Biomedical subjects

K L Jang

Publications and source records attributed to K L Jang.

At least 37 records · Page 2Linked to original sources

PubMed1999

Activation of the thymidine kinase promoter by herpes simplex virus type 1 immediate early proteins.

The herpes simplex virus type 1 (HSV-1) thymidine kinase (TK) gene promoter contains binding sites for the cellular transcription factors such as Spl, CTF, and TFIID, each of which affects basal level expression of the TK gene. The transcription of the TK gene was induced by viral immediate early proteins, ICP0 and ICP4 in an additive manner, but was repressed by ICP22 and ICP27. To gain further insights into the role of ICP0 and ICP4 for expression of the TK gene during virus infection, several mutants with deletions or point mutations in each of the transcriptional regulatory elements were generated starting at -109 and progressing toward +1. According to the CAT assay involving these mutants, the cellular transcription factor (CTF) binding site was necessary for efficient expression in the presence of transfected ICP0 and ICP4 or during virus infection, whereas the Sp1 binding site had a minor effect on ICP0-mediated TK expression. These results indicate that the immediate early proteins of HSV-1 regulate expression of the TK gene during virus infection by modulating activities of cellular transcription factors such as CTF.

Animals↗

PubMed1999

Heritability of anxiety sensitivity: a twin study.

OBJECTIVE: In attempting to explain the familial predisposition to panic disorder, most studies have focused on the heritability of physiologic characteristics (e.g., CO2 sensitivity). A heretofore unexplored possibility is that a psychological characteristic that predisposes to panic-anxiety sensitivity-might be inherited. In this study, the authors examined the heritability of anxiety sensitivity through use of a twin group. METHOD: Scores on the Anxiety Sensitivity Index were examined in a group of 179 monozygotic and 158 dizygotic twin pairs. Biometrical model fitting was conducted through use of standard statistical methods. RESULTS: Broad heritability estimate of the Anxiety Sensitivity Index as a unifactorial construct was 45%. Additive genetic effects and unique environmental effects emerged as the primary influences on anxiety sensitivity. There was no evidence of genetic discontinuity between normal and extreme scores on the Anxiety Sensitivity Index. CONCLUSIONS: This study suggests that one psychological risk factor for the development of panic disorder-anxiety sensitivity-may have a heritable component. As such, anxiety sensitivity should be considered in future research on the heritability of panic disorder.

Adolescent↗

PubMed1999

Individual differences in multiple dimensions of aggression: a univariate and multivariate genetic analysis.

Previous behaviour genetic studies of aggression have yielded inconsistent results: reported heritabilities for different types of aggressive behaviour ranging from 0 to 0.98. In the present study, 247 adult twin pairs (183 MZ pairs; 64 same-sex DZ pairs) were administered seven self-report questionnaires which yielded 18 measures of aggression. Univariate genetic analyses showed moderate to high heritabilities for 14 of these 18 measures and for a general aggression factor and three correlated aggression factors extracted from the measures. Multivariate genetic analyses showed sizeable genetic correlations between the different dimensions of aggression. Thus, individual differences in many types of aggressive behaviour are attributable to some extent to genetic factors and there is considerable overlap between the genes that operate on different types of aggressive behaviour.

Adult↗

PubMed1999

Why do measures of normal and disordered personality correlate? A study of genetic comorbidity.

The genetic and environmental correlations between measures of normal (NEO-FFI) and abnormal personality (Dimensional Assessment of Personality Pathology: DAPP-BQ) were estimated in a sample of 545 volunteer general population twin pairs (269 monozygotic and 276 dizygotic pairs). The largest genetic correlations were observed between the 18 DAPP-BQ dimensions and NEO-FFI neuroticism (range = .05 to .81; median = .48), extraversion (range = -.65 to .33; median = -.28), agreeableness (range = -.65 to .00; median = -.38), and conscientiousness (range = -.76 to .52; median = -.31). The smallest genetic correlations were found between the DAPP-BQ dimensions and NEO-FFI openness (range = -.17 to .20; median = -.04). The environmental correlations are lower in magnitude but show the same pattern of correlations between DAPP-BQ and NEO-FFI scales. These results indicate that these two scales share a common broad-based genetic architecture, whereas the environmental influences show greater scale specificity.

