Total antioxidant levels, gender, and age as risk factors for DNA damage in lymphocytes of the elderly

Application of the comet assay for the evaluation of DNA damage from frozen human whole blood samples: Implications for human biomonitoring

This study proposes the application of the comet assay for the evaluation of DNA damage from frozen human whole blood samples that could be readily used in human biomonitoring and epidemiological studies. It was done on simply frozen whole blood samples collected from male volunteers (N = 60) aliquoted in small volumes and stored at -80 °C without the addition of cryopreservatives for a period of 5 years. To test the applicability of the alkaline comet assay for the evaluation of DNA damage in frozen whole blood, samples were quickly thawed at 37 °C and immediately embedded in an agarose matrix followed by an alkaline comet assay procedure. We concluded that the whole blood freezing and prolonged storage do not severely affect comet assay values, although background values were higher compared to our historical control data from the fresh whole blood. Even the influence of the variables tested, such as age, body mass index, smoking habit and alcohol consumption were in agreement with our previous data using fresh blood. The obtained results suggest that the comet assay could be applied to frozen blood samples, if properly stored, even for decades, which would certainly facilitate large-scale human biomonitoring and long-term epidemiological studies.

Plasma total antioxidant status and cognitive impairments in first-episode drug-naïve patients with schizophrenia

Accumulating evidence suggest that excessive reactive oxygen species-induced oxidative damage may underlie neurodegeneration and cognitive impairment in several disorders including schizophrenia. In this study we examined the association of oxidative stress with cognitive deficits in first-episode drug-naïve (FEDN) patients with schizophrenia. We recruited 54 FEDN patients and 50 age- and sex-matched healthy controls and examined the Measurement and Treatment Research to Improve Cognition in Schizophrenia Consensus cognitive Battery (MCCB) and plasma total antioxidant status (TAS). Psychopathological symptoms were assessed using the Positive and Negative Syndrome Scale. The results showed that plasma TAS levels were significantly lower in the patients than those in the healthy subjects (94.7 ± 25.0 U/ml vs 156.6 ± 46.7 U/ml, p < 0.0001). The patients scored lower than healthy controls on the MCCB total score, speed of processing, attention/vigilance and managing emotion test index and STROOP test. For the patients, TAS was associated with some domains of cognitive deficits in schizophrenia, such as speed of processing, attention/vigilance and emotion managing. Our results suggested that oxidative stress may be involved in the pathophysiology of schizophrenia at the early of stage and its cognitive impairment.

Effect of age and sex on the level of DNA strand breaks and oxidatively damaged DNA in human blood cells

DNA damage measured by the comet assay is a well-established biomarker in studies on environmental and occupational exposures, dietary factors and clinical outcomes. Age and sex are typically regarded as confounding factors that are controlled by either selective inclusion criteria of subjects or adjustment in the statistical analysis. This review assesses the influence of age and sex on levels of DNA damage in leukocytes in study populations of healthy subjects. Analysis of unadjusted results in the studies indicates that the level of DNA strand breaks increases by 1% per year (95% CI: 0.9%-1.1%, linear regression analysis weighted for the number of subjects in the individual studies). The studies also show a slightly higher level of DNA strand breaks in men than women (8%, 95% CI: 0.4%-17%) in unadjusted analyses, which is not robust in studies with adjusted analyses. The attenuation of effect in adjusted analyses of DNA strand breaks in leukocytes indicates that the effect of age and sex may be driven by differences in lifestyle factors or other exposures. There do not appear to be differences related to age and sex on basal levels of oxidatively damaged DNA in leukocytes. In summary, the results indicate influences of both age and sex on DNA damage in the comet assay, which may be mediated by lifestyle factors or external exposures rather than direct effects of age and sex.

The complex association between the antioxidant defense system and clinical status in early psychosis

Oxidative stress is a pathophysiological mechanism potentially involved in psychiatric disorders. The objective of this study was to assess the relationship between total antioxidant status (TAS) and the functional status of patients with a first episode of psychosis at the onset of the disease. For this purpose, a sample of 70 patients aged between 9 and 17 years with a first episode of psychosis were followed up for a period of two years. Blood samples were drawn to measure TAS levels at three time points: at baseline, at one year, and at two years. Clinical symptoms and functioning were also assessed at the same time points using various scales. Linear regression analysis was performed to investigate the relationship between TAS and clinical status at each assessment, adjusting for potential confounding factors. The distribution of clinical variables was grouped in different percentiles to assess the dose-response in the relation between clinical variables and TAS. At baseline, patient's score on Children's Global Assessment Scale (CGAS) was directly and significantly associated with TAS with a monotonic increase in percentiles, and surprising this association was reversed after one and two years of follow-up with a monotonic decrease. In summary at the onset of the illness, TAS is positively related to clinical status, whereas as the illness progresses this correlation is reversed and becomes negative. This may be the result of an adaptive response.

Primary DNA Damage in Dry Cleaners with Perchlorethylene Exposure

BACKGROUND

Perchloroethylene is a halogenated solvent widely used in dry cleaning. International agency of research on cancer classified this chemical as a probable human carcinogen.

OBJECTIVE

To evaluate the extent of primary DNA damage in dry cleaner workers who were exposed to perchloroethylene as compared to non-exposed subjects. The effect of exposure modifying factors such as use of personal protective equipment, perceived risk, and reported safe behaviors on observed DNA damage were also studied.

METHODS

59 exposed and non-exposed workers were selected from Yazd, Iran. All the 33 exposed workers had work history at least 3 months in the dry cleaning shops. Peripheral blood sampling was performed. Microscope examination was performed under fluorescent microscope (400×). Open comet software was used for image analysis. All biological analysis was performed in one laboratory.

RESULTS

Primary DNA damage to leukocytes in dry cleaners was relatively high. The median tail length, %DNA in tail, and tail moment in exposed group were significantly higher than those in non-exposed group. There was no significant difference between smokers and nonsmokers in terms of tail length, tail moment, and %DNA in tail. There was no significant correlation between duration of employment in dry cleaning and observed DNA damage in terms of tail length, tail moment and %DNA in tail. Stratified analysis based on exposed and nonexposed category showed no significant relationship between age and observed DNA damage.

CONCLUSION

Occupationally exposure to perchloroethylene can cause early DNA damage in dry cleaners.

Applicability of the comet assay in evaluation of DNA damage in healthcare providers' working with antineoplastic drugs: a systematic review and meta-analysis

BACKGROUND

Unintended occupational exposure to antineoplastic drugs (ANDs) may occur in medical personnel. Some ANDs are known human carcinogens and exposure can be monitored by genotoxic biomarkers.

OBJECTIVE

To evaluate the obstacles to obtaining conclusive results from a comet assay test to determine DNA damage among AND exposed healthcare workers.

METHODS

We systematically reviewed studies that used alkaline comet assay to determine the magnitude and significance of DNA damage among health care workers with potential AND exposure. Fifteen studies were eligible for review and 14 studies were used in the meta-analysis.

RESULTS

Under random effect assumption, the estimated standardized mean difference (SMD) in the DNA damage of health care workers was 1.93 (95% CI: 1.15-2.71, p < 0.0001). The resulting SMD was reduced to 1.756 (95% CI: 0.992-2.52, p < 0.0001) when the analysis only included nurses. In subgroup analyses based on gender and smoking, heterogeneity was observed. Only for studies reporting comet moment, I2 test results, as a measure of heterogeneity, dropped to zero. Heterogeneity analysis showed that date of study publication was a possible source of heterogeneity (B = -0.14; p < 0.0001).

CONCLUSIONS

A mixture of personal parameters, comet assay methodological variables, and exposure characteristics may be responsible for heterogenic data from comet assay studies and interfere with obtaining conclusive results. Lack of quantitative environmental exposure measures and variation in comet assay protocols across studies are important obstacles in generalization of results.

