Hepatocyte growth factor gene therapy prevents radiation-induced liver damage

AIM: To transfer human HGF gene into the liver of rats by direct electroporation as a means to prevent radiationinduced liver damage.METHODS: Rat whole liver irradiation model was accomplished by intra-operative approach. HGF plasmid was injected into liver and transferred by electroporation using a pulse generator. Control rats (n = 8) received electrogene therapy (EGT) vehicle plasmid and another 8rats received HGF-EGT 100 μg 48 h before WLIR.Expression of HGF in liver was examined by RT-PCR and ELISA methods. Apoptosis was determined by TUNEL assay. Histopathology was evaluated 10 wk after whole liver irradiation.RESULTS: Marked decrease of apoptotic cells and downregulation of transforming growth factor-beta 1 (TGF-β1)mRNA were observed in the HGF-EGT group 2 d after liver irradiation compared to control animals. Less evidence of radiation-induced liver damage was observed morphologically in liver specimen 10 wk after liver irradiation and longer median survival time was observed from HGF-EGT group (14 wk) compared to control rats (5 wk). (P = 0.031).CONCLUSION: For the first time it has been demonstrated that HGF-EGT would prevent liver from radiation-induced liver damage by preventing apoptosis and down-regulation of TGF-β1.

Protection effect of Emodin pretreatment on intestinal I-RI damage of intestinal mucosa in ratsa

Objective:To linvestigate the protective effect and mechanism of emodin pretreatment on intestinal mucosa of rats with intestinal ischemia-reperfusion injury.Methods:A total of 50SD rats were randomly divided into control group,model group,emodin groups of low,medium and high dose,with 10 in each group.Ischemia-reperfusion injury(I-RI)mode was established by using noninvasive clamp on superior mesentericartery(SMA).Control group and model group were pretreated with 0.5%sodium carboxymethyl cellulose solution lavage 2 h before operation,emodin groups of low,medium and high dose were given emodin lavage with 20,40,60 mg/kg pretreatment,femoral venous blood before the lavage pretreatment(TO)and 1 h ischemia(Tl),and inferior vena venous blood after 1 h of reperfusion(T2)were extracted from each group of rats for detection of serun level of intestinal fatty acid binding protein(I-FABP),tumor necrosis factor(TNF-α),endotoxin,interleukin 6(IL-6),and die content of diamine oxidase(DAO);Mter model establishment,the rats were sacrificed,intestine homogenate was prepared by using blind intestinal tissue to detect intestinal tissue myeloperoxidase(MPO],malondialdehyde(MDA)and superoxide dismutase(SOD)levels.And upper small intestine tissue was retrieved,followed by fixation and conventional HE staining to observe intestinal tissue morphology under light microscopy.Results:In emodin groups of low,medium and high dose at T1 and T2,I-FABP,TNF-α,endotoxin.IL,-6 and DAO level were significandy lower than that of model group(P<0.05);in emodin group of low,medium and high dose,MPO and MDA content in intestinal tissue homogenate was significantly lower than that in model group(P<0.05),SOD level was significantly higher than that of model group(P<0.05).Intestinal damage of emodin low,medium and high dose groups were significandy lighter than model group.Conclusions:Emodin pretreatment has certain protective effect on intestinal mucosa in ischemia reperfusion injury.

Temperature-resistant and salt-tolerant mixed surfactant system for EOR in the Tahe Oilfield

A new temperature-resistant and salt-tolerant mixed surfactant system(referred to as the SS system)for enhancing oil recovery at the Tahe Oilfield(Xinjiang,China)was evaluated.Based on the analysis of the crude oil,the formation water and rock components in the Tahe Oilfield,the long-term thermal stability,salt tolerance and the ability to change the wettability,interfacial activity and oil washing efficiency of the mixed surfactant system were studied.The system contains the anionic surfactant SDB and another cationic surfactant SDY.When the total mass concentration of the SS solution is 0.15 wt%,m(SDB)/m(SDY)ratio is 1 to 1,and excellent efficiencies are achieved for oil washing for five kinds of Tahe Oilfield crude oils(more than 60%).In addition,after adding cationic surfactant,the adsorption capacity of the surfactant is further reduced,reaching 0.261 mg/g.The oil displacement experiments indicate that under a temperature of 150°C and a salinity of 24.6×104 mg/L,the SS system enhances the oil recovery by over 10%after water flooding.The SS anionic–cationic surfactant system is first presented in the open literature that can be successfully applied to obtain predictions of Tahe Oilfield carbonate reservoirs with a high temperature and high salinity.

Distribution,characteristics and influencing factors of fresh groundwater resources in the Loess Plateau,China

The fresh groundwater in the Loess Plateau serves as a major source of water required for the production and livelihood of local residents and is greatly significant for regional economic and social development and ecological protection.This paper analyzes the hydrogeological conditions and groundwater characteristics in the Loess Plateau,expatiates on the types and distribution characteristics of the fresh groundwater in the plateau,and analyzes the influencing factors and mechanisms in the formation of the fresh groundwater in the plateau as a priority.Based on this,it summarizes the impacts of human activities and climatic change on the regional fresh groundwater.The groundwater in Loess Plateau features uneven temporal-spatial distribution,with the distribution space of the fresh groundwater closely relating to precipitation.The groundwater shows a distinct zoning pattern of hydrochemical types.It is fresh water in shallow parts and is salt water in deep parts overall,while the fresh water of exploration value is distributed only in a small range.The storage space and migration pathways of fresh groundwater in the loess area feature dual voids,vertical multilayers,variable structure,poor renewability,complex recharge processes,and distinct spatial differences.In general,the total dissolved solids(TDS)of the same type of groundwater tends to gradually increase from recharge areas to discharge areas.Conditions favorable for the formation of fresh groundwater in loess tablelands include the low content of soluble salts in strata,weak evaporation,and special hydrodynamic conditions.Owing to climate change and human activities,the resource quantity of regional fresh water tends to decrease overall,and the groundwater dynamic field and the recharge-discharge relationships between groundwater and surface water have changed in local areas.Human activities have a small impact on the water quality but slightly affect the water quantity of the groundwater in loess.

Effect of intestinal function-recovering decoction on treatment of multiple organ dysfunction syndrome in rats

Objective:To analyze the effect of intestinal function-recovering decoction on multiple organ dysfunction syndrome in rats,and to investigate a novel solution to multiple organ dysfunction syndrome.Methods:Multiple organ dysfunction syndrome was induced in 60 Sprague-Dawley rats by intestinal ischemia-reperfusion combined with cecal ligation and puncture.Then these rats were intragastrically administered physiological saline(group Ⅰ,n=20),ampicillin(group Ⅱ,n=20) or intestinal function-recovering decoction(group Ⅲ,n=20).After treatment, serum malondialdehyde and superoxide dismutase levels were compared among three groups. Simultaneously,bacterial culture of various organ tissues was performed and bacterial and endotoxin translocation were observed.Results:Compared with group 1,serum malondialdehyde, alanine aminotransferase and aspartate aminotransferase levels were significantly decreased(all P<0.05) and serum superoxide dismutase level was significantly increased(P<0.05) in the group Ⅲ. However,there were no significant differences in these indices between groups Ⅱ and Ⅲ(P>0.05). The rate of bacterial translocation in the groups Ⅱ and Ⅲ was significantly lower than in the group Ⅰ(P<0.05),and no significant difference was observed between groups Ⅱ and Ⅲ(P>0.05). Conclusions:Intestinal function-recovering decoction can significantly reduce endotoxin and bacterial translocation and stabilize enteral oxidative-antioxidative balance.