Biomedical subjects
Publications and source records attributed to A Caspi.
Explore the source record for details and available documents.
Do spouses become more similar over time? What processes contribute to enduring similarities between them? Using the 20-year Kelly Longitudinal Study of couples, no support for the hypothesis that couples increasingly resemble each other with time was found. Rather, couples maintain the same degree of similarity across 20 years. Structural equation analyses suggest that the shared environmental experiences of couples play a significant role in maintaining these similarities over time. We distinguish the shared marital environment from the shared rearing environment and consider developmental and dynamic-relational factors that moderate the relative importance of nonshared and shared environmental experiences in life-span personality development. Whereas nonshared influences in one's family of origin contribute to development in childhood and adolescence, shared influences in one's family of destination may contribute a great deal to development in adulthood.
We tested predictions about psychosocial factors in the onset of menarche using data from a longitudinal study of 16-year-old girls. Belsky, Steinberg, and Draper have proposed a model that seeks to explain individual differences in maturational timing in terms of stressful childhood experiences. Their model hypothesizes that (1) individuals who grow up under conditions of family stress (2) experience behavioral and psychological problems which (3) provoke earlier reproductive readiness. In this study, the effect of family stressors on menarche was mediated by neither behavior problems nor weight, contrary to the predictions. However, the most provocative proposition advanced by Belsky et al. received empirical support. Family conflict and father absence in childhood predicted an earlier age of menarche, and these factors in combination with weight showed some evidence of an additive influence on menarche. A genetic inheritance model may provide a more parsimonious account of these data than does a conditional adaptation model derived from sociobiology.
Explore the source record for details and available documents.
We describe a familial cardiomyopathy affecting three generations of family members with similar electrocardiographic abnormalities and human leukocyte antigen (HLA) haplotype. Autopsy findings in two of our patients were diagnostic of hypertrophic cardiomyopathy, although surviving affected members do not show ventricular hypertrophy on echocardiography. One patient's echocardiogram revealed giant atria in the absence of ventricular hypertrophy, suggesting a restrictive form of cardiomyopathy. In this kindred, an HLA haplotype appearing in affected, but not in healthy, family members may predict occurrence of disease during its presymptomatic phase in subsequent generations.
Thrombolysis is now generally accepted as the initial treatment for patients with acute myocardial infarction (AMI). The extent to which this therapy is implemented in daily practice and the reasons for exclusion from thrombolytic therapy among 413 consecutive patients with AMI hospitalized in 18 coronary care units in Israel during a 1-month survey were prospectively investigated. Thrombolytic therapy administered to 145 patients (35%) was given to 38% of men versus 29% of women (p = not significant), to 38% of patients less than 75 years old compared with 18% of the very elderly (p less than 0.005), and more often to patients with a first or anterior AMI (40 and 48%) than to counterparts with recurrent or inferior AMI (23 and 31%, respectively, p less than 0.005 for both). The 2 most frequent reasons for excluding patients from thrombolysis were late arrivals to coronary care units (33%) and lack of ST elevation on the admission electrocardiogram (28%). Hospital mortality was 6% in the thrombolytic group versus 20% in patients found ineligible for thrombolysis. The significance of this difference is not clear as treatment was not randomized.
The antiischemic properties of nisoldipine, a dihydropyridine calcium antagonist, were assessed in a multicenter, double-blind, placebo-controlled trial by repeated exercise testing and 72-hour ambulatory electrocardiographic monitoring in 82 patients with coronary artery disease. Patients with positive treadmill stress test results and greater than or equal to 2 ischemic episodes per 24 hours were included in this study. Administration of all chronic antiischemic medications except beta blockers were discontinued. During the first week all patients received placebo twice daily. During the second and third weeks, 41 patients received nisoldipine 10 mg and 41 patients received placebo twice daily. In the placebo group there were no changes in exercise parameters or in ambulatory electrocardiographic parameters. In the nisoldipine group, exercise duration increased from 403 to 448 seconds (p = 0.0035), time to 1 mm of ST depression increased from 224 to 298 seconds (p = 0.002), time to pain increased from 241 to 321 seconds (p = 0.01), and maximal ST depression was reduced from 2.6 to 2.3 mm (p = 0.002). Among the ambulatory electrocardiographic parameters in the nisoldipine group, only the number of episodes was reduced, from 14.4 to 11.6 (p = 0.0013) per patient. There was no significant reduction in total ischemic time (132 vs 120 minutes per patient). No significant side effects were observed. This is the largest clinical trial to date on the effects of nisoldipine on myocardial ischemia. The results indicate that nisoldipine was effective in improving all exercise parameters and only partially effective in suppressing ischemia during daily activity.