Recent physical activity in relation to DNA damage and repair using the comet assay

BACKGROUND

Limited evidence suggests that very high-intensity exercise is positively associated with DNA damage but moderate exercise may be associated with DNA repair.

METHODS

Participants were 220 healthy, Washington State 50- to 76-year-olds in the validity/biomarker substudy of the VITamins And Lifestyle (VITAL) cohort, who provided blood samples and completed questionnaires assessing recent physical activity and demographic and health factors. Measures included nested activity subsets: total activity, moderate- plus high-intensity activity, and high-intensity activity. DNA damage (n = 122) and repair (n = 99) were measured using the comet assay. Multivariate linear regression was used to estimate regression coefficients and associated 95% confidence intervals (CIs) for relationships between MET-hours per week of activity and each DNA outcome (damage, and 15- and 60-minute repair capacities).

RESULTS

DNA damage was not associated with any measure of activity. However, 60-minute DNA repair was positively associated with both total activity (β = 0.21, 95% CI: 0.0057-0.412; P = .044) and high-intensity activity (β = 0.31, 95% CI: 0.20-0.60; P = .036), adjusting for age, sex, BMI, and current multivitamin use.

CONCLUSIONS

This study is the first to assess broad ranges of activity intensity levels related to DNA damage and repair. Physical activity was unrelated to DNA damage but was associated with increased repair.

Cognitive function, plasma MnSOD activity, and MnSOD Ala-9Val polymorphism in patients with schizophrenia and normal controls

Excessive reactive oxygen species are thought to produce oxidative damage that underlies neurodegeneration and cognitive impairment in several disorders including schizophrenia. The functional Ala-9Val polymorphism of the mitochondrial enzyme manganese superoxide dismutase (MnSOD), which detoxifies superoxide radicals to hydrogen peroxide, has been associated with schizophrenia. However, no study has reported its role in cognitive deficits of schizophrenia as mediated through MnSOD activity. We recruited 923 schizophrenic inpatients and 566 healthy controls and compared them on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), plasma MnSOD activity, and the MnSOD Ala-9Val polymorphism. We assessed patient psychopathology using the Positive and Negative Syndrome Scale. We showed that the MnSOD Ala-9Val polymorphism may not contribute directly to the susceptibility to schizophrenia. The Ala variant was associated with worse attention performance among chronic schizophrenic patients but not among normal controls. Plasma MnSOD activity was significantly decreased in patients compared with that in normal controls. Moreover, MnSOD activity among the schizophrenic Ala allele carriers was correlated with the degree of cognitive impairments, especially attention and RBANS total score. We demonstrated an association between the MnSOD Ala-9Val variant and poor attention in schizophrenia. The association between higher MnSOD activity and cognitive impairment in schizophrenia is dependent on the MnSOD Ala-9Val polymorphism.

Improvement of metabolic parameters in healthy older adult men following a fasting calorie restriction intervention

OBJECTIVE

Calorie restriction and intermittent fasting are two dietary interventions that can improve aging. Religious fasting also suggested having similar benefit; however, such studies are still scarce. Thus, this study aimed to determine the effect of fasting calorie restriction (FCR) on metabolic parameters and DNA damage among healthy older adult men.

METHODS

A randomized controlled study was done on men, aged 50-70 years in Klang Valley, Malaysia. Subjects were divided into two groups; FCR (reduction of 300-500 kcal/d combined with 2 days/week of Muslim Sunnah Fasting) and control. Assessment was ascertained at three time point; baseline, weeks 6 and 12. Blood samples were analyzed for lipid profile, DNA damage and malondialdehyde (MDA).

RESULTS

The FCR group reduced their energy intake for approximately 18% upon completion of the study. A significant interaction effect was found in body weight, body mass index, fat percentage, fat mass, blood pressure, total cholesterol, low-density lipoprotein cholesterol and the ratio of total cholesterol/high-density lipoprotein cholesterol (p < 0.05). A significant improvement (p < 0.001) in total DNA rejoining cells and MDA (p < 0.05) was also observed in the FCR group.

CONCLUSION

FCR improved metabolic parameters and DNA damage in healthy older adult men. Therefore, there is a need to further examine the mechanism of FCR.

Cytogenetic status of healthy children assessed with the alkaline comet assay and the cytokinesis-block micronucleus cytome assay

In the present study the alkaline comet assay and the cytokinesis-block micronucleus cytome (CBMN Cyt) assay were used to evaluate the baseline frequency of cytogenetic damage in peripheral blood lymphocytes (PBLs) of 50 healthy children from the general population in Croatia (age, 11.62±1.81 years). Mean values of tail length, tail intensity and tail moment, as comet assay parameters, were 12.92±0.10, 0.73±0.06 and 0.08±0.01, respectively. The mean frequency of micronuclei (MN) for all subjects was 2.32±0.28 per 1000 bi-nucleated cells, while the mean frequency of nucleoplasmic bridges (NPBs) was 1.72±0.24 and of nuclear buds (NBUDs) 1.44±0.19. The mean nuclear division index (NDI) was 1.70±0.05. When comet-assay parameters were considered, higher mean values for all three were found for the female population. According to the Mann-Whitney U test applied on the results of the comet assay, the only statistically significant difference between the male and female populations was found for tail length. Similar to the results obtained by the comet assay, girls showed higher mean values of all three measured parameters of the CBMN Cyt assay. This difference was statistically significant for total number of NPBs only. In the case of the NDI, a higher mean value was also obtained in girls, but this difference was not statistically significant. The results obtained present background data that could be considered as normal values for healthy children living in urban areas, and can later on serve as baseline values for further toxicological monitoring. Additionally, the usefulness of both techniques in measuring cytogenetic damage during bio-monitoring of children is confirmed.

Plasma total antioxidant status and cognitive impairments in schizophrenia

Oxidative stress-induced damage to neurons may contribute to cognitive deficits during aging and in neurodegenerative disorders. Schizophrenia has a range of cognitive deficits that may evolve from oxidative stress, and this study examines this association of oxidative stress with cognitive deficits in schizophrenia. We recruited 296 chronic schizophrenia patients and 181 healthy control subjects and examined the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and plasma total antioxidant status (TAS) in both groups. Schizophrenia symptoms were assessed using the positive and negative syndrome scale (PANSS). Our results showed that TAS levels were significantly lower in patients than controls (179.6 ± 81.0 U/ml vs. 194.8 ± 46.0 U/ml, p<0.05). Cognitive scores on the RBANS and nearly all of its five subscales (all p<0.001) except for the Visuospatial/Constructional index (p>0.05) were significantly lower in schizophrenia patients than normal controls. For the patients, TAS was inversely associated with some domains of cognitive deficits in schizophrenia, such as Attention and Immediate Memory. Our findings suggest that oxidative stress may be involved in the pathophysiology of schizophrenia, and its associated cognitive impairment.

The association between Healthy Eating Index-2005 scores and disability among older Americans

BACKGROUND

several studies examining diet and functional status of individuals have focused on single nutrients or food groups. Studies examining the relationship between diet and health have increasingly witnessed a shift in focus from single nutrients to overall diet quality. The objective of this study was to examine the association between overall diet quality and self-reported disability.

SETTING

the 1999-2004 National Health and Nutrition Examination Survey (NHANES).

SUBJECTS

a nationally representative sample of Americans ≥60 years.

METHODS

overall diet quality was assessed using the United States Department of Agriculture's (USDA) Healthy Eating Index-2005 (HEI-2005). Self-reported measures of disability included activities of daily living (ADLs), instrumental activities of daily living (IADLs), leisure and social activities (LSAs), lower extremity mobility (LEM) and general physical activities (GPAs).

RESULTS

older adults with higher HEI-2005 scores were less likely to experience LEM (P for trend = 0.001) and GPAs (P for trend < 0.001) disability. Compared with older adults whose HEI-2005 scores were in the lowest quartile, the likelihood of both IADLs and GPAs disability were significantly lower in those with HEI-2005 scores in quartiles two, three and four. Compared with those who had HEI-2005 scores in the lowest quartile, the odds of LEM disability were significantly lower for those with HEI-2005 scores in the highest quartile.

