Luteal phase of the menstrual cycle in young healthy women is associated with decline in interleukin 2 levels.

The aim of this study was to look at the possible changes in the blood levels of Interleukin 2 (IL2) during the sexual cycle in generally healthy, young, regularly menstruating women. The concentrations of progesterone and 17beta-estradiol were measured using radioimmunological assay. The bioactivity of interleukin 2 was measured using a biological test on the IL2-sensitive CTLL cell line. The percentage of lymphocytes with intracellular IL2 was determined by flow cytometry. Eighteen healthy volunteers (19-29 years old) were examined on days 5, 8, 14, 18 and 25 of the same cycle. All women were characterised by a regular menstrual cycle as per physiological levels of 17beta-es-tradiol and progesterone. The luteal phase of the cycle was characterised by both a decrease of IL2 blood levels and a decrease in the percentage of intracellular 1L2-containing lymphocytes stimulated in vitro. The IL2 level fluctuations observed during the menstrual cycle may be one factor causing pre-menstrual infections observed in young women. On the other hand, the decrease of IL2 may be seen as a start of the immune suppression necessary for an embryo's nidation.     

Emotion recognition accuracy in healthy young females is associated with cycle phase

Several studies reported a significant influence of ovarian hormone status on cognition and person perception. In particular, it has been stated that female mating preferences are shifted during the menstrual cycle. It remains, however, unclear if facial emotion recognition, a prerequisite for successful social interaction, is also influenced by estradiol and progesterone levels. Hence, we investigated 32 healthy right-handed females, 15 during their follicular phase and 17 during their luteal phase and compared their recognition accuracy. Hormone levels were correlated with several neuropsychological parameters. Subjects were matched for age and education and did not differ in any neuropsychological function. Analysis of emotion recognition performance (ANOVA) revealed a significant effect of phase, showing higher accuracy in the follicular group. Furthermore, a significant negative correlation between progesterone level and emotion recognition performance emerged, indicating higher accuracy with lower progesterone levels, hence supporting the group differences. Our results indicate a significant association of menstrual cycle phase and thus ovarian hormone concentration on facial emotion recognition, with progesterone exerting a special influence on this social-emotional ability.     

Evidence that DNA damage is associated to phenylalanine blood levels in leukocytes from phenylketonuric patients

Phenylketonuria (PKU) is an inborn error of phenylalanine (Phe) metabolism, biochemically characterized by the accumulation of Phe and its metabolites in blood and tissues of affected patients. Treatment for PKU consists of a protein restricted diet supplemented with a mixture containing essential amino acids (other than Phe) and micronutrients. In recent years several authors have studied the pathomechanisms of the disease and demonstrated the existence of lipid and protein oxidative damage in PKU patients. In this work we investigated the in vivo and in vitro effects of Phe on DNA damage determined by the alkaline comet assay using silver staining and visual scoring. We found a dose-dependent effect of Phe on DNA damage in leukocytes from normal individuals incubated with different concentrations of Phe. Additionally, by analyzing blood leukocytes from two groups of treated PKU patients based on their blood Phe levels, we verified that the DNA damage index was significantly higher in PKU patients with high Phe blood levels (DI = 68.2 ± 12.3), compared to well-treated patients and the control group (healthy individuals). Furthermore, well-treated PKU patients had greater DNA damage (DI = 44.9 ± 7.6) relatively to controls (DI = 12.7 ± 4.1). Our present in vitro and in vivo findings indicate that DNA damage occurs in peripheral blood from PKU patients and is associated to Phe blood levels.     

