Pigmented lesions in newborn infants

1058 newborn infants were examined. Forty-one (3-9%) had clinically discernible pigmented lesions compatible with melanocytic naevi. Biopsy was performed on thirty-four of the forty-one and of these; eleven, representing 1-01% of the infants, proved to be melanocytic naevi. No giant (garment) naevi were seen in this series. Two of the eleven naevi pathologically examined showed histological changes similar to those that have been reported in some giant naevi, but the remaining nine were not only different from criteria usually assigned to giant naevi, but they also differed from the usual adult naevi, in that most were predominantly junctional. None of the melanocytic naevi in this series showed any suggestion of malignant change. In newborn infants it is often impossible clinically to distinguish naevi from other types of pigmented lesions, as only eleven out of the thirty-four pigmented lesions were melanocytic naevi. Seven of the eleven melanocytic naevi were under 1-5 cm in diameter. No pigmented lesions were found on the palms, soles or genitalia.     

Effects of outcome expectancies and disinhibition on ad lib alcohol consumption

CD95 ligand (CD95L) potently induces apoptosis by activating CD95 on target cells. It has recently been reported that melanoma cells in vivo express a significant amount of CD95L, thereby being immediately able to kill CD95-bearing immunocompetent cells specific for cancer antigens, which infiltrate the lesions. In this study, we employed immunohistochemistry using an antibody directed against CD95L to investigate at which stage the melanoma CD95L expression is turned on. Skin biopsies of 49 lesions from 46 patients were assessed. These included benign and dysplastic naevi, melanoma in situ, stage I melanomas (Clark's level 2 or 3), advance-phase melanomas (Clark's level 4 or 5) and lymph node metastases. CD95L was expressed in all of the advance-phase melanomas as well as lymph node metastases of cutaneous origin, whereas neither melanoma in situ, benign naevi nor dysplastic naevi reacted positively with the antibody. To investigate a link between positivity and tumour size, the data were analysed on the basis of Breslow thickness, and indicated that expression was observed only when tumours were thicker than 0.75 mm. We next compared expression of CD95L and HMB-45. CD95L was positive only in melanomas in a more advanced phase than stage I, whereas HMB-45 was not only expressed in melanoma cells but also in benign pigmented naevi. This indicated the advantage of CD95L staining to diagnose melanoma. The present study indicates the significant correlation between tumorigenicity and expression of CD95L, and thereby raises the possibility that CD95L may be a useful diagnostic marker for malignant melanomas.     

Genetic and environmental influences on the relationships between family connectedness, school connectedness, and adolescent depressed mood: Sex differences.

This study investigated (a) genetic and environmental contributions to the relationship between family and school environment and depressed mood and (b) potential sex differences in genetic and environmental contributions to both variation in and covariation between family connectedness, school connectedness, and adolescent depressed mood. Data are from 2,302 adolescent sibling pairs (mean age?=?16 years) who were part of the National Longitudinal Study of Adolescent Health. Although genetic factors appeared to be important overall, model-fitting analyses revealed that the best-fitting model was a model that allowed for different parameters for male and female adolescents. Genetic contributions to variation in all 3 variables were greater among female adolescents than male adolescents, especially for depressed mood. Genetic factors also contributed to the correlations between family and school environment and adolescent depressed mood, although, again, these factors were stronger for female than for male adolescents. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adolescents' relationships to siblings and mothers: A multivariate genetic analysis.

Research has consistently demonstrated that children's behavior toward their siblings tends to resemble interactions occurring in the parent–child relationship. This study examined the relative contributions of genetic and environmental influences to the covariation between sibling relationships and mother–adolescent relationships. Reported and observed family interactions were assessed for 719 same-sex sibling pairs of varying degrees of genetic relatedness. The covariance between mother–adolescent and sibling interactions was decomposed into genetic, shared, and nonshared environmental components. The overlapping effects of shared environment on the two relationship subsystems explained most of the covariance. Smaller but significant genetic and nonshared environmental effects were also found. The consistency of these findings with family processes, such as modeling, is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Genetic contributions to continuity, change, and co-occurrence of antisocial and depressive symptoms in adolescence

In adolescence, antisocial and depressive symptoms are moderately stable and modestly correlated with each other. We examined the genetic and environmental origins of the stability and change of antisocial and depressive symptoms and their co-occurrence cross-sectionally and longitudinally in a national sample of 405 adolescents. Monozygotic (MZ) and dizygotic (DZ) twins and full, half, and unrelated siblings 10-18 years of age from non-divorced and step-families were studied over a 3-year period. Composite measures of adolescent self-reports, parent reports, and observational measures of antisocial and depressive symptoms were analysed in multivariate behavioural genetic models. Results indicated that the majority of the stability in and co-occurrence between dimensions could be accounted for by genetic factors. Non-shared environmental risks and, for antisocial symptoms, shared environmental risks also contributed to the stability. Genetic influences on change were observed, but only for antisocial behaviour. In addition, the longitudinal association between antisocial behavioural and later depressive symptoms was also found to be genetically mediated, but this effect was nonsignificant after controlling for stability. Results were discussed in light of the potential contributions of development behavioural genetic research in understanding individual differences in the stability and change of maladjustment.     

