ABSTRACT
The optimal timing of glucocorticoid treatment for coronavirus disease 2019 (COVID-19) pneumonia is uncertain. We evaluated the clinical outcomes of methylprednisolone therapy (MPT) for patients with a high-risk common type (HRCT) COVID-19 pneumonia. We conducted a multicenter retrospective cohort study in Northeast China. A comparison was performed between the standard treatment (SDT) group and the SDT + MPT group to determine the efficacy of methylprednisolone in treating HRCT COVID-19 pneumonia. We collected the medical records of 403 patients with HRCT COVID-19 pneumonia (127 in the SDT + MPT group and 276 in the SDT group). None of the patients had received mechanical ventilation or died. Furthermore, there were no side effects associated with MPT. Patients in the SDT + MPT group treated with methylprednisolone received an intravenous injection for a median interval of five days (interquartile range of 3 to 7 days). The trends in lymphocyte count, C-reactive protein, interleukin 6, lactic acid dehydrogenase, respiratory rate, SpO2, PaO2, D-dimer and body temperature were similar between the SDT + MPT and SDT groups. The results for the SDT + MPT group seemed to improve faster than those for the SDT group; however, the results were not statistically significant. Clinical outcomes revealed that the average hospitalized days and the rate of progression to severe type COVID-19 pneumonia in both the SDT + MPT group and the SDT group were 14.56 ± 0.57 days versus 16.55 ± 0.3 days (p = 0.0009) and 21.26% (27/127) versus 32.4% (89/276) (p = 0.0247), respectively. The 16-day nucleic acid negative rate was higher in the SDT + MPT group than in the SDT group, 81.73% (104/127) versus 65.27% (180/276) (p = 0.0006). MPT effectively prevents patients with HRCT COVID-19 pneumonia from progressing to the severe stage.
Subject(s)
COVID-19 Drug Treatment , Glucocorticoids/therapeutic use , Humans , Methylprednisolone/adverse effects , Methylprednisolone/therapeutic use , Retrospective Studies , SARS-CoV-2 , Treatment OutcomeABSTRACT
Treatment of dairy wastewater by a two-stage membrane process with ultrafiltration (UF) and nanofiltration (NF) was investigated. The results showed that the flux of UF was higher at pH = 4.6 than that at pH = 8 because the resistance of the fouling membrane was lower at the isoelectric point of protein (pH = 4.6) in UF operation. Protein rejection exceeded 99% by UF + NF operation. Lactose rejections were 98.5 and 54% for UF + NF90 and UF + NF270 respectively. Experiments on membrane cleaning showed that the fouling layer of UF and NF was mainly protein and casein which could be removed by aqueous NaOH with pH = 10. The result of long-term experiments showed that the chemical oxygen demand (COD) of NF90 permeates was below 70 mg/L consistently and the wastewater could be concentrated to 24% by a two-stage membrane process.
Subject(s)
Dairying , Industrial Waste/analysis , Membranes, Artificial , Nanotechnology/methods , Ultrafiltration/methods , Waste Disposal, Fluid/methods , Water Purification/methods , Biofouling , Biological Oxygen Demand Analysis , Hydrogen-Ion Concentration , Sodium Hydroxide/chemistry , SolutionsABSTRACT
Plant cells cultured in bioreactors are strongly influenced by mechanical forces. However, the molecular mechanism of plant cell mechanoreception has maintained unclear. In animal cells, the Arg-Gly-Asp (RGD) motif can be found in proteins of the extracellular matrix. Integrins link the intracellular cytoskeleton of cells with the extracellular matrix by recognizing this RGD motif. Integrin has been demonstrated to function as an apparatus not only for adhesion but also for mechanotransduction. In plant cells, the molecules that mediate the structural continuity between wall and membrane are unknown. Here, we found that synthetic RGD peptide could dramatically reduce the level of phosphorylation of MAPK-like cascades that are activated by shear stress and reduce the alkalinization response, production of reactive oxygen species (ROS) and accumulation of phenolics by Taxus cuspidata cells during shear stress. These results implicate that a RGD recognition system may exist in Taxus cells and play an important role in signal transduction of shear stress. Although the Arabidopsis genome database shows that the plant seems to lack a homologue of animal integrin, plant cells may use other RGD-binding proteins to recognize the RGD motif. The correlative mechanism is discussed.
Subject(s)
Oligopeptides/pharmacology , Signal Transduction/drug effects , Taxus/cytology , Blotting, Western , Cells, Cultured , Chromatography, Liquid , Mitogen-Activated Protein Kinases/metabolism , Phenols/metabolism , Reactive Oxygen Species/metabolism , Stress, Mechanical , Tandem Mass Spectrometry , Taxus/drug effects , Taxus/metabolismABSTRACT
The importance of nitric oxide (NO) in regulating plant cell responses to environmental stresses is becoming evident. Here the possible role of NO in suspension cultures of Taxus cuspidata under shear stress was investigated in a Couette-type shear reactor. It was found that shear stress with 190 s(-1) caused NO generation in 8 h. NO formation can be inhibited by N-nitro-L-arginine, a nitric oxide synthase inhibitor. Moreover, the activity of glutathione S-transferase (GST), a principal enzyme responsible for detoxification, decreased during shear stress. This inactivation partially recovered when NOS inhibitor or NO scavenger was added into cell cultures during shear stress. Treatment with reactive nitrogen species (RNS) also caused inactivation of GST in cells. The results indicate that NO plays a crucial role in GST inactivation in Taxus cuspidata cells under shear stress.
