109 research outputs found
Ballast saving balloons with a film of specific optical properties
Large plastic balloon play an important role for scientific observations at high altitude in the field of astrophysics and geophysics. In these observations, it has been well recognized that the long duration balloon flights are indispensable for precise observations. For a normal zero pressure balloon, we need to drop ballast to keep a level altitude during day and night to prevent from altitude excursions. This is due to the temperature change of lifting gas, and the duration of the balloon is limited when all the ballast on board the balloon has been exhausted. In this paper, we discuss a possibility of minimizing the temperature variation of the lifting gas using specific balloon films with suitable optical properties and show the optical properties of some test films for this purpose
Factors affecting serum albumin in the perioperative period of colorectal surgery: a retrospective study
尿路上皮癌微小環境内におけるDisabled Homolog 2 (DAB2) は腫瘍細胞上皮間葉転換を介して遊走能・浸潤能を高める
Disabled homolog-2 (DAB2) has been reported to be a tumor suppressor gene. However, a number of contrary studies suggested that DAB2 promotes tumor invasion in urothelial carcinoma of the bladder (UCB). Here, we investigated the clinical role and biological function of DAB2 in human UCB. Immunohistochemical staining analysis for DAB2 was carried out on UCB tissue specimens. DAB2 expression levels were compared with clinicopathological factors. DAB2 was knocked-down by small interfering RNA (siRNA) transfection, and then its effects on cell proliferation, invasion, and migration, and changes to epithelial-mesenchymal transition (EMT)-related proteins were evaluated. In our in vivo assays, tumor-bearing athymic nude mice subcutaneously inoculated with human UCB cells (MGH-U-3 or UM-UC-3) were treated by DAB2-targeting siRNA. Higher expression of DAB2 was associated with higher clinical T category, high tumor grade, and poor oncological outcome. The knock-down of DAB2 decreased both invasion and migration ability and expression of EMT-related proteins. Significant inhibitory effects on tumor growth and invasion were observed in xenograft tumors of UM-UC-3 treated by DAB2-targeting siRNA. Our findings suggested that DAB2 expression was associated with poor prognosis through increased oncogenic properties including tumor proliferation, migration, invasion, and enhancement of EMT in human UCB.博士(医学)・甲第768号・令和3年3月15日© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)
In vivo regeneration of rat laryngeal cartilage with mesenchymal stem cells derived from human induced pluripotent stem cells via neural crest cells
The laryngotracheal cartilage is a cardinal framework for the maintenance of the airway for breathing, which occasionally requires reconstruction. Because hyaline cartilage has a poor intrinsic regenerative ability, various regenerative approaches have been attempted to regenerate laryngotracheal cartilage. The use of autologous mesenchymal stem cells (MSCs) for cartilage regeneration has been widely investigated. However, long-term culture may limit proliferative capacity. Human-induced pluripotent stem cell-derived MSCs (iMSCs) can circumvent this problem due to their unlimited proliferative capacity. This study aimed to investigate the efficacy of iMSCs in the regeneration of thyroid cartilage in immunodeficient rats. Herein, we induced iMSCs through neural crest cell intermediates. For the relevance to prospective future clinical application, induction was conducted under xeno-free/serum-free conditions. Then, clumps fabricated from an iMSC/extracellular matrix complex (C-iMSC) were transplanted into thyroid cartilage defects in immunodeficient rats. Histological examinations revealed cartilage-like regenerated tissue and human nuclear antigen (HNA)-positive surviving transplanted cells in the regenerated lesion. HNA-positive cells co-expressed SOX9, and type II collagen was identified around HNA-positive cells. These results indicated that the transplanted C-iMSCs promoted thyroid cartilage regeneration and some of the iMSCs differentiated into chondrogenic lineage cells. Induced MSCs may be a promising candidate cell therapy for human laryngotracheal reconstruction
Laryngeal Cartilage Regeneration of Nude Rats by Transplantation of Mesenchymal Stem Cells Derived from Human-Induced Pluripotent Stem Cells
Previous studies transplanted human-induced pluripotent stem cells (hiPSCs)-derived mesenchymal stem cells (iMSCs) into thyroid cartilage defect of X-liked severe combined immunodeficiency (X-SCID) rats and confirmed transplanted cell survival and cartilage regeneration. Thus, this study aimed to investigate the contribution of iMSC transplantation to thyroid cartilage regeneration of nude rats. iMSCs were induced from hiPSCs via a neural crest cell lineage. Then, clumps formed from an iMSC/extracellular matrix complex were transplanted into thyroid cartilage defects in nude rats. The larynx was removed and histological and immunohistochemical analyses were performed 4 or 8 weeks after the transplantation. Human nuclear antigen (HNA)-positive cells were observed in 11 of 12 (91.7%) rats, which indicated that transplanted iMSCs survived in thyroid cartilage defects in nude rats. HNA-positive cells co-expressed SOX9, and type II collagen was identified around HNA-positive cells in 8 of 12 rats (66.7%), which indicated cartilage-like regeneration. Cartilage-like regeneration in nude rats in this study was comparable to the previous report on X-SCID rats (HNA-positive cells were observed in all 14 rats and cartilage-like regeneration was observed in 10 of 14 rats). This result suggests that nude rats could be an alternative to X-SCID rats in thyroid cartilage regeneration experiments using iMSCs, and this nude rat cartilage transplantation model may develop cartilage regeneration research concerning fewer problems such as infection due to immunosuppression
Identification of 45 New Neutron-Rich Isotopes Produced by In-Flight Fission of a 238U Beam at 345 MeV/nucleon
A search for new isotopes using in-flight fission of a 345 MeV/nucleon 238U
beam has been carried out at the RI Beam Factory at the RIKEN Nishina Center.