It is now widely acknowledged that personality and behaviour are shaped in large measure by interactions between the person and the environment. There are many kinds of interaction but we suggest that three types play particularly important roles both in sustaining behavioural continuity across the life course and in guiding the trajectory of the life course itself. Reactive interaction occurs when different individuals exposed to the same environment experience it, interpret it and react to it differently. Evocative interaction occurs when an individual's personality evokes distinctive responses from others. Proactive interaction occurs when individuals select or create environments of their own. Within this framework we also examine systematic change and turning points in behavioural development. We have recently advanced a paradoxical theory suggesting that behavioural continuities are especially likely to be evident during periods of social discontinuity; that is, dispositional factors influence behaviour most when individuals enter new situations and assume new statuses. This model receives empirical support from both experimental and longitudinal-correlational research. The model also presents interesting implications for our understanding of turning points in behavioural development: to effect change in the life course, new situations must eliminate old options and create new opportunities. Convergent evidence from experimental and naturalistic designs is introduced to support this claim.
Many current discussions of hereditary factors in psychopathology focus on twin studies as the primary source of evidence supporting the importance of genetic determinants. In summarizing the results of these studies, authors often derive estimates of concordance rates by collapsing across studies and presenting mean or median rates. This practice implicitly assumes that the concordance rates yielded by different studies represent equally reliable estimates of the population mean. The present study evaluates the validity of this assumption. Reports of twin studies of schizophrenia and affective disorder were reviewed. A meta-analysis was conducted to examine the influence of methodological factors on concordance rates. Analyses indicated that both sample-selection and zygosity-determination procedure are systematically associated with concordance rates. For schizophrenia, MZ concordance rates are significantly lower when samples are selected from a twin register as opposed to a psychiatric facility. Lower MZ concordance rates are also yielded by studies that employ laboratory procedures to determine zygosity. Implications of the findings for future research are discussed.
The emergence of new behaviors and the reorganization of psychological structures are often attributed to critical events and crises in the life course. A fundamentally different perspective is offered: Potentially disruptive transitions produce personality continuity, not change. The behavioral responses of adolescent girls to the onset of menarche was studied in a longitudinal study of an unselected birth cohort. Predictions from 3 rival hypotheses about the relation between pubertal change and social psychological change were first tested: the stressful change, off time, and early-timing hypotheses. The results supported the early-timing hypothesis. Whether stressful, early menarche generated new behavioral problems or accentuated premenarcheal dispositions was then tested. The results supported an accentuation model: Stressful transitions accentuated behavioral problems among girls who were predisposed to behavioral problems earlier in childhood. Speculations are offered for a broader theory about the role of individual differences in the life course.
Aortic dissecting aneurysm is a rare, serious complication of pregnancy. This condition was diagnosed in a 34-year-old woman in the 38th week of pregnancy. Cesarean section was immediately performed, and was followed by surgical repair of the dissection. A normal male infant was delivered.
Right ventricular dysplasia (RVD) is characterized by partial or total replacement of part of the right ventricular musculature by fatty and fibrous tissue. In its typical form it presents with ventricular tachycardia, usually in the fourth decade of life. 6 men and 2 women (mean age 55.6 years), referred for evaluation of arrhythmias or other cardiac symptoms, were diagnosed as having RVD on echocardiography after other causes of right ventricular enlargement were excluded. The mean age was 55.6 years, older than originally reported. 5 presented with supraventricular arrhythmias, including atrial flutter, atrial fibrillation, supraventricular tachycardia and sick-sinus syndrome. Only 2 had ventricular tachycardia; in 1 patient no arrhythmia was found. We conclude that RVD includes a wide spectrum of arrhythmias, of which ventricular tachycardia is probably not the most common. The incidence of RVD in the older population may be greater than originally reported, and may include a slowly developing form of the disease. In some cases RVD may be the pathophysiological basis of lone atrial fibrillation and sick-sinus syndrome.
How is personality stability possible amid the myriad of social changes and transformations that characterize a human life? We argue that by choosing situations that are compatible with their dispositions and by affiliating with similar others, individuals may set in motion processes of social interchange that sustain their dispositions across time and circumstance. To test this proposition we examined mate selection, using data on married couples from two ongoing longitudinal studies at the Institute of Human Development, University of California, Berkeley. Consistent with other research, the results point to homogamy as a basic norm in marriage. More important, the results show that marriage to a similar other promotes consistency in the intraindividual organization of personality attributes across middle adulthood. We offer some speculations for a more relational approach to the problem of individual continuity and change.
Actively sensitized guinea pigs were rendered Mg(2+)-deficient for 2-3 weeks and then subjected to immune stress. No differences could be seen between treated and control groups prior to immune challenge. 1-2 h after antigen challenge, 95% of the Mg(2+)-deficient animals were observed to be anaphylactic, i.e. apathetic