Prediction of tumor response after neoadjuvant chemoradiotherapy in rectal cancer using (18)fluorine-2-deoxy-D-glucose positron emission tomography-computed tomography and serum carcinoembryonic antigen: a prospective study.

PURPOSE: To investigate the association between (18)fluorine-2-deoxy-D-glucose positron emission tomography-computed tomography ((18)F-FDG PET/CT) parameters, serum carcinoembryonic antigen (CEA), and tumor response in patients with rectal cancer receiving neoadjuvant chemoradiotherapy (nCRT). METHODS: Sixty-four patients with T3-4 and/or node-positive rectal cancer receiving nCRT followed by surgery were prospectively studied. PET/CT was performed before, and in 28 patients, both before and after nCRT. The pre-/post-nCRT maximum standardized uptake (SUVmax) values, differences between pre-/post-nCRT SUVmax (∆SUVmax), response index of SUVmax (RI-SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and CEA were measured. The ability of PET/CT parameters and CEA to predict Mandard's tumor regression grade (TRG) and pathological complete remission (pCR) were evaluated. RESULTS: 31 patients were identified as responders (TRG 1-2), and 19 exhibited pCR. For responders, significant differences were found for ΔSUVmax (24.88 vs. 15.39 g/ml, p = 0.037), RI-SUVmax (0.76 vs. 0.63, p = 0.025), ΔSUVmean (14.43 vs. 8.65 g/ml, p = 0.029), RI-SUVmean (0.77 vs. 0.63, p = 0.011), CEA-pre (6.30 vs. 27.86 µg/L, p < 0.001), CEA-post (2.22 vs. 5.49 µg/L, p = 0.002), ΔCEA (4.08 vs. 23.13 µg/L, p < 0.001), and RI-CEA (0.25 vs. 0.55, p = 0.002). Differences between pCR and non-pCR patients were noted as RI-SUVmean (0.77 vs. 0.65, p = 0.043), MTV-pre (9.87 vs. 14.62 cm(3), p = 0.045), CEA-pre (5.62 vs. 22.27 µg/L, p = 0.002), CEA-post (1.95 vs. 4.72 µg/L, p = 0.001), and ΔCEA (3.68 vs. 17.99 µg/L, p = 0.013). Receiver operating characteristic analysis revealed that RI-SUVmean exhibited the greatest accuracy in predicting responders, whereas CEA-post and ΔCEA exhibited the greatest accuracy in predicting pCR. CONCLUSIONS: (18)F-FDG PET/CT parameters and CEA are accurate tools for predicting tumor response to nCRT in rectal cancer.

Cervical lymph node hyperplasia on [(18)F]-fluorodeoxyglucose positron emission tomography/computed tomography scan after treatment of children and adolescents with malignant lymphoma.

PURPOSE: To define imaging manifestations and clinical prognosis of cervical lymph node hyperplasia using [(18)F]-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) scanning after treatment of children and adolescents with malignant lymphoma. METHODS: Children and adolescent patients with malignant lymphoma who had high FDG uptake in their cervical lymph nodes via PET/CT after treatment, which was not due to tumor recurrence or residue, were retrospectively analyzed. RESULTS: Twenty-seven patients with a median age of 12 years were included; 11 had Hodgkin's disease and 16 had non-Hodgkin's lymphoma. The time from PET/CT scan to completion of therapy was 1-36 months, 85.2% (23/27) of which took place within 12 months. Three patients had confirmed lymph node follicular hyperplasia by biopsy, while all 27 patients achieved disease-free survival during the follow-up period. The maximum standardized uptake values (SUVmax) of cervical lymph nodes were 2.2-16.2 and the maximum short axis ranged from 0.3 to 1.2 cm. Cervical lymph node hyperplasia was noted in neck levels I-V, and neck level II bilaterally had the highest incidence (100%). Bilateral cervical lymph node hyperplasia was symmetrical in terms of both the SUVmax and affected locations. Thymic hyperplasia and nasopharyngeal lymphoid hyperplasia were both observed in 24 patients (88.9%). There was no relationship in terms of the SUVmax between cervical lymph nodes and thymic tissue, cervical nodes or nasopharyngeal lymphoid tissue. CONCLUSION: Cervical lymph node hyperplasia with high FDG uptake on PET/CT scans found after treating children and adolescents with malignant lymphoma can be benign processes. Awareness of this possibility may help avoid invasive procedures and over-treatment.