CONCLUSION

older adults who do not adhere to the 2005 Dietary Guidelines for Americans report disability more frequently than those who do adhere to the guidelines.

Age-related sex differences in glutathione peroxidase and oxidative DNA damage in a healthy Mexican population

BACKGROUND AND OBJECTIVE

It has been proposed that women have an estrogen activity-linked biological antioxidant advantage and that this advantage is lost in the postmenopausal stage. The latter remains controversial. Our aim was to determine age-related sex differences in oxidative stress and oxidative DNA damage in a healthy Mexican population.

METHODS

A cross-sectional and comparative study was carried out in a convenience sample of 162 healthy subjects aged as follows: (1) 25-44 years (n = 35 women and 38 men), (2) 45-64 years (n = 41 women and 27 men), and (3) >or=65 years (n = 13 women and 8 men). We measured plasma lipoperoxides (LPO), superoxide dismutase (SOD), glutathione peroxidase (GPx), and DNA damage by comet assay.

RESULTS

We found greater activity of GPx in women than in men according to age increase (p < 0.05). This activity is maintained in old age in women. In contrast, men exhibited a significant diminution in GPx according to age increase. Similarly, we observed a greater percentage of cells without oxidative DNA damage in women in the 45-64-years age group and in the group of women aged >or=65 years.

CONCLUSIONS

Our findings suggest that women have a more efficient antioxidant activity than men, which has been linked with the greater longevity observed in women.

The protective effect of the flavonoids on food-mutagen-induced DNA damage in peripheral blood lymphocytes from colon cancer patients

The food mutagens IQ (2-amino-3-methylimidazo[4,5-f]quinoline) and PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine) are heterocyclic amines (HCA), generated when heating proteinaceous food. This study investigates the protective potential of the flavonoids quercetin (Q) and rutin (R) against oxidative stress induced in vitro by IQ and PhIP in lymphocytes from healthy individuals and untreated, newly diagnosed colon cancer patients using the Comet assay. In the presence of up to 500μM Q and R, the DNA damage resulting from a high dose of PhIP (75μM) or IQ (150μM) was significantly reduced (P<0.001) to levels comparable to six times lower IQ or 7.5 times lower PhIP doses. Lymphocytes from colon cancer patients had greater baseline DNA damage than those from healthy individuals (P<0.01) and this higher level of damage was also observed throughout in vitro treatment. Except for the >50years of age group and male gender, confounding factors such as smoking, drinking and/or dietary habits were not found to be significant. In conclusion, flavonoids reduced oxidative stress caused by food mutagens in vitro in lymphocytes of healthy individuals and colon cancer patients. Thus, dietary supplementation with flavonoid-rich vegetables and fruits may prove very effective in protecting against oxidative stress.

Antineoplastic Drugs as a Potential Risk Factor in Occupational Settings: Mechanisms of Action at the Cell Level, Genotoxic Effects, and Their Detection Using Different Biomarkers

U članku je prikazana osnovna podjela antineoplastičnih lijekova prema mehanizmima djelovanja na razini stanice. Objašnjeni su mehanizmi genotoksičnosti najvažnijih vrsta lijekova koji se primjenjuju u okviru uobičajenih protokola za liječenje zloćudnih novotvorina. Navedena je važeća klasifikacija antineoplastika prema kancerogenom potencijalu, podaci o mutagenom potencijalu te je prikazana njihova podjela u skladu s anatomsko-terapijsko-kemijskim sustavom klasifikacije. Sustavno su prikazani najvažniji rezultati svjetskih i hrvatskih istraživanja na populacijama radnika izloženih antineoplasticima, provedenih u razdoblju 1980.-2009. s pomoću četiri najčešće primjenjivane metode: analize izmjena sestrinskih kromatida, analize kromosomskih aberacija, mikronukleus-testa i komet-testa. Objašnjena su osnovna načela navedenih metoda te raspravljene njihove prednosti i nedostaci. Biološki pokazatelji daju važne podatke o individualnoj osjetljivosti profesionalno izloženih ispitanika koji mogu poslužiti unaprjeđenju postojećih uvjeta rada i upravljanju rizicima pri izloženosti genotoksičnim agensima. Na osnovi prednosti i nedostataka citogenetičkih metoda zaključeno je da je mikronukleus-test, koji podjednako uspješno dokazuje klastogene i aneugene učinke, jedna od najboljih metoda dostupnih za otkrivanje štetnih djelovanja antineoplastičnih lijekova koji su u aktivnoj primjeni.

DNA and cytogenetic damage in white blood cells of postmenopausal breast cancer patients treated with radiotherapy

The primary and residual genome damage and its elimination rate were evaluated in peripheral blood lymphocytes of breast cancer patients treated with adjuvant radiotherapy after surgical removal of the tumor by mastectomy or quadrantectomy. The levels of DNA/chromosome damage were estimated before, throughout, as well as after six months, respectively one year after the radiotherapy, using the alkaline comet assay, the chromosome aberration analysis and the cytokinesis-block micronucleus assay. The marked individual differences in the baseline genome damage were observed in patients, which additionally increased until the end of the radiotherapy cycle. The levels of DNA/cytogenetic damage slowly declined during post-irradiation period; although in the majority of subjects they did not return to pre-therapy levels. In addition to the well-established comet parameters, the long-tailed nuclei were also proved as a useful indicator of individual DNA damage and response to radiation. One of the most important observation was that older breast cancer patients, irradiated after mastectomy, had higher values of almost all parameters evaluated. We found positive correlations between the comet assay parameters and the cytogenetic biomarkers that confirmed their complementary value in the assessment of the radiation sensitivity/susceptibility in elderly breast cancer patients. The specific patterns of DNA damage observed in the majority of subjects after a prolonged exposure to ionizing radiation indicate the possibility of adaptive response. Such results may also be linked to the hormesis theory and support previous observations, but the underlying mechanisms should be further investigated on a much larger population.

The nutritional pattern of frailty - Proceedings from the 5th Italian Congress of Endocrinology of Aging, Parma, Italy, 27-28 March 2009

Frailty has become one of the 'hot spots' in geriatric research. Frailty has multifactorial origin, and is regarded as a fundamental risk factor for deteriorating health status and disability in elderly people and is highly prevalent in the population above the age 65. It is estimates that prevalence rates up to 27% and pre-frailty rates up to 50% qualify for the term "epidemic". Although the role of nutritional deficiency in the development of age-related frailty was suggested long ago, research conducted in this area is relatively recent. The critical role of micronutrients in this context suggests the need to improve the quality of food eaten by elderly people whereas quantity of food appears to be less relevant. This review summarizes the recent literature on the nutritional pathways to frailty with particular focus on the effect of energy, protein and micronutrients.

Correlates of antioxidant nutrients and oxidative DNA damage differ by race in a cross-sectional study of healthy African American and white adults

Although antioxidant nutrients and oxidative DNA damage have been associated with carcinogenesis, few studies have investigated the factors that influence antioxidant intake and oxidative DNA damage in racially diverse populations. Demographic, behavioral, and diet-related psychosocial correlates of plasma antioxidant (carotenoids, vitamin C, and vitamin E) concentrations and oxidative DNA damage were examined using data from a cross-sectional study of 147 generally healthy, nonsmoking African American and white adults in North Carolina, aged 20 to 45 years. All participants completed self-administered demographic, diet, and health questionnaires and provided semifasting (> or = 6 hours) blood samples. Multivariate regression analyses were computed separately for each race to determine associations between the potential correlates with plasma antioxidant concentrations and oxidative DNA damage, separately. Our findings suggest appreciable differences by race. Only a few factors (age, supplement use, and several psychosocial factors) were associated with antioxidant concentrations in African Americans, whereas these and additional factors, including physical activity, waist circumference, and passive smoke exposure, were associated with antioxidant concentrations in whites. For oxidative DNA damage, passive smoke exposure was significantly associated with oxidative DNA damage in African Americans, and age and alcohol were significant in whites. In addition, the regression models generally explained more of the variance in plasma antioxidant concentrations and oxidative DNA damage in whites than in African Americans. Considering the salient correlates differed by race, this work has important implications for the design and implementation of future research studies investigating antioxidant nutrients and/or oxidative stress, especially those in racially diverse populations.

