Sister chromatid exchange and micronucleus frequency in human lymphocytes of 1,650 subjects in an Italian population: II. Contribution of sex, age, and lifestyle

Sister chromatid exchange (SCE) and micronuclei (MN) analysis was carried out on 1,650 healthy individuals living in Pisa and in two nearby small cities, Cascina and Navacchio (Ca-Na). The effect of smoking on SCEs was linearly correlated with the number of cigarettes per day, and an increase of 7.3% SCEs was detectable for as few cigarettes as 1-10/day. Ex-smokers showed intermediate mean values of SCEs (8.09 +/- 1.88) in comparison with never smokers (7.54 +/- 1.61) and current smokers (8.45 +/- 1.94). Mean values of SCEs of ex-smokers decreased linearly with time of smoking cessation, reaching the mean values of never smokers within 8 years. The extent of SCE decrease was inversely proportional to the number of cigarettes previously smoked. No interaction between smoking habits and coffee or alcohol drinking on SCEs was observed. A borderline (P = 0.053) increase in mean SCE values in coffee drinkers (more than 3 cups/day) was found. The age effect on SCEs was remarkable in Ca-Na, but not in Pisa donors. Job type was not associated with significant modification of mean values of SCEs. Multiple logistic regression analysis revealed a statistically significant association between the proportion of high frequency cells (HCF) outliers and coffee consumption. Age and sex appeared to be by far the most important variables associated with modifications in MN frequency, which increased by 0.04 per thousand and 0.02 per thousand per year in males and females, respectively. Children and young donors (age < or = 40 years) showed lower MN frequency regardless of sex, whereas sex appeared to determine a significantly higher increase of MN only in females older than 40 years. In contrast, in males the MN rate by age tended to level off after the age of 30-50. MN frequencies of Pisa blue- and white-collar workers were statistically significantly higher than in students (+0.71 and +0.55 per thousand, respectively). Smoking did not determine any increase of MN frequency. A total lack of correlation (P = 0.913) between MN and SCEs was observed.     

ACTH-producing carcinoma of the pituitary with haematogenic metastases

Two laboratories equipped with CAS 200 (Becton Dickinson Image Cytometry Systems, San Jose, CA) instruments participated in this study of variability of DNA analysis of bladder tumor specimens. Formalin fixed paraffin embedded specimens were disaggregated and centrifuged onto microscope slides from ten bladder tumor specimens and two specimens of normal urothelium. Sources of variability considered were Specimen, Slide, Run, Laboratory, and Error. Slides were systematically scanned and 200 cells measured followed by the operator selecting 100 nuclei with abnormal morphology. DNA index (DI) and hyperdiploid fraction (HDF) were calculated from the DNA frequency distributions. For systematic sampling, 92% of the variability was due to Specimen indicating that differences in HDF values between specimens reflect biological differences. With selective sampling, only 67% of the variability in HDF is due to Specimen differences. Other factors, Laboratory, Error, and Laboratory x Specimen interaction each accounted for approximately 10% of the variability. Similarly variability of DI with selective sampling was also higher, and less specimen dependent than systematic sampling. It is important that sampling schemes and selection criteria be carefully documented in order to control variability. Enriched (or selective) sampling for abnormal cells has the potential to increase sensitivity but specimen classification based on these measurements must depend on determination of the frequency of such cells in the total population.     

Chromosomal aberrations in lymphocytes predict human cancer: a report from the European Study Group on Cytogenetic Biomarkers and Health (ESCH)