NBS1 Glu185Gln polymorphism and susceptibility to urinary system cancer: a meta-analysis.

A number of studies have investigated the association between the NBS1 Glu185Gln (rs1805794, 8360 G>C) polymorphism and risk for urinary system cancer including bladder cancer, prostate cancer, and renal cell cancer; however, the findings are conflicting. We conducted a meta-analysis focusing on eight published studies with 3,542 cases and 4,210 controls to derive a more precise evaluation of the relationship between the NBS1 Glu185Gln polymorphism and urinary system cancer susceptibility. Overall, the NBS1 Glu185Gln polymorphism was significantly related to increased risk for urinary system cancer (homozygous model: odds ratio (OR)=1.23, 95 % confidence interval (95% CI)= 1.05­1.44, p=0.011; heterozygous model: OR=1.14, 95% CI=1.04­1.26, p=0.008; dominant model: OR=1.16, 95% CI=1.05­1.27, p=0.002; and Gln vs. Glu: OR=1.12, 9% CI=1.04­1.20, p=0.002) and further stratification analysis indicated an increased risk for bladder cancer (heterozygous model: OR=1.13, 95% CI=1.02­1.26, p=0.022; dominant model: OR=1.14, 95% CI=1.03­1.26, p=0.014; and Gln vs. Glu: OR=1.09, 95%CI=1.01­1.18, p=0.023) and Caucasian populations (homozygous model: OR=1.33, 95% CI=1.11­1.59, p=0.002; heterozygous model: OR=1.16, 95% CI=1.04­1.30, p=0.009; dominant model: OR=1.19, 95% CI=1.07­1.32, p=0.001; and Gln vs. Glu: OR=1.15, 95% CI=1.06­1.25, p<0.001). Despite some limitations, this meta-analysis established some solid statistical evidence for the association between NBS1 Glu185Gln polymorphism and increased risk for urinary system cancer, especially for bladder cancer, but more well-designed prospective studies are needed to further verify our findings.

Therapeutic effects of a recombinant mutant of the human ciliary neurotrophic factor in a mouse model of metabolic syndrome.

Metabolic syndrome (MS) is highly prevalent in developed countries and becoming a serious worldwide public health issue. In this study, we established a MS model by feeding male C57BL/6J mice with a high-fat diet (10%) for 18.5 weeks, studied the therapeutic effects of a recombinant mutant of the human ciliary neurotrophic factor (rhmCNTF) 0.1 (C-0.1) or 0.3 (C-0.3) mg x kg(-1) per day subcutaneously or pair feeding (PF, which mice were restricted to the same amount of food as eaten by C-0.3 treated mice) in MS mice. After 10 days treatment, rhmCNTF reduced obesity related indices, ameliorated glucose and lipid metabolism abnormality, and enhanced insulin sensitivity. In addition, liver function and antioxidant ability of MS mice were improved by rhmCNTF. Pair feeding revealed the same effects as C-0.3 on obesity related indices and insulin sensitivity, but aggravated hepatic steatosis and hepatic function. The results suggest that rhmCNTF could serve as an effective therapeutic agent for MS and related diseases.

Protective effect of a Potentilla anserine polysaccharide on oxidative damages in mice.

Potentilla anserine polysaccharide (PAP) was studied in vivo to investigate its antioxidant activity using the model of dexamethasone-induced oxidative stress in mice. The investigation demonstrated that PAP at 50, 100 or 200mg/kg body weight for 7 days respectively increased thymus index and spleen index, glutathione level, superoxidase dismutase activity and total antioxidant capacity in both thymus and spleen and decreased the content of H(2)O(2) in spleen and NO in both thymus and spleen of mice. The results revealed that PAP was able to overcome dexamethasone-induced oxidative stress and might play an important role in repairs of oxidative damage in immunological system.