Lipoprotein-associated phospholipase A2 activity is associated with coronary artery disease and markers of oxidative stress: a case-control study

BACKGROUND

Lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) is a lipoprotein-bound enzyme that can release atherogenic isoprostanes from esterified phospholipids and that may be involved in inflammation and atherosclerosis.

OBJECTIVE

This study investigates the association between Lp-PLA(2) activity and coronary artery disease (CAD) in relation to oxidative stress markers, in particular urinary 8-epi-prostaglandin F(2alpha) (8-epi-PGF(2alpha)).

DESIGN

We conducted a case-control study in which the cross-sectional relation between Lp-PLA(2) activity, lipoproteins, and oxidative stress markers was determined in 799 patients with angiographically confirmed CAD and 925 healthy controls.

RESULTS

Lp-PLA(2) activity was significantly (P < 0.001) higher in CAD cases than in controls (32.9 +/- 0.46 and 29.7 +/- 0.42 nmol . mL(-1) . min(-1), respectively). Both elevated Lp-PLA(2) activity and urinary excretion concentrations of 8-epi-PGF(2alpha) were associated with greater CAD risk (P for trend < 0.001). Odds ratios for the upper quartiles of Lp-PLA(2) activity and 8-epi-PGF(2alpha).excretion were 2.47 (95% CI: 1.79, 3.40) and 2.19 (1.52, 3.15), respectively, after adjustment for sex, age, BMI, blood pressure, smoking and alcohol consumption status, and LDL and HDL cholesterol. When we examined the additive effect of both markers for CAD risk, the relation between 8-epi-PGF(2alpha) and CAD was weakened above the second quartile of Lp-PLA(2) activity. Moreover, Lp-PLA(2) activity was positively correlated with urinary excretion concentrations of 8-epi-PGF(2alpha) in controls (r = 0.277, P < 0.001) and cases (r = 0.202, P < 0.001) and with the tail moment of lymphocyte DNA (r = 0.213, P < 0.001) in controls.

CONCLUSION

This study shows an association of elevated Lp-PLA(2) activity with CAD risk in relation to oxidant stress and thus supports a proatherogenic role of Lp-PLA(2).

Genome damage in oropharyngeal cancer patients treated by radiotherapy

AIM

To estimate genome damage in oropharyngeal cancer patients before, during, and after radiotherapy and to measure the persistence of caused genome damage relevant in the evaluation of secondary cancer risk.

METHODS

DNA damage was evaluated in peripheral blood lymphocytes of 10 oropharyngeal cancer patients using alkaline comet assay, analysis of structural chromosome aberrations, and micronucleus assay. Blood samples were taken 2 hours before irradiation on day 1 of the first radiotherapy cycle, 2 hours after the application of the first dose, in the middle of the radiotherapy cycle, within 2 hours after the last received radiotherapy dose, and after 6 and 12 months after radiotherapy.

RESULTS

In most participants, the highest level of primary DNA damage was recorded in blood samples collected after the administration of first radiation dose (mean tail length 25.04+/-6.23 mum). Most patients also had increased frequency of comets with long tail-nucleus (LTN comets) after the administration of the first radiation dose (mean, 10.50+/-7.71 per 100 comets), which remained increased in the middle of radiotherapy (mean, 18.30+/-27.62 per 100 comets). Later on, the levels of primary DNA damage as recorded by the comet assay, slightly diminished. The frequency of structural chromosome aberrations in lymphocytes gradually increased during the radiation cycle (26.50+/-27.72 per 100 metaphases at the end of the therapy), as well as the frequency of micronuclei (mean total number of micronuclei 167.20+/-35.69 per 1000 binuclear cells).

CONCLUSION

Oropharyngeal cancer patients had relatively high levels of primary DNA damage in their peripheral blood lymphocytes even before therapy. The frequency of complex structural chromosome aberrations and the frequency of micronuclei increased with the progression of the radiation cycle and the doses delivered. As the frequency of chromosomal aberrations a year after radiotherapy mostly did not return to pre-therapy values, it represents an important risk factor related to the onset of second cancer.

High dosage of ascorbic acid and alpha-tocopherol is not useful for diminishing oxidative stress and DNA damage in healthy elderly adults

AIM

To determine the useful dosage of ascorbic acid and alpha-tocopherol against oxidative stress and DNA damage in the elderly.

METHODS

A double-blind controlled clinical assay carried out in a sample of 66 healthy subjects divided into three age-paired random groups with 22 subjects in each group. Group A received placebo and group B was administered 500 mg of ascorbic acid and 400 IU of alpha-tocopherol, whereas group C received 1,000 mg of ascorbic acid and 400 IU of alpha-tocopherol for a 6-month period. The following measurements were performed before and after the 6-month treatment period: thiobarbituric acid reactive substances (TBARS); total antioxidant status (TAS); superoxide dismutase (SOD), and glutation peroxidase (GPx) and DNA damage by comet assay.

RESULTS

After 6 months, group B subjects exhibited an increase in SOD and GPx enzyme levels; however, this was not statistically significant (p > 0.05). Likewise, TBARS and TAS concentrations remained unchanged (p > 0.05). In addition, in group C the decrease in TBARS and increase in SOD, GPx, and TAS were not statistically significant (p > 0.05). Similarly, average DNA migration showed no significant differences with high-dosage ascorbic acid and alpha-tocopherol.

CONCLUSION

These findings suggest that administration of 1,000 mg of ascorbic acid plus 400 IU of alpha-tocopherol for 6 months is not useful for diminishing oxidative stress and DNA damage in healthy elderly adults.

Relation of serum total antioxidant status with metabolic risk factors in Korean adults

The purpose of the present study was to examine the relation of total antioxidant status (TAS) to metabolic risk factors in Korean adults. Anthropometric measures, blood pressure, serum lipids and fasting glucose were determined in 406 men and women. TAS was measured by using commercially available Randox kit. Serum TAS was significantly positively correlated with body weight (p=0.004), body mass index (BMI) (p=0.033), waist circumference (p=0.017), total cholesterol (p=0.038) and triglyceride (TG) (p<0.001). The mean TAS of hypertriglyceridemic subjects (TG ≥150 mg/dl) was significantly higher than that of subjects whose TG was lower than 150 mg/dl (p=0.001). When central obesity, TG, high density lipoprotein cholesterol, fasting glucose and blood pressure were considered as metabolic risk factors, TAS was shown to be elevated with increased number of metabolic risk factors (p=0.004). The positive association between TAS and a number of metabolic risk factors suggests that increased TAS may not always indicate one's healthier condition. In order to help understand TAS as a marker of total antioxidant capacity in humans with various metabolic conditions, it is needed to clarify the factors affecting TAS in relation to changes in metabolic risk factors.

