenic Growth Peptide

As major complications of chemoradiotherapy, myelosuppression and hematopoietic-system damage severely affect immunologic function and can delay or even terminate treatment for cancer patients. Although several specific cytokines have been used for hematopoiesis recovery, their effect is limited, and they may increase the risk of tumor recurrence. In this study, osteogenic growth peptide functionalized tetrahedral framework nucleic-acid nanostructures (OGP-tFNAs) are prepared; they combine the positive hematopoiesis stimulating effect of OGP and the drug carrying function of tFNAs. The potential of OGP-tFNAs for hematopoietic stimulation and microenvironment regulation is investigated. It is shown that OGP-tFNAs can protect bone marrow stromal cells from 5-fluorouracil (5-FU)-induced DNA damage and apoptosis. OGP-tFNAs pretreatment activates the extracellularly regulated protein kinase signal and downregulates apoptosis-related proteins. OGP-tFNAs also alleviate the chemotherapy-induced inhibition of hematopoiesis-related cytokine expression, which is crucial for hematopoiesis reconstitution. In conclusion, OGP-tFNAs can protect hematopoietic cells and their microenvironment from chemotherapy-induced injuries and myelosuppression, while promoting hematopoiesis regeneration.