Adolescent↗

PubMed1998

Seasonal mood change and personality: an investigation of genetic co-morbidity.

Clinical observations and empirical studies suggest that Seasonal Affective Disorder (SAD) is related to personality. The present study estimates the genetic and environmental correlations between the Global Seasonality Score (GSS) from the Seasonal Pattern Assessment Questionnaire and personality measures, assessed using the NEO Five Factor Inventory (NEO-FFI) and the Dimensional Assessment of Personality Pathology (DAPP) in a volunteer sample of 163 monozygotic (MZ) pairs (102 female and 61 male pairs) and 134 dizygotic (DZ) pairs (70 female, 38 male and 26 opposite-sex pairs). Large genetic correlations were found between the GSS and NEO-FFI Neuroticism (0.52: 95% CI = 0.36-0.71) and DAPP-BQ Cognitive Dysregulation (0.50: 95% CI = 0.30-0.71), Affective Lability (0.49: 95% CI = 0.29-0.77), Anxiousness (0.37: 95% CI = 0.18-0.55) and Stimulus Seeking (0.45: 95% CI = 0.25-0.64) scales. The genetic correlations with the remaining scales, such as Extraversion (0.06: 95% CI = -0.16-0.26), Compulsivity (-0.09: 95% CI = -0.31-0.12) and Submissiveness (0.15: 95% CI = -0.05-0.34) were uniformly small. All environmental correlations between the GSS and personality scales were < or = 0.19. These results provide evidence that the observed correlations between these seasonality and personality dimensions are attributable to common genetic factors and that environmental influences are domain specific.

Adolescent↗

PubMed1998

Analysis of the envelope region of hepatitis G virus isolated from Korean patients.

The genetic diversity of hepatitis G virus (HGV) was investigated. By using a RT-PCR procedure, 14% of either HBV (hepatitis B virus)- or HCV (hepatitis C virus)-positive Korean hepatitis patients were proved to be HGV positives. Nucleotide sequences in the E1 region of the eight isolates from Korean patients and the six previously reported isolates were compared. Nucleotide substitutions spread uniformly throughout the E1 region. Sequence homology among the Korean isolates was 84-99% and 88-99% at the nucleotide and amino acid sequences, respectively, whereas those from different geographic areas was slightly lower at both levels. At least two genotypes might exist among the Korean HGV isolates. Compared to the corresponding region of HCV, the E1 sequence from HGV is moderately conserved. In addition, as frameshift mutations were observed in most of the Korean isolates compared to the prototype HGV sequence, the Korean isolates might not use the translational initiation site of the prototype HGV for polyprotein translation. Because a putative signal sequence of E1 for entry into endoplasmic reticulum starts from the N-terminus of the polyprotein, and capsid-like peptides composed of basic amino acids could not be detected from the upstream region of E1, the core protein of HGV is absent, or at least not present, at the region next to 5'-UTR. Therefore, HGV could be clearly distinguished from other genera of Flaviviridae.

Amino Acid Sequence↗

PubMed1998

Phenotypic and genetic structure of traits delineating personality disorder.

BACKGROUND: The evidence suggests that personality traits are hierarchically organized with more specific or lower-order traits combining to form more generalized higher-order traits. Agreement exists across studies regarding the lower-order traits that delineate personality disorder but not the higher-order traits. This study seeks to identify the higher-order structure of personality disorder by examining the phenotypic and genetic structures underlying lower-order traits. METHODS: Eighteen lower-order traits were assessed using the Dimensional Assessment of Personality Disorder-Basic Questionnaire in samples of 656 personality disordered patients, 939 general population subjects, and a volunteer sample of 686 twin pairs. RESULTS: Principal components analysis yielded 4 components, labeled Emotional Dysregulation, Dissocial Behavior, Inhibitedness, and Compulsivity, that were similar across the 3 samples. Multivariate genetic analyses also yielded 4 genetic and environmental factors that were remarkably similar to the phenotypic factors. Analysis of the residual heritability of the lower-order traits when the effects of the higher-order factors were removed revealed a substantial residual heritable component for 12 of the 18 traits. CONCLUSIONS: The results support the following conclusions. First, the stable structure of traits across clinical and nonclinical samples is consistent with dimensional representations of personality disorders. Second, the higher-order traits of personality disorder strongly resemble dimensions of normal personality. This implies that a dimensional classification should be compatible with normative personality. Third, the residual heritability of the lower-order traits suggests that the personality phenotypes are based on a large number of specific genetic components.