Natural antioxidant pedicularioside G inhibits angiogenesis and tumourigenesis in vitro and in vivo.

Pedicularioside G is a new compound of phenylpropanoid glycosides, isolated from Pedicularis striata in our laboratory. Pedicularioside G inhibited two major angiogenic responses, human umbilical vein endothelial cell proliferation and migration, as well as neovascularization in a chicken embryo chorioallantoic membrane model. In addition, pedicularioside G inhibited human hepatoma cells proliferation and migration in vitro along with transplanting tumour formation and growth in a chicken embryo chorioallantoic membrane model. So pedicularioside G has anti-angiogenic, antitumour growth, antimetastatic and antitumoural effects. Pedicularioside G also remarkably reduced reactive oxygen species level in both vein endothelial cells and hepatoma cells in a concentration-dependent manner. These results suggest that the anti-angiogenic and antitumoural effects of pedicularioside G might partially attribute to its antioxidative activity.

The effect of 17 sesquiterpenes on cell viability and telomerase activity in the human ovarian cancer cell line HO-8910.

Using the MTT assay and the telomeric repeat amplification protocol (TRAP)-based PCR-ELISA assay, the cytotoxicity and telomerase inhibiting ability of 17 sesquiterpenes (extracted from Chinese herbs) were tested in the human ovarian cancer cell line HO-8910. The results indicated that seven sesquiterpenes inhibited cell proliferation without having an effect on telomerase activity; two sesquiterpenes inhibited neither cell proliferation nor telomerase activity; and the other eight sesquiterpenes inhibited both cell proliferation and telomerase activity to a certain extent. Without exception, none of these 17 sesquiterpenes could only inhibit telomerase activity without inhibiting cell proliferation. This indicated that the telomerase inhibiting activity is not a universal mechanism for all anticancer drugs but is only one of several possible mechanisms. The structure-activity relationships of 5 groups of sesquiterpenes are also discussed. This study may help to develop anticancer drugs.

DNA damage and oxidative stress induced by Helicobacter pylori in gastric epithelial cells: protection by vitamin C and sodium selenite.

The direct effect of intact Helicobacter pylori on gastric epithelial cells SGC-7901 and the protection given by the antioxidants vitamin C and sodium selenite were studied. Incubation of SGC-7901 cells with H. pylori simultaneously caused a significant increase of DNA damage (DNA strand breakage and DNA fragmentation) and ROS formation, as well as a significant decrease of intracellular GSH content in a H. pylori multiplicity of infection (MOI) dependent manner in gastric cells. ROS formation was strongly positively correlated while GSH content was negatively correlated with DNA strand breakage and fragmentation, indicating that DNA damage may be mainly caused by H. pylori-induced oxidative stress in gastric cells. The antioxidants, vitamin C and sodium selenite, directly increased GSH content while diminishing ROS formation and DNA damage in H. pylori-infected SGC-7901 cells, indicating that vitamin C and sodium selenite can protect gastric cells against H. pylori damage. The protections by vitamin C and sodium selenite further demonstrated that DNA damage may be derived from oxidative stress in H. pylori-infected gastric cells. The results suggested that DNA damage caused by H. pylori-induced oxidative stress may be one important factor in the pathogenesis of H. pylori, and that vitamin C and sodium selenite may have a preventive or therapeutic role against H. pylori-associated gastric diseases.

The relationship between structure and antioxidative activity of piperidine nitroxides.