Aging-related oxidative stress in healthy humans

Oxidative stress has been reported to increase with aging; however, the scientific evidence is controversial. We therefore aimed to analyze the relationship between aging and some markers of oxidative stress. A cross-sectional and comparative study was carried out in a sample of 249 healthy subjects: (i) 25-29 years (n = 22); (ii) 30-39 years (24); (iii) 40-49 years (30); (iv) 50-59 years (48); (v) 60-69 years (60), and (vi) >or= 70 years (65). We measured lipoperoxides and total antioxidant status in plasma and superoxide dismutase and glutathione peroxidase activities in erythrocytes. There was an age-related increase in lipoperoxides, which was evident in the comparison of the group of 25-29 years (0.22 0.11 micromol/l) with the group of 60-69 years (0.38 +/- 0.18 micromol/l, p < 0.01) and >or= 70 years (0.42 +/- 0.19, p < 0.001). Conversely, the total antioxidant status showed an age-related decrease (25-29 years, 1.4 +/- 0.31 mmol/l vs 60-69 years, 1.1 +/- 0.21 and >or= 70 years, 1.1 +/- 0.22, p < 0.05 for each). In erythrocytes, glutathione peroxidase activity showed an age-related decrease (25-29 years, 7,966 +/- 1,813 UI/l vs 60-69 years, 6,193 +/- 2,235 and >or= 70 years, 6,547 +/- 2,307, p < 0.001 for each), whereas superoxide dismutase activity was similar in all age groups. Importantly, there was no age-related change in oxidative stress markers in subjects of < 60 years. These findings suggest that age of >or= 60 years may be associated with increased oxidative stress.

DNA damage, a biomarker of carcinogenesis: its measurement and modulation by diet and environment

Free radicals and other reactive oxygen or nitrogen species are constantly generated in vivo and can cause oxidative damage to DNA. This damage has been implicated to be important in many diseases, including cancer. The assessment of damage in various biological matrices, such as tissues, cells, and urine, is vital to understanding this role and subsequently devising intervention strategies. During the last 20 years, many analytical techniques have been developed to monitor oxidative DNA base damage. High-performance liquid chromatography-electrochemical detection and gas chromatography-mass spectrometry are the two pioneering contributions to the field. Currently, the arsenal of methods available include the promising high-performance liquid chromatography-tandem mass spectrometry technique, capillary electrophoresis, 32P-postlabeling, antibody-base immunoassays, and assays involving the use of DNA repair glycosylases such as the comet assay. The objective of this review is to discuss the biological significance of oxidative DNA damage, evaluate the effectiveness of several techniques for measurement of oxidative DNA damage in various biological samples and review current research on factors (dietary and non-dietary) that influence DNA oxidative damage using these techniques.

Age- and gender-related oxidative status determined in healthy subjects by means of OXY-SCORE, a potential new comprehensive index

Oxidative stress has been related to various diseases, gender and ageing, and has been measured by various markers. The authors developed a procedure to compute a global oxidative stress index (OXY-SCORE), reflecting both oxidative and antioxidant markers in healthy subjects. Its performance was tested in relation to age and gender and in coronary artery disease (CAD) patients. Eighty-two healthy subjects and 20 CAD patients were enrolled. Plasma free and total malondialdehyde (F- and T-MDA), glutathione disulphide/reduced form ratio (GSSG/GSH) and urine isoprostanes (iPF2alpha-III) levels were combined as oxidative damage markers (damage score). GSH, alpha- and gamma-tocopherol (TH) levels, and individual antioxidant capacity were combined as antioxidant defence indexes (protection score). The OXY-SCORE was computed by subtracting the protection score from the damage score. Among single parameters, T-MDA and iPF2alpha-III significantly correlated with age; only GSH and both tocopherols correlated with male gender in healthy subjects. The OXY-SCORE was positively associated with age (p=0.004) and male gender (p=0.03). As expected, the OXY-SCORE was higher in CAD with a very significant p-value (<0.0001), after adjusting for age, gender and smoking. Combining different markers can potentially provide a powerful index in the evaluation of oxidative stress related to age, gender and CAD status.

Multiplexed proteomic analysis of oxidation and concentrations of cerebrospinal fluid proteins in Alzheimer disease

BACKGROUND

Carbonylation is an irreversible oxidative modification of proteins that has been linked to various conditions of oxidative stress, aging, physiological disorders, and disease. Increased oxidative stress is thus also considered to play a role in the pathogenesis of age-related neurodegenerative disorders such as Alzheimer disease (AD). In addition, it has recently become evident that the response mechanisms to increased oxidative stress may depend on sex. Several oxidized carbonylated proteins have been identified in plasma and brain of AD patients by use of 2-dimensional oxyblotting.

METHODS

In this pilot study, we estimated the concentrations and carbonylation of the most abundant cerebrospinal fluid proteins in aging women and men, both AD patients suffering from mild dementia and individuals exhibiting no cognitive decline. Oxidized carbonylated proteins were analyzed with 2-dimensional multiplexed oxyblotting, mass spectrometry, and database searches.

RESULTS

Signals for beta-trace, lambda chain, and transthyretins were decreased in probable AD patients compared with controls. The only identified protein exhibiting an increased degree of carbonylation in AD patients was lambda chain. The concentrations of proteins did not generally differ between men and women; however, vitamin D-binding protein, apolipoprotein A-I, and alpha-1-antitrypsin exhibited higher extents of carbonylation in men.

CONCLUSIONS

None of the brain-specific proteins exhibited carbonylation changes in probable AD patients compared with age-matched neurological controls showing no cognitive decline. The carbonylation status of proteins differed between women and men. Two-dimensional multiplexed oxyblotting is applicable to study both the concentrations and carbonylation of cerebrospinal fluid proteins.

Glutathione S-transferase genotypes modify lung function decline in the general population: SAPALDIA cohort study

Background

Understanding the environmental and genetic risk factors of accelerated lung function decline in the general population is a first step in a prevention strategy against the worldwide increasing respiratory pathology of chronic obstructive pulmonary disease (COPD). Deficiency in antioxidative and detoxifying Glutathione S-transferase (GST) gene has been associated with poorer lung function in children, smokers and patients with respiratory diseases. In the present study, we assessed whether low activity variants in GST genes are also associated with accelerated lung function decline in the general adult population.

Methods

We examined with multiple regression analysis the association of polymorphisms in GSTM1, GSTT1 and GSTP1 genes with annual decline in FEV1, FVC, and FEF_25–75 during 11 years of follow-up in 4686 subjects of the prospective SAPALDIA cohort representative of the Swiss general population. Effect modification by smoking, gender, bronchial hyperresponisveness and age was studied.

Results

The associations of GST genotypes with FEV1, FVC, and FEF_25–75 were comparable in direction, but most consistent for FEV1. GSTT1 homozygous gene deletion alone or in combination with GSTM1 homozygous gene deletion was associated with excess decline in FEV1 in men, but not women, irrespective of smoking status. The additional mean annual decline in FEV1 in men with GSTT1 and concurrent GSTM1 gene deletion was -8.3 ml/yr (95% confidence interval: -12.6 to -3.9) relative to men without these gene deletions. The GSTT1 effect on the FEV1 decline comparable to the observed difference in FEV1 decline between never and persistent smoking men. Effect modification by gender was statistically significant.

Conclusion

Our results suggest that genetic GSTT1 deficiency is a prevalent and strong determinant of accelerated lung function decline in the male general population.

Evaluation of micronucleus frequencies and DNA damage in glass workers exposed to arsenic

Arsenic (As) is a known human carcinogen; however, very little is known about the health consequences of occupational exposure to As. In the present study, we assessed the genotoxic damage in the blood cells and in the buccal cells of south Indian glass factory workers who are occupationally exposed to As. The As content in the whole blood of 200 workers and 165 controls was evaluated with inductively coupled plasma mass spectrometry. Blood leukocytes from the subjects were monitored for the level of DNA damage using the Comet assay (mean comet tail length); buccal cells were used to determine the frequency of micronuclei (MN). The mean As concentration was significantly higher in the workers (56.76 microg/L) than in the controls (11.74 microg/L) (P < 0.001). The workers also had increased frequencies of MN in the buccal cells and increased levels of DNA damage in leukocytes compared to the controls (P < 0.001). There were significant correlations between the genotoxicity endpoints that were evaluated and blood As concentration, smoking, age, and the duration of working in the factory. Also, a significant correlation was observed between the frequency of MN and comet tail-length for the worker samples. Our findings indicate that chronic occupational exposure to As is genotoxic and that the Comet assay and micronucleus test are useful assays for evaluating genotoxicity in humans occupationally exposed to As.