Adolescent↗

PubMed1998

Heritability of facet-level traits in a cross-cultural twin sample: support for a hierarchical model of personality.

The common variance among personality traits can be summarized in the factors of the five-factor model, which are known to be heritable. This study examined heritability of the residual specific variance in facet-level traits from the Revised NEO Personality Inventory. Analyses of raw and residual facet scales across Canadian (183 monozygotic [MZ] and 175 dizogotic [DZ] pairs) and German (435 MZ and 205 DZ pairs) twin samples showed genetic and environmental influences of the same type and magnitude across the 2 samples for most facets. Additive genetic effects accounted for 25% to 65% of the reliable specific variance. Results provide strong support for hierarchical models of personality that posit a large number of narrow traits in addition to a few broader trait factors or domains. Facet-level traits are not simply exemplars of the broad factors they define; they are discrete constructs with their own heritable and thus biological basis.

Adolescent↗

PubMed1998

Twin study of dissociative experience.

The relative influence of genetic and environmental influences on measures of pathological and nonpathological dissociative experience was estimated using a classic twin-study design. Subjects were 177 monozygotic and 152 dizygotic volunteer general population twin pairs who completed two measures of dissociative capacity identified from the items comprising the Dissociative Experiences Scale (DES). Additive genetic influences accounted for 48% and 55% of the variance in scales measuring pathological and nonpathological dissociative experience, respectively. Heritability estimates did not differ by gender. The genetic correlation between these measures was estimated at .91, suggesting common genetic factors underlying pathological and nonpathological dissociative capacity. Genetic and environmental correlations between the DES scales and measures of personality disorder traits (Dimensional Assessment of Personality Pathology-Basic Questionnaire; DAPP-BQ) were also estimated. Significant genetic correlations (median = .38) were found between the DES scales and DAPP-BQ cognitive dysregulation, affective lability, and suspiciousness, suggesting that the genetic factors underlying particular aspects of personality disorder also influence dissociative capacity.

Adolescent↗

PubMed1998

Nature vs nurture: are leaders born or made? A behavior genetic investigation of leadership style.

With the recent resurgence in popularity of trait theories of leadership, it is timely to consider the genetic determination of the multiple factors comprising the leadership construct. Individual differences in personality traits have been found to be moderately to highly heritable, and so it follows that if there are reliable personality trait differences between leaders and non-leaders, then there may be a heritable component to these individual differences. Despite this connection between leadership and personality traits, however, there are no studies of the genetic basis of leadership using modern behavior genetic methodology. The present study proposes to address the lack of research in this area by examining the heritability of leadership style, as measured by self-report psychometric inventories. The Multifactor Leadership Questionnaire (MLQ), the Leadership Ability Evaluation, and the Adjective Checklist were completed by 247 adult twin pairs (183 monozygotic and 64 same-sex dizygotic). Results indicated that most of the leadership dimensions examined in this study are heritable, as are two higher level factors (resembling transactional and transformational leadership) derived from an obliquely rotated principal components factors analysis of the MLQ. Univariate analyses suggested that 48% of the variance in transactional leadership may be explained by additive heritability, and 59% of the variance in transformational leadership may be explained by non-additive (dominance) heritability. Multivariate analyses indicated that most of the variables studied shared substantial genetic covariance, suggesting a large overlap in the underlying genes responsible for the leadership dimensions.