We have investigated the relationship between structure and antioxidative activity of piperidine nitroxides which were substituted by different groups at the 4-position. All of the tested piperidine nitroxides inhibited malondialdehyde (MDA) generation caused either spontaneously or by a hydroxyl free radical generation system (Fe2+-ascorbic acid) in homogenates of liver, heart and kidney of rats, and antagonized H2O2-induced haemolysis from rat erythrocytes in a concentration-dependent manner. The same rank was followed: Bis-(4-amino-2,2,6,6-tetramethyl piperidinooxyl) (4-BIS-Tempo) and 4-azido-2,2,6,6-tetramethyl piperidinooxyl (4-N(3)-Tempo) > 4-isothiocyanate-2,2,6,6-tetramethyl piperidinooxyl (4-ISO-Tempo), 4-2', 4'-dinitrophenylhy-drazone-2,2,6,6-tetramethyl piperidinooxyl (4-D-Tempo), 4-sulfonate-2,2,6,6-tetramethyl piperidinooxyl (4-S-Tempo) and 4-amino-2,2,6,6-tetramethyl piperidinooxyl (4-NH(2)-Tempo) > 4-acetate ester-2,2,6,6-tetramethyl piperidinooxyl (4-A-Tempo) and 4-benzoate-2,2,6,6-tetramethyl piperidinooxyl (4-B-Tempo). With the exception of 4-A-Tempo and 4-D-Tempo, the tested piperidine nitroxides inhibited superoxide anion (O(2*-)) release from neutrophils stimulated by zymosan. The concentration required for inhibiting O(2*-) release was higher than that of inhibiting MDA formation and haemolysis. However, 4-amino-2,2,6,6-tetramethyl piperidine (4-NH2-TempH) and other 4-position substitutes, such as NaN3 and isothiocyanate, had no effects on MDA formation, haemolysis or O(2*-) release. The results indicated that nitroxides have a wide range of scavenging reactive oxygen species (ROS) actions. The nitroxide moiety was the essential group while the 4-position substitutes could influence the activity of nitroxides on scavenging ROS.

Biphasic regulation of angiogenesis by reactive oxygen species.

Reactive oxygen species (ROS) are believed to be important molecules in the regulation of angiogenesis. However, direct evidence is obtained from hydrogen peroxide only. The comparison of superoxide anion (O2-), hydrogen peroxide (H202) and hydroxyl radical (HO*) effects on angiogenesis in one angiogenic model were studied. Tube formation, migration and adhesion of endothelial cells were enhanced with a low concentration of O2 generated by 500 [microM xanthine (X) and 1 mU/ml xanthine oxidase (XO), but significantly inhibited as the XO increased to 10 mU/ml or more. Low concentrations of H2O2 (0.01-1 microM) induced tube formation and the maximal tube formation was achieved at 0.1 microM which also induced cell migration and adhesion, while high concentrations of H2O2 (100 microM) inhibited tube formation and cell migration. Both H2O2 and O2 inhibited cell proliferation at high concentration only. HO* at low concentration neither inhibited nor stimulated the tube formation, cell proliferation and migration but inhibited at high concentration. The effects of O2 were significantly abolished by catalase (CAT) alone or in combination with superoxide dismutase (SOD), but not by inactive CAT or SOD alone. Active CAT, but not inactive CAT, also reversed the effects of H2O2. Pretreatment with GSH effectively reversed the inhibitory effects of HO*. Therefore, our results suggest that ROS have biphasic effects on angiogenesis, which indicated that pharmacologically regulating cellular ROS levels might serve as an anti-angiogenic or angiogenic principles. They also provide a theoretical basis for the development and rational use of novel angiogenic and anti-angiogenic drugs.

Rosmarinic acid inhibits angiogenesis and its mechanism of action in vitro.

Rosmarinic acid (RA), a water-soluble polyphenolic compound with anti-oxidative and anti-inflammatory activities, inhibited several important steps of angiogenesis including proliferation, migration, adhesion and tube formation of human umbilical vein endothelial cells (HUVEC) in a concentration-dependent manner. RA also reduced intracellular reactive oxygen species (ROS) level, H2O2-dependent VEGF expression and IL-8 release of endothelial cells. These findings suggested that the anti-angiogenic potential of RA might be related to its anti-oxidative activity, which further resulted in the inhibition of ROS-associated VEGF expression and IL-8 release.

Oxidative stress in Graves' disease patients and antioxidant protection against lymphocytes DNA damage in vitro.

