High exogenous humus inhibits greenhouse gas emissions from steppe lakes.

Although freshwater lakes are considered to be an important source of greenhouse gas (GHG) emissions, the potential driving mechanisms of such emissions are not well understood, especially in steppe lakes. In this study, the GHG emission characteristics in Hulun Lake Basin, including Hulun Lake, Beier Lake, Wulannuoer Lake, and their surrounding watersheds were investigated. The average methane (CH4) and nitrous oxide (N2O) emission fluxes released from rivers were 67.84 ± 20.53 and 0.11 ± 0.04 µg m-2·min-1, which were larger than those of lakes, with values of 28.60 ± 13.02 and 0.06 ± 0.02 µg m-2·min-1, respectively. Conversely, the average carbon dioxide (CO2) emission flux from lakes (1816.58 ± 498.98 µg m-2·min-1) was higher than that of rivers of (1795.41 ± 670.49 µg m-2·min-1). The water in Hulun Lake Basin was rich in organic matter and had a high chemical oxygen demand (COD). Three-dimensional fluorescence combined with a parallel factor analysis (3D-EEM-PARAFAC) demonstrated that the organic matter was composed of four humus types (from Component 1 (C1) to Component 4 (C4)), of which, C1 and C4 were terrestrial humus. The fluorescence index (FI) and humification index (HIX) indicated that the organic matter in the water was mainly imported from exogenous humus. The GHG emission fluxes were negatively correlated with these four components, indicating that GHG emissions were mainly affected by the organic matter source and components, and humus was the most important factor that inhibited GHG emissions in steppe lakes. However, the GHG emission flux was relatively high in some areas of the lake, especially in areas with high nutrient levels or where algal blooms occurred, as evidenced by the significantly positive correlations with total nitrogen (TN), total phosphorous (TP), and chlorophyll-a (chl-a) (p < 0.01). The algae-derived organic matter simulated the decomposition of refractory humus, thus, promoting GHG emissions. These findings are crucial for accurately evaluating the GHG emission fluxes, understanding the carbon cycle, and proposing future management strategies for steppe lakes.

Effect of Shengbai Decoction on Chemotherapy-Induced Myelosuppression and Survival of Gastric Cancer Patients After Radical Resection: A Retrospective Study.

BACKGROUND Myelosuppression is one of the most common chemotherapy-induced adverse events and results in a series of clinical symptoms. This study aimed to evaluate the effect of Shengbai decoction (SD) on chemotherapy-induced myelosuppression and survival of gastric cancer (GC) patients after radical resection. MATERIAL AND METHODS We retrospectively analyzed data from 115 patients with stage II-III GC who underwent adjuvant chemotherapy after radical resection between May 2015 and June 2017 in our hospital. Among these patients, 57 received Shengbai decoction along with adjuvant chemotherapy (SD group), while 58 received adjuvant chemotherapy alone (control group). Medical records, including adverse events, the treatment completion rate of adjuvant chemotherapy, 3-year overall survival (OS), and 3-year recurrence-free survival (RFS), were compared. RESULTS Patient characteristics did not differ significantly between the 2 groups. No adverse events related to Shengbai decoction were reported in the SD group. Patients in the SD group had less neutropenia (P=0.0430), thrombocytopenia (P=0.0323), and anemia (P=0.0497). The SD group had a significantly lower probability of dose reduction (P=0.0448). The completion rate of adjuvant chemotherapy of the SD group was considerably higher than that of the control group (P=0.0398). The SD group had a significantly better 3-year RFS (P=0.0369) and 3-year OS (P=0.0455) than the control group. CONCLUSIONS Shengbai decoction effectively improved postoperative survival of patients with GC by alleviating chemotherapy-induced myelosuppression and improving the completion rate of adjuvant chemotherapy.

[Research progress on active components and mechanism of Isatidis Radix for influenza virus].

Isatidis Radix is the dried root of the Isatis indigotica, with pharmacological effects such as heat-clearing and detoxification, cooling blood and pharyngeal relief, antibacterial and anti-inflammatory effects. It is often used clinically to prevent and treat influenza and other diseases. In this paper, relevant domestic and foreign literatures in recent years were summarized, and it was found that Isatidis Radix lignans, indole alkaloids, polysaccharides, etc. were the main active components against influenza virus. Then its pharmacological effects and the mechanism of action were reviewed, providing a basis for in-depth research on the antiviral effect of Isatidis Radix.

Natural product derived phytochemicals in managing acute lung injury by multiple mechanisms.

Acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome (ARDS) as common life-threatening lung diseases with high mortality rates are mostly associated with acute and severe inflammation in lungs. With increasing in-depth studies of ALI/ARDS, significant breakthroughs have been made, however, there are still no effective pharmacological therapies for treatment of ALI/ARDS. Especially, the novel coronavirus pneumonia (COVID-19) is ravaging the globe, and causes severe respiratory distress syndrome. Therefore, developing new drugs for therapy of ALI/ARDS is in great demand, which might also be helpful for treatment of COVID-19. Natural compounds have always inspired drug development, and numerous natural products have shown potential therapeutic effects on ALI/ARDS. Therefore, this review focuses on the potential therapeutic effects of natural compounds on ALI and the underlying mechanisms. Overall, the review discusses 159 compounds and summarizes more than 400 references to present the protective effects of natural compounds against ALI and the underlying mechanism.

Cytoprotective Effects Evaluation of a Novel Danshensu Derivative DEX-018 against Oxidative Stress Injury in HUVECs.

Ischemic heart disease (IHD) is one of the most common cardiovascular diseases with high morbidity and mortality. Danshensu (DSS) is widely used in the treatment of coronary heart disease. In this study, the carboxy group of DSS was esterified with edaravone to synthesize the novel DSS derivative DEX-018 to achieve a synergistic protective effect and overcome the structural deficiency of DSS. The pharmacological effect of DEX-018 against tert-butyl hydrogen peroxide (t-BHP) induced oxidative damage in human umbilical vein endothelial cells (HUVECs) was evaluated. The results demonstrated that pretreatment with DEX-018 significantly increased cell viability and superoxide dismutase (SOD) activity and decreased the lactate dehydrogenase (LDH) leakage rate, malondialdehyde (MDA) level and intracellular reactive oxygen species (ROS) level. In addition, DEX-018 inhibited cell apoptosis and reversed the expression of apoptosis-related proteins (Bcl-2, Bax, and caspase-3) in HUVECs stimulated by t-BHP. Further study on the mechanism of DEX-018 revealed that the expression of p-Akt and p-extracellular signal-regulated kinase 1/2 (ERK1/2) was increased, which suggested that DEX-018 may protect HUVECs against t-BHP induced oxidative injury via the Akt and ERK1/2 signaling pathways. To further validate the correlation, CCK8 was used to detect cell viability after treatment with DEX-018 plus Akt inhibitor (MK2206) and phosphadylinositol 3-kinase (PI3K) inhibitor (LY294002). Compared with DEX-018 alone, MK2206 or LY294002 significantly decreased cell viability of HUVECs, indicating that the protective effect of DEX-018 against t-BHP induced oxidative injury was significantly weakened. It was further verified that the antioxidant and anti-apoptotic effects of DEX-018 were partly related to the PI3K-Akt signaling pathway.

COUP­TFII promotes epithelial­mesenchymal transition by inhibiting miR­34a expression in colorectal cancer.

Chicken ovalbumin upstream promoter­transcription factor II (COUP­TFII) expression is upregulated in colorectal cancer and is associated with its progression and a poor prognosis. The aim of the present study was to determine whether COUP­TFII regulates colorectal cancer cell (CRC) invasion and migration by inhibiting microRNA (miR)­34a. Transwell system and wound healing assays were performed to examine cell invasiveness and migration, respectively. Reverse transcription polymerase chain reaction and western blotting were used to detect the RNA and protein levels of target molecules, respectively. The results revealed that COUP­TFII knockdown significantly inhibited CRC invasion and migration. In addition, the expression of miR­34a, a well­known tumor suppressor was revealed to be inversely correlated with COUP­TFII expression. The miR­34a mimic significantly reduced CRC invasion and migration abilities, while the miR­34a inhibitor enhanced CRC invasion and migration activity. There was no significant difference between the negative small interfering RNA and miR­34a inhibitor groups following knockdown of COUP­TFII. Furthermore, western blotting demonstrated that miR­34a mimics inhibited the epithelial­mesenchymal transition (EMT) process of CRCs, while the miR­34a inhibitor had the opposite effect. Taken together, the results demonstrate that miR­34a regulates CRC invasion and migration by examining the mechanism by which COUP­TFII regulates EMT.

A preventive injection of endothelial progenitor cells prolongs lifespan in stroke-prone spontaneously hypertensive rats.

