Rationale: Managing the health of vulnerable groups is an important component of health care. Given the long-term burden of radiation-release incidents among those exposed, managing the health of vulnerable groups following a nuclear disaster is very important. However, there is limited information available concerning the long-term management of the health effects of radiation exposure in vulnerable groups following nuclear disasters. After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, Minamisoma City launched internal radiation exposure monitoring program for local residents, using whole body counter (WBC) units. In 2017, a man of low socio-economic status (SES), was found to have the highest level of internal contamination detected in a person living in the Soma District in recent years. This report describes the case so that the lessons learned can be applied in future nuclear disaster settings. Patient concerns: A 77-year-old Japanese man, who had been homeless for 2 months and had been staying in the exclusion zone of Minamisoma City, was brought to our hospital. He had become homeless because a lack of communication between social support services had led to his eviction from leased housing after free housing support for evacuees was terminated. Diagnoses: He was admitted with a diagnosis of dehydration and malnutrition. A WBC unit was used to assess his body burden of radioactive cesium. This revealed levels of Cs-134 and Cs-137 of 538 Bq/body and 4,993 Bq/body, respectively. Intervention: He received intravenous fluid therapy and health monitoring. The paperwork required for him to receive public income support was processed during hospitalization. Outcome: He was discharged to public housing after 9 days, and municipal workers started visiting him regularly after his discharge. Lessons: A high level of internal radiation contamination may occur after a nuclear disaster. This may be associated with a decline in social support, poverty, and social isolation, and may have more impact on people in poor health than on the general population. It would be useful to strengthen linkages between local government and welfare service providers to increase social support for vulnerable groups requiring health care, not only following disasters, but also under normal circumstances.

Kidney organoids possess the potential to revolutionize the treatment of renal diseases. However, their growth and maturation are impeded by insufficient growth of blood vessels. Through a PubMed search, we have identified 34 studies that attempted to address this challenge. Researchers are exploring various approaches including animal transplantation, organ-on-chips, and extracellular matrices (ECMs). The most prevalent method to promote the maturation and vascularization of organoids involves transplanting them into animals for in vivo culture, creating an optimal environment for organoid growth and the development of a chimeric vessel network between the host and organoids. Organ-on-chip technology permits the in vitro culture of organoids, enabling researchers to manipulate the microenvironment and investigate the key factors that influence organoid development. Lastly, ECMs have been discovered to aid the formation of blood vessels during organoid differentiation. ECMs from animal tissue have been particularly successful, although the underlying mechanisms require further research. Future research building upon these recent studies may enable the generation of functional kidney tissues for replacement therapies.