DNA damage to peripheral blood lymphocytes of patients with Graves' disease (GD) was studied in vitro before and after treatment with antioxidants, melatonin, quercetin, N-acetylcysteine (NAC) and vitamin C. DNA damage (comet %) was remarkably higher in patients (23.7 +/- 5.5%) than that in healthy persons (9.8 +/- 3.2%, p < 0.01). Plasma malondialdehyde (MDA) content (7.90 +/- 1.77 microM) of patients was significantly higher than that of healthy persons (4.71 +/- 1.19 microM, p < 0.01). Also, the plasma total antioxidant capacity (TAC) (7.53 +/- 1.35 U/ml) in GD patients was significantly lower than that in healthy persons (10.56 +/- 2.21 U/ml, p < 0.01). Negative correlations were observed between plasma TAC and DNA damage in lymphocytes (r = -0.599, p < 0.01), and between plasma TAC and MDA (r = -0.40, p < 0.05) in GD patients. After treatment with 100 microM melatonin, quercetin or NAC for 4 h in vitro, DNA damage in lymphocytes in GD patients declined significantly (from 23.8 +/- 4.4% to 14.4 +/- 4.0%, p < 0.001 for melatonin, from 23.4 +/- 4.7% to 18.1 +/- 4.3%, p < 0.01 for quercetin, from 23.7 +/- 4.0% to 18.7 +/- 5.7%, p < 0.05 for NAC), while there was little change with concentrations of 1-100 microM of vitamin C. However, 1000 microM vitamin C enhanced DNA damage significantly (from 23.8 +/- 2.3% to 30.3 +/- 3.9%, p < 0.05). Our results showed that oxidative stress existed in GD patients and the antioxidants melatonin, quercetin and NAC are beneficial for DNA damage in lymphocytes of GD patients in vitro.

Redifferentiation of human hepatoma cell induced by 6-(p-chlorophenyl)-3-[1-(p-chlorophenyl)-5-methyl-1 H-1,2,3-triazol-4-yl]-s-triazolo[3,4-b]-1,3,4-thiadiazole (TDZ).

6-(p-Chlorophenyl)-3-[1-(p-chlorophenyl)-5-methyl-1 H-1,2,3-triazol-4-yl]-s-triazolo[3,4-b]-1,3,4-thiadiazole (TDZ) is a derivative of various substituted s-triazolo[3,4-b]-1,3,4-thiadiazoles, which are associated with diverse pharmacological activities. However, the antitumor activity of TDZ is not well understood. To evaluate its role on tumor cell lines, we have examined the effect of TDZ on two tumor lines: human hepatoma cell (SMMC-7721) in vitro and Sarcoma180 tumor (S180) in vivo. The cytotoxicity of TDZ on human hepatoma cells was assessed using the MTT assay. The inhibition on tumor growth was evaluated by means of trypan blue exclusion test in vitro, and using a Sarcoma180 tumor (S180) animal model in vivo. A scanning electronic microscope was used to discover the morphological changes on cell surface, cell electrophoresis was employed to determine the changes of cell surface negative charges, and alpha-fetoprotein was applied as a biomarker of hepatoma. The effect of TDZ on DNA synthesis was determined by a [3H]-thymidine incorporation assay, and cell cycle distribution by flow cytometry. The IC50 value of TDZ on SMMC-7721 cells was 52.9 microg/ml (48 h). However, TDZ could inhibit the growth of SMMC-7721 cells at concentrations far lower than the IC50 value. Treated with the same low concentrations of TDZ, microvilli on the surface of SMMC-7721 cells decreased obviously, electrophoresis rate of cells reduced from 2.14 microm ms(-1) x V(-1) x cm(-1) of control to 1.54 and 1.56 microm x s(-1) x V-1 x cm(-1), the content of AFP dropped from 205.14 +/- 6.41 ng x mg(-1) Pr to 115.68 +/- 3.47 and 78.57 +/- 2.35 ng mg(-1) Pr, and the DNA replication was inhibited by 26.8% and 45.2%. These results indicated that TDZ may inhibit proliferation of cancer cells by reversing SMMC-7721 cells malignant phenotypic characteristics and inducing redifferentiation. Flow cytometry showed that TDZ-treated cells resulted in a higher proportion of cells in S phase compared with untreated cells, and only when the concentration reached 64 microg/ml, the apoptosis could happen at the rate of 4.2%. Detection of the inhibition of Sarcoma 180 tumor growth in vivo showed that TDZ reduced the tumor weight and 69.08% of the growth was inhibited. TDZ could inhibit the proliferation of tumors in vitro and in vivo; the possible antitumor mechanism might be inducing redifferentiation at a lower dosage on vitro.