There is a pressing need for new approaches to prevent stroke. Endothelial progenitor cells (EPCs) promote vascular repair and revascularization in the ischemic brain. The present study sought to evaluate whether preventive delivery of EPCs could prevent or protect against stroke. Stroke-prone spontaneously hypertensive rats (SHR-SP) received a single injection of EPCs, and their survival time was monitored. In addition, at 28 and/or 42 days after a single injection of EPCs, SHR-SP and mice were subjected to cerebral ischemia, and cerebral ischemic injury, local angiogenesis and in vivo EPC integration were determined. Other experiments examined the effects of EPC conditioned medium, and the distribution of donor EPCs taken from GFP transgenic mice. It was found that EPC-pretreated SHR-SP showed longer lifespans than untreated controls. A single preventive injection of EPCs could produce persistent protective effects against cerebral ischemic injury (lasting at least 42 days), and promote local angiogenesis in the ischemic brain, in two types of animals (SHR-SP and normotensive mice). EPCs of donor origin could be detected in the recipient peripheral blood, and integrated into the recipient ischemic brains. Furthermore, it was suggested that mouse EPCs might exert paracrine effects on cerebral ischemic injury in addition to their direct angiogenic effects. In conclusion, a single preventive injection of EPCs prolonged the lifespan of SHR-SP, and protected against cerebral ischemic injury for at least 7 weeks. It is implied that EPC injection might be a promising candidate for a preventive role in patients at high risk for stroke.

Metformin accelerates wound healing in type 2 diabetic db/db mice.

Wound healing impairment is increasingly recognized to be a consequence of hyperglycemia­induced dysfunction of endothelial precursor cells (EPCs) in type 2 diabetes mellitus (T2DM). Metformin exhibits potential for the improvement of endothelial function and the wound healing process. However, the underlying mechanisms for the observed beneficial effects of metformin application remain to be completely understood. The present study assessed whether metformin, a widely used therapeutic drug for T2DM, may accelerate wound closure in T2DM db/db mice. Genetically hyperglycemic db/db mice were used as the T2DM model. Metformin (250 mg/kg/day; intragastric) was administered for two weeks prior to EPC collection and wound model creation in db/db mice. Wound healing was evaluated by alterations in the wound area and the number of platelet endothelial cell adhesion molecule­positive cells. The function of the isolated bone marrow­derived EPCs (BM­EPCs) was assessed by a tube formation assay. The number of circulating EPCs, and the levels of intracellular nitric oxide (NO) and superoxide (O2­) were detected by flow cytometry. Thrombospondin­1 (TSP­1) expression was determined by western blot analysis. It was observed that treatment with metformin accelerated wound healing, improved angiogenesis and increased the circulating EPC number in db/db mice. In vitro, treatment with metformin reversed the impaired BM­EPC function reflected by tube formation, and significantly increased NO production while decreasing O2­ levels in BM­EPCs from db/db mice. In addition, TSP­1 expression was markedly attenuated by treatment with metformin in cultured BM­EPCs. Metformin contributed to wound healing and improved angiogenesis in T2DM mice, which was, in part, associated with stimulation of NO, and inhibition of O2­ and TSP­1 in EPCs from db/db mice.

Chronic Exposure to Subtherapeutic Antibiotics Aggravates Ischemic Stroke Outcome in Mice.

Subtherapeutic antibiotics have been widely used in agriculture since the 1950s, which can be accumulated in human body through various approaches and may have long-term consequences. However, there is limited information about the link between chronic subtherapeutic antibiotic exposure and the outcome of ischemic brain injury. Here we showed that long-term treatment with subtherapeutic chlortetracycline, penicillin or vancomycin, which were widely used in agriculture approved by US Food and Drug Administration (FDA), could impair EPC functions, reduce ischemic brain angiogenesis and aggravate cerebral ischemic injury and long-term stroke outcomes in mice. In addition, transplantated EPCs from chronic antibiotic-treated mice showed a lower therapeutic effect on cerebral ischemic injury reduction and local angiogenesis promotion compared to those from control mice, and EPCs from the donor animals could integrate into the recipient ischemic brain in mice. Furthermore, transplanted EPCs might exert paracrine effects on cerebral ischemic injury reduction in mice, which could be impaired by chronic antibiotic exposure. In conclusion, chronic subtherapeutic antibiotic exposure aggravated cerebral ischemic injury in mice, which might be partly attributed to the impairment of both EPC-mediated angiogenesis and EPCs' paracrine effects. These findings reveal a previously unrecognized impact of chronic subtherapeutic antibiotic exposure on ischemic injury.

Simvastatin ameliorates ionizing radiation-induced apoptosis in the thymus by activating the AKT/sirtuin 1 pathway in mice.