Chromosomal aberrations (CAs), sister chromatid exchanges (SCEs), and micronuclei (MN) in peripheral blood lymphocytes have for decades been used as cytogenetic biomarkers to survey genotoxic risks in the work environment. The conceptual basis for this application has been the idea that increased cytogenetic damage reflects an enhanced cancer risk. Nordic and Italian cohorts have been established to evaluate this hypothesis, and analyses presented previously have shown a positive trend between CA frequency and increased cancer risk. We now report on a pooled analysis of updated data for 3541 subjects examined for CAs, 2703 for SCEs, and 1496 for MN. To standardize for interlaboratory variation, the results for the various cytogenetic end points were trichotomized on the basis of the absolute value distribution within each laboratory as "low" (1-33 percentile), "medium" (34-66 percentile), or "high" (67-100 percentile). In the Nordic cohort, there was an elevated standardized incidence ratio (SMR) for all cancer among subjects with high CA frequency [1.53; 95% confidence interval (CI), 1.13-2.05] but not for those with medium or low CA frequency. In the Italian cohort, a SMR in cancer of 2.01 (95% CI, 1.35-2.89) was obtained for those with a high CA frequency level, whereas the SMRs for those with medium or low did not noticeably differ from unity. Cox's proportional hazards models gave no evidence that the effect of CAs on total cancer incidence/mortality was modified by gender, age at test, or time since test. No association was seen between the SCEs or the MN frequencies and subsequent cancer incidence/mortality. The present study further supports our previous observation on the cancer predictivity of the CA biomarker, which seems to be independent of age at test, gender, and time since test. The risk patterns were similar within each national cohort. This result suggests that the frequency of CAs in peripheral blood lymphocytes is a relevant biomarker for cancer risk in humans, reflecting either early biological effects of genotoxic carcinogens or individual cancer susceptibility.     

Infiltration Variability in Furrow Irrigation

In this paper, the contribution of different sources of variability to irrigation water depth variability was quantified using a combination of variance techniques. This method was applied using field measurements from irrigation events performed on a loamy soil with a low-infiltration rate. Infiltration variability was estimated with blocked furrow infiltrometers. The assumptions made for the application of the combination of variance techniques proved to be valid. The major variability source turned out to be the soil intake characteristics, whose variance accounted for 45–71% of the variance in infiltrated depth under first irrigation conditions. Opportunity time and wetted perimeter were less variable in subsequent irrigations and the soil intake characteristics variability accounted for a percentage of total variance beyond 76%, being at times beyond 95%. The combination of variance techniques can be used to complement standard evaluation methods in order to take into account the influence of different variability sources.     

Induction of sister chromatid exchanges in fibroblasts from normal donors and from patients with xeroderma pigmentosum after combined treatment with ultraviolet radiation and modulated low frequency electric currents

Dermal fibroblasts derived from normal donors as well as from patients with xeroderma pigmentosum (XP) were exposed in vitro to ultraviolet radiation of 254 nm wavelength and to weak electric 4, 000 Hz currents modulated in amplitude with 50 Hz. Treatment with this so-called interferential current (IFC) increased the rate of sister chromatid exchanges (SCE) in all fibroblast types up to roughly 50% above the spontaneous level. When IFC was applied in combination with UV-radiation, it lowered UV-induced increase of the SCE-rate. A reduction of UV-induced SCEs was seen when XP-cells were exposed to IFC prior to UV-treatment, compared to the reverse order of treatment. The order of exposure has only been analysed in 5 XP patients, not in normal donors. The relationships between different combinations of exposure parameters (IFC-amperage, UV-dose, cell pathology, order of treatment) were examined by analysis of variance (ANOVA).     

Reproducibility and accuracy of the diagnosis of cervical intraepithelial neoplasia (CIN) in 15 Italian laboratories: a national pilot project. Development of new indices of diagnostic variability. National Work Group for the expert quality control in cervico-vaginal cytopathology

OBJECTIVES: To assess reliability and accuracy of cervical smear diagnoses, to evaluate the effectiveness of the participation in a programme of slide exchange in increasing reliability and to re-examine the agreement in discriminating between CIN 2 and CIN 3 (merged in High grade SIL in the Bethesda System). SETTING: 15 laboratories participating on a voluntary basis throughout Italy, for a period of 1 year. METHOD: Phase one: circulation of 40 slides including all main diagnostic categories; discussion of results by representatives of participating centres. Phase two: circulation of another 40 similar slides. For each slide, not only a diagnosis but also recommendations for further examinations and a judgment on diagnostic difficulty were asked. Common measures of reliability and accuracy and (the latter only for slides on which a consensus diagnosis was reached corresponding to the histological diagnosis) were calculated; three new indices of diagnostic variability were also computed. RESULTS: Consensus diagnosis among representatives of participating laboratories on about 90% of the slides was reached both in the first and in the second phase. On 3 slides it was impossible to reach a consensus diagnosis even among external referees. In both phases, the study showed a marked variability among diagnoses, recommendations and judgment on diagnostic difficulty and, on some slides, a worrying lack of reliability in the determination of precancerous lesions. The agreement on discrimination between CIN 1 and CIN 2 was low, but it was slightly better between CIN 2 and CIN 3. No significant relationship between accuracy and workload was found. External quality control or better said, continuous quality improvement activities are essential but should be conducted in a more systematic way with greater involvement of cytotechnicians.     