Genetic and environmental variance in content dimensions of the MMPI.

To evaluate genetic and environmental variance in the Minnesota Multiphasic Personality Inventory (MMPI), I studied 9 factor scales identified in the 1st item factor analysis of normal adult MMPIs in 820 adolescent and young adult co-twins. Conventional twin comparisons documented heritable variance in 6 of the 9 MMPI factors (Neuroticism, Psychoticism, Extraversion, Somatic Complaints, Inadequacy, Cynicism); significant influence from shared environmental experience was found for 4 factors (Masculinity vs Femininity, Extraversion, Religious Orthodoxy, Intellectual Interests). Genetic variance was more evident in results from sisters than those of brothers, and a developmental-genetic analysis, using hierarchical multiple regressions of double-entry matrixes of raw data, revealed that in 4 MMPI factor scales, genetic effects were significantly modulated by age and/or gender during the developmental period from early adolescence to early adulthood. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Genetic and shared environmental influences on adolescent BMI: interactions with race and sex

The present study uses a behavioral genetic design to investigate the genetic and environmental influences on variation in adolescent body mass index (BMI) and to determine whether the relative influences of genetic and environmental factors on variation in BMI are similar across racial groups and sexes. Data for the present study come from the National Longitudinal Study on Adolescent Health (Add Health), a large, nationally representative study of adolescent health and health-related behaviors. The Add Health sample contains a subset of sibling pairs that differs in levels of genetic relatedness, making it well suited for behavioral genetics analyses. The present study examines whether genetic and environmental influences on adolescent BMI are the same for males and females and for Black and White adolescents. Results indicate that genetic factors contribute substantially to individual differences in adolescent BMI, explaining between 45 and 85% of the variance in BMI. Furthermore, based on an analysis of opposite-sex sibling pairs, the genes that influence variation in adolescent BMI are similar for males and females. However, the relative importance of genetic and environmental influences on variation in BMI differs for males and females and for Blacks and Whites. Although parameter estimates could be constrained to be equal for Black and White males, they could not be constrained to be equal for Black and White females. Moreover, the best-fitting model for Black females was an ADE model, for White females it was an ACE model, and for males it was an AE model. Thus, shared environmental influences are significant for White female adolescents, but not for Black females or males. Likewise, nonadditive genetic influences are indicated for Black females, but not for White females or males. Implications of these results are discussed.     

Computer analysis in oral lichenoid reactions

To improve diagnostic procedures and facilitate clinical decision-making, computer-assisted image analysis was performed on color slides from 30 patients with histopathologically verified oral lichenoid reactions. Areas from white hyperkeratotic and adjacent red inflamed areas of the lesions were selected and subjected to image analysis. The digitization of the color slides was done by means of an image scanner, and the digital information was transmitted to a personal computer for subsequent feature extraction and analysis. The different oral lesions were characterized as the difference in mean values between white hyperkeratotic and red inflamed areas, respectively, compared with clinically normal tissue. Statistical analyses were made on three different color systems: Red-Green-Blue (RGB), normalized red-green-blue (rgb), and Intensity-Hue-Saturation (IHS). The results showed statistically significant differences in all color systems for both the hyperkeratotic areas and adjacent inflammatory reactions. A linear correlation was obtained when the results of the image analysis of color variations were compared with a clinical score system for hyperkeratosis and inflammation evaluated by two investigators independently.     

The origins of individual differences in adjective check list scores.

Genetic and environmental contributions to individual differences in Adjective Check List (ACL) scores were estimated in a study of 61 pairs of identical (MZ) and fraternal (DZ) twin girls of grade-school age. Comparisons of the intraclass correlation coefficients of MZ and DZ groups for each of the ACL scales showed genetic contributions to 9 scales and systematic environmental contributions to 7 scales. The proportions of genetic and environmental variance are discussed in the context of other research findings, and the problems of scale validity in this population are examined. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Computer simulation of sample size and experimental design in human psychogenetics.

Applied a method of computer simulation to the investigation of problems connected with the genetic analysis of continuously variable behavioral characters in human populations. The efficiency with which various components of genetic and environmental variation could be detected was related to sample size. Results indicate that a convincing partition of the genetic variance into its additive and nonadditive components required much larger samples than those frequently employed in human psychogenetics. (15 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What to do with significant multivariate effects in multivariate analyses of variance.