Fission fragments were analyzed and identified by using the superconducting
in-flight separator BigRIPS. We observed 45 new neutron-rich isotopes: 71Mn,
73,74Fe, 76Co, 79Ni, 81,82Cu, 84,85Zn, 87Ga, 90Ge, 95Se, 98Br, 101Kr, 103Rb,
106,107Sr, 108,109Y, 111,112Zr, 114,115Nb, 115,116,117Mo, 119,120Tc,
121,122,123,124Ru, 123,124,125,126Rh, 127,128Pd, 133Cd, 138Sn, 140Sb, 143Te,
145I, 148Xe, and 152Ba
Inhibitory Effects of Chlorella Extract on Airway Hyperresponsiveness and Airway Remodeling in a Murine Model of Asthma
Chlorella extract (CE) has been shown to induce production of T helper-1 cytokines, and regulate serum IgE levels in animal models of asthma. We aimed to evaluate whether CE could inhibit ovalbumin (OVA)-induced airway hyperresponsiveness (AHR) and airway remodeling in a murine model of asthma. Balb/c mice were allocated to four groups: a control group (no OVA exposure, not given CE), a CE group (no OVA exposure, given CE), an asthma group (sensitized/challenged with OVA, not given CE) and a CE+asthma group (sensitized/challenged with OVA, given CE). In the asthma and CE+asthma groups, mice were sensitized with OVA on day 0 and day 12, and then challenged with OVA on three consecutive days. In the CE and CE+asthma groups, the mice were given feed containing 2% CE. We assessed AHR to methacholine, and analyzed bronchoalveolar lavage fluid (BALF), serum, lung tissue and spleen cells. Administration of CE was associated with significantly lower AHR in OVA-sensitized and challenged mice. CE administration was also associated with marked reduction of total cells, eosinophils and T helper-2 cytokines (IL-4, IL-5 and IL-13) in BALF. In addition, administration of CE significantly decreased the numbers of periodic acid-Schiff (PAS)-positive cells in OVA-sensitized and challenged mice. Administration of CE also directly suppressed IL-4, IL-5 and IL-13 production in spleen cells of OVA-sensitized and challenged mice. These results indicate that CE can partly prevent AHR and airway remodeling in a murine model of asthma
Ghrelin Treatment of Cachectic Patients with Chronic Obstructive Pulmonary Disease: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial
BACKGROUND: Pulmonary cachexia is common in advanced chronic obstructive pulmonary disease (COPD), culminating in exercise intolerance and a poor prognosis. Ghrelin is a novel growth hormone (GH)-releasing peptide with GH-independent effects. The efficacy and safety of adding ghrelin to pulmonary rehabilitation (PR) in cachectic COPD patients were investigated. METHODOLOGY/PRINCIPAL FINDINGS: In a multicenter, randomized, double-blind, placebo-controlled trial, 33 cachectic COPD patients were randomly assigned PR with intravenous ghrelin (2 µg/kg) or placebo twice daily for 3 weeks in hospital. The primary outcomes were changes in 6-min walk distance (6-MWD) and the St. George Respiratory Questionnaire (SGRQ) score. Secondary outcomes included changes in the Medical Research Council (MRC) scale, and respiratory muscle strength. At pre-treatment, serum GH levels were increased from baseline levels by a single dose of ghrelin (mean change, +46.5 ng/ml; between-group p<0.0001), the effect of which continued during the 3-week treatment. In the ghrelin group, the mean change from pre-treatment in 6-MWD was improved at Week 3 (+40 m, within-group p = 0.033) and was maintained at Week 7 (+47 m, within-group p = 0.017), although the difference between ghrelin and placebo was not significant. At Week 7, the mean changes in SGRQ symptoms (between-group p = 0.026), in MRC (between-group p = 0.030), and in maximal expiratory pressure (MEP; between-group p = 0.015) were better in the ghrelin group than in the placebo group. Additionally, repeated-measures analysis of variance (ANOVA) indicated significant time course effects of ghrelin versus placebo in SGRQ symptoms (p = 0.049) and MEP (p = 0.021). Ghrelin treatment was well tolerated. CONCLUSIONS/SIGNIFICANCE: In cachectic COPD patients, with the safety profile, ghrelin administration provided improvements in symptoms and respiratory strength, despite the lack of a significant between-group difference in 6-MWD. TRIAL REGISTRATION: UMIN Clinical Trial Registry C000000061
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