Granulocyte colony-stimulating factor increases extracellular glutamic acid uptake and suppresses free radicals in an experimental model of amyotrophic lateral sclerosis

Excitatory amino acid toxicity and free radical damage play important roles in amyotrophic lateral sclerosis. Granulocyte colony-stimulating factor （G-CSF） protects nerve cells exposed to high-concentrations of glutamic acid, suggesting positive effects in the treatment of amyotrophic lateral sclerosis. The present study induced in vitro motor neuron injury using glutamic acid excitotoxicity, and the biochemical effects of G-CSF on glutamic acid concentration were determined. In addition, the effects of G-CSF on superoxide dismutase, glutathione peroxidase activity in motor neurons, and malondialdehyde and nitric oxide contents were analyzed. Immunohistochemistry was performed to measure neuronal survival. Results revealed that G-CSF significantly suppressed free radical activity, inhibited excitotoxicity, and reduced apoptosis and loss of motor neurons in the anterior horn of the spinal cord.

Effect of Diazepam on the Contents of Amino Acids and Free Radical during Ischemia/Reperfusion Injury

The protective effect and mechanism of diazepam on ischemia neurons during cerebral ischemia and reperfusion were studied. Sixty three Wistar rats were divided randomly into nine groups: control group , ischemia groups including subgroups of is3h, is3 h/rep1 h, is3 h/rep2 h, is3 h/rep3 h, diazepam treated groups , including subgroups of is3 h, is3 h/rep1 h, is3 h/rep2 h, is3 h/rep3 h with Zea longa's animal model of middle cerebral artery occlusion. The comparison between the ischemia group and diazepam treated group showed that diazepam could obviously decrease the production of glutamate, asparate, MDA and increase the synthesis and release of GABA, SOD and GSH PX. It was concluded that diazepam exerted its protective effects on neurons through complex mechanisms of regulating the synthesis and release of excitotary/inhibitory amino acids and free radicals.

The damage effects of oxy free radicals and fulvic acid on chondrocytes

The damage effects of oxy free radical and fulvic acid on cultivated chicken embryo chondrocytes were studied. The results show that the growrth of chondrocytes is inhibited and the morphology of the cells altered. The collagen synthesizing capability of the damaged cell changes somewhat. A noteworthy change of the type of collagen synthesized by the abnormal cells was observed by CMC-chromatography and amino acid analysis. The results indicated that the abnonml cells tend to synthesize type I instead of type II collagen, which is synthesized and secreted by the intact chondrocyte.

The oxidation damage of type II collagen by oxy free radicals and fulvic acid

The features of oxidative damage to type II collagen from pig cartilage, induced by · OH, O2- and fulvic acid from epidemic district of KBD, were studied in vitro. The results from amino acid analysis of the damaged collagen are characterized by a decrease in hydroxyproline and proline contents, and an increase in glutamic acid content. The change arc dependent on·OH and FA concentration. It is postulated that the FA or other toxic xenobiotics induce the generation of free radicals, which play the role of the trigger in KBD development.

Humic acid and free radical in environment of Kaschin-Beck disease areas

The humic acid contents in drinking water and soil in Kaschin-Beck disease areas were found more than that of non-disease areas in this research. Changes of free radical concentration in drinking water were agreed with that of humic acid contents in drinking water of Kaschin-Beck disease areas. A positive correlation of free radical concentration and humic acid content in drinking water has been shown (r=0.913) . The structure of I. R. spectra of humic acid under ultraviolet light has been changed. Thus it indicated that free radical was resulted from benzoqiunonyl groups of humic acid in environment.

