208 research outputs found

    Small-for-Size Liver Transplantation Increases Pulmonary Injury in Rats: Prevention by NIM811

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    Pulmonary complications after liver transplantation (LT) often cause mortality. This study investigated whether small-for-size LT increases acute pulmonary injury and whether NIM811 which improves small-for-size liver graft survival attenuates LT-associated lung injury. Rat livers were reduced to 50% of original size, stored in UW-solution with and without NIM811 (5 μM) for 6 h, and implanted into recipients of the same or about twice the donor weight, resulting in half-size (HSG) and quarter-size grafts (QSG), respectively. Liver injury increased and regeneration was suppressed after QSG transplantation as expected. NIM811 blunted these alterations >75%. Pulmonary histological alterations were minimal at 5–18 h after LT. At 38 h, neutrophils and monocytes/macrophage infiltration, alveolar space exudation, alveolar septal thickening, oxidative/nitrosative protein adduct formation, and alveolar epithelial cell/capillary endothelial apoptosis became overt in the lungs of QSG recipients, but these alterations were mild in full-size and HSG recipients. Liver pretreatment with NIM811 markedly decreased pulmonary injury in QSG recipients. Hepatic TNFα and IL-1β mRNAs and pulmonary ICAM-1 expression were markedly higher after QSG transplantation, which were all decreased by NIM811. Together, dysfunctional small-for-size grafts produce toxic cytokines, leading to lung inflammation and injury. NIM811 decreased toxic cytokine formation, thus attenuating pulmonary injury after small-for-size LT

    COMMUNICATION Proteomic and transcriptomic analysis of visual long-term memory in Drosophila melanogaster

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    ABSTRACT The fruit fly, Drosophila melanogaster, is able to discriminate visual landmarks and form visual long-term memory in a flight simulator. Studies focused on the molecular mechanism of long-term memory have shown that memory formation requires mRNA transcription and protein synthesis. However, little is known about the molecular mechanisms underlying the visual learning paradigm. The present study demonstrated that both spaced training procedure (STP) and consecutive training procedure (CTP) would induce long-term memory at 12 hour after training, and STP caused significantly higher 12-h memory scores compared with CTP. Labelfree quantification of liquid chromatography-tandem mass spectrometry (LC-MS/MS) and microarray were utilized to analyze proteomic and transcriptomic differences between the STP and CTP groups. Proteomic analysis revealed 30 up-regulated and 27 down-regulated proteins; Transcriptomic analysis revealed 145 up-regulated and 129 down-regulated genes. Among them, five candidate genes were verified by quantitative PCR, which revealed results similar to microarray. These results provide insight into the molecular components influencing visual long-term memory and facilitate further studies on the roles of identified genes in memory formation

    Follow-up of patients with COVID-19 by the Delta variant after hospital discharge in Guangzhou, Guandong, China

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    The B.1.617.2 (Delta) variant of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has contributed to a new increment in cases across the globe. We conducted a prospective follow-up of COVID-19 cases to explore the recurrence and potential propagation risk of the Delta variant and discuss potential explanations for the infection recurrence. A prospective, non-interventional follow-up of discharged patients who had SARS-CoV-2 infections by the Delta variant in Guangdong, China, from May 2021 to June 2021 was conducted. The subjects were asked to complete a physical health examination and undergo nucleic acid testing and antibody detection for the laboratory diagnosis of COVID-19. In total, 20.33% (25/123) of patients exhibited recurrent positive results after discharge. All patients with infection recurrence were asymptomatic and showed no abnormalities in the pulmonary computed tomography. The time from discharge to the recurrent positive testing was usually between 1-33 days, with a mean time of 9.36 days. The cycle threshold from the real-time polymerase chain reaction assay that detected the recurrence of positivity ranged from 27.48 to 39.00, with an average of 35.30. The proportion of vaccination in the non-recurrent group was higher than that in the recurrently positive group (26% vs. 4%; χ2 = 7.902; P < 0.05). Two months after discharge, the most common symptom was hair loss and 59.6% of patients had no long-term symptoms at all. It is possible for the Delta variant SARS-CoV-2 patients after discharge to show recurrent positive results of nucleic acid detection; however, there is a low risk of continuous community transmission. Both, the physical and mental quality of life of discharged patients were significantly affected. Our results suggest that it makes sense to implement mass vaccination against the Delta variant of SARS-CoV-2

    NIM811 Prevents Mitochondrial Dysfunction, Attenuates Liver Injury, and Stimulates Liver Regeneration After Massive Hepatectomy

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    Massive hepatectomy (MHX) leads to failure of remnant livers. Excessive metabolic burden in remnant livers may cause mitochondrial dysfunction. This study investigated whether blockade of the mitochondrial permeability transition (MPT) with N-methyl-4-isoleucine cyclosporin (NIM811) improves the outcome of MHX

