Role of oxygen free radicals in patients with acute pancreatitis

AIM:The generation of oxygen free radicals has been implicated in the pathogenesis of experimental pancreatitis. The aim of this study was to determine the role of oxygen free radicals in patients with acute pancreatitis. METHODS:The plasma levels of C-reactive protein(CRP), lipid peroxide(LPO),myeloperoxidase(MPO)and superoxide dismutase(SOD)were measured in 13 patients with acute pancreatitis and 14 healthy volunteers. RESULTS:Among the patients with acute pancreatitis,there were higher plasma levels of LPO and MPO and lower SOD activity in patients with severe pancreatitis than in those with mild pancreatitis.However,there was no significant difference in the serum marker of oxidative stress no matter what the etiology was.The LPO level was especially correlated with the concentration of serum CRP and CT severity index. CONCLUSION:The oxygen free radicals may be closely associated with inflammatory process and the severity of acute pancreatitis.Especially,the concentration of plasma LPO is a meaningful index for determining the severity of the disease.

Changes in erythrocyte membrane ATPases and plasma lipid peroxides in upper abdominal surgery under intravenous procaine-balanced anesthesia

AIM To observe the changes in erythrocyte membrane ATPases and plasma lipid peroxides (LPO) patients with in abdominal surgery under intravenous procaine-balanced anesthesia.METHODS By determining the ATPase activities of erythrocyte membrane, effects of upper abdominal surgery under intravenous procaine-balanced anesthesia on the function of erythrocytes were observed in 15 patients undergoing cholecystectomy and gastrectomy (5 males and 10 females, aged 45.9±10.20 years and weighed 60.60kg±11.93kg). All patients were free from severe renal, hepatic, pulmonary, cardiac, metabolic and endocrinological diseases and acute infection for at least 2 weeks before surgery. Patients receiving any drug known to affect carbohydrate metabolism prior to anesthesia were excluded from the study.RESULTS Erythrocyte membrane Na+, K+-ATPase, Mg2+-ATPase, Ca2+, Mg2+-ATPase activities were not significantly changed 60min-90min after incision as compared with 30min before anesthesia, but were decreased markedly 10min and 24 hours after completion of operation (P＜0.01). Plasma lipid peroxides (LPO) were increased significantly 24 hours after surgery (P＜0.01) following an initially marked but transient reduction. Plasma LPO changes were not correlated with erythrocyte membrane ATPase activities, r=-0.0396, -0.0097 and 0.4383, respectively (P＞0.05).CONCLUSION Abdominal surgical trauma under intravenous procaine-balanced anesthesia may be associated with the decreased ATPase activities of erythrocyte membrane and increased LPO in plasma.

Novel perspective in pancreatic cancer therapy:Targeting ferroptosis pathway

Pancreatic cancer is a highly lethal malignancy with low resection and survival rates and is not sensitive to radiotherapy and chemotherapy.Ferroptosis is a novel form of nonapoptotic regulated cell death characterized by the accumulation of lipid peroxides and reactive oxygen species involved in iron metabolism.Ferroptosis has a significant role in the occurrence and development of various tumors.Previous studies have shown that regulating ferroptosis-induced cell death inhibited tumor growth in pancreatic cancer and was synergistic with other antitumor drugs to improve treatment sensitivity.Herein,we discuss the mechanism,inducers,and developments of ferroptosis in pancreatic cancer to provide new strategies for the treatment of the malignancy.