Effects of Water─soluble Components Isolated from Salviamilltiorrhiza on Oxygen Free Radical Generation and LipidPeroxidation

The effects of water─soluble components isolated from Salvia miltiorrhiza on oxygen free radical prodction and lipid peroxidation were estimated. Five components(10 μmol/L)were shown to inhibit superoxide anion generation by xanthine─xanthine oxidase system. It was also demonstrated that six components( 100 μmol/L) prevented H_2O_2─induced hemolysis and MDA fonnation in mouse erythrocytes.The effects of Sal A, Sal B, Sal C and Ros A were dose dependent. In Langendorff rat heart, pretreatment with Sal A 20μmol/L significantly prevented MDA production induced by 30 min reoxygenation after 45 min anoxia.The results indicated that there were also other potent antioxidant componentts in Salvia milliorrhiza besides Dphl and Pal. The protection of Sal A against myocardial anoxiareoxygenation inury may be mainly ascribed to its oxygen free radical scavenging activity.

Antioxidation and scavenging effects on free radicals of some extracts from Chinese medicines

The inhibiting effects of CHinonin,Quercetin and Tannic Acid on the lipid oxidation (LPO) induced by irradiation were investigated by means of a modified TBA spectrophotometry.The scavenging effects of theses three active compounds on free radicals were studied by ESR technique.The results showed that antioxidation effects of Chinonin and Quercetin were better than that of Tannic Acid;though scavenging effects of the threee active compounds were similar.

Removal of pathogenic indicator microorganisms during partial nitrification:the role of free nitrous acid

Digested wastewater contains pathogenic microorganisms and high ammonia concentrations,which can pose a potential risk to public health.Effective removal of pathogens and nitrogen is crucial for the post-treatment of digested wastewater.Partial nitrification-anammox is an energy-saving nitrogen removal process.Free nitrous acid(FNA),an intermediate product of partial nitrification,has the potential to inactivate microorganisms.However,the efficiency and mechanisms of FNA-related inactivation in pathogens during partial nitrification remains unclear.In this study,Enterococcus and Escherichia coli(E.coli)were selected to investigate the efficiency and mechanisms of FNA-related inactivation in partial nitrification process.The results revealed that 83%±13%and 59%±27%of E.coli and Enterococcus were removed,respectively,in partial nitrification process at FNA concentrations of 0.023−0.028 mg/L.When the concentration of FNA increased from 0 to 0.5 mg/L,the inactivation efficiencies of E.coli and Enterococcus increased from 0 to 99.9%and 89.9%,respectively.Enterococcus exhibited a higher resistance to FNA attack compared to E.coli.3D-laser scanning microscopy(3D-LSM)and scanning electron microscopy(SEM)revealed that FNA exposure caused the surface collapse of E.coli and Enterococcus,as well as visible pore formation on the surface of E.coli cells.4',6-Diamidino-2-phenylindole dihydrochloride n-hydrate(DAPI)/propidium iodide(PI)and biomolecule leakage confirmed that inactivation of E.coli and Enterococcus occurred due to breakdown of cell walls and cell membranes.These findings indicate that partial nitrification process can be used for the removal of residual pathogenic microorganisms.

New perspectives in free nitrous acid (FNA) uses for sustainable wastewater management

The biocidal effects of free nitrous acid (FNA) have found applications in multiple units in an urban wastewater system, including sewer networks, wastewater treatment processes, and sludge treatment processes. However, these applications are associated with chemical costs as both nitrite and acid are needed to produce FNA at the required levels. The recent discovery of novel acid-tolerant ammonia oxidizers offers the possibility to produce FNA from domestic wastewater, enabling the development of next-generation FNA-based technologies capable of achieving self-sustaining FNA production. In this study, we focus on the concept of in situ FNA generation facilitated by acid-tolerant ammonia oxidizers and highlight the multiple benefits it creates, after a brief review of the historical development of FNA-based technologies. We will discuss how wastewater systems can be made more energy-efficient and sustainable by leveraging the potential of acid-tolerant ammonia oxidizers.

