Allogeneic stem cell transplantation for trisomy 8-positive myelodysplastic syndrome or myelodysplastic/myeloproliferative disease with refractory Behçet's disease: Case report and the review of literature.

We had two cases of trisomy 8-positive myelodysplastic syndrome (MDS) with incomplete Behçet's disease (BD) in which the remissions of both diseases were maintained by allogeneic stem cell transplantation (allo-SCT). Among MDS with BD patients, sometimes it is difficult to control the symptoms of BD with standard therapies such as corticosteroids and tumor necrosis factor (TNF) inhibitors. Although there should be careful consideration regarding indications for transplantation, our two cases, in which refractory BD was completely controlled by allo-SCT, suggest that allo-SCT can be one of the treatment options for higher-risk MDS with BD patients.

[Treatment for acute leukemia showing PCR-positivity of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) at initial diagnosis: a case report and review of literature].

The novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is rapidly spreading across the world. We encountered two patients with COVID-19 who underwent treatment for acute leukemia at initial diagnosis. Both the patients received conventional induction therapy without the exacerbation of COVID-19. Although the impact of SARS-CoV-2 on the treatment of leukemia is unclear, our treatment experience suggests that there is no major contraindication to standard chemotherapy for acute leukemia in patients with COVID-19. As COVID-19 continues to be a threat worldwide, further evaluations of large cohorts are needed for future treatment decisions for acute leukemia with COVID-19.

Time course of programmed cell death, which included autophagic features, in hybrid tobacco cells expressing hybrid lethality.

KEY MESSAGE: PCD with features of vacuolar cell death including autophagy-related features were detected in hybrid tobacco cells, and detailed time course of features of vacuolar cell death were established. A type of interspecific Nicotiana hybrid, Nicotiana suaveolens × N. tabacum exhibits temperature-sensitive lethality. This lethality results from programmed cell death (PCD) in hybrid seedlings, but this PCD occurs only in seedlings and suspension-cultured cells grown at 28 °C, not those grown at 36 °C. Plant PCD can be classified as vacuolar cell death or necrotic cell death. Induction of autophagy, vacuolar membrane collapse and actin disorganization are each known features of vacuolar cell death, but observed cases of PCD showing all these features simultaneously are rare. In this study, these features of vacuolar cell death were evident in hybrid tobacco cells expressing hybrid lethality. Ion leakage, plasma membrane disruption, increased activity of vacuolar processing enzyme, vacuolar membrane collapse, and formation of punctate F-actin foci were each evident in these cells. Transmission electron microscopy revealed that macroautophagic structures formed and tonoplasts ruptured in these cells. The number of cells that contained monodansylcadaverine (MDC)-stained structures and the abundance of nine autophagy-related gene transcripts increased just before cell death at 28 °C; these features were not evident at 36 °C. We assessed whether an autophagic inhibitor, wortmannin (WM), influenced lethality in hybrid cells. After the hybrid cell began to die, WM suppressed increases in ion leakage and cell deaths, and it decreased the number of cells containing MDC-stained structures. These results showed that several features indicative of autophagy and vacuolar cell death were evident in the hybrid tobacco cells subject to lethality. In addition, we documented a detailed time course of these vacuolar cell death features.

Endosomal trafficking pathway regulated by ARA6, a RAB5 GTPase unique to plants.

Lineage-specific expansion, followed by functional diversification of key components that act in membrane trafficking, is thought to contribute to lineage-specific diversification of organelles and membrane trafficking pathways. Indeed, recent comparative genomic studies have indicated that specific expansion of RAB and SNARE molecules occurred independently in various eukaryotic lineages over evolutionary history. However, experimental verification of this notion is difficult, because detailed functional analyses of RAB and SNARE proteins uniquely acquired by specific lineages are essential to understanding how new membrane trafficking pathways may have evolved. Recently, we found that a plant-specific RAB GTPase, ARA6, and a plant-unique R-SNARE, VAMP727, mediate a trafficking pathway from endosomes to the plasma membrane in Arabidopsis thaliana. Although a similar endosomal trafficking pathway was also reported in animals, the molecular machineries acting in these trafficking systems differ between animals and plants. Thus, trafficking pathways from endosomes to the plasma membrane appear to have been acquired independently in animal and plant systems. We further demonstrated that the ARA6-mediated trafficking pathway is required for the proper salt-stress response of A. thaliana. These results indicate that acquisition of a new membrane trafficking pathway may be associated with maximization of the fitness of each organism in a lineage-specific manner.

A case of primary leiomyoma of the liver in a patient without evidence of immunosuppression.

A 31-year-old Japanese male was admitted to our hospital for investigation of an asymptomatic nodular lesion of the liver detected by abdominal ultrasonography (US) during a routine medical examination. Computed tomography (CT) revealed a single, hypovascular mass 35 mm in diameter, within the left lobe of the liver. The tumor demonstrated hypointensity on T1-weighted, and hyperintensity on T2-weighted magnetic resonance (MR) imaging. Hematological and biochemical investigations were normal. There were no abnormalities of the gastrointestinal or urinary tracts. A left lateral segmentectomy of the liver was performed. Pathological examination of the nodule revealed a primary leiomyoma of the liver, with positive immunohistochemical staining for vimentin and desmin antigens. Primary leiomyoma of the liver is rare, with the majority of cases associated with immunodeficiency disorders. This patient had no evidence of any underlying disease. Primary leiomyoma of the liver should be considered when a nodular lesion is found in a patient without evidence of viral hepatitis.