Association of catalase genotype with oxidative stress in the predication of colorectal cancer: modification by epidemiological factors / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>This paper aims to assess the interaction between common variations in catalase (CAT) polymorphic gene and environmental factors for antioxidant defense enzyme in modulating individual susceptibility to colorectal cancer (CRC).</p><p><b>METHODS</b>A case-control study with 880 colorectal cancer cases and 848 controls was conducted to investigate whether variations in the catalase (CAT) gene, one of the genes involved in scavenging oxidative stress, influenced susceptibility to CRC.</p><p><b>RESULTS</b>The interaction between life style and genotypes as well as with their effects on colorectal cancer was deduced from the present study. Significant difference (P = 0.01) was identified in the distribution of CAT genotype between the colorectal cancer cases and the controls. The CRC cases had significantly lower mean activity than the controls (P < 0.01). Correlation analyses revealed statistically significant correlations between CAT activity and CAT genotype (P < 0.01).</p><p><b>CONCLUSION</b>The risk of CRC was associated with smoking, low vegetable consumption, high pork and poultry consumptions, and low or high BMI. This is the first study reporting an association of polymorphism CAT-21A > T with colorectal cancer. Low CAT activity was associated with an increased risk of CRC; however, no evidence was found to support an association between CAT-21A > T polymorphism and CRC risk.</p>

Evaluation of oxidative stress in colorectal cancer patients / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To evaluate the oxidative stress in patients with colorectal cancer and to investigate the relationship between oxidative stress and colorectal cancer.</p><p><b>METHODS</b>Seventy-six subjects were divided into two groups (36 colorectal cancer patients as the study group and 40 normal healthy individuals as the control group). Their protein oxidation, DNA damage, lipid peroxidation and antioxidants, vitamin C, vitamin E, glutathione (GSH), and antioxidative enzymes in serum were detected.</p><p><b>RESULTS</b>The levels of protein carbonyl and advanced oxidation protein products (AOPP) were significantly higher in the study group than in the control group (P<0.01). Serum 8-OHdG was significantly increased in the study group compared to the control group (P<0.01). However, the mean serum level of MDA and conjugated diene was lower in the study group than in the control group (P<0.01). The activity of antioxidative enzymes was significantly decreased in the study group compared to the control group (P<0.01). Serum vitamins C and E concentrations were significantly reduced in the study group compared to the control group (P<0.01).</p><p><b>CONCLUSION</b>Colorectal cancer is associated with oxidative stress, and assessment of oxidative stress and given antioxidants is important for the treatment and prevention of colorectal cancer.</p>

Oxidative damage to DNA and its relationship with diabetic complications / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To detect the oxidative DNA damage in diabetic patients and to investigate the relationship of oxidative DNA damage with diabetes and diabetic nephropathy.</p><p><b>METHODS</b>Single cell gel electrophoresis (SCGE) was used to detect the DNA strand breaks in peripheral blood lymphocytes, and oxidative DNA damage product and serum 8-OHdG were determined by a competitive ELISA in 47 cases, including 25 patients without diabetic complications, 22 patients with diabetic nephropathy and 25 normal control subjects.</p><p><b>RESULTS</b>Diabetic patients showed greater oxidative damage to DNA. The percentage of comet cells and the length of DNA migration (comet tail length) of peripheral blood lymphocytes were significantly increased in patients with diabetes, and significantly higher in patients with diabetic nephropathy than in diabetic patients without vascular complications (P < 0.05). There was a significant increase in serum 8-OHdG in diabetic patients compared with normal subjects (P < 0.05). Moreover, serum 8-OHdG was much higher in patients with diabetic nephropathy than in diabetic patients without vascular complications (P < 0.05).</p><p><b>CONCLUSION</b>There is severe oxidative DNA damage in diabetic patients. Enhanced oxidative stress may be associated with diabetes, especially in patients with diabetic nephropathy.</p>