STUDY ON THE FREE RADICALS PRODUCED FROM PHOTOLYSIS OF PEROXIDIZED LINOLEIC ACID BY ESR SPIN TRAPPING TECHNIQUE

Lipid peroxidation of polyunsaturate fatty acid is the main reason for the production of toxic materials in putrid food oil. The free radicals and other products produced from the peroxidation process can damage the membrane, protein and DNA and may induce cancer and other brain, myocardial and vascular diseases. Lipid peroxidation is also an important reason for aging. So it has raised a wide interest and attention of biological and

Stability and Intramolecular Hydrogen Bond of the Free Radicals of Gallic Acid and Its Esters

Gallic acid and its alkyl and phenyl gallate usually exist in gall and tea. They have very good properties in antioxygenation, antisepsis, astringency, etc., there-fore they are generally used in the industries of grease, dyestuff, spinning and weaving, metallurgy, chemistry, petroleum, food, medicine, etc. It has been known

Study on Generation of Oxygen Free Radicals in Hepatocytes Induced by Fulvic Acid

Fulvic acid (FA), a soluble fraction of the humic adds, is a group of polymers with a number of quinone moieties. It induces oxidative damage to cell, resulting in reduction of GSH-Px activity and increase of SOD activity in rat blood and liver or muscle tissues. This is possibly due to an interruption of the oxidation-antioxidation mechanism in cells.

Formation mechanisms of nitrous acid(HONO) during the haze and non-haze periods in Beijing,China

As an important precursor of hydroxyl radical(OH),nitrous acid(HONO)plays a significant role in atmospheric chemistry.Here,an observation of HONO and relevant air pollutants in an urban site of Beijing from 14 to 28 April,2017 was performed.Two distinct peaks of HONO concentrations occurred during the observation.In contrast,the concentration of particulate matter in the first period(periodⅠ)was significantly higher than that in the second period(periodⅡ).Comparing to HONO sources in the two periods,we found that the direct vehicle emissionwas an essential source of the ambient HONO during both periods at night,especially in periodⅡ.The heterogeneous reaction of NO_(2)was the dominant source in periodⅠ,while the homogeneous reaction of NO with OH was more critical source at night in periodⅡ.In the daytime,the heterogeneous reaction of NO_(2)was a significant source andwas confirmed by the good correlation coefficients(R^(2))between the unknown sources(P_(unknown))with NO_(2),PM_(2.5),NO_(2)×PM_(2.5)in periodⅠ.Moreover,when solar radiation and OH radicals were considered to explore unknown sources in the daytime,the enhanced correlation of P_(unknown)with photolysis rate of NO_(2)and OH(J_(NO_(2))×OH)were 0.93 in periodⅠ,0.95 in periodⅡ.These excellent correlation coefficients suggested that the unknown sources released HONO highly related to the solar radiation and the variation of OH radicals.

Inhibitory effects of chitosan on superoxide anion radicals and lipid free radicals

With the electron spin resonance (ESR) technique, the inhibitory effects of chitosan on superoxide anion radicals and linoleic acid lipid radicals were found. The inhibitory ratio E for these two kinds of radicals is in proportion to the concentration of chitosan. It was also observed that E for linoleic acid lipid radicals increased with the increase of the degree of deacetylation and decreased with the increase of the molecular weight of chitosan.

Effect of SP-A/B in lipoic acid on acute paraquat poisoning

BACKGROUND: This study was undertaken to observe the concentration of SP-A/B and the pulmonary surfactant in the lung tissue of rats with acute lung injury/acute respiratory distress syndrome caused by paraquat poisoning after the treatment of metabolic antioxidant-lipoic acid and whether its influence was related to TNF-α.METHODS: Sixty-six male Sprage-Dawley rats were randomly divided into three groups: normal control group(NS group), 6 rats; paraquat poisoning group(PQ group), 30 rats; and paraquat+lipoic acid treatment group(LA group), 30 rats. The rats in the PQ and LA groups were subdivided into 3-, 6-, 12-, 24-, 48-hour subgroups, with 6 rats in each group. After the rats were sacrificed, lung tissue from the same part was taken from the rats. After HE staining, histological changes were observed in the tissue under a light microscope. Lung tissue was also taken to test the levels of superoxide dismutase(SOD) and malondialdehyde(MDA). Whole blood(0.8 mL) without anticoagulant was drawn from the tail vein of rats for the determination of the TNF-α level. The total RNA of the lung tissue was collected, and the Rt-PCR method was used to measure the levels of SP-A and SP-B mRNA.RESULTS: HE staining showed that histopathological changes were milder in the LA group than in the PQ group. There were significant differences in MDA and SOD levels between different intervals both in intergroups and intragroups except the 3-hour subgroup(P<0.01). Likewise, the significant differences in the levels of TNF-α were also present between the three groups and between different intervals(P<0.01). The significant differences in SP-A mRNA and SP-B mRNA amplification ratio were seen between the three groups at the same intervals(P<0.01), but the differences between different intervals in the PQ group were statistically significant(P<0.05). The differences between different intervals in the LA group were statistically significant(P<0.01).CONCLUSION: Lipoic acid in acute paraquat poisoning could diminish lung tissue damage by regulating directly tumor necrosis factor and indirectly the content of pulmonary surfactant so as to reduce pulmonary edema, improve lung compliance, and finally protect lung tissues.