Simvastatin is a HMG-CoA reductase inhibitor widely used to lower plasma cholesterol and to protect against cardiovascular risk factors. The aim of this study was to investigate whether simvastatin attenuates ionizing radiation-induced damage in the mouse thymus and to elucidate the possible mechanisms invovled. For this purpose, male C57BL/6J mice aged 6 weeks were used and exposed to 4 Gy 60Co Î³-radiation with or without simvastatin (20 mg/kg/day, for 14 days). Apoptosis was determined by terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling (TUNEL) assay or transmission electron microscopy (TEM) examination. Thymocytes were also isolated and incubated in DMEM supplemented with 10% FBS at 37˚C and exposed to 8 Gy 60Co Î³-radiation with or without simvastatin (20 µM). The expression levels of Bcl-2, p53, p-p53, AKT, sirtuin 1 and poly(ADP-ribose) polymerase (PARP) were determined by western blot analysis. TUNEL and TEM examination revealed that simvastatin treatment significantly mitigated ionizing radiation-induced apoptosis in the mouse thymus. It was also found that simvastatin treatment increased AKT/sirtuin 1 expression following exposure to ionizing radiation in vivo and in vitro. In the in vivo model, but not in the in vitro model, Bcl-2 and PARP expression was augmented and that of p53/p-p53 decreased following treatment with simvastatin. On the whole, our findings indicate that simvastatin exerts a protective effect against ionizing radiation-induced damage in the mouse thymus, which may be partially attributed to the activation of the AKT/sirtuin 1 pathway.

Metformin ameliorates insulitis in STZ-induced diabetic mice.

BACKGROUND & AIMS: Metformin is currently the most widely used first-line hypoglycemic agent for diabetes mellitus. Besides glucose-lowering action, there is increasingly interest in the potential anti-inflammatory action of this drug. In the present study, we investigated the actions of metformin on experimental insulitis using STZ-induced diabetic mice. METHODS: Mice with acute diabetes induced by STZ were administered metformin by gavage. Changes of blood glucose and body weight, and the daily amount of food and water intake were measured. Pancreatic tissues were collected for histologic analyses. Pathological assessment and immunohistochemistry analysis were used to determine the effect of metformin on insulitis. Inflammatory cytokines in the pancreas and insulin levels were measured through ELISA analysis. RESULTS: Metformin significantly reduced blood glucose levels and improved aberrant water intake behavior in experimental diabetic mice. No significant differences were observed in terms of body weight and food intake behavior in metformin-treated animals. In the STZ-induced model of diabetes, we found the appearance of pronounced insulitis. However, metformin administration reduced the severity of insulitis assessed by blind pathological scoring. In addition, metformin treatment improved insulin levels in experimental diabetic mice. ELISA assay revealed decreased levels of inflammatory response marker IL-1ß and TNF-α in the pancreatic tissues following metformin treatment. CONCLUSION: Metformin attenuated insulitis in the STZ-induced mice model of diabetes. This islet-protective effect might be partly correlated with the anti-inflammatory action of metformin.

Isolation and characterization of putative mesenchymal stem cells from mammalian gut.

Here, we provide a protocol for reliable isolation and subculture of putative mesenchymal stem cells from mice colons. This method provides a good approach to cultivate and characterize putative colonic mesenchymal stem cells (cMSCs). A high purity of cMSCs can be obtained according to this protocol. The whole isolation processes of cMSCs take about 2 h with two important digestion steps involved. Only with common culture medium, maturation of cMSCs in culture proceeds approximately 2 weeks to allow relevant researches to be conducted. This protocol sheds light on better cultivation of MSCs in vitro from post-natal colon tissues. These putative cMSCs share common phenotypic property with those in vivo reported, and contain potential lineage differentiation capacity. The successful culture of cMSCs in vitro provides an ideal model for study of MSCs biology in the intestine.

Early nasogastric feeding versus parenteral nutrition in severe acute pancreatitis: A retrospective study.

OBJECTIVE: To compare the efficacy and safety of early nasogastric enteral nutrition (EN) with total parenteral nutrition (TPN) in patients with severe acute pancreatitis (SAP). METHODS: From July 2008 to July 2014,185 patients with SAP admitted to our centre were enrolled in this retrospective study. They were divided into EN group (n=89) and TPN group (n=96) based on the nutrition support modes. Patients in EN group received nasogastric EN support, while patients in TPN group received TPN support within 72 hours of disease onset. The medical records were reviewed and clinical factors were retrospectively analyzed. RESULTS: There were no significant differences in baseline characteristics between two groups. EN group had significantly lower incidence of pancreatic infections (P=0.0333) and extrapancreatic infections (P=0.0431). Significantly shorter hospital stay (P=0.0355) and intensive-care stay (P=0.0313) were found in EN group. TPN group was found to have significantly greater incidence of multiple organ dysfunction syndrome (MODS) (P=0.0338) and mortality (P=0.0382). Moreover, the incidence of hyperglycemia was significantly higher in TPN group (P=0.0454). CONCLUSIONS: Early nasogastric EN was feasible and significantly decreased the incidence of infectious complications as well as the frequency of MODS and mortality caused by SAP.