Biomedical subjects

A Caspi

Publications and source records attributed to A Caspi.

At least 19 recordsLinked to original sources

PubMed2006

Trends in cannabis use prior to first presentation with schizophrenia, in South-East London between 1965 and 1999.

BACKGROUND: There is evidence that cannabis use might be relevant to the aetiology of schizophrenia. We aimed to measure any change in cannabis use over time in those first presenting with schizophrenia in South-East London from 1965 to 1999, and compare this with change in use in those presenting with non-psychotic psychiatric disorders. METHOD: The rate of cannabis use in the year prior to first ever presentation was measured over seven time periods. Logistic regression modelling was used to determine (a) whether cannabis use changed over time, after controlling for age, sex and ethnicity, and (b) whether there was an interaction between diagnosis and time. RESULTS: Cannabis use increased over time in both the schizophrenia group [odds ratio per time period (OR) 2.03, 95% confidence interval (CI) 1.74-2.38, p<0.0001] and the non-psychotic disorders group (OR 1.24, 95% CI 1.05-1.47, p=0.012), after controlling for age, sex and ethnicity. However, the effect of time was significantly greater in the schizophrenia group than in the non-schizophrenia group (chi2=17, p<0.0001). CONCLUSION: Cannabis use in the year prior to presentation with schizophrenia increased markedly between 1965 and 1999, and disproportionately so compared to increase in cannabis use in other psychiatric disorders.

Adult↗

PubMed2006

MAOA, maltreatment, and gene-environment interaction predicting children's mental health: new evidence and a meta-analysis.

Previous research on adults has shown that a functional polymorphism in the promoter region of the monoamine oxidase A (MAOA) gene moderates the impact of childhood maltreatment on risk for developing antisocial behavior. Thus far, attempts to replicate this finding have been mixed. The current study (i) presents new data investigating this finding in a sample of 975 seven-year-old boys, and (ii) evaluates the extant data by conducting a meta-analysis of published findings. We replicated the original finding by showing that the MAOA polymorphism moderates the development of psychopathology after exposure to physical abuse, we extended the finding to childhood closer in time to the maltreatment experience, and we ruled-out the possibility of a spurious finding by accounting for passive and evocative gene-environment correlation. Moreover, meta-analysis demonstrated that across studies, the association between maltreatment and mental health problems is significantly stronger in the group of males with the genotype conferring low vs high MAOA activity. These findings provide the strongest evidence to date suggesting that the MAOA gene influences vulnerability to environmental stress, and that this biological process can be initiated early in life.

Adolescent↗

PubMed2006

Genetic and environmental influences on age at sexual initiation in the Colorado Adoption Project.

Whereas the majority of research on adolescent sexual initiation has focused solely on environmental factors, the present study used behavioral genetic analyses to investigate the relative contributions of genetic and environmental influences. Structural equation models were fitted to data from adoptive and non-adoptive sibling pairs (231 biologically related pairs and 169 unrelated pairs) from the Colorado Adoption Project. Information from censored individuals who had not yet experienced sexual initiation was maximized by adapting the twin survival analysis method of Pickles et al. (Behav Genet 24(5):457-468, 1994) to accommodate adoptive and non-adoptive siblings. Point estimates of variance components from an ACE model, including additive genetic (A), shared environmental (C), and non-shared environmental (E) influences were 28%, 24%, and 48%, respectively. Despite the lower point estimate for shared environmental effects than additive genetic effects, a CE model provided the best fit to the data. However, because adoptive siblings provide a direct estimate of shared environmental influences there is greater power to detect shared environmental effects in adoption designs. Evidence for genetic influences from our data were somewhat lower than those obtained in previous twin studies, possibly reflecting a return to more socially conservative sexual attitudes, changing sexual behaviors, or ambiguities in the wording of questions commonly used in research on adolescent sexuality.

Adolescent↗

PubMed2004

The saccadic system more readily co-processes orthogonal than co-linear saccades.

Real-life visual tasks such as tracking jumping objects and scanning visual scenes often require a sequence of saccadic eye movements. The ability of the ocular motor system to parallel process saccades has been previously demonstrated. We recorded the monocular eye movements of five normal human subjects using the magnetic search coil technique in a double step paradigm. Initial target jumps were always purely horizontal or purely vertical. We were interested in the latency to onset of the second saccade as a function of direction in relation to the first saccade. When the inter stimulus interval (ISI) was 150 or 180 ms orthogonal second saccades were of significantly shorter latency than second co-linear saccades. When the ISI was 250 ms the latencies of orthogonal and co-linear second saccades were statistically indistinguishable. Based on these findings it is postulated that the ocular motor system can more readily co-process orthogonal than co-linear saccades.