THE EFFECTS OF RADIX SALVIAE MILTIORRHIZAE ON LIPID ACCUMULATION OF PEROXIDIZED LOW DENSITY LIPOPROTEIN IN MOUSE PERITONEAL MACROPHAGES ?LIPID ANALYSIS AND MORPHOLOGICAL STUDIES

Mouse peritoneal macrophages were incubated in DMEM with pox-LDL and Rradlx Salviae Miltiorrhizae (RSM) to investigate the effects of RSM on the internalization of peroxidized low density lipoprotein (pox-LDL) by using lipid analysis and electron microscopy. Lipid peroxide (LPO) concentrations were increased slightly in the medium after incubation of macrophages with normal LDL (n-LDL), while decreased significantly in the media after incubation of macrophages with pox-LDL. In the three groups with pox-LDL, it could be found that there was a dose-dependent decrease of concentrations of LPO and total cholesterol (TCH) in the two RSM groups, and the decrease in the two RSM groups was much greater than in the group without RSM. RSM accelerated a more decrease of LPO than cholesterol contents in the media containing pox-LDL. The ultrastructural studies also showed that RSM induced the accumulation of lipid droplets in the cytoplasm of mouse peritoneal macrophages. The results suggested that RSM could accelerate the phagocytosis and degradation of pox-LDL by macrophages.

AN AB INITIO STU DY ON THE CORELATION BETWEEN THE ABSOLUTE CONFIGURATION AND THE CD SPECTRA OF ORGANIC PEROXIDES

Correlation between the absolute configuration and the CD spectra of organic peroxides was studied by ab initio method with a mo- d el moleeule CH_3-O-O-CH_3.For P form when 0°≤θ(twist angle of C-O-O-C) <90°, there is positive Cotton effect;when 90°<θ≤180°, there is nega- tive Cotton effect;the curve is bisignate at θ=90°.

Study on the Analgesic Effect and Mechanism of Zhitong Capsule (止痛胶囊) in Adjuvant Arthritis Rats

Objective: To observe the analgesic effect of Zhitong Capsule (止痛胶囊, ZTC) and study its mechanism in adjuvant arthritis (AA) rats. Methods: Forty-eight male Sprague-Dawley rats were randomly divided into six groups with 8 rats in each group. On the first day, except to those in the normal group that were treated with normal saline, the same amount of Freund's complete adjuvant (FCA) was given through intradermal injection into the right hind paw to all the rats in the other groups. From the 17th day of the modeling on, the rats in groups of ZTC were administered daily through gastrogavage with a dose of 1000, 500, 250 mg/kg respectively, while equal volume of normal saline was given to those in the normal group and model group, and an equal volume of aspirin (ASA) solution was given to rats in the ASA group through gastrogavage for 10 days, once per day, and on the 27th day, the analgesic effect of ZTC was measured with heat withdraw method. The activities and contents of superoxide dismutase (SOD) and lipid peroxides (LPO) in serum were observed by spectrophotometry, and the level of beta-endorphin (β-EP) in hypothalamus were determined by the assay of immunohistochemistry. Results: ZTC showed significant effects on enhancing the pain threshold and at the same time it increased the activities of SOD and reduced the contents of LPO in serum. ZTC could also increase the level of β-EP in hypothalamus. Conclusion: ZTC has analgesic effect and its mechanism is probably related with its effect in inhibiting the level of oxygen free radicals in serum and increasing the level of β-EP of hypothalamus in rats.KEY WORD Zhitong Capsule, adjuvant arthritis, superoxide dismutase, lipid peroxides, β-endorphin

Relative Explosive Strength of Some Explosive Mixtures Containing Urea and/or Peroxides

Several mixtures,based on urea derivatives and some inorganic oxidants,including also alumina,were studied by means of ballistic mortar techniques with TNT as the reference standard.The detonation pressure(P),detonation velocity(D),detonation energy(Q),and volume of gaseous product at standard temperature and pressure(STP),V,were calculated using EXPLO5V6.3 thermochemical code.The performance of the mixtures studied was discussed in relation to their thermal reactivity,determined by means of differential thermal analysis(DTA).It is shown that the presence of hydrogen peroxide in the form of its complex with urea(i.e.as UHP)has a positive influence on the explosive strength of the corresponding mixtures which is linked to the hydroxy-radical formation in the mixtures during their initiation reaction.These radicals might initiate(at least partially)powdered aluminum into oxidation in the CJ plane of the detonation wave.Mixtures containing UHP and magnesium are dangerous because of potential auto-ignition.