NADPH oxidase produces reactive oxygen species and maintains survival of rat astrocytes.

Reactive oxygen species (ROS) produced by activated astrocytes have been considered to be involved in the pathogenesis of neurodegenerative diseases, while NADPH oxidase is an essential enzyme involved in ROS-mediated signal transduction. The goal of the present study was to determine whether NADPH oxidase plays a role in ROS generation and cell survival in rat astrocytes. We found that the release of ROS in rat astrocytes was significantly increased by stimulation with calcium ionophore or opsonized zymosan, which are known to trigger a respiration burst in phagocytes by the NADPH oxidase pathway. Further study indicated that diphenylene iodonium (DPI), an inhibitor of NADPH oxidase, significantly suppressed the increase of ROS release caused by the calcium ionophore or opsonized zymosan. Cell survival assay and fluorescence double dyeing with acridine orange and ethidium bromide showed that DPI dose- and time-dependently decreased the viability of normal astrocytes, whereas exogenous supplementation of H2O2 can reverse the survival of DPI-treated astrocytes. For the first time, our results suggest that NADPH oxidase is an important enzyme for the generation of ROS in astrocytes, and the ROS generated by NADPH oxidase play an essential role in astrocyte survival.

In vitro effects on proliferation, telomerase activity and apoptosis of an eremophilanoid sesquiterpene from Senecio oldhamianus maxim in cultured human tumor cell lines.

8,11-Dioxol-6-en-9alpha, 10alpha-epoxy-8beta-hydroxyeremophilane (HEM), a new eremophilanoid sesquiterpene, was isolated from Senecio oldhamianus Maxim. Its effects of cytotoxicity, telomerase activity, apoptosis and related genes expression in two human tumor cell lines, human hepatoma cells SMMC-7721 and human oophoroma cells HO-8910, were studied. Hydroxycamptothecine (HCPT) was used as a positive control. The IC50 of cytotoxicity by HEM were 24.9 +/- 2.1 and 19.4 1.6 microM in SMMC-7721 and HO-8910 cells respectively, and 0.35 +/- 0.10 and 0.27 +/- 0.08 microM for HCPT. HEM inhibited telomerase activity with the IC50 35.9 +/- 3.2 microM in SMMC-7721 and 25.6 +/- 2.6 microM in HO-8910 cells, while HCPT had no effect on telomerase activity in both tumor cell lines. HEM 20-30 microM induced apoptosis in SMMC-7721 cells from 5.7% to 18.4% and in HO-8910 cells from 7.6% to 67.1%. While HCPT 0.1-0.5 microM induced apoptosis in SMMC-7721 cells from 6.5% to 13.3% and in HO-8910 cells from 9.9% to 30.9%. HEM 30 microM significantly decreased Bcl-2 protein expression to 58.7% in SMMC-7721 and to 57.6% in HO-8910 cells. While HCPT 0.5 microM significantly decreased Bcl-2 protein expression to 64.3% in SMMC-7721 and to 70.0% in HO-8910 cells. HEM 25 microM and 30 microM significantly increased P53 protein expression 2.3-3.6-fold in SMMC-7721 and 3.0-5.7- fold in HO-8910 cells. While HCPT 0.5 microM significantly increased P53 protein expression 3.3-fold in SMMC-7721 and 2.7-fold in HO-8910 cells. Overall, HCPT exhibited a more potent effect on cytotoxicity and apoptosis in the two tumor cell lines than HEM did. However HEM can inhibit telomerase activity in the two tumor cell lines but HCPT cannot.