Illusory tilt and Euclidean schemes as factors in performance on the water-level task.

Predictions made by models of water-level acquisition were tested to understand better the sensory factors, cognitive factors, or both, that differentiate people who fail the test (low scorers) from people who pass (high scorers). Experiments 1 and 2 showed that in a horizontal-edge detection task, low scorers were less likely than high scorers to "see" liquid edges in tilted containers as horizontal. Experiment 3 showed that water-level type displays belong to a class of tilt illusions that arise from early visual processes for both low and high scorers, but only high scorers spontaneously use cognitive schemes to minimize illusory tilt. In Experiment 4, high scorers, but not low scorers, overrode the orientation illusion in a production task. The findings suggest bottom-up processes cause embedded lines to be misperceived for both groups, but high scorers are more likely to use cognitive schemes spontaneously to overcome the orientation illusion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sensation Seeking Scale as a predictor of need for stimulation during sensory restriction.

Tested the hypothesis that the Zuckerman Sensation Seeking Scale (SSS) predicts strength of need for stimulation under conditions of sensory restriction. The SSS was administered to 214 male undergraduates. During a 3-hr isolation period, 15 high- and 15 low-SSS scorers were free to button press for visual, auditory, and kinesthetic stimulation. Except for visual stimulation high-SSS scorers button pressed at a higher rate than low-SSS scorers, but the differences were not significant. Low-SSS scorers showed a significantly greater need for visual stimulation than high-SSS scorers. High-SSS scorers showed a significant preference for kinesthetic stimulation, while low-SSS scorers had a significant preference for visual stimulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of method in treatment effectiveness research: Evidence from meta-analysis.

A synthesis of 319 meta-analyses of psychological, behavioral, and educational treatment research was conducted to assess the influence of study method on observed effect sizes relative to that of substantive features of the interventions. An index was used to estimate the proportion of effect size variance associated with various study features. Study methods accounted for nearly as much variability in study outcomes as characteristics of the interventions. Type of research design and operationalization of the dependent variable were the method features associated with the largest proportion of variance. The variance as a result of sampling error was about as large as that associated with the features of the interventions studied. These results underscore the difficulty of detecting treatment outcomes, the importance of cautiously interpreting findings from a single study, and the importance of meta-analysis in summarizing results across studies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fair today, fair tomorrow? A longitudinal investigation of overall justice perceptions.

Most work on organizational justice has been cross-sectional and focused on specific justice dimensions rather than perceptions of overall justice. As a result, little is known about how overall justice perceptions unfold over time. This study attempts to bridge gaps in the literature by examining overall organizational and overall supervisory justice perceptions of 213 individuals over 3 points in time. Results showed significant variability in overall justice perceptions across time. Specifically, within-person variance accounted for 24% and 29% of the total variance in overall organizational and supervisory justice, respectively. Further, compared with specific justice dimensions, trust emerged as a particularly strong predictor of within-person and between-person variance in overall justice perceptions. Implications for the justice literature and organizational practice are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Extreme academic talent: Profiles of perfect scorers.

This study provides information on characteristics of students who scored perfectly on at least one subtest of the American College Testing Assessment Program (English, Mathematics, Social Studies, or Natural Sciences). The sample consisted of 5,615 perfect scorers from a total population of 729,606 high school juniors and seniors. Boys had a higher incidence of perfect scores in each subtest except English. Asians and Whites were overepresented among perfect scorers, and all other ethnic groups were underrepresented. "Perfection" in one academic area did not assure comparable high performance in other academic areas. Few perfect scorers planned college majors or careers in the disciplines in which they attained perfect scores. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Validity generalization results for two job groups in the petroleum industry.