Aging sensitizes toward ROS formation and lipid peroxidation in PS1M146L transgenic mice

Mutations in the presenilins (PS) account for the majority of familial Alzheimer disease (FAD) cases. To test the hypothesis that oxidative stress can underlie the deleterious effects of presenilin mutations, we analyzed lipid peroxidation products (4-hydroxynonenal (HNE) and malondialdehyde) and antioxidant defenses in brain tissue and levels of reactive oxygen species (ROS) in splenic lymphocytes from transgenic mice bearing human PS1 with the M146L mutation (PS1M146L) compared to those from mice transgenic for wild-type human PS1 (PS1wt) and nontransgenic littermate control mice. In brain tissue, HNE levels were increased only in aged (19-22 months) PS1M146L transgenic animals compared to PS1wt mice and not in young (3-4 months) or middle-aged mice (13-15 months). Similarly, in splenic lymphocytes expressing the transgenic PS1 proteins, mitochondrial and cytosolic ROS levels were elevated to 142.1 and 120.5% relative to controls only in cells from aged PS1M146L animals. Additionally, brain tissue HNE levels were positively correlated with mitochondrial ROS levels in splenic lymphocytes, indicating that oxidative stress can be detected in different tissues of PS1 transgenic mice. Antioxidant defenses (activities of antioxidant enzymes Cu/Zn-SOD, GPx, or GR) or susceptibility to in vitro oxidative stimulation was unaltered. In summary, these results demonstrate that the PS1M146L mutation increases mitochondrial ROS formation and oxidative damage in aged mice. Hence, oxidative stress caused by the combined effects of aging and PS1 mutations may be causative for triggering neurodegenerative events in FAD patients.

Total antioxidant capacity is impaired in different structures from aged rat brain

Our data support a disproportion between free radicals levels and scavenging systems activity in different cerebral regions of the aging rat. We investigated the total reactive antioxidant potential and reactivity levels, which represent the total antioxidant capacity, in different cerebral regions of the aging rat (cortex, striatum, hippocampus and the cerebellum). In addition, we have determined several oxidative stress parameters, specifically the free radicals levels, the macromolecules damage (lipid peroxidation and carbonyl content), as well as the antioxidant enzymes activities in different cerebral areas from young (2 months-old), mature adult (6 months-old) and old (24 months-old) male Wistar rats. Free radicals levels, determined by 2',7'-dichlorofluorescein diacetate probe, were higher in striatum, cerebellum and hippocampus from aged rats. There was an age-related increase in lipoperoxidation in hippocampus and cerebral cortex. In the cerebellum, a high activity of superoxide dismutase and a decrease of catalase activity were observed. The striatum exhibited a significant catalase activity decrease; and glutathione peroxidase activity was diminished in the hippocampus of mature and aged rats. There was a marked decrease of total antioxidant capacity in hippocampus in both reactivity and potential levels, whereas striatum and cerebral cortex displayed a reduction on reactivity assay. We suggest that age-related variations of total antioxidant defenses in brain may predispose structures to oxidative stress-related neurodegenerative disorders.

Relationship between oxidative stress and cognitive impairment in the elderly of rural vs. urban communities

Psychological stress and environmental pollution are frequently associated to urban environment and oxidative stress (OxS). Likewise, OxS is a risk factor for cognitive impairment (CI) in the elderly. Therefore, we hypothesized that the prevalence of CI in subjects of the urban area could be higher than in those of the rural area, and linked to higher OxS. The aim of the study was to determine the relationship between OxS and CI in elderly individuals from rural and urban settings in Mexico. Plasmatic TBARS, plasma total antioxidant status, and the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx) were measured in 104 urban and 85 rural elderly individuals. Cognitive functions were evaluated through the Mini Mental State Examination. We found a greater proportion of subjects with OxS and CI in urban than in rural areas (25% vs. 9%), with an odds ratio of 5.67 (CI95% 1.14-38.02, p < 0.05). Our findings suggest that the elderly in urban areas have more OxS and a higher risk of developing CI compared with elderly individuals in a rural environment.

A review of antioxidants and Alzheimer's disease

BACKGROUND

In this article, we review a diverse body of research and draw conclusions about the usefulness, or lack there-of, of specific antioxidants in the prevention of Alzheimer's disease (AD).

METHODS

The National Library of Medicine's database was searched for the years 1996-2004 using the search terms "Alzheimer's, anti-oxidants, antioxidants."

RESULTS

Over 300 articles were identified and 187 articles were selected for inclusion based on relevance to the topic. Agents that show promise in helping prevent AD include: 1) aged garlic extract, 2) curcumin, 3) melatonin, 4) resveratrol, 5) Ginkgo biloba extract, 6) green tea, 7) vitamin C and 8) vitamin E.

CONCLUSIONS

While the clinical value of antioxidants for the prevention of AD is often ambiguous, some can be recommended based upon: 1) epidemiological evidence, 2) known benefits for prevention of other maladies, and 3) benign nature of the substance. Long-term, prospective studies are recommended.

Effect of long-term hormone therapy on telomere length in postmenopausal women

Telomeres undergo attrition with each cell division, and telomere length is associated with age-related diseases and mortality in the elderly. Estrogen can influence the attrition of telomeres by diverse mechanisms. This is a retrospective case control study that investigated the influence of long-term hormone therapy (HT) on telomere length in postmenopausal women. We recruited 130 postmenopausal women from 55 to 69 years of age for this study, and divided them into two groups. The first group included 65 women who had been on estrogen and progesterone therapy for more than five years (HT group). The other group was composed of 65 women matched in age to the HT group who had never had HT (non- HT group). The relative ratios of telomere length of study subjects to a reference DNA from a healthy young female were measured using quantitative PCR. Plasma levels of lipid profiles, total antioxidant status (TAS), C-reactive proteins (CRP), fasting glucose levels, and estradiol levels were measured. Age at menopause, vitamin use, and exercise, alcohol, and cigarette smoking histories were also assessed in a questionnaire. Mean duration (+/- SD) of HT was 8.4 +/- 2.3 years. Prevalence of vitamin use and regular exercise were higher in the HT group than in the non-HT group (p < 0.01). Relative telomere length ratios in the HT group were significantly greater than those in the non-HT group (p < 0.01). HT was significantly correlated with the relative telomere length ratio in multivariate analysis when potential confounding variables were controlled for (p < 0.05). In conclusion, telomere lengths were longer in postmenopausal women who had a history of long-term HT than in postmenopausal women without HT. Long-term HT in postmenopausal women may alleviate telomere attrition.

Antioxidant enzymes in hypertensive and hypertriglyceridemic rats: effect of gender

In a model of hypertensive and hypertriglyceridemic rats (HTG), in which oxidative stress is increased, the influence of gender upon activities of catalase (CAT), glutathione peroxidase (GPX), and superoxide dismutase (SOD) was investigated. Statistically significant differences between antioxidant enzyme activities and treatment with relation to gender were analyzed. Weanling Wistar rats were given normal rat chow and either tap water for control group or 30% sucrose solution for HTG group, for 5-6 months. At the end of the experimental period, blood pressure was significantly higher in both male and female HTG groups, but males showed higher values than females. Serum, heart, kidney, and liver were obtained to determine antioxidant enzyme activities. Activities of CAT and GPX tended to be higher in male animals. A larger number of significant changes in enzyme activities associated with gender appears in HTG than in controls, which indicates the harmful effect of the treatment.