Relationship among the status of the human oocyte, the 17 beta-estradiol concentration in the antral fluid and the follicular size

We studied the relationship among the status of the human oocytes, the E2 concentration in the antral fluid and the follicular size in the different phases of the menstrual cycle, in order to determine the microenvironment of the follicles with healthy or degenerative oocytes in the human ovary. In the follicular phase of the menstrual cycle, follicles which contained a healthy but not degenerative oocyte had a significantly higher level of 17 beta-estradiol (E2). In the late follicular phase, the larger follicles (greater than or equal to 13 mm, in diameter) had only health oocytes. It seems that the follicle containing a degenerative oocyte does not develop physiologically until maturation of the preovulatory follicle. In the luteal phase, there were no relationships among the status of the oocyte, E2 concentration in the antral fluid and the follicular size. However, the E2 levels of the antral follicles with healthy oocytes in an ovary with corpus luteum were significantly lower than those in the contralateral ovary. The results suggest that the corpus luteum may exert an influence on the adjacent follicles.     

Biomonitoring of DNA damage in peripheral blood lymphocytes of subjects with dental restorative fillings

Dental fillings provide a major iatrogenic exposure to xenobiotic compounds due to the high prevalence of surface restorations in developed countries. Experimental data suggest that both amalgams, which contain mercury, and resin-based dental materials cause an impairment of the cellular pro- and anti-oxidant redox balance. The aim of this study was to assess the potential genotoxicity of dental restorative compounds in peripheral blood lymphocytes of young exposed subjects compared with controls. The study examined, by use of the comet assay, 68 carefully selected subjects taking into account the major known confounding factors. In the 44 exposed subjects, the mean numbers of restored surfaces was 3.0 and 3.8 in males and females, respectively. Tail length, percentage of DNA in the tail, tail moment or Olive tail moment were twofold higher in the exposed group than in unexposed controls, with significant differences. No significant difference was observed between amalgam and composite fillings. Furthermore, as shown by multivariate analysis, the association between dental fillings and DNA damage was enhanced by the number of fillings and by the exposure time. Among the lifestyle variables, a moderate physical activity showed a protective effect, being inversely correlated to the DNA damage parameters evaluated. On the whole, the use of DNA-migration allowed us to detect for the first time the potential adverse impact on human health of both kinds of dental filling constituents, the amalgams and the methacrylates. The main mechanism underlying the genotoxicity of dental restorative materials of various nature may be ascribed to the ability of both amalgams and methacrylates to trigger the generation of cellular reactive oxygen species, able to cause oxidative DNA lesions.     

The thymidylate synthase tandem repeat polymorphism is not associated with homocysteine concentrations in healthy young subjects

Thymidylate synthase (TYMS) and 5,10-methylenetetrahydrofolate reductase (MTHFR) may compete for their common cofactor 5,10-methylenetetrahyhdrofolate (5,10-meTHF). Limiting 5,10-meTHF results in elevated homocysteine, especially in individuals homozygous for the T allele of the MTHFR C677T polymorphism. The TYMS gene has a tandem repeat polymorphism (two repeats or three repeats, designated 2R or 3R, respectively), which may also affect homocysteine concentrations. The 3R allele is subject to increased translational efficiency in vitro and the 3R3R genotype is associated with both decreased serum folate and elevated plasma homocysteine (tHcy) in a population of Singapore Chinese. We assessed the relationship between TYMS genotype and key biochemical and genetic variables in a random sample of 392 healthy young Northwestern European men and women. The tHcy concentrations for 3R3R homozygotes (median 8.5 mol/l) did not differ significantly from those for 2R2R homozygotes (median 8.7 mol/l) or 2R3R heterozygotes (median 9.3 mol/l) in the population as a whole (P=0.43), or in subsets of subjects with low serum folate (P=0.60) or the MTHFR 677TT genotype (P=0.90). Furthermore, there was no trend toward elevated tHcy in 3R3R homozygotes. Similarly, the TYMS tandem repeat polymorphism was not associated with serum folate concentrations. Our findings indicate that the TYMS 3R3R genotype is not a determinant of homocysteine in this sample of healthy young Caucasian adults from Northern Ireland.     