Estimated the transituational generalizability (or "transportability") of the validities of 4 types of cognitive tests (Bennett Mechanical Comprehension Test, Richardson-Bellows-Henry Chemical Comprehension and RBH Arithmetic Reasoning Tests, and general intelligence) and a weighted biographical information blank for performance in 2 petroleum industry job groups. Generalizability was strongly supported for mechanical and chemical comprehension tests for both jobs. In the case of the chemical comprehension tests, virtually all variance of observed validity coefficients was accounted for by artifacts, and thus the hypothesis of situational specificity was rejected. Support for generalizability was substantial for general mental ability and arithmetic reasoning tests. It was found, however, that corrections for variance due to sampling error accounted for an average of 90% of all variance due to artifacts, indicating the relative unimportance of differences between sudies in criterion reliability and in range restriction in accounting for variation in observed validities. Generalizable multivariate validities were estimated for various test batteries using beta and unit weights. Finally, true score beta weights were used to estimate the causal role of the 4 cognitive abilities in job performance. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Refinements in validity generalization methods: Implications for the situational specificity hypothesis.

Using a large database, this study examined 3 refinements of validity generalization procedures: (1) a more accurate procedure for correcting the residual standard deviation (SD) for range restriction to estimate SDp, (2) use of r? instead of study-observed rs in the formula for sampling error variance, and (3) removal of non-Pearson rs. The 1st procedure does not affect the amount of variance accounted for by artifacts. The addition of the 2nd and 3rd procedures increased the mean percentage of validity variance accounted for by artifacts from 70 to 82%, a 17% increase. The cumulative addition of all 3 procedures decreased the mean SDp estimate from .150 to .106, a 29% decrease. Six additional variance-producing artifacts were identified that could not be corrected for. In light of these it was concluded that the obtained estimates of mean SDp and mean validity variance accounted for were consistent with the hypothesis that the true mean SDp value is close to zero. These findings provide further evidence against the situational specificity hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Peer preferences and social interaction among third-grade children in an integrated school district.

Assessed social interaction among Black and White 3rd-grade children in 9 classrooms. The children were in integrated schools since kindergarten. Two methods were employed: a roster-and-rating sociometric technique and a classroom behavioral observation procedure using sequential time sampling. Sociometric data were obtained for 179 White and 48 Black children. Observational data were obtained for 39 White and 39 Black children. Both race and sex were found to be significant determinants of sociometric ratings for play and work. Omega-squared analyses, however, indicated that sex accounted for 43.2% of the variance on play and 35.2% on work, while race accounted for only about 1% of the variance on each measure. The observational data indicate a positive pattern of classroom interaction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A comparative study on the effect of MNU on human lymphocyte cultures in vitro evaluated by O6-mdG formation, micronuclei and sister chromatid exchanges induction

N-Nitroso-compounds are a large group of chemicals present in a number of environmental sources and many of them are mutagens as well as carcinogens in experimental animals. Among the known N-nitroso-compounds, N-nitroso-N-methylurea (MNU) is a strong mutagen. In this study an effort has been made to compare the ability of MNU to methylate the O6-guanosine site in DNA and to induce micronuclei and sister chromatid exchanges in human lymphocyte cultures in vitro. To quantitate O6-methyldeoxyguanosine (O6-mdG) a highly sensitive immunoassay, immuno-slot-blot (ISB), has been used. For the evaluation of micro nuclei (MN) the cytokinesis block micronucleus method has been used. Different concentrations (75, 100, 125 micrograms/ml) were tested. At the highest concentration tested for the MN induction, 125 micrograms/ml, the occurrence of binucleates and micro nuclei is higher than twice in relation to control and a reduction in NDI is also observed. The same concentrations were used for the estimation of sister chromatid exchanges (SCEs) induction. The mean number of SCEs at 125 micrograms/ml is almost three times that of the control level. The concentrations tested for the quantitation of O6-mdG were 200, 300 and 400 micrograms/ml and this was done because for the test system we used and for the given experimental conditions the first indication of O6-mdG formation was at 200 micrograms/ml. Our results show that methylation of O6-guanosine increases with concentration and at 400 micrograms/ml the concentration of O6-mdG is 5.83 fmol/microgram DNA, while at the control level it is 2.40 fmol/microgram DNA. Since O6-mdG formation is observed in higher concentrations than those of MN and SCE induction it would be interpreted that O6-mdG levels are not correlated with the studied cytogenetic effects although one has to take into consideration the total promutagenic lesions in DNA, induced by MNU, as well as AGT repair activity.     