An experimental study on hepatocyte mitochondrion damage during acute biliary sepsis

In order to elucidate the mechanism of liver damage due to acute biliary sepsis,thechanges of hepatocyte mitochondria were observed during biliary sepsis in the rot.Mitochondrial cal-cium content,lysosome fragility of the hepatocytes,lipid peroxide (LPO) level of fiver tissue,omithine carbamyltransferase (OCT),mitochondrial glutamic-oxaloacetic transaminase (m-GOT) andhepatoplastin were determined.It was found that there were overloading of calcium in mitochondria,increase of lysosome fragility,and accumulation of LPO in the liver.These events would result inadverse effects on mitochondrial function The activity of OCT and m-GOT was significantly in-creased,which suggests that mitochondria are seriously damaged since the 2 enzymes mainly comefrom hepatocyte mitochondria.And the liver reserving function declined progressively.Our study indi-cates that mitochondrial damage does exist during acute biliary sepsis,which might playan important role in liver damage.

Level of lipid peroxides and cuprozinc superoxide dismutase in gastric mucosa and serum of gastrectomized patients

The level of lipid peroxides (LPO) and copper-zinc containing superoxide dismutase (SOD-Ⅰ) in the gastric mucosa and serum was determined in 141 samples from 25 patients after con-ventional subtotal gastrectomy (11 cases of Billroth Ⅰ and 14 cases of Billroth Ⅱ) and 11 patientsafter pylorus and antroseromuscular flap preserving gastrectomy (PAFPG).Those of 11 normal subjects were examined likewise to serve as control.It was found that:(1) The average LPO levelwas much higher and the average SOD-Ⅰ level much lower in the gastric mucosa of the patientsafter conventional subtotal gastrectomy especially the Billroth Ⅱ type than in that of those afterPAFPG.(2) In 36 specimens of stump mucosa,the average LPO level was significantly higher inthe tissue around the anastomotic ring than in that of the body of the stump;no marked differ-ence of SOD-Ⅰ level between the 2 was revealed.(3) The LPO value in the stump mucosa waspositively correlated to and the SOD-Ⅰ value negatively correlated to the pH value of gastric juice.These rindings suggest that the reation of oxygen free radicals in the stump mucosa may be influ-enced by the intragastric pH or by the type of digestive continuity reconstruction,and that thereaction of oxygen free radicals especially the lipid peroxidation may play a role in the pathogenesisof the lesions in the anastomotic stoma.

Alterations of mitochondrial function in ischemia/reperfusion cat heart

The effect of myocardium being subjected to 60 min ischemia and 60 min reperfusion incat cardiopulmonary bypass on level of lipid peroxides(LPO),function of myocardial mitochon-dria and activity of superoxides dismutase(SOD)was studied. Myocardial mitochondrial functionwas depressed slightly 60 rain after ischemia but significantly 60 min after reperfusion.Increasedlipid peroxides content and decreased activity of SOD were observed at 60 rain after ischemia.Af-ter reperfusion,the activity of SOD continued decreasing,and LPO elevated still further.Theseresults support the hypothesis that free radicals may contribute to myocardial reperfusion injury.

A study of pathological changes and pathogenesis of myocardial infarction in rats

One hundred and fifty Wistar rats were randomized into a control group with shamoperation and a left coronary artery occlusion group.Specimens of the blood and myocardiumwere collected at different intervals m 2 months after operation.The morphological changes ofthe myocardium were observed trader optical and electron microscope.Malondialdehyde(MDA)level of the serum and myocardial homogenate,and the activities of lactic dehydrogenase(LDH),succinic dehydrogenase(SDH)and ATPase and histochemical changes of calcium in the ischemicmyocardium were studied.It was found that the mafia changes of myocardial infarction weremyocardial necrosis in the early stage and repair in the late stage.The ultrastructural changes ofischemic injury appeared quite early and involved ahnost all the subcellular organelles.The repairin the late stage was mainly incomplete regeneration of a few myoo.trdM cells.The significanceof the“junction-like”structure of fibroblasts was not dean,it was probably one of themorphological basis of scars.The activities of the enzymes were quickly suppressed afterocclusion,which suggests the exhaustion of energy metabolism.The MDA level of the myocardialhomogenate elevated in the first 24 h after occlusion,suggesting that myocardial ischemia can in-crease lipid peroxidation reduced by oxygen free radicals,It might be one of the Factors of theirreversibility of ischemic myocardial damage.