Adult↗

PubMed2004

Co-occurrence of ADHD and low IQ has genetic origins.

Previous studies show that the symptoms of attention deficit hyperactivity disorder (ADHD) and lower intelligence quotient (IQ) covary in children. We investigated the aetiology of this association in a large population-based sample of 5-year-old twins. The twins were individually assessed on an IQ test, and data on ADHD symptoms were obtained from mother interviews and teacher ratings. Confirming previous studies, the phenotypic correlation between ADHD symptom scores and IQ was -0.3 and, in a categorical analysis, children with a Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) ADHD research diagnosis obtained IQ scores nine points lower, on average, than comparison children. We show here that the co-occurrence of ADHD and lower IQ has genetic origins: 86% of the association between ADHD symptom scores and IQ, and 100% of the association between ADHD diagnosis and IQ, was accounted for by genetic influences that are shared by ADHD and IQ. Some candidate genes for ADHD could also contribute to variation in IQ or vice versa.

Analysis of Variance↗

PubMed2004

Socioeconomic inequalities in oral health in childhood and adulthood in a birth cohort.

OBJECTIVES: To determine whether adult oral health is predicted by (a) childhood socioeconomic advantage or disadvantage (controlling for childhood oral health), or (b) oral health in childhood (controlling for childhood socioeconomic advantage or disadvantage), and whether oral health in adulthood is affected by changes in socioeconomic status (SES). METHODS: Participants in a longstanding cohort study underwent systematic dental examination for dental caries and tooth loss at ages 5 and 26 years. The examination at age 26 years included the collection of data on periodontal attachment loss and plaque level. Childhood SES was determined using parental occupation, and adult SES was determined from each study member's occupation at age 26 years. Regression models were used to test the study hypotheses. RESULTS: Complete data were available for 789 individuals (47.4% female). After controlling for childhood oral health, those who were of low SES at age 5 years had substantially greater mean DFS and DS scores by age 26 years, were more likely to have lost a tooth in adulthood because of caries, and had greater prevalence and extent of periodontitis. A largely similar pattern was observed (after controlling for childhood SES) among those with greater caries experience at age 5 years. For almost all oral health indicators examined, a clear gradient was observed of greater disease at age 26 years across socioeconomic trajectory groups, in the following order of ascending disease severity and prevalence: 'high-high', 'low-high' (upwardly mobile), 'high-low' (downwardly mobile) and 'low-low'. CONCLUSION: Adult oral health is predicted by not only childhood socioeconomic advantage or disadvantage, but also by oral health in childhood. Changes in socioeconomic advantage or disadvantage are associated with differing levels of oral health in adulthood. The life-course approach appears to be a useful paradigm for understanding oral health disparities.

Adult↗

PubMed2004

[Out-of-hospital resuscitation in Israel 2000].

The aim of the study was to evaluate the impact of pre-hospital cardio-pulmonary resuscitation, performed by mobile intensive cardiac care units of Magen David Adom (MDA) teams in the framework of a national survey conducted in the period February and March 2000. During the survey, MDA performed 539 resuscitations, 485 of which were performed by mobile intensive care units of MDA, and they constitute the study population of the present analysis. The average age of the patients was 70.5 years, and 68% were men. The mean response time of the mobile intensive care units was 10.3 minutes. In 14% of the cases, a bystander initiated basic cardiac life support before the arrival of the MDA team. Upon arrival of the resuscitation team, 242 patients (50%) had asystole, 19% ventricular tachycardia (VT)/ventricular fibrillation (VF), 13% pulseless electrical activity (PEA), and 18% had other severe arrhythmias. One hundred and ninety-nine patients (41%) were transferred alive to the hospital after successful resuscitation. Hospital summaries were obtained for 148 of these patients. The cause of cardiac arrest was cardiac in 64% of the cases and 48% of the patients who reached the hospital had a previous history of heart disease. Fifty-three patients (11%) were discharged alive from the hospital. Patients discharged alive were younger, more promptly resuscitated, 78% had a cardiac cause of death and 38% of them were in ventricular tachycardia/fibrillation when first seen by the resuscitation team. The rate of successful resuscitation to discharge in the sub-group with VT/VF was 21%, and only 4% for patients in asystole, which is in line with other studies. However, the rate of initiation of resuscitation by bystanders is low in Israel. These data may help the medical staff and the health policy providers in Israel.