Efficient antioxidant capacity against lipid peroxide levels in healthy elderly of Mexico City

We evaluated antioxidant activity against lipid peroxide levels (LPO) in healthy elderly and adults of Mexico City in comparison with a population of a rural area. The study included free-living subjects: 38 adults aged <60 years and 129 older subjects aged > or = 60 years of urban Mexico City in addition to 37 adults aged <60 years and 88 older subjects aged > or = 60 years of rural area (Actopan, Hidalgo State, Mexico). LPO were observed as higher in adults and elderly of the urban area than among rural subjects (P<0.01), although LPO levels were similar in rural adults and elderly (P>0.05); conversely, in urban area levels were higher in the elderly than in adults (P<0.01). On the other hand, the superoxide dismutase in urban elderly was higher than that in rural elderly (P<0.05) but similar between urban adults and urban elderly (P>0.05). Total oxidant status in urban elderly was higher than that in rural elderly (P<0.01). Our findings allow us to conclude that the urban elderly (residents of Mexico City) have higher oxidative stress than the rural-dwelling elderly, though the urban elderly have efficient antioxidant capacity as a response to elevated LPO.

Measurement of total antioxidant capacity in gingival crevicular fluid and serum in dogs with periodontal disease

OBJECTIVE

To determine whether gingival crevicular fluid (GCF) and serum total antioxidant capacities (TACs) correlate with the degree of severity of periodontal disease in dogs.

ANIMALS

41 Toy and Miniature Poodles.

PROCEDURES

After assessment of the degree of severity of naturally occurring periodontitis, GCF samples from both maxillary fourth premolars and a blood sample were collected from each dog. The condition of the periodontium of the entire dentition and at each site of GCF collection was recorded. Clinical parameters assessed included plaque index, gingival index, and probing depth. Radiographic analysis of alveolar bone level was also performed. Total antioxidant capacity was measured in GCF and serum samples by use of a commercial kit.

RESULTS

Dogs with gingivitis and minimal periodontitis had significantly higher TAC in GCF than dogs with advanced periodontitis. Bivariate regression analysis revealed significant negative correlations between TAC in GCF and clinical parameters and age. The TAC in serum was significantly negatively correlated with the degree of gingival inflammation but was not significantly correlated with age.

CONCLUSIONS AND CLINICAL RELEVANCE

TAC in GCF is related to the degree of severity of periodontal disease in dogs. This is likely the result of release of reactive oxygen species by activated phagocytes and fibroblasts in the inflamed periodontal tissues. The results of our study suggest that the local delivery of antioxidants may be a useful adjunctive treatment for periodontitis in dogs.

Enhanced Sensitivity to Oxidant-Induced Micronucleus Frequency in Elderly Individuals Is Not Associated with Glutathione S- Transferase M1 (GSTM1) Null Genotype in Lymphocytes

BACKGROUND

A large number of studies have demonstrated that various kinds of DNA damage accumulate during aging and that oxidative stress possibly contributes to this process. Glutathione S-transferase M1 (GSTM1) can prevent their possible effects on DNA via detoxification of reactive substances that induced oxidative stress.

OBJECTIVE

To investigate the relationship between GSTM1 polymorphism and DNA sensitivity to oxidative stress with age, we used micronucleus (MN) frequency as a marker of DNA damage in lymphocytes from young and elderly subjects.

METHODS

This study was performed in 30 young (age range 20-36 years) and 30 elderly (age range 66-87 years) healthy individuals who were chosen on the basis of their GSTM1 genotype (15 GSTM1 null and 15 GSTM1 positive for each group). Lymphocytes were cultured after Ficoll isolation and treated for 48 h with a 30-muM dose of cumene hydroperoxide (CumOOH), a dose that does not decrease cell viability.

RESULTS

There was no significant difference in the MN frequency observed in control cultures from young and elderly individuals. However, the MN frequency in CumOOH-treated cultures was significantly higher in the elderly group than the young group (p < 0.001). No association was found between the GSTM1 phenotype and CumOOH-induced MN frequency.

CONCLUSIONS

The results suggest that lymphocytes of elderly individuals are more susceptible to in vitro MN induction by CumOOH. However, this difference in susceptibility is not explained by the lack of GSTM1.

The -1131T-->C polymorphism in the apolipoprotein A5 gene is associated with postprandial hypertriacylglycerolemia; elevated small, dense LDL concentrations; and oxidative stress in nonobese Korean men

BACKGROUND

Apolipoprotein A5 plays an important role in modulating triacylglycerol metabolism in experimental animal models.

OBJECTIVE

The objective was to determine associations of the common apolipoprotein A5 gene (APOA5) -1131T-->C polymorphism with postprandial lipemic response and other cardiovascular disease risk factors in humans.

DESIGN

Healthy, nonobese subjects [n = 158; mean (+/-SEM) age: 33.8 +/- 1.2 y; body mass index (in kg/m(2)): 23.3 +/- 0.3] were subdivided into 3 genotype groups: TT (n = 85), TC (n = 56), and CC (n = 17). We measured fasting and postprandial lipid concentrations, lipid peroxidation, C-reactive protein concentrations, and DNA damage.

RESULTS

Fasting triacylglycerol concentrations in carriers of the C allele were higher (P < 0.05) than in carriers of the TT genotype. No other significant genotype-related differences were observed for any of the other baseline measures. After consumption of a mixed meal, carriers of the C allele had significantly greater increases in total chylomicron and VLDL triacylglycerol than did subjects with the TT genotype. Moreover, carriers of the C allele had higher dense LDL, serum C-reactive protein, and urinary 8-epi-prostaglandin F(2alpha) concentrations and more lymphocyte DNA damage. Conversely, we did not find significant genotype-related differences in postprandial glucose, insulin, or free fatty acid measures.

CONCLUSIONS

Our data confirm the genetic modulation of serum fasting triacylglycerol concentrations by the APOA5 gene polymorphism and extend this observation to postprandial triacylglycerol concentrations and to markers of oxidation and inflammation. The presence of the C allele in the APOA5 promoter region at position 1131 could be a significant factor contributing to higher cardiovascular disease risk in Koreans independently of common environmental factors.

Antioxidants and physical performance in elderly persons: the Invecchiare in Chianti (InCHIANTI) study

BACKGROUND

Muscle strength and physical performance in old age might be related to the oxidative damage caused by free radicals.

OBJECTIVE

The objective was to assess the correlation of plasma concentrations and daily dietary intakes of antioxidants with skeletal muscle strength and physical performance in elderly persons.

DESIGN

This study is part of the Invecchiare in Chianti (InCHIANTI) study, which was conducted in 986 Italians aged > or = 65 y. Physical performance was assessed on the basis of walking speed, ability to rise from a chair, and standing balance. Knee extension strength was assessed with a hand-held dynamometer. The European Prospective Investigation into Cancer and Nutrition (EPIC) questionnaire was used to evaluate the daily dietary intakes of vitamin C, vitamin E, beta-carotene, and retinol. Plasma alpha- and gamma-tocopherol concentrations were measured. Adjusted linear regression analyses were used to calculate regression coefficients per SD increase in plasma concentrations and daily dietary intakes.

RESULTS

In adjusted analyses, plasma alpha-tocopherol was significantly correlated with knee extension (beta = 0.566, P = 0.003) and the summary physical performance score (beta = 0.044, P = 0.008). Plasma gamma-tocopherol was associated only with knee extension strength (beta = 0.327, P = 0.04). Of the daily dietary intake measures, vitamin C and beta-carotene were significantly correlated with knee extension strength, and vitamin C was significantly associated with physical performance (beta = 0.029, P = 0.04).

CONCLUSIONS

Plasma antioxidant concentrations correlate positively with physical performance and strength. Higher dietary intakes of most antioxidants, especially vitamin C, appear to be associated with higher skeletal muscular strength in elderly persons.

Telomere dysfunction of lymphocytes in patients with Alzheimer disease

OBJECTIVE

The objective of this study was to investigate the telomerase activity of phytohemagglutinin-activated lymphocytes from patients with Alzheimer disease.

BACKGROUND

There is impairment of immune function in patients with Alzheimer disease, and the perturbation of immune system is involved the pathogenesis of Alzheimer disease. However, the mechanism of the impairment is unclear so far.