Chromosome instability in lymphocytes from a patient with Werner's syndrome is not associated with DNA repair defects

Different cellular parameters used to detect genetic instability were analyzed in lymphocytes from a patient affected by Werner's syndrome (WS). Cytogenetic studies indicated the presence of structural and numerical chromosomal abnormalities and the occurrence of variegated translocation mosaicism. The baseline mutation frequency was similar to that observed in normal donor samples. DNA repair investigations showing a normal capability to perform UV-induced DNA repair synthesis and a normal sensitivity to various mutagens (UVC light, mono- and bi-functional alkylating agents) indicate that different DNA repair mechanisms act normally in WS. In this feature, WS appears to differ from the other genetically determined syndromes in which chromosomal instability is associated with a marked hypersensitivity to specific DNA-damaging agents.     

The level of Hsp27 in lymphocytes is negatively associated with a higher risk of lung cancer

Heat shock proteins (Hsps) can protect cells, organs, and whole organisms against damage caused by abnormal environmental hazards. Some studies have reported that lymphocyte Hsps may serve as biomarkers for evaluating disease status and exposure to environmental stresses; however, few epidemiologic studies have examined the associations between lymphocyte Hsps levels and lung cancer risk. We examined lymphocyte levels of Hsp27 and Hsp70 in 263 lung cancer cases and age- and gender-matched cancer-free controls by flow cytometry. Multivariate logistic regression models were used to estimate the association between lymphocyte Hsps levels and lung cancer risk. Our results showed that Hsp27 levels were significantly lower in lung cancer cases than in controls (16.5 vs 17.8 mean fluorescence intensity, P < 0.001). This was not observed for Hsp70 levels. Further stratification analysis revealed that lymphocyte Hsp27 levels were negatively associated with lung cancer risk especially in males and heavy smokers. There was a statistical trend of low odd ratios (95% confidence intervals) and upper tertile levels of Hsp27 [1.000, 0.904 (0.566–1.444) and 0.382 (0.221–0.658, P _trend = 0.001) in males and 1.000, 0.9207 (0.465–1.822) and 0.419 (0.195–0.897, P _trend = 0.036) in heavy smokers] after adjustment for confounding factors. These results suggest that lower lymphocyte Hsp27 levels might be associated with an increased risk of lung cancer. Our findings need to be validated in a large prospective study. Feng Wang and Maohui Feng contributed equally to this work.     

Insulin resistance is associated with DNA damage in peripheral blood cells in non-diabetic patients with genotype 1 chronic hepatitis C

Abstract

Background. In chronic liver diseases of different etiologies, including viral hepatitis, genotoxic effects of oxidative stress have been shown, both in clinical and in experimental conditions, suggesting that this mechanism may contribute to the evolution of the disease. Aim. To evaluate DNA damage in the peripheral blood of untreated non-diabetic patients with chronic hepatitis C and control subjects, and its correlation with demographic, anthropometric, biochemical, and histological parameters in the patient sample. Patients and methods. This study comprised 100 subjects of both genders, 60 of whom were treatment-naïve patients with positive serology for genotype 1 hepatitis C. The remaining 40 were blood donors with negative serology for hepatitis who were used as control subjects, and matched by gender, age, weight, and BMI. DNA damage was determined using the comet assay in the total peripheral blood. Results. The DNA damage evaluated by the comet assay revealed higher values in the group of patients with hepatitis compared with that in the control group. The relationships of the comet assay with the studied variables were assessed using multivariate analysis; significant correlations were only identified with insulin (r = 0.343, p = 0.008) and Homeostasis Model Assessment Insulin Resistance (HOMA-IR) (r = 0.331, p = 0.011). Conclusion. Patients with genotype 1 chronic hepatitis C have higher rates of DNA damage, as determined by comet assay and this alteration is correlated with the HOMA index of insulin resistance.     