Aged↗

PubMed2002

The dopamine D4 receptor and the hyperactivity phenotype: a developmental-epidemiological study.

Attention-deficit hyperactivity disorder (ADHD) affects 2-6% of school-age children and is a precursor of behavioural problems in adolescence and adulthood. Underlying the categorical definition of ADHD are the quantitative traits of activity, impulsivity, and inattention which vary continuously in the population. Both ADHD and quantitative measures of hyperactivity are heritable, and influenced by multiple genes of small effect. Several studies have reported an association between clinically defined ADHD and the seven-repeat allele of a 48-bp tandem repeat polymorphism in the third exon of the dopamine D4 receptor gene (DRD4). We tested this association in a large, unselected birth cohort (n = 1037) using multiple measures of the hyperactivity phenotype taken at multiple assessment ages across 20 years. This longitudinal approach allowed us to ascertain whether or not DRD4 has a general effect on the diagnosed (n = 49) or continuously distributed hyperactivity phenotype, and related personality traits. We found no evidence to support this association.

Adolescent↗

PubMed2002

Structure characterization of human serum proteins in solution and dry state.

The present report describes application of advanced analytical methods to establish correlation between changes in human serum proteins of patients with coronary atherosclerosis (protein metabolism) before and after moderate beer consumption. Intrinsic fluorescence, circular dichroism (CD), differential scanning calorimetry and hydrophobicity (So) were used to study human serum proteins. Globulin and albumin from human serum (HSG and HSA, respectively) were denatured with 8 m urea as the maximal concentration. The results obtained provided evidence of differences in their secondary and tertiary structures. The thermal denaturation of HSA and HSG expressed in temperature of denaturation (Td, degrees C), enthalpy (DeltaH, kcal/mol) and entropy (DeltaS kcal/mol K) showed qualitative changes in these protein fractions, which were characterized and compared with fluorescence and CD. Number of hydrogen bonds (n) ruptured during this process was calculated from these thermodynamic parameters and then used for determination of the degree of denaturation (%D). Unfolding of HSA and HSG fractions is a result of promoted interactions between exposed functional groups, which involve conformational changes of alpha-helix, beta-sheet and aperiodic structure. Here evidence is provided that the loosening of the human serum protein structure takes place primarily in various concentrations of urea before and after beer consumption (BC). Differences in the fluorescence behavior of the proteins are attributed to disruption of the structure of proteins by denaturants as well as by the change in their compactability as a result of ethanol consumption. In summary, thermal denaturation parameters, fluorescence, So and the content of secondary structure have shown that HSG is more stable fraction than HSA.

Blood Proteins↗

PubMed2001

Persistence and perceived consequences of cannabis use and dependence among young adults: implications for policy.

AIMS: To document patterns of cannabis use and dependence from late-adolescence through to the mid-twenties; to describe perceived consequences of cannabis use among young people; and to consider policy implications of these findings. METHODS: This was a longitudinal study of the Dunedin Multidisciplinary Health and Development Study birth cohort with repeated measures of cannabis use at ages 18, 21 and 26 years. RESULTS: Twelve month prevalence rates of cannabis use (just over 50%) and dependence (just under 10%) remained stable between age 21 and 26 years, contrary to an expected decline. Cannabis dependence, as distinct from occasional use, was associated with high rates of harder drug use, selling of drugs and drug conviction. Cumulatively, almost 3/4 of our cohort had tried cannabis by age 26. Young people thought the risk of getting caught using cannabis was trivial, and that using cannabis had few negative social consequences. CONCLUSIONS: The persistent high rates of cannabis use and dependence among young New Zealand adults raises important issues for policy makers. Current laws are not particularly effective in deterring use. Whereas occasional use does not appear to present a serious problem, cannabis dependence among users is a serious public health issue that warrants immediate action.

Adolescent↗

PubMed2001

Brain drain or OE? Characteristics of young New Zealanders who leave.