Protective effect of ascorbic acid on cyclophosphamide induced testicular gametogenic and androgenic disorders in male rats

Aim:To study the detrimental effects of cyclophosphamide on the testicular androgenic and gametogenic activities through endocrine inhibition and/or induction of oxidative stress in male albino rats and to evaluate the protective effect of ascorbic acid.Methods:The testicular△^(5),3β-hydroxysteroid dehydrogenase(HSD),17β-HSD,peroxidase and catalase activities along with the levels of malondialdehyde(MDA)and conjugated dienes in testicular tissue were measured for the evaluation of testicular oxidative stress.The plasma testosterone(T)level was measured by immunoassay.Various germ cells at stageⅦof spermatogenic cycle were quantified from testicular stained sections.Results:Cyclophosphamide treatment results in a significant inhibition in the testicular△^(5),3β-HSD and 17β-HSD activities,a decrease in plasma T level and a diminution in the counts of various germ cells.Moreover,this treatment was also associated with a significant inhibition of the peroxidase and catalase activities along with high levels of MDA and conjugated dienes in the testis.All these changes were reversed by ascorbic acid co-administration.Conclusion:Cyclophosphamide treatment at the dosage used caused testicular gametogenic and androgenic disorders as well as induced testicular oxidative stress that can be reversed by ascorbic acid co-administration.

The Synthesis Technique of Polyacrylic Acid Superplasticizer

Using water separation technique,acrylic acid （AA） and polyethylene glycol （PEG） 1000,of which the ratio was 1.5,were esterified and the optimum esterification ratio of 90% could be reached under the condition of 110 ℃×3 h.Using polyoxyethylene acrylate macromonomer （PA） prepared in the esterification,AA and sodium methylacryl sulfonate （MAS） as monomers,a copolymer which could be used as superplasticizer was prepared by free radical coolymerization in n（PA）：n（AA）：n（MAS） of 1：7：3.When the synthesis condition was 80 ℃× 5 h,the optimal dosage of initiator was 3.0%-4.0%,the fluidity of cement paste with the samples could reach 270 mm.By analyzing the effect of the content of residual small molecule sulfonic monomer on the properties of sample,n（MAS）/n（PA） was controlled in a range of 2.5-3.8.

Apoptosis of pancreatic cancer BXPC-3 cells induced by indole-3-acetic acid in combination with horseradish peroxidase

AIM： To explore the mechanisms underlying the apoptosis of human pancreatic cancer BXPC-3 cells induced by indole-3-acetic acid （IAA） in combination with horseradish peroxidase （HRP）. METHODS： BXPC-3 cells derived from human pancreatic cancer were exposed to 40 or 80 μmol/L IAA and 1.2 μg/mL HRP at different times. Then, Mn- assay was used to detect the cell proliferation. Flow cytometry was performed to analyze cell cycle. Terminal deoxynucleotidyl transferasemediated dUTP nick end labeling assay was used to detect apoptosis. 2,7-Dichlorofluorescin diacetate uptake was measured by confocal microscopy to determine free radicals. Level of malondialdehyde （MDA） and activity of superoxide dismutase （SOD） were measured by biochemical methods. RESULTS： IAA/HRP initiated growth inhibition of BXPC-3 cells in a dose- and time-dependent manner. Flow cytometry revealed that the cells treated for 48 h were arrested at G1/G0. After exposure to 80 μmol/L IAA plus 1.2 μg/mL HRP for 72 h, the apoptosis rate increased to 72.5‰, which was nine times that of control. Content of MDA and activity of SOD increased respectively after treatment compared to control. Meanwhile, IAA/HRP stimulated the formation of free radicals. CONCLUSION： The combination of IAA and HRP can inhibit the growth of human pancreatic cancer BXPC-3 cells in vitro by inducing apoptosis.