A study on mitochondrial respiratory dysfunction and lipid peroxidation in the liver after radiation,burn,and combined radiation-burn injuries in mice

Male mice were subjected to 6 Gy total body irradiation,20% TBSAfull-thickness burns,or combined radiation-burn injury and lipid peroxides(LPO),vita-min E,sulfhydryl group,respiratory control ratio(RCR),ADP/O ratio,and cytochromeoxidase activity of the liver mitochondria were determined in the first 9 d postinjury.Theresults are as follows:(1)LPO level increased in the early postinjury stage after combinedradiation-burn injury,on the 5th-7th day after irradiation and on the 7th day postburn.(2)Vitamin E level decreased significantly in the two groups of radiation and burn inju-ries but showed no significant decrease after combined injury.(3)The sulfhydryl groupshowed a tendency to increase in all the 3 groups.(4)The activity of cytochrome oxidaseincreased significantly on the 7th day after radiation but decreased considerably in theburn and combined injury groups.(5)RCR and ADP/O ratio decreased more significantlyin the combined injury group than in either the radiation group or the burn group.These facts suggest that the respiratory dysfunction of the liver mitochondria results mostprobably from the damage on the mitochondrial membrane due to lipid peroxidation.

Enhanced myocardial protection with Ginsenosides in St.Thomas' Hospital cardioplegic solution

Several studies suggest that Ginsenosides have a protective effect on myocardialischemia and reperfusion injury.Using the isolated working rat heart model the effect ofthe St.Thomas’ Hospital cardioplegic solution containing different concentrations ofGinsenosides on the enhancement of myocardial protection following hypothennic ischemicarrest(20 ℃,120min)was evaluated.The concentrations of Ginsenosides in thecardioplegic solutions were 0(control),50,100,and 150μg/ml,respectively.Recoveries ofaortic flow,cardiac output,and minute work markedly improved by adding Ginsenosidesto cardioplegia.Dose-response tests indicated the best protective effect in the group using100 μg/ml,where the generation of thiobarbituric acid reactive materials(malondialdehyde,MDA)markedly reduced.These results showed that Ginsenosides may enhance themyocardial protection of the St.Thomas′ Hospital cardioplegic solution,and that additionof Ginsenosides to cardioplegia may protect the ischemic myocardium from free-radical in-jury.

Changes in erythrocyte membrane ATPase and plasma lipid peroxides during perioperative period

Changes in erythrocyte membrane ATPases and plasma lipid peroxides（LPO） were studiedperioperatively in 15 abdominal surgical patients under intravenous procaine-balanced anesthesia.The resultsrevealed that erythrocyte membrne Na+-K+ATPase,Mg2+ATPase and Ca2+-Mg2+ATPase activities werenot significantly changed at 60～90 min after incision as compared with 30 min before anesthesia,but weredecreased markedly at 10 rain and 24 hours after completion of operation（P【0.01）.Plasma LPO wereincreased significantly by 24 hours after surgery（P【0.01） following an initially marked but transientreduction.Plasma LPO changes were not correlated with erythrocyte membrane ATPase activities,r=-0.0396,-0.0097 and-0.4383 respeetively（P】0.05）.These correlations are suggested to be inducedby neuroendoerine responses after anesthesia and/or surgical trauma.