Adult↗

PubMed1998

Purification and characterization of a novel levanoctaose-producing levanase from Pseudomonas strain K-52.

Levan-assimilating micro-organisms from soil samples were screened for levanoligosaccharide-generating enzyme production. The isolated strain K-52 produced an extracellular levanoctaose-generating enzyme and was identified as belonging to genus Pseudomonas. The levanase was purified to homogeneity by (NH4)2SO4 fractionation and successive column chromatography on DEAE-cellulose, phenyl-Toyopearl 650 M, Sephadex G-100 and hydroxyapatite. The molecular mass of the enzyme was estimated as approx. 38 kDa by both SDS/PAGE and gel filtration, and its isoelectric point was approx. pH 4.8. The optimum temperature and pH for the enzyme reaction were 35 and 7.0 respectively. The enzyme was stable at a pH range of 6.0-9.0 at 4 degrees C and up to 40 degrees C at pH 6.8. The enzyme activity was inhibited by Fe2+, Cu2+, Hg2+ and Ag2+. The levanase was specific toward 2,6-beta-D-fructosidic linkages of levan and did not hydrolyse other polysaccharides such as inulin and dextran. Chemical modification on the levanase suggested that cysteine and histidine residues are essential for enzyme activity. The levanoctaose liberated by levanase reaction was used selectively only by the intestinal beneficial micro-organisms, such as Bifidobacterium and Lactobacillus spp.

Bacterial Proteins↗

PubMed1997

Gender differences in the heritability of seasonal mood change.

The study estimated gender differences in the magnitude of genetic and environmental influence in seasonal mood change. The self-report Seasonal Pattern Assessment Questionnaire (SPAQ) was completed by 339 volunteer reared-together twinpairs (187 monozygotic pairs, 152 dizygotic pairs) and analysed using biometric genetic models. The SPAQ yields a global seasonality score (GSS) which is an index of change in sleep patterns, social activities, mood, weight, appetite, and energy level. The GSS was significantly heritable among males and females, estimated to account for 69% and 45% of the total variance, respectively. For the individual symptoms, changes in sleep patterns, social activities, mood, appetite, and energy levels were accounted for primarily by additive genetic effects in both males (median, 45.5%) and females (median, 30.5%). For both sexes, weight changes were not heritable. Sex-by-genotype analyses suggested that the genetic factors influencing female seasonality may not be the same as those influencing male seasonality.

Adolescent↗

PubMed1997

Environmental predictors of personality differences: a twin and sibling study.

Nonshared environmental influences have consistently been shown to account for at least as much of the variance in personality as genetic factors, but the nature of these nonshared influences has largely remained unidentified. To identify environmental predictors of differential personality development, the Personality Research Form and 4 measures of people's perceptions of their background environments were administered to 143 adult twin pairs (93 monozygotic [MZ] and 50 dizygotic [DZ] and 66 pairs of same-sex nontwin (NT) siblings. Differences between MZ twins, DZ twins, and NT siblings in a number of dimensions of personality were significantly related to differences on the environmental measures, and phenotypic correlations between the personality and environment measures were themselves entirely attributable to correlated nonshared environmental effects.

Adult↗

PubMed1997

The relationship between seasonal mood change and personality: more apparent than real?

A number of recent research reports have reported significant relationships between seasonal mood change (seasonality) and personality. However, some of the results are difficult to interpret because of inherent methodological problems, the most important of which is the use of samples drawn from the southern as opposed to the northern hemisphere, where the phenomenon of seasonality may be quite different. The present study examined the relationship between personality and seasonality in a sample from the northern hemisphere (minimum latitude = 49 degrees N). A total of 297 adults drawn from the general population (112 male and 185 female subjects) completed the Seasonal Pattern Assessment Questionnaire, and the results obtained confirmed most of the previously reported relationships and showed that these are reliable across (i) different hemispheres, (ii) different measures of personality and (iii) clinical and general population samples. However, the impact of the relationship seems to be more apparent than real, with personality accounting for just under 15% of the total variance.