DNA damage and changes of antioxidative enzymes in chronic benzene poisoning mice / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the damage effect of benzene on DNA and its mechanism and the changes of antioxidative enzymes in vivo.</p><p><b>METHODS</b>DNA break in bone marrow cells and peripheral blood lymphocytes of mice exposed to benzene by 4 h static inhalation per day at different concentrations for two months were analyzed with single cell gel electrophoresis (SCGE). Meanwhile, the activity of SOD, GSH-Px and the level of MDA in liver, spleen and brain were detected.</p><p><b>RESULTS</b>In low and high dosage groups, the rate of DNA migration of bone marrow cells (83.56% +/- 10.28%, 92.54% +/- 15.93%) and peripheral blood lymphocytes (41.27% +/- 6.03%, 65.79% +/- 11.62%) were higher than those in control (4.13% +/- 0.52% and 2.21% +/- 0.31% respectively, P<0.05]. The activity of SOD in liver [(754.33 +/- 116.30), (694.26 +/- 116.30) U/mg pro] and GSH-Px [(22.52 +/- 3.31), (18.56 +/- 4.97) U/mg pro] were lower than those in control [(999.92 +/- 188.24) and (35.31 +/- 6.63) U/mg pro respectively, P<0.05, P<0.01]. But there was no significant difference between the two dosage groups. The activity of GSH-Px in spleen of both groups [(31.38 +/- 2.71), (25.30 +/- 7.44) U/mg pro] were lower than that of control [(37.11 +/- 3.42) U/mg pro, P<0.05] and there was significant difference between the two dosage groups. The activity of GSH-Px in brain of both groups [(5.70 +/- 0.84), (5.24 +/- 1.19) U/mg pro, P<0.05] were lower than that of control [(7.10 +/- 0.46) U/mg pro, P<0.05], but there was no significant difference between the two dosage groups. The level of MDA in brain of high dosage group [(3.99 +/- 1.15) nmol/mg pro] was higher than that of control [(2.58 +/- 0.53) nmol/mg pro, P<0.05].</p><p><b>CONCLUSION</b>Chronic benzene poisoning may result in DNA break in bone marrow cells and peripheral blood lymphocytes and decrease in the activity of antioxidative enzymes.</p>

Development of a new biosensor for biochemical oxygen demand / 中华预防医学杂志

<p><b>OBJECTIVE</b>To use a new kind of fixing material, i.e. Sol-Gel organic-inorganic hybridized material to immobilize bacterium to detect Biochemical oxygen demand quickly.</p><p><b>METHODS</b>The biosensor was fabricated using a thin film in which Hansenula anomala was immobilized by sol-gel and an oxygen electrode. The optimum measurement for biochemical oxygen demand was at pH 7.0; 28 degrees C; response time 3 - 12 min. Pure organic compound, sewage and rate of recovery were detected with the biosensor.</p><p><b>RESULTS</b>It shows that the BOD biosensor can be used to detect many organic compounds such as amino acid, glucide. It is suitable to monitor sewage and industrial waste water which has low level alcohols and phenols. The microbial membrane can work 3 months and remain its 70% activity. It is measured that the rate of recovery of BOD is between 90% to 105% in sewage.</p><p><b>CONCLUSION</b>The study confirmed the effectiveness and usefulness of BOD sensor, which is quick, convenient, low cost and reliable with little interference.</p>

Effect of yeast RNA on physical functions, morphology of hepatic cells and brain neurons in aged rats / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the effect of exogenous nucleic acid on physical functions, morphology of hepatic cells and brain neurons in aged rats.</p><p><b>METHODS</b>Thirty two aged Wistar rats (20 month-old) were divided randomly into four groups (one aged control group and three aged experimental groups) and eight young rats (3 month-old) was set as young control group. Control groups were fed on standard chow and experimental groups were fed on standard chow supplemented with 93.75 mg/kg (high-dosage group), 46.88 mg/kg (middle-dosage group) and 9.38 mg/kg (low-dosage group) of yeast RNA respectively. SOD, MDA, HDL, sex hormone and growth hormone were determined at the end of a 4-week observation. The microcosmic images of the hepatic cells and brain neurons using the image-pro plus (V.4.0) were also observed.</p><p><b>RESULTS</b>SOD, serum HDL and growth hormone levels in the high dosage group were significantly higher (P < 0.05) than that in the aged control group, and the levels were not different from that in the young control group. MDA level of all yeast RNA supplemented groups was significantly lower than that of aged control group (P < 0.05) and that was not different from the young control group. Serum testosterone of the high and middle dosage groups reached the level of young control group, and that was much higher than the aged control and low dosage group (P < 0.05). Estradiol levels among the aged rats were not different, and those were much lower than the young control group (P < 0.05). Much more number of brain neurons were observed in the high-dose group than other aged rats (P < 0.05). Brain neurons, hepatic cells and karyons in the high-dose group were bigger than that in other aged rats (P < 0.05).</p><p><b>CONCLUSION</b>Exogenous yeast RNA might play an important role in physical functions, the morphology of brain neurons and hepatic cells in natural aged rats. There might have a dose-effect relationship in the process.</p>