Clinical Observation on Treatment of Rheumatoid Arthritis with Fengshi Xiandan in 53 Cases

We have successfully developed Fengshi Xiandan (风湿仙丹) and used it to treat 53 cases of rheumatoid arthritis (RA),with indomethacin used to treat another 53 cases of RA as the controls.The results showed that the rate of cure and obvious effect was 54.7% and the total effective rate was 92.4% in the treatment group,as compared to 26.4% and 66.0% respectively in the control group,with an obvious difference in curative effect between the two groups (P<0.01).The improvement of all the main clinical symptoms and signs except arthralgia in the treatment group was superior to that in the control group (P<0.05 or P<0.01). The improvement of erythrocyte sedimentation rate (ESR),rheumatoid factor (RF),C-reaction protein (CRP), immunoglobulin (Ig),T-lymphocyte subgroups,micro-circulation in nail fold,and red blood cell (RBC) and hemoglobin (Hb) of anemia patients in the treatment group was superior to that in the control group (P<0.05 or P<0.01).There was an obvious difference (P<0.05 or P<0.01) in superoxide dismutase (SOD) of RBC and lipid peroxide (LPO) of plasma before treatment in the two groups as compared to normal group (P<0.05 or P<0.01).The level of SOD and LPO after treatment in the treatment group obviously tended to normal as compared to that befbre treatment (P<0.05 or P<0.01).The reduction of LPO in the treatment group was obviously superior to that in the control group (P<0.01).The result shows that Fengshi Xiandan (风湿仙丹) with an obvious curative effect on RA can not only control the symptoms of RA but also improve its pathologic damage and prevent its development.

Amperometric Biosensors Sensitive to Organic Peroxides Based on Immobilization of Redox Organic Dyes and Horseradish Peroxidase in Polyester Ionomer Film

Simple and effective organic biosensors sensitive to organic peroxides such as 2 butanone per oxide and tertbutyl hydroperoxide are constructed by immobilizing a series of redox organic dyes and horseradish peroxidase in Eastman AQ polymer film. The organic dyes are methylene blue, methylene green, meldola blue, new methylene blue N and N methyl phenazine methosulphate. The biosensors display high sensitivity and fast response to tertbutyl hydroperoxide and 2 butanone peroxide because of high efficiency of electron transfer between immobilized horseradish peroxidase and the electrode via the redox organic dyes. The comparison of the biosensors employing different organic dyes is made in formal potential, linear range and response time.

Synthesis, characterization, and biological activities of Pt(Ⅱ) and Pd(Ⅱ2',3',4',5,7-pentahydroxy flavone

Pt(Ⅱ) and Pd(Ⅱ) complexes with 2′,3′,4′,5,7-pentahydroxy-flavone weresynthesized and characterized by elemental analysis, molar conductance, IR, ~1HNMR, TG-DTA, UV-Visspectroscopic techniques, and fluorescence analysis. The scavenging effect on the superoxide radical(O_2^-) and the inhibitory effect on lipid peroxides were also investigated. Both the ligand andthe complexes exhibit scavenging effect on superoxide radicals, and the effect of the complexes isgreater than that of the ligand. The Pt(Ⅱ) complex exhibits the strongest scavenging efficiency.Both Pt(Ⅱ) and Pd(Ⅱ) complexes have the inhibitory effect on lipid peroxides, and the effect ofthe complexes is greater than that of the ligand, but the Pt(Ⅱ) complex has a high effect ofpromoting lipid peroxides.

Exogenous Vitamin K3 and Peroxides Can Alleviate Hypoxia in Bean Seedlings (<i>Phaseolus vulgaris</i>L.)