Adolescent↗

PubMed1997

Gender-specific etiological differences in alcohol and drug problems: a behavioural genetic analysis.

Although gender differences in the consumption and abuse of alcohol and drugs are frequently reported, the etiology of these differences has received limited attention. The present study applied biometric genetic analyses to determine whether self-report questionnaire items assessing problem alcohol and drug use are influenced by gender-specific genetic and environmental influences. The sample consisted of 693 volunteer general population twin pairs (209 monozygotic female, 138 monozygotic male, 170 dizygotic female, 82 dizygotic male, 94 dizygotic opposite-sex twin pairs). Heritability analyses showed that most aspects of drug and alcohol problems were differentially heritable by gender. Significant additive genetic effects were found only in males, whereas in females, most substance use problems were wholly determined by environmental factors. In both genders, non-shared environmental factors accounted for the largest proportion of the variance, and further gender-by-genotype analyses showed that these influences were not gender specific, but rather were common to males and females. Some preliminary evidence was also obtained that the use of illicit drugs may be etiologically distinct from the use of licit drugs in females and males.

Adolescent↗

PubMed1996

Heritability of the big five personality dimensions and their facets: a twin study.

The genetic and environmental etiology of the five-factor model of personality as measured by the revised NEO Personality Inventory (NEO-PI-R) was assessed using 123 pairs of identical twins and 127 pairs of fraternal twins. Broad genetic influence on the five dimensions of Neuroticism, Extraversion, Openness, Agreeableness, and Conscientiousness was estimated at 41%, 53%, 61%, 41%, and 44%, respectively. The facet scales also showed substantial heritability, although for several facets the genetic influence was largely nonadditive. The influence of the environment was consistent across all dimensions and facets. Shared environmental influences accounted for a negligible proportion of the variance in most scales, whereas nonshared environmental influences accounted for the majority of the environmental variance in all scales.

Adolescent↗

PubMed1996

Heritability of personality disorder traits: a twin study.

Genetic and non-genetic influences on the hierarchy of traits that delineate personality disorder as measured by the Dimensional Assessment of Personality Problems (DAPP-DQ) scale were examined using data from a sample of 483 volunteer twin pairs (236 monozygotic pairs and 247 dizygotic pairs). The DAPP-DQ assesses four higher-order factors, 18 basic dimensions and 69 facet traits of personality disorder. The correlation coefficients for monozygotic and dizygotic twin pairs ranged from 0.26 to 0.56 and from 0.03 to 0.41, respectively. Broad heritability estimates ranged from 0 to 58% (median value 45%). Additive genetic effects and unique environmental effects emerged as the primary influences on these scales, with unique environmental influences accounting for the largest proportion of the variance for most traits at all levels of the hierarchy.

Adolescent↗

PubMed1995

Alcohol and drug problems: a multivariate behavioural genetic analysis of co-morbidity.

Multivariate biometrical genetic analyses of self-report questionnaire items assessing problem alcohol and drug use were performed on data obtained from a sample of 438 volunteer twin pairs (236 monozygotic twin pairs, 247 dizygotic twin pairs). Additive genetic influences were moderate for all alcohol abuse items (21-46%), frequency of drug use (32%) and illicit drug use (32%). Prescribed drug use and debilitating drug use were largely environmentally determined (86% and 94%, respectively). The influence of environmental factors that influence all members of a family to the same degree (shared family environment) on each item was generally small (0-20%), whereas the influence of environmental factors unique to each family member (non-shared environment) comprised over half of the total variance on all items. Genetic factor analyses identified three uncorrelated common genetic factors. The first genetic factor appears to represent problems associated with alcohol and drug use, such as the inability to fulfil obligations at home, work or school. The second genetic factor is more specific to drug use and represents a general liability towards drug use, illicit or otherwise. The third genetic factor is specific to the alcohol use items only. The observed co-morbidity of alcohol and drug misuse can be attributed largely to a non-shared environmental factor common to both domains. Genetic co-morbidity appears to be limited to alcohol and substance misuse behaviours that interfere with normal daily functioning.

Adolescent↗