    Exposure to 1800 MHz radiofrequency radiation impairs neurite outgrowth of embryonic neural stem cells

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    A radiofrequency electromagnetic field (RF-EMF) of 1800 MHz is widely used in mobile communications. However, the effects of RF-EMFs on cell biology are unclear. Embryonic neural stem cells (eNSCs) play a critical role in brain development. Thus, detecting the effects of RF-EMF on eNSCs is important for exploring the effects of RF-EMF on brain development. Here, we exposed eNSCs to 1800 MHz RF-EMF at specific absorption rate (SAR) values of 1, 2, and 4 W/kg for 1, 2, and 3 days. We found that 1800 MHz RF-EMF exposure did not influence eNSC apoptosis, proliferation, cell cycle or the mRNA expressions of related genes. RF-EMF exposure also did not alter the ratio of eNSC differentiated neurons and astrocytes. However, neurite outgrowth of eNSC differentiated neurons was inhibited after 4 W/kg RF-EMF exposure for 3 days. Additionally, the mRNA and protein expression of the proneural genes Ngn1 and NeuroD, which are crucial for neurite outgrowth, were decreased after RF-EMF exposure. The expression of their inhibitor Hes1 was upregulated by RF-EMF exposure. These results together suggested that 1800 MHz RF-EMF exposure impairs neurite outgrowth of eNSCs. More attention should be given to the potential adverse effects of RF-EMF exposure on brain development

    P27Kip1, regulated by glycogen synthase kinase-3β, results in HMBA-induced differentiation of human gastric cancer cells

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    <p>Abstract</p> <p>Background</p> <p>Gastric cancer is the second most common cause of global cancer-related mortality. Although dedifferentiation predicts poor prognosis in gastric cancer, the molecular mechanism underlying dedifferentiation, which could provide fundamental insights into tumor development and progression, has yet to be elucidated. Furthermore, the molecular mechanism underlying the effects of hexamethylene bisacetamide (HMBA), a recently discovered differentiation inducer, requires investigation and there are no reported studies concerning the effect of HMBA on gastric cancer.</p> <p>Methods</p> <p>Based on the results of FACS analysis, the levels of proteins involved in the cell cycle or apoptosis were determined using western blotting after single treatments and sequential combinations of HMBA and LiCl. GSK-3β and proton pump were investigated by western blotting after up-regulating Akt expression by Ad-Akt infection. To investigate the effects of HMBA on protein localization and the activities of GSK-3β, CDK2 and CDK4, kinase assays, immunoprecipitation and western blotting were performed. In addition, northern blotting and RNase protection assays were carried out to determine the functional concentration of HMBA.</p> <p>Results</p> <p>HMBA increased p27Kip1 expression and induced cell cycle arrest associated with gastric epithelial cell differentiation. In addition, treating gastric-derived cells with HMBA induced G0/G1 arrest and up-regulation of the proton pump, a marker of gastric cancer differentiation. Moreover, treatment with HMBA increased the expression and activity of GSK-3β in the nucleus but not the cytosol. HMBA decreased CDK2 activity and induced p27Kip1 expression, which could be rescued by inhibition of GSK-3β. Furthermore, HMBA increased p27Kip1 binding to CDK2, and this was abolished by GSK-3β inhibition.</p> <p>Conclusions</p> <p>The results presented herein suggest that GSK-3β functions by regulating p27Kip1 assembly with CDK2, thereby playing a critical role in G0/G1 arrest associated with HMBA-induced gastric epithelial cell differentiation.</p

    Mechanisms of hydration inhibition on the surface of montmorillonite in deep shale via molecular dynamic simulation

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    Borehole instability is one of the most complicated technical problems in oil and gas exploration and development.The hydration and expansion of clay minerals is the critical factor causing wellbore instability in which the surface hydration is difficult to be removed due to the large hydration potential.In this light, through molecular dynamic simulation, this paper probed into the CaCl2 inhibitory effect of concentrations, temperatures and pressures on the surface hydration of montmorillonite which revealed the macroscopic mechanism.Results indicated that inhibition of cations were achieved by binding water molecules on the surface of montmorillonite and decreasing the transport and conductivity of water molecules, thereby regulating the invasion of water molecules into the surface of montmorillonite.The ability of inorganic salts to inhibit surface hydration were CaCl2&gt;NaCl&gt;MgCl2&gt;KCl.The study found that calcium ions easily adsorbed surface water molecules to form stable outer sphere complex.With the increase of CaCl2 concentration, coordination number, hydration number and hydration radius of calcium ion decreased, and the inhibitory effect diminished.When the temperature increased and the pressure decreased, the conductivity and transport capacity of water molecules was enhanced in the system, the coordination number of calcium ion descended, and mechanical strength declined
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