Sister-chromatid exchanges and cell-cycle kinetics in the lymphocytes of workers occupationally exposed to a chemical mixture in the tyre industry

Cytogenetic studies of clinically healthy workers employed in the rubber industry showed an increase in chromosome aberrations (CAs), sister-chromatid exchanges (SCEs) and a decrease in proliferation indices (PIs). The aim of the present study was to establish, using the SCE and PI tests, genotoxic effects of hazardous chemicals in the rubber industry. An increase in mean SCEs in the lymphocytes of vulcanizers as compared to controls was observed. Since the PI in the exposed group was insignificantly decreased as compared to the controls, it could be concluded that the SCE test is the most sensitive cytogenetic test for the detection of a genotoxic effect of chemicals in the rubber industry. There was no evidence in the present study that the genotoxic effect of chemicals in the rubber industry was enhanced by cigarette smoking.     

A factor analysis of? scores.

17 True-False (T-F) and forced-choice (F-C) personality and attitude scales were administered to 130 students. Each scale was scored for the number of evasive of? responses. All of the? scores had a high degree of internal consistency as measured by Kuder-Richardson Formula 21 estimates of internal consistency. The? scores were intercorrelated and the correlation matrix factor analyzed. Factor I, which accounted for 60.68% of the total variance, was interpreted as the tendency to give evasive responses to items in a T-F format. Factor II, which accounted for 16.38% of the total variance, was interpreted as the tendency to give evasive response to personality items in an F-C format. The third factor, which accounted for 5.62% of the total variance, was interpreted as the tendency to give evasive responses to the T-F items dealing with beliefs, opinions, and moral precepts. The probability of an evasive response to an item was found to be unrelated to the social desirability scale value of the item. (18 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reduced interlitter variability in rats resulting from a restricted mating period, and reassessment of the "litter effect''

Rats were mated for two or 15 hours and variability of day-12-embryos in weight, protein content, and [3H]thymidine incorporation was compared in the long mating period (LMP) and short mating period (SMP) groups by a 2-level nested analysis of variance. Variability in day-20 fetal weight was similarly compared. In both groups day-12 embryonic weight was relatively more variable than day-20 fetal weight, and variability was less in SMP than LMP animals for each comparison made, although statistical significance was attained only for thymidine incorporation. "Litter effects' were noted but not of the magnitude reported by other investigators. It was concluded that inappropriate statistical methods have encouraged the belief that among-litter variability usually exceeds within-litter fetal weight variability. The teratological implications of reduced development variability and the "litter effect' are discussed.     

"Relation of eighth graders' family structure, gender, and family environment with academic performance and school behavior": Correction to Kurdek and Sinclair.

Reports an error in "Relation of eighth graders' family structure, gender, and family environment with academic performance and school behavior" by Lawrence A. Kurdek and Ronald J. Sinclair (Journal of Educational Psychology, 1988[Mar], Vol 80[1], 90-94). Table 2 contained incorrect data. The first column of data contained correlations whose signs should have been reversed. The complete correct table appears in the erratum. (The following abstract of the original article appeared in record 1988-24801-001.) The purpose of this study was to assess how family structure, gender, and family environment were related to both academic performance (end-of-the-year grades and quantitative and verbal achievement factor scores) and school behavior (number of days absent, number of days tardy, and number of in-school detentions). Subjects were 219 middle-class eighth graders (96 boys, 123 girls). Generally, students in two-parent nuclear families had better academic performance and less problematic school behavior than did students in either mother-custody or stepfather families. Boys had more detentions than did girls. Despite significant differences among the three family structures, the family structure variable accounted at most for only 7% of the variability in academic performance and school behavior. A family environment that emphasized achievement and intellectual pursuits accounted for variability in end-of-the-year grades beyond that accounted for by family structure, gender, and family conflict. The joint consideration of family structure, gender, and family environment accounted at most for 17% of the variance in academic performance and school behavior. For students in the mother-custody and stepfather families, contact with father was unrelated to academic performance. Findings are discussed in terms of models of achievement motivation and behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Regional differentiation of blood group frequencies in the Polish population

The paper presents frequency distributions of alleles of eight blood group systems (ABO, MN, Rh, Hp, Gm(a), AcP, PGM1, EsD) in the Polish population. The blood group determinations concerning 10521 individuals (were carried out during paternity testing in regional serological laboratories throughout the country). Detailed information on the place of residence for all the subjects was also available. Blood group frequencies of subjects living in five regions of Poland were compared with historical date. The analysis has shown an almost complete disappearance of genetic variability in respect of the analysed traits between local populations inhabiting various regions of Poland.