Increased sister chromatid exchange in the peripheral blood lymphocytes of young women who smoke cigarettes

Rates of sister chromatid exchange in dividing human peripheral blood lymphocytes were determined and compared between smoking and non smoking young women between the ages of 16 and 25. Chromosomes block-stained with Giemsa were also examined for chromosome aberrations. A striking difference in the frequency of sister chromatid exchange was found between young women who smoked and those who did not. Smokers scored a significantly higher, F(1) = 15.99, p = 0.0015, rate of sister chromatid exchange than non smokers. Smokers scored a higher mean of SCEs per cell (12.771, SD 3.53) than non smokers (9.712, SD 2.53). Smokers also scored a higher range of SCEs (4 to 28) as opposed to non smokers (4 to 17). No statistical difference was found between smokers and non smokers for the frequency of chromosome aberrations. The significantly higher frequency of exchange in young smoking women may indicate that initial damage to the DNA in many of these women has probably already occurred, thus causing an increased risk of developing cancer later in life.     

Evaluation of spontaneous DNA damage in lymphocytes of healthy adult individuals from high-level natural radiation areas of Kerala in India

Inhabitants of the high-level natural radiation areas (>1 mSv year(-1)) of Kerala in southwest India were evaluated for basal damage (spontaneous DNA strand breaks and alkali-labile sites) by the alkaline comet assay and oxidative DNA damage (ENDO III- and hOGG1-sensitive sites) by the enzyme-modified comet assay. Of the 67 adult male subjects studied, 45 were from high-level natural radiation areas and 22 subjects were from a nearby normal-level natural radiation area (≤1 mSv year(-1)). Basal damage due to the age and residential area (normal-level natural radiation area/high-level natural radiation areas) of the donors showed significant interaction (P < 0.001) when all subjects were analyzed using a general linear model (GLM). In subgroup analysis, basal damage increased with age in subjects from the normal-level natural radiation area (P = 0.02), while a significant negative correlation (P = 0.002) was observed in subjects from high-level natural radiation areas. Further, basal damage in elderly subjects from high-level natural radiation areas was significantly (P < 0.001) lower compared to the subjects from the normal-level natural radiation area. Oxidative DNA damage was not influenced by age, smoking habit or residential area in the entire sample. However, in a subgroup analysis, hOGG1-sensitive sites showed a significant increase with age in subjects from high-level natural radiation areas (P = 0.005). ENDO III-sensitive sites increased with natural radiation exposure in subjects from high-level natural radiation areas (P = 0.02), but when stratified according to smoking, a significant increase was observed only in smokers (P = 0.01). To the best of our knowledge, this is the first study on basal and oxidative DNA damage in healthy adults of this population. However, our findings need more validation in a larger study population.     

The role of spontaneous DNA damage in the radiosensitivity of thymus lymphocytes

The most radiosensitive thymus cortical lymphocytes are highly sensitive to inhibitors of repair of spontaneous DNA lesions known by endonucleases: this is indicative of different level of injury to cells. The preincubation of cells with chemical inductors of differentiation increases the number of spontaneous lesions in them. The preincubation of thymocytes with concanavalin A removes almost completely the differences in the level of injury.     

Gender-related differences in basal DNA damage in lymphocytes of a healthy Indian population using the alkaline Comet assay

The Comet assay, a sensitive, rapid and non-invasive technique, measures DNA damage in individual cells and has found wide acceptance in epidemiological and biomonitoring studies to determine the DNA damage resulting from lifestyle, occupational and environmental exposure. The present study was undertaken to measure the basal level of DNA damage in a normal, healthy Indian male and female population. Out of the 230 volunteers included in this study, 124 were male and 106 were female. All the individuals belonged to a comparable socio-economic background and aged between 20 and 30 years. They were also matched for their smoking and dietary habits. The period of sample collection was also matched. The results revealed a statistically significant higher level of DNA damage in males when compared to females as evident by an increase in the Olive tail moment [3.76+/-1.21 (arbitrary units) for males as compared to 3.37+/-1.47 for females (P<0.05)], tail DNA (%) [10.2+/-2.96 for males as compared to 9.40+/-2.83 for females (P<0.05)] and tail length (microm) [59.65+/-9.23 for males and 49.57+/-14.68 for females (P<0.001)]. To our knowledge, this report has, for the first time demonstrated significant differences in the basal level of DNA damage between males and females in a normal healthy Indian population.