AIMS: To characterise the emigration patterns of young New Zealanders. METHODS: The 980 members of the Dunedin Multidisciplinary Health and Development Study participating in the "age-26" (1998-1999) assessment provided information about emigration behaviour, qualifications, aspects of physical and mental health and personality. RESULTS: 26% of the sample had moved overseas to live between the ages of 18 and 26, with the United Kingdom and Australia being the most common destinations. Compared to non-emigrants, emigrants had higher IQ scores, were better qualified, leaner and fitter, and had happier and less stress-prone personalities. Based on their planned return date, 63% of emigrants were considered to be on their OE overseas experience (OE, return in <5 years), 18% were defined as brain-drain emigrants (return in >5 years or never) and 18% were uncertain about their return. Brain-drain emigrants were more likely than OE emigrants to leave for better work opportunities, and they were also more likely to go to Australia. However, there were no differences in terms of qualifications, intelligence and personality between OE and brain-drain emigrants. CONCLUSIONS: Most young New Zealanders in this cohort who left for overseas were embarking on their OE. Brain-drain emigrants make up a sizeable minority of emigrants, but appear to possess no more skills than those who plan or choose to return.

Adolescent↗

PubMed2001

A new dimension in retrograde flow: centripetal movement of engulfed particles.

Centripetal motion of surface-adherent particles is a classic experimental system for studying surface dynamics on a eukaryotic cell. To investigate bead migration over the entire cell surface, we have developed an experimental assay using multinuclear giant fibroblasts, which provide expanded length scales and an unambiguous frame of reference. Beads coated by adhesion ligands concanavalin A or fibronectin are placed in specific locations on the cell using optical tweezers, and their subsequent motion is tracked over time. The adhesion, as well as velocity and directionality of their movement, expose distinct regions of the cytoplasm and membrane. Beads placed on the peripheral lamella initiate centripetal motion, whereas beads placed on the central part of the cell attach to a stationary cortex and do not move. Careful examination by complementary three-dimensional methods shows that the motion of a bead placed on the cell periphery takes place after engulfment into the cytoplasm, whereas stationary beads, placed near the cell center, are not engulfed. These results demonstrate that centripetal motion of adhering particles may occur inside as well as outside the cell. Inhibition of actomyosin activity is used to explore requirements for engulfment and aspects of the bead movement. Centripetal movement of adherent particles seems to depend on mechanisms distinct from those driving overall cell contractility.

Actins↗

PubMed2001

Tezosentan (an intravenous endothelin receptor A/B antagonist) reduces peripheral resistance and increases cardiac power therefore preventing a steep decrease in blood pressure in patients with congestive heart failure.

OBJECTIVE: This study investigated the effect of tezosentan (an intravenous endothelin-1 receptor antagonist) on vascular resistance and cardiac function and determined the dose response in patients with stable congestive heart failure (CHF) due to left ventricular systolic dysfunction. METHODS: In a double-blind fashion, tezosentan or placebo were administered in ascending doses (5, 20, 50, 100 mg h(-1)) to 38 CHF (NYHA class III) patients with ejection fraction or=15 mmHg. Systemic vascular resistance index (SVRi) was estimated as mean arterial blood pressure [(MAP-right atrial pressure)/cardiac index (CI)]. Cardiac function was assessed as cardiac power index (Cpi), calculated as pressure x flow (MAP x CI), where MAP represents pressure and CI represents cardiovascular flow. RESULTS AND DISCUSSION: Compared to the placebo, tezosentan induced a dose-dependent decrease in SVRi (-32%), an increase in Cpi (+20%) and a small decrease in MAP (-9%). By contrast, patients treated with nitrate vasodilators or nesiritide (a natriuretic peptide) showed a decrease in SVRi not accompanied by a significant increase in Cpi leading to a steep decrease in MAP. CONCLUSIONS: The use of Cpi in the assessment of the hemodynamic effects of tezosentan, provides a useful alternative characterization of the complex influences of vasodilators on cardiac function in patients with CHF.

Adult↗

PubMed2001

Childhood predictors differentiate life-course persistent and adolescence-limited antisocial pathways among males and females.

This article reports a comparison on childhood risk factors of males and females exhibiting childhood-onset and adolescent-onset antisocial behavior, using data from the Dunedin longitudinal study. Childhood-onset delinquents had childhoods of inadequate parenting, neurocognitive problems, and temperament and behavior problems, whereas adolescent-onset delinquents did not have these pathological backgrounds. Sex comparisons showed a male-to-female ratio of 10:1 for childhood-onset delinquency but a sex ratio of only 1.5:1 for adolescence-onset delinquency. Showing the same pattern as males, childhood-onset females had high-risk backgrounds but adolescent-onset females did not. These findings are consistent with core predictions from the taxonomic theory of life-course persistent and adolescence-limited antisocial behavior.

