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BackgroundMesenchymal stem cells (MSCs) are a favored cell source for regenerative medicine because of their multilinage potential. However, the conventional monolayer technique used to culture MSCs, inadequately overcomes their low differentiation capacity. Culture of MSCs in multicellular spheroids, more accurately mimics the in-vivo microenvironment; thus, resolving this problem. In this study, we assessed whether the osteoregenerative potential of MSC spheroids is greater than that of monolayer MSCs.ResultsMSC spheroids were generated from rat MSCs (rMSCs) using low-binding plates. Real-time reverse transcription-polymerase chain reaction and immunocytochemical analysis indicated that osteogenic properties were accelerated in MSC spheroids compared with monolayer rMSCs when treated with an osteoblast-inducer reagent for 7 days. Moreover, increased calcium deposition was visualized in MSC spheroids using Alizarin red staining. In a rat calvarial defect model, micro-computed tomography and histological assays showed that MSC spheroid-engrafted defects experienced enhanced bone regeneration.ConclusionsOur in-vitro and in-vivo results reveal that MSCs in the spheroid culture exhibit enhanced osteoregenerative efficiency compared with monolayer MSCs.

Background Japan implemented a large-scale quarantine on the Diamond Princess cruise ship in an attempt to control the spread of the novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in February 2020. Objective We aim to describe the medical activities initiated and difficulties in implementing quarantine on a cruise ship. Methods Reverse transcription–polymerase chain reaction (RT-PCR) tests for SARS-CoV-2 were performed for all 3711 people (2666 passengers and 1045 crew) on board. Results Of those tested, 696 (18.8%) tested positive for coronavirus disease (COVID-19), of which 410 (58.9%) were asymptomatic. We also confirmed that 54% of the asymptomatic patients with a positive RT-PCR result had lung opacities on chest computed tomography. There were many difficulties in implementing quarantine, such as creating a dividing traffic line between infectious and noninfectious passengers, finding hospitals and transportation providers willing to accept these patients, transporting individuals, language barriers, and supporting daily life. As of March 8, 2020, 31 patients (4.5% of patients with positive RT-PCR results) were hospitalized and required ventilator support or intensive care, and 7 patients (1.0% of patients with positive RT-PCR results) had died. Conclusions There were several difficulties in implementing large-scale quarantine and obtaining medical support on the cruise ship. In the future, we need to prepare for patients’ transfer and the admitting hospitals when disembarking the passengers. We recommend treating the crew the same way as the passengers to control the infection. We must also draw a plan for the future, to protect travelers and passengers from emerging infectious diseases on cruise ships.

SummaryInterleukin-27 (IL-27) is a new IL-12-related heterodimeric cytokine comprising a novel p28 molecule and the Epstein-Barr-virus-induced gene 3 (EBI3) molecules. It augments initiation of T helper type 1-mediated immunity by enhancing the proliferation and cytokine production of T cells. In this study, we examined whether a secreted form of IL-27 subunits would inhibit IL-27-mediated immunological responses. COS-7 cells transduced with the mouse (m) p28 gene secreted a monomeric mp28 protein; however, those transduced with the mEBI3 gene did not detect a mEBI3 protein in the culture supernatants. The secreted mp28 prevented the IL-27-mediated signal transduction and activator of transcription 1 phosphorylation and subsequently inhibited the IL-27-mediated intercellular adhesion molecule-1 induction and interferon-c production in CD4 + T cells. We generated mp28-expressing murine carcinoma Colon 26 cells and inoculated a mixture of the mp28-and mIL-27-expressing Colon 26 cells into syngeneic BALB/c mice. Simultaneous production of mp28 and mIL-27 from Colon 26 cells suppressed IL-27-mediated anti-tumour effects in the mice. We examined the p28-mediated immune suppression by inoculating mp28-expressing myoblasts into allogeneic mice. Forced production of mp28 suppressed the allogeneic cytotoxic T-lymphocyte induction and subsequently retarded the graft rejection. Furthermore, production of both mp28 and mp40, which inhibits the functions of IL-12 and IL-23, prolonged the graft survival longer than the grafts expressing either mp28 or mp40. We propose that p28 can be a regulatory subunit for IL-27-mediated cellular immune responses and a possible therapeutic agent to suppress unfavourable immune responses.

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Interleukin (IL)‐27, composed of p28 and EBV‐induced gene 3 subunits, has diverse functions in enhancing cell‐mediated immunity and silencing the immunity. We examined whether forced expression of the p28‐linked EBI3 gene in human oesophageal carcinoma cells (Eca109) produced antitumour effects in a T cell‐defective condition. Tumour growth of Eca109 cells expressing IL‐27 (Eca109/IL‐27) was retarded in nude mice compared with parental and vector DNA‐transduced tumours and survival of the mice inoculated with Eca109/IL‐27 cells was prolonged. Expression of the tumour necrosis factor‐α, IL‐1β and IL‐6 genes was up‐regulated in Eca109/IL‐27 tumour specimens while the tumours remained small in size but the increased transcription was subsequently down‐regulated in enlarged tumours. Spleen cells from mice‐bearing Eca109/IL‐27 tumours produced interferon‐γ and showed YAC‐1‐targeted cytotoxic activities greater than those of mice inoculated with parental or vector DNA‐transducer tumours. Numbers of DX5+CD69+ natural killer cells in spleen of mice‐bearing Eca109/IL‐27 tumours and those of CD31+ cells within Eca109/IL‐27 tumours remained the same as found in mice‐bearing parental or vector DNA‐transduced tumours. These data collectively suggest that the IL‐27‐mediated antitumour effects produced in a mature T cell‐defective condition were attributable to enhanced interferon‐γ production and natural killer activities.

Interlayer exchange coupling (IEC) in trilayers, which consist of a full Heusler Co2MnSi (CMS) phase as ferromagnetic layers separated by a Cr spacer layer, has been investigated. The shape of magnetization loops shows unusual oscillatory behavior with the thickness of Cr. The oscillation period is about 3.3–3.5nm. The charecteristics of magnetization curves show that 90° coupling plays a dominant role in IEC between CMS layers. Moreover, the strength of 90° coupling turns out to be very high (up to −1.85ergs∕cm2) around the first oscillation peak.

Human induced pluripotent stem (iPS) cells can differentiate into hepatocyte lineages, although the phenotype of the differentiated cells is immature compared to adult hepatocytes. Improvement of cell-cell interactions between epithelium and mesenchyme is a potential approach to address this phenotype issue. In this study, we developed a model system for improving interactions between human iPS-derived hepatic progenitor cells (iPS-HPCs) and human iPS-derived hepatic stellate cell-like cells (iPS-HSCs). The phenotype of iPS-HSCs, including gene and protein expression profiles and vitamin A storage, resembled that of hepatic stellate cells. Direct co-culture of iPS-HSCs with iPS-HPCs significantly improved hepatocytic maturation in iPS-HPCs, such as their capacity for albumin production. Next, we generated iPS cell lines overexpressing LIM homeobox 2 (LHX2), which suppresses myofibroblastic changes in HSCs in mice. Hepatocytic maturation in iPS-HPCs was significantly increased in direct co-culture with iPS-HSCs overexpressing LHX2, but not in co-culture with a human hepatic stellate cell line (LX-2) overexpressing LHX2. LHX2 regulated the expression of extracellular matrices, such as laminin and collagen, in iPS-HSCs. In conclusion, this study provides an evidence that LHX2 upregulation in iPS-HSCs promotes hepatocytic maturation of iPS-HPCs, and indicates that genetically modified iPS-HSCs will be of value for research into cell-cell interactions.