The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19) and the ensuing worldwide pandemic. The spread of the virus has had global effects such as activity restriction, economic stagnation, and collapse of healthcare infrastructure. Severe SARS-CoV-2 infection induces a cytokine storm, leading to acute respiratory distress syndrome (ARDS) and multiple organ failure, which are very serious health conditions and must be mitigated or resolved as soon as possible. Mesenchymal stem cells (MSCs) and their exosomes can affect immune cells by inducing anti-inflammatory macrophages, regulatory T and B cells, and regulatory dendritic cells, and can inactivate T cells. Hence, they are potential candidate agents for treatment of severe cases of COVID-19. In this review, we report the background of severe cases of COVID-19, basic aspects and mechanisms of action of MSCs and their exosomes, and discuss basic and clinical studies based on MSCs and exosomes for influenza-induced ARDS. Finally, we report the potential of MSC and exosome therapy in severe cases of COVID-19 in recently initiated or planned clinical trials of MSCs (33 trials) and exosomes (1 trial) registered in 13 countries on ClinicalTrials.gov.

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Eleven gliomas were serially cultivated and examined for DNA distribution by flow cytometry and simultaneously for morphological features by light microscopy at the various passage levels until passage 50 at most. Seven gliomas (four low-grade gliomas, three anaplastic gliomas) showed a similar DNA distribution pattern with a main diploid and small tetraploid peaks at various passages. In this group, only one culture formed a permanent cell line, whereas six cultures showed a limited growth ranging from 6 to 24 passages. In contrast, the other four gliomas (each an anaplastic glioma) showed a marked change of DNA distribution through passages and finally a single DNA aneuploid population prospered. Each of these four gliomas yielded established cell lines. Thus, it is suggested that the change of DNA ploidy and prosperity of DNA aneuploid populations in flow cytometry might be used as early and reliable indices for the later establishment of glioma-derived permanent cell lines. Since the changes of DNA distribution are frequently associated with the morphological changes, as seen in the latter group, careful tracing of morphological features is valuable in determining of the fate of cultures, especially in the absence of a flow cytometer. The correlation between the potential to become established cell lines and histology of the original gliomas is also discussed.

Ulcerative colitis, a chronic and recurrent inflammatory disease, is localized to the colonic mucosa but can affect other organs and lead to various complications. Gastroduodenitis associated with ulcerative colitis has been reported. However, little is known about esophageal ulcers. We herein report two rare cases of esophageal ulcers associated with ulcerative colitis. Furthermore, the clinical and histological characteristics of 18 previously reported cases are summarized. This case series and literature review will encourage the accurate diagnosis and treatment of esophageal ulcers associated with ulcerative colitis.

Background and Aims: Decompensated cirrhosis with fibrosis progression causes portal hypertension followed by an oedematous intestinal tract. These conditions weaken the barrier function against bacteria in the intestinal tract, a condition called leaky gut, resulting in invasion by bacteria and bacterial components. Here, we investigated the role of outer-membrane vesicles (OMVs) of Escherichia coli, which is the representative pathogenic gut-derived bacteria in patients with cirrhosis in the pathogenesis of cirrhosis. Methods:We investigated the involvement of OMVs in humans using human serum and ascites samples and also investigated the involvement of OMVs from E. coli in mice using mouse liver-derived cells and a mouse cirrhosis model.