Alteration of chemical behavior of L-ascorbic acid in combination with nickel sulfate at different pH solutions in vitro

Objective:To evaluate the alteration of chemical behavior of L-ascorbic acid(vitamin C) with metal ion(nickel) at different pH solutions in vitro.Methods:Spectra of pure aqueous solution of L-ascorbic acid(E mark) compound and NiSO_4(H_2O)(sigma USA) were evaluated by UV visible spectrophotometer.Spectral analysis of L-ascorbic acid and nickel at various pH(2.0, 7.0,7.4 and 8.6) at room temperature of 29℃ was recorded.In this special analysis,combined solution of L-ascorbic acid and nickel sulfate at different pH was also recorded.Results:The result revealed that λ_(max)(peak wavelength of spectra) of L-ascorbic acid at pH 2.0 was 289.0 run whereas at neutral pH 7.0,λ_(max) was 29S.4 run.In alkaline pH 8.6,λ_(max) was 295.4 nm and at pH 7.4 the λ_(max) of L-ascorbic acid remained the same as 295.4 nm.Nickel solution at acidic pH 2.0 was 394.5 nm,whereas at neutral pH 7.0 and pH 7.4 were the same as 394.5 nm.But at alkaline pH 8.6,λ_(max) value of nickel sulfate became 392.0 nm.The combined solution of L-ascorbic acid and nickel sulfate(6 mg/mL each) at pH 2.0 showed 292.5 nm and 392.5 nm,respectively whereas at pH 7.0,L-ascorbic acid showed 296.5 nm and nickel sulfate showed 391.5 nm.At pH 7.4,L-ascorbic acid showed 297.0 nm and nickel sulfate showed 394.0 nm in the combined solution whereas at pH 8.6(alkaline) L-ascorbic acid and nickel sulfate were showing 297.0 and 393.5 nm,respectively. Conclusions:Results clearly indicate an altered chemical behavior of L-ascorbic acid either alone or in combination with nickel sulfate in vitro at different pH.Perhaps oxidation of L-ascorbic acid to L-dehydro ascorbic acid via the free radical(HSc*) generation from the reaction of H,ASc + Ni(Ⅱ) is the cause of such alteration of λ_(max),value of L-ascorbic acid in the presence of metal nickel.

Dialkyl phosphinic acids:Synthesis and applications as extractant for nickel and cobalt separation

Three kinds of dialkylphosphinic acids(DAPAs),i.e.dihexylphophinic acid(DHPA),di-(2,4,4-trimethylpentyl) phosphinic acid(DTMPPA)and didecylphophinic acid(DDPA),were synthesized through free radical addition reaction.The influence of the types of initiator,reation time and reaction temperature on the yield of DAPAs were investigated.The products were characterized by NMR and MS.By using DHPA,DTMPPA and DDPA(10%in kerosene)as extractants,the extraction of Co2 +and Ni2 +in sulphate medium at different equilibrium pH values were measured.The results show that the maximum yield of DHPA, DTMPPA and DDPA can all be achieved at about 130℃under the initiation of di-tert-butyl peroxide(DTBP).All the extraction of cobalt with respect to DHPA,DDPA and DTMPPA precedes that of nickel.The difference in pH1/2 value(defined as the pH at which 50%metal extraction occurs)between cobalt and nickel increases in the following sequence from large to small:DHPA,DDPA and DTMPPA,which indicates that the separation ability for cobalt and nickel ascends from DHPA,DDPA to DTMPPA.