[Apoptosis and regulation of expressions of apoptosis-related gene Bcl-2 and p53 induced by selenium dioxide in three leukemia cell lines].

OBJECTIVE: To investigate the mechanisms underlying the effect of selenium dioxide (SeO(2)) on the proliferation, apoptosis, and apoptosis-related gene expressions of Bcl-2 and p53 in 3 leukemia cell lines NB4, K562 and HL-60. METHODS: The three leukemia cell lines were treated with 3, 10 and 30 mmol/L SeO(2) and apoptosis detected by flow cytometry and analysis of p53 and Bcl-2 expressions. RESULTS: SeO(2) at 10 and 30 mmol/L could inhibit the proliferation of three leukemia cell lines. SeO(2) treatment at 30 mmol/L for 48 h induced an apoptosis rate of 54.0 %, 46.5 %, 49.6 % in NB4, K562, and HL-60 cells respectively, and down-regulated Bcl-2 expression in NB4 and K562 but not in HL-60 cells. CONCLUSION: SeO(2) can induce apoptosis in NB4, K562 and HL-60 leukemia cells, involving the down-regulation of Bcl-2 and up-regulation of p53.

Oxidative damage of biomolecules in mouse liver induced by morphine and protected by antioxidants.

This study investigates the oxidative damage of biomolecules in livers of mice treated with morphine intraperitoneally. The oxidative damage of DNA as measured by single cell electrophoresis and high-performance liquid chromatography equipped with electrochemical and UV detection, the protein carbonyl content was measured by 2,4-dinitrophenylhydrazine method, and the malondialdehyde content was measured by the HPLC method. The activities of antioxidative enzymes, superoxide dismutase, catalase and glutathione peroxidase, and the activity of alanine aminotransferase were assayed by spectrophotometer method. Glutathione and oxidized glutathione were detected by fluorescence spectrophotometer method. All the indexes of oxidative damage, such as 8-OHdG, protein carbonyl group and malondialdehyde content, and the activity of alanine aminotransferase (n=27) increased significantly compared to those of control (n=27) (P<0.01) in livers of morphine-administered alone mice, while the indexes related with the in vivo antioxidative capacity, such as the ratio of glutathione and oxidized glutathione, activities of superoxide dismutase, catalase and glutathione peroxidase significantly decreased (P<0.01). When mice were treated with morphine combined with exogenous antioxidants, glutathione and ascorbic acid, all the indexes of oxidative damage and the activity of alanine aminotransferase showed no changes as compared to those of control (P>0.05), i.e., both glutathione and ascorbic acid completely abolished the damage of morphine on the hepatocyte. These results implied that morphine caused a seriously oxidative stress in mice livers and hence caused hepatotoxicity, while exogenous antioxidants were able to prevent the oxidative damage of biomolecules and hepatotoxicity caused by morphine. Thus, blocking oxidative damage may be a useful strategy for the development of a new therapy for opiate abuse.

Redifferentiation of human hepatoma cells induced by synthesized coumarin.

The effects of synthesized 7-OH-4-CH(3)-coumarin on proliferation and differentiation of human hepatoma carcinoma cell line, SMMC-7721, were examined. Results showed that 7-OH-4-CH(3)-coumarin suppressed the proliferation of the SMMC-7721 cells in a dose-dependent manner, with an IC(50) value of 356 +/- 1.8 .M, while concentrations< or =200 mM could trigger differentiation. After treatment with this compound at 100 mM, the growth curve of human hepatoma cells decreased markedly. When treated with 50 and 100 mM, the cells' electrophoresis rate decreased from 2.2 mm/s/V/cm in the control group to 1.5 and 1.8 mm/s/V/cm, respectively, and the alpha-fetoprotein content decreased from 123 ng/mg in the control group to 68 and 45 ng/mg, respectively. The microvilli on the surface of treated cells were also reduced. All the above indexes related to cell malignancy were alleviated significantly. Results showed that 7-OH-4-CH(3)-coumarin could reverse human hepatoma cells' malignant phenotypic characteristics and induce redifferentiation.