Significant multivariate tests in the multivariate analysis of variance are often followed by analyses of the contributions of individual dependent variables to those significant effects. There has been little agreement, however, as to which specific analyses should be performed. The use of the 2 most common techniques, analysis of variance for each dependent variable and discriminant analysis, are discussed and then illustrated in a computer study. It is suggested that the purpose of the user should determine the technique chosen as the 2 methods are not alternative approaches to the same problem. Analysis of variance can be used for hypothesis testing of individual variables and is appropriate for research. The value of discriminant analysis is in prediction and classification, although it can indicate complex relationships between measures in hypothesis testing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Genetic models for the analysis of data from the families of identical twins

Genetic models are described which exploit the unique relationships that exist within the families of identical twins to obtain weighted least squares estimates of additive, dominance and epistatic components of genetic variance as well as estimates of the contributions of X-linked genes, maternal effects and three sources of environmental variation. Since all of the relationships required to achieve a resolution of these variance components are contained within each family unit, the model would appear to be superior to previous approaches to the analysis of quantitative traits in man.     

Environmental and genetic variance in children's observed and reported maladaptive behavior

The genetic and environmental contributions to children's maladaptive behavior are assessed in a sample of 154 twin pairs (77 MZ twin pairs and 77 DZ twin pairs), who range in age from 6 to 11 years. To bridge the strengths of behavioral genetic methods and environmental assessment techniques, we use a multimethod, multimeasure approach to data collection, and analyze the data using behavioral genetic modeling techniques. Results indicate that genetic variation accounts for a majority of the variance in parent-reported child maladaptive behavior (average = 62%). One parent-report measure also suggests a smaller, significant contribution of shared environmental variance. In contrast to the parental ratings, the observational coding and global impressions of parent-twin interactive behavior suggest that shared environment is the primary source of variance accounting for parent and child maladaptive behavior. This is due, in part, to the direct influence one's interactive partner has on the expression of maladaptive behavior in an interactive setting. When controlling for the co-participant's behavior, genetic variation increases and shared environmental variation decreases.     

"Blue" variant of naevus spilus

We report on a 29-year-old female patient with an unusual pigmented lesion of the face. Clinically the lesion looked like a pigment patch of the naevus spilus type, while histological examination revealed the presence of dermal melanocytosis and multiple common blue naevi with a discrete lentiginous component in addition. The melanocytic nature of the infiltrate was ascertained by immunohistochemistry analysis using S 100 protein and HMB 45 antibodies. We interpret this lesion as agminated blue naevi in association with lentigo simplex, an unusual variant of speckled lentiginous naevus.     

Genetic and environmental contributions to the association between quantitative ultrasound and bone mineral density measurements: a twin study

This study was designed to assess the relative contributions of genetic and environmental factors to the variation and covariation of quantitative ultrasound (QUS) measurements and their relationships to bone mineral density (BMD). Forty-nine monozygotic (MZ) and 44 dizygotic (DZ) female twins between 20 and 83 years of age (53 +/- 13 years, mean +/- SD) were studied. Digital (phalangeal) QUS (speed of sound [SOS]) and calcaneal QUS (broadband ultrasound attenuation [BUA] and velocity of sound [VOS]) were measured using a DBM Sonic 1200 ultrasound densitometer and a CUBA ultrasound densitometer, respectively. Femoral neck (FN), lumbar spine (LS), and total body (TB) BMD were measured using dual-energy X-ray absorptiometry. Familial resemblance and hence heritability (proportion of variance of a trait attributable to genetic factors) were assessed by analysis of variance, univariate, and multivariate model-fitting genetic analyses. In both QUS and BMD parameters, MZ twins were more alike than DZ pairs. Estimates of heritability for age- and weight-adjusted BUA, VOS, and SOS were 0.74, 0.55, and 0.82, respectively. Corresponding indices of heritability for LS, FN, and TB BMD were 0.79, 0.77, and 0.82, respectively. In cross-sectional analysis, both BUA and SOS, but not VOS, were independently associated with BMD measurements. However, analysis based on intrapair differences suggested that only BUA was related to BMD. Bivariate genetic analysis indicated that the genetic correlations between BUA and BMD ranged between 0.43 and 0.51 (p < 0.001), whereas the environmental correlations ranged between 0.20 and 0.28 (p < 0.01). While the genetic correlations within QUS and BMD measurements were significant, factor analysis indicates that common genes affect BMD at different sites. Also, individual QUS measurements appear to be influenced by some common sets of genes rather than by environmental factors. Significant environmental correlations were only found for BMD measurements and ranged between 0.50 and 0.65 (p < 0.001). These data suggest that QUS and BMD measurements are highly heritable traits. While it appears that there is a common set of genes influencing both QUS and BMD measurements, specific genes yet to be identified appear to have greater effects than that of shared genes in each trait.     