METHODS

We analyzed telomerase activities of phytohemagglutinin-activated lymphocytes from 187 cases of patients with Alzheimer disease, 53 cases of patients with vascular dementia, and 80 cases of age-matched healthy controls, respectively. Telomerase activity was measured using the telomeric repeat amplification protocol-based telomerase polymerase chain reaction enzyme-linked immunosorbent assay. We also detected the proliferation activity of peripheral blood mononuclear cells from 10 cases of patients with Alzheimer disease or 10 cases of age-matched healthy controls by [3H] thymidine incorporation.

RESULTS

Telomerase activity of phytohemagglutinin-activated lymphocytes in Alzheimer disease patients was significantly elevated compared with healthy controls (P < 0.01) and vascular dementia patients (P < 0.01), respectively. There was significant statistical correlation between the telomerase activities of lymphocytes and the degree of dementia in Alzheimer disease patients. The proliferation activity of peripheral blood mononuclear cells to phytohemagglutinin was significantly decreased in Alzheimer disease patients compared with age-matched healthy controls (P < 0.01).

CONCLUSIONS

Our data suggest that there could be an accelerated telomere dysfunction in lymphocytes of Alzheimer disease patients, which induces the increase of telomerase activity and the decrease of proliferation activity of lymphocytes, and subsequently results in the impairment of immune function in Alzheimer disease patients.

Visceral fat accumulation determines postprandial lipemic response, lipid peroxidation, DNA damage, and endothelial dysfunction in nonobese Korean men

Visceral fat has been associated with multiple cardiovascular disease (CVD) risk factors. The aim of this study was to identify anthropometrical measures most closely associated with some well-known CVD risk factors. Because most Asians at risk have normal body mass index (BMI) according to Western standards, we studied healthy nonobese Korean males (n = 102; age: 36.5 +/- 0.8 years, BMI: 23.8 +/- 0.2 kg/m2). Visceral fat area (VFA) at the fourth lumbar vertebra was associated with increased postprandial triglyceride (TG) response (r = 0.53, P < 0.001) and with plasma malondialdehyde (MDA) (r = 0.36, P < 0.01) and PGF2alpha (r = 0.24, P < 0.05). When matched for BMI and age, men with high VFA (HVFA) (>/=100 cm2; n = 27) had higher blood pressure (P < 0.01), increased consumption of cigarettes (P < 0.01), and lower ratio of energy expenditure to calorie intake (P < 0.01) as compared with low VFA men (<100 cm2; n = 27). Men with HVFA showed higher TG, glucose, and insulin responses following fat and oral glucose tolerance tests respectively higher plasma concentrations of MDA (P < 0.001), urinary PGF2alpha (P < 0.05), and lymphocytes deoxyribonucleic acid tail moments (P < 0.01). Conversely, HVFA was associated with lower testosterone, insulin-like growth factor-1, and brachial artery flow-mediated dilation (P < 0.001). In conclusion, our data indicate that visceral fat accumulation, even in nonobese men, is a major factor contributing to increased CVD risk.

Age-related increases in plasma malondialdehyde and protein carbonyl levels and lymphocyte DNA damage in elderly subjects

OBJECTIVES

Increased oxidative stress has been hypothesized to play an important role in the aging process. A role for oxidative damage in normal aging is supported by studies in experimental animals, but there is limited evidence in humans. To investigate the relationship between the oxidative stress and aging in humans, we determined lipid and protein oxidation in plasma as well as DNA damage in lymphocytes in young and elderly subjects.

DESIGN AND METHODS

55 healthy subjects were divided into young (21-40 years) and elderly (61-85 years) groups. Plasma malondialdehyde (MDA), protein carbonyl (PC) levels, and grade of DNA damage in lymphocytes using comet assay as well as total ferric reducing antioxidant power (FRAP) in plasma were determined in young and elderly subjects.

RESULTS

Plasma MDA and PC levels were found to be increased in plasma of elderly subjects as compared to young subjects. Increases in endogenous and H2O2-induced DNA damage were also observed in lymphocytes of elderly subjects. In addition, we detected a significant decrease in FRAP values in elderly subjects. Plasma MDA, PC levels and endogenous and H2O2-induced DNA damage were positively correlated with aging, but negatively with FRAP values.

CONCLUSION

We evaluated MDA, PC levels and lymphocyte DNA damage altogether in both young and elderly subjects for the first time. The results of this study strongly support the presence of increased oxidative stress in elderly subjects.

Alterations in the oxidation products, antioxidant markers, antioxidant capacity and lipid patterns in plasma of patients affected by Papillon-Lefèvre syndrome

Papillon-Lefèvre syndrome (PLS) is an uncommon disease. Less than 300 cases have been described. PLS is characterized by the association between palmar plantar hyperkeratosis (PPK) and severe precocious periodontitis that results in the premature loss of both the primary and secondary dentitions. It is known that periodontitis (PE), the destructive phase of periodontal disease, is a multifactor phenomenon involving a variety of molecular species, among them free radicals and reactive oxygen species (ROS). Antioxidants have been shown to play a critical role in modulating ROS-induced damages during PE. We wondered if patients belonging to a family group with different grades of PLS severity may present altered plasma concentrations of oxidation products as well as of lipophilic antioxidants, like Coenzyme Q or vitamin E, which are molecules that possess well-known antioxidant properties and could play a role in PE processes. We also wondered about the actual plasma total antioxidant capacity of these subjects as well as a complete identification of their plasma fatty acids features, which have been never investigated before. The results we obtained indicate an impairment in the antioxidant capacity of the subjects characterized by abnormally high hydroperoxide levels and, in some cases, by altered CoQ and vitamin E contents. Moreover, an essential fatty acid deficiency (EFAD) was registered on the basis of the peculiar plasma fatty acid patterns found (i.e. low PUFA, high MUFA and high delta-9 desaturase activity). This finding would support the hypothesisby Gutteridge and co-workers (Free Radic. Res. 1998, 28: 109-114) that conditions exist in which some forms of oxidative stress can lead to changes characteristic of EFAD.

X-inactivation pattern in multiple tissues from two Leber's hereditary optic neuropathy (LHON) patients

The more frequent manifestation of ophthalmological abnormalities in males, relative to females, is an unexplained feature of Leber's hereditary optic neuropathy (LHON) that suggests an X-linked modifying gene acting in concert with the pathogenic LHON mitochondrial DNA (mtDNA) mutation. In addition, segregation analysis of the optic neuropathy in LHON pedigrees was compatible with the presence of a recessive-modifying gene on chromosome X. According to this two-locus model, females would be affected only if homozygous or if they were susceptible to skewed X-inactivation. Attempts both to localize the putative LHON-modifying gene by linkage analysis and to find an excess of skewed X-inactivation in affected females were unsuccessful, although the inactivation pattern was only studied in DNA isolated from blood cells. We had the opportunity to analyze a wide range of tissues at autopsy, including the optic nerves and the retina, from two LHON female patients. We found no evidence of skewed X-inactivation in the affected tissues, thus weakening further the hypothesized involvement of a specific X chromosome locus in the pathophysiological expression of LHON.

An impairment of phagocytic function is linked to a shorter life span in two strains of prematurely aging mice

In previous cross-sectional studies on Swiss mouse populations we have shown that at the same chronological age, animals that take longer to explore a simple T-maze (slow mice) are hyper-emotional and show an impairment of the immune system than those which quickly explore the maze (fast mice). Therefore, we have proposed that the slow mice are a model of prematurely aging mice (PAM). In the present work we have carried out a longitudinal study of age-dependent changes in key functions of phagocytic cells (peritoneal macrophages) such as phagocytosis and superoxide anion production in both male and female Swiss (outbred strain) and BALB/c (inbred strain) PAM and non-prematurely aging mice (NPAM). Gender differences were found showing the females better phagocytic and digestion capacities with concomitant longer life span. The PAM showed an impaired phagocytosis capacity and intracellular superoxide anion production as well as an increase of its extracellular production as compared to NPAM, which could be related to the shortened life span of those animals in both sexes and strains.