DNA damage in healthy term neonate.

BACKGROUND: The process of childbirth is accompanied by an increase in oxidative aggression. AIM: To determine DNA damage and oxidative stress in healthy term neonates at birth. DESIGN: A total of 34 healthy full-term neonates, 22 healthy adults and 20 samples of colostrum from mothers of full-term neonates were examined. The malondialdehyde (MDA), DNA damage, GSH/GSSG ratio and total antioxidant capacity (TAC) in mononuclear cells isolated from umbilical blood and adult peripheral blood were measured. Moreover, the TAC of colostrum was also measured. The protective activity of five natural polyphenols against H(2)O(2)-induced DNA damage in mononuclear cells of umbilical blood was studied. RESULTS: A high level of DNA damage (p<0.001) accompanied with lower TAC (p<0.05) and GSH/GSSG ratio (p<0.001) and with higher level of MDA (p<0.001) in umbilical blood compared with those of healthy adult peripheral blood. The natural polyphenols, 7,8-dihydroxy-4-methyl coumarin, quercetin and resveratrol, are able to protect mononuclear cells of umbilical blood from oxidative attack. However, other two polyphenols, rutin and 7-hydroxy-4-methyl coumarin, do not. The TAC of colostrum is significantly higher than that of umbilical blood (p<0.001). CONCLUSIONS: The DNA oxidative damage in mononuclear cells of umbilical blood as well as other indexes related to redox status provided evidence that a sudden increase in oxygenation exposes the neonate into oxidative stress. Colostrum with a significant high TAC is very important for health care in infants against the oxidative stress.

Effects of reactive oxygen species on lymphokine-activated killer cells in patients with bladder cancer.

AIM: To investigate the effect of reactive oxygen species on the proliferation of lymphokine-activated killer (LAK) cells in patients with bladder cancer and their cytolysis to bladder tumor cells. METHODS: Sodium nitroprusside (SNP) was used as nitric oxide (NO) donor. The superoxide anion (O2-.) was generated in the complete medium (CM) supplemented with N-methylphenazonium methyl sulfate (PMS) 3-120 micromol/L and nicotinamide adenine dinucleotide (NADH) 18 - 600 micromol/L. The hydroxyl radical (.OH) was produced by adding ascorbic acid (AA) 0.5 - 400 micromol/L and ferrous sulfate (Fe2+) 0.05 - 40 micromol/L in CM. LAK cell proliferation and cytotoxicity were assayed in the presence of NO, .OH, or O2-. Bladder cancer cell lines BIU-87 and EJ were cultured as target cells and cytotoxicity of LAK cells were determined by MTT assay. RESULTS: The proliferation of LAK cells induced by interleukin-2 (IL-2) was inhibited by hydroxyl radical from 48 h to 96 h in a dose-dependent fashion and was inhibited to 34.5 % compared with control at 96 h in the concentration of ascorbic acid 400 micromol/L and ferrous sulfate 40 micromol/L. The inhibition induced by.OH can be overcome by certain concentrations of mannitol or editic acid. On the contrary, the proliferation of LAK cells induced by IL-2 was stimulated by certain concentrations of NO or O2-. The stimulation induced by O2-. can be overcome to control level by superoxide dismutase (SOD) 3 10(5) U/L. Exogenous O2-. resulted in an increase in cytotoxicity of LAK cells against BIU87 and EJ cells. However, the LAK cells cytotoxicity treated with hydroxyl radical or SOD showed no difference as compared with the control. CONCLUSION: NO and O2-. enhanced the proliferation and activation and O2-. up-regulated antitumor cytotoxicity of LAK cells in patients with bladder cancer. The growth of LAK cells induced by IL-2 was down-regulated by hydroxyl radical. The effects of these reactive oxygen species on the proliferation of LAK cells induced by IL-2 were different.