Adolescent↗

PubMed2001

Why are children born to teen mothers at risk for adverse outcomes in young adulthood? Results from a 20-year longitudinal study.

This 20-year longitudinal study showed that the young adult offspring of teen mothers are at risk for a range of adverse outcomes including early school leaving, unemployment, early parenthood, and violent offending. We tested how much the effect of teen childbearing on offspring outcomes could be accounted for by social selection (in which a woman's characteristics that make her an inadequate parent also make her likely to bear children in her teens) versus social influence (in which the consequences of becoming a teen mother also bring harm to her children, apart from any characteristics of her own). The results provided support for both mechanisms. Across outcomes, maternal characteristics and family circumstances together accounted for approximately 39% of the effect of teen childbearing on offspring outcomes. Consistent with a social-selection hypothesis, maternal characteristics accounted for approximately 18% of the effect of teen childbearing on offspring outcomes; consistent with a social-influence hypothesis, family circumstances accounted for 21% of the teen childbearing effect after controlling for maternal characteristics. These results suggest that public policy initiatives should be targeted not only at delaying childbearing in the population but at supporting individual at-risk mothers and their children.

Adolescent↗

PubMed2001

Beer consumption and changes in stability of human serum proteins.

The aim of this study was to evaluate the influence of beer consumption (BC) on the functional and structural properties of human serum proteins (HSP). Thirty-eight volunteers (after coronary bypass) were divided into two groups: experimental (EG) and control (CG). Nineteen volunteers of the EG consumed 330 mL per day of beer (about 20 g of alcohol) for 30 consecutive days. The CG volunteers consumed mineral water instead of beer. Blood samples were collected from EG and CG patients before and after the experiment. Albumin (Alb), globulin (Glo), and methanol-precipitable proteins (MPP) from human serum were denatured with 8 M urea. Fluorescence and electrophoresis were employed in order to elucidate urea-induced conformational changes and structural behavior of proteins. The measured fluorescence emission spectra were used to estimate the stability of native and denatured protein fractions before and after BC. It was found that before BC the fractions most stable to urea denaturation were Glo, Alb, and MPP fractions. After BC in most of the beer-consuming patients (EG) some changes in native and denatured protein fractions were detected: a tendency to lower stability and minor structural deviations. These qualitative changes were more profound in MPP than in Alb and Glo. Thus, Glo is more resistible to alcohol influence than Alb, which in turn is more resistible than MPP. No serum protein changes were detected in patients of CG.

Beer↗

PubMed2001

Male mental health problems, psychopathy, and personality traits: key findings from the first 14 years of the Pittsburgh Youth Study.

This paper reviews key findings on juvenile mental health problems in boys, psychopathy, and personality traits, obtained in the first 14 years of studies using data from the Pittsburgh Youth Study. This is a study of 3 samples, each of about 500 boys initially randomly drawn from boys in the 1st, 4th, and 7th grades of public schools in Pittsburgh. The boys have been followed regularly, initially each half year, and later at yearly intervals. Currently, the oldest boys are about 25 years old, whereas the youngest boys are about 19. Findings are presented on the prevalence and interrelation of disruptive behaviors, ADHD, and depressed mood. Results concerning risk factors for these outcomes are reviewed. Psychological factors such as psychopathy, impulsivity, and personality are described. The paper closes with findings on service delivery of boys with mental health problems.

Attention Deficit and Disruptive Behavior Disorder↗

PubMed2001

A computer-based method for the assessment of body-image distortions in anorexia-nervosa patients.

A computer-based method for the assessment of body-image distortions in anorexia nervosa and other eating-disorder patients is presented in this paper. At the core of the method is a realistic pictorial simulation of lifelike weight changes, applied to a real source image of the patient. The patients, using a graphical user interface, adjust their body shapes until they meet their self-perceived appearance. Measuring the extent of virtual fattening or slimming of a body with respect to its real shape and size allows direct quantitative evaluation of the cognitive distortion in body image. In a preliminary experiment involving 33 anorexia-nervosa patients, 70% of the subjects chose an image with simulated visual weight gain between 8%-16% as their "real" body image, while only one of them recognized the original body image. In a second experiment involving 30 healthy participants, the quality of the weight modified images was evaluated by pairwise selection trials. Over a weight change range from -16% to +28%, in about 30% of the trials, artificially modified images were mistakenly taken as "original" images, thus demonstrating the quality of the artificial images. The method presented is currently in a clinical validation phase, toward application in the research, diagnosis, evaluation, and treatment of eating disorders.

Agnosia↗