Oxygen limiting conditions are a common occurrence in root zones of most crop plants and can adversely affect nearly all aspects of plant growth and development including its survival. The objective of this study was to determine the effectiveness of a novel redox cycling agent, vitamin K3, and various peroxides including hydrogen peroxide, calcium peroxide and magnesium peroxide in alleviating the effects of hypoxia in bean seedlings grown in nutrient culture. All the anti-hypoxic agents including vitamin K3 had a positive impact on the overall growth of bean seedlings under hypoxic conditions, but their responses were variable depending on the concentration. With regard to shoot growth, vitamin K3 (5 μM) increased the leaf area significantly, by more than 58% over the hypoxic control plants and produced the highest stem fresh weight similar to calcium peroxide (20 μM) and magnesium peroxide (10 μM). In addition, the use of vitamin K3 resulted in the highest accumulation of chlorophyll (chla + chlb) in the leaves, an increase of nearly two-fold over the hypoxic control plants. Furthermore under hypoxia, calcium peroxide (20 μM) and magnesium peroxide (10 μM) produced the highest leaf biomass (FW) followed by vitamin K3. Vitamin K3 (1 μM) also favored root growth in bean seedlings under hypoxia;it produced the largest increase in root length and root biomass (DW) similar to calcium peroxide and magnesium peroxide. Based on the overall shoot and root growth response of bean seedlings to various anti-hypoxic substances under hypoxic conditions, calcium peroxide, magnesium peroxide and vitamin K3 performed better than hydrogen peroxide. These findings show that vitamin K3 and peroxide salts are effective in alleviating hypoxic stress in bean seedlings and also, further highlight their potential for dealing with hypoxia in wide ranging situations.

Apple Peel Biochemical Changes after Foliar Application of Combined Boron and Calcium II. Photosynthetic Pigments, Total Peroxides and Photochemical Efficiency

Understanding of the physiological effect of post-full-bloom foliar boron combined with calcium (B+Ca) on apple (Malus domestica) peel tissues is envisaged to give way to the unknown mode-of-action by which these mineral regimens suppress fruit sunburn-browning incidence in orchards. Promotion of this mineral approach among growers, as a certainly cheaper alternative to mitigate fruit sunburn-browning incidence in apple orchards necessitates clear elucidation of its mode-of-action. This study investigated peel photosynthetic pigments and total peroxides (as a measure of oxidative stress) in three apple cultivars, ‘Cripps Pink’, ‘Golden Delicious’ and ‘Granny Smith’ which were treated with four B+Ca treatments varying in levels of B and Ca as well as inclusion of zinc (Zn) in one treatment. Randomized complete block design experiments with five replications were conducted at commercial farms in Western Cape, South Africa. Significant (p < 0.05) treatment effect for major pigment aspects and total peroxides occurred in all cultivars, but with strong influence of cultivar and fruit age. For instance, effect of varying B, Ca and possible B+Ca duet-effect on photosynthetic pigments occurred in ‘Cripps Pink’, whereas the Zn-treatment was mainly responsible for significant treatment effects in both ‘Golden Delicious’ and ‘Granny Smith’ apples. Significant treatment effect for total peroxides occurred in ‘Cripps Pink’ and ‘Granny Smith’, yet significant interaction effect occurred with ‘Golden Delicious’, however, these significant results did not yield meaningful peel oxidative stress differences among the treatments. Foliar treatment differences in photochemical efficiency (Fv/Fm) were not significant. The study concludes with firm evidence that foliar B+Ca treatment composition has a significant effect on apple peel photosynthetic pigments depending on cultivar, and Zn is not desirable in the formulation of these treatments.

Preparation of Polymer-Mineral Nanocomposites Based on Vinyl Monomers and Dispersed Inorganic Oxides

The polymer-mineral composites were synthesized using vinyl monomers styrene, methyl acrylate, and butyl acrylate with nano dispersed oxides Fe2O3, Cr2O3, V2O5 and SiO2 in the presence of benzoyl peroxide and other peroxide initiators. Benzoyl peroxide adsorption on Fe2O3, Cr2O3, and V2O5 surfaces was studied. The adsorption parameters were found: adsorption-desorption equilibrium constants, maximum adsorption, and the area occupied by the molecule benzoyl peroxide on the surface of the adsorbent. The molecular weights of the polymers in the composites and the degree of grafting of the macromolecules of the polymer to the surface of oxides were studied. It has been found that the surface of the dispersed oxides influences the rate of thermal decomposition of the peroxide initiators and the polymerization parameters of the vinyl monomers.