Genetic and environmental influences on global family conflict.

This study examined genetic and environmental influences on global family conflict. The sample comprised 872 same-sex pairs of twin parents, their spouses/partners, and one adolescent child per twin from the Twin and Offspring Study in Sweden. The twins, spouses, and child each reported on the degree of family conflict, and there was significant agreement among the family members’ ratings. These shared perspectives were explained by one common factor, indexing global family conflict. Genetic influences explained 36% of the variance in this common factor, suggesting that twins’ heritable characteristics contribute to family conflict, via genotype-environment correlation. Nonshared environmental effects explained the remaining 64% of this variance, indicating that twins’ unique childhood and/or current family experiences also play an important role. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Epistasis and its contribution to genetic variance components

We present a new parameterization of physiological epistasis that allows the measurement of epistasis separate from its effects on the interaction (epistatic) genetic variance component. Epistasis is the deviation of two-locus genotypic values from the sum of the contributing single-locus genotypic values. This parameterization leads to statistical tests for epistasis given estimates of two-locus genotypic values such as can be obtained from quantitative trait locus studies. The contributions of epistasis to the additive, dominance and interaction genetic variances are specified. Epistasis can make substantial contributions to each of these variance components. This parameterization of epistasis allows general consideration of the role of epistasis in evolution by defining its contribution to the additive genetic variance.     

Ultraviolet exposure and the development of banal and atypical naevi--a cross-sectional study on Cura?ao and in The Netherlands

The atypical naevus is both a risk factor for and a precursor lesion of melanoma. Sunlight is known to be an important aetiological factor for melanoma. Whether solar exposure is also involved in the initiation of (atypical) naevi is an issue of current interest. We performed a cross-sectional study among 270 inhabitants in the cloudy Netherlands and 282 white Dutch immigrants of the tropical island Cura?ao to investigate whether solar exposure plays a role in the development of atypical naevi. All participants were interviewed and underwent total skin examination; banal melanocytic naevi and atypical naevi were counted. There was no significant difference in the mean number of melanocytic naevi > or = 2 mm or > or = 5 mm between Cura?ao and the Netherlands. Furthermore, there was no significant difference in the mean crude and age standardized prevalence of atypical naevi between the Netherlands and Cura?ao. In both groups individuals with atypical naevi had significantly more total naevi. Concerning the role of sun exposure in the development of naevi in the Netherlands, we found that the total naevus count had a significant association with cumulative sun exposure before the age of 12 as well as with two or more painful sunburns before the age of 12. In Cura?ao these relationships were not observed. In contrast, however, on Cura?ao the presence of atypical naevi showed an association (odds ratio = 2.6, 95% confidence interval 1.1-6.0) with the highest level of cumulative sun exposure and with painful sunburns before the age of 12 (odds ratio = 2.6, 95% confidence interval 1.2-5.5). In the Dutch group these associations were not significant. We hypothesize that in the development of banal naevi there is an association between the total number of naevi and sun exposure only at low exposure levels; however, after overstepping a critical threshold a further association between melanocytic naevi and sun exposure is lacking. Sunlight exposure before the age of 12 plays a complex role: only very high exposure levels seem to contribute to the development of atypical naevi.     

Sex differences in the causes of self-reported adolescent delinquency.

Sex differences in the causes of self-reported adolescent delinquency were examined in full and half siblings born to a nationally representative sample of women in the United States. Qualitative sex differences in the genes that influence delinquency were not detected. Similarly, the proportions of variance in both aggressive and nonaggressive delinquency attributable to genetic and environmental influences did not differ significantly between girls and boys. Nonetheless, total variance in delinquency was greater among boys, and a scalar sex-differences model suggested that genetic and environmental influences on delinquency have less effect on population variation in delinquency among girls. Similarly, a test of the polygenic multiple threshold model suggested that girls require greater causal liability for the expression of delinquency than boys. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Can personality explain genetic influences on life events?

Previous research in the Swedish Adoption/Twin Study of Aging (SATSA) has found genetic influences on life events (R. Plomin et al, see record 1990-14029-001). The present study extends this finding by examining sex differences in genetic and environmental contributions to life events and by examining personality as a mediator of genetic influences on life events in SATSA. Analyses were based on 320 twin pairs, including identical and fraternal twins reared together and apart (mean age 58.6 yrs). Controllable, desirable, and undesirable life events revealed significant genetic variance only for women. There was no significant genetic variance for either sex for uncontrollable events. Multivariate analysis of personality (as indexed by Neuroticism, Extraversion, and Openness to Experience) and life events suggest that all of the genetic variance on controllable, desirable, and undesirable life events for women is common to personality. Thus, in this sample of older adult women, genetic influences on life events appear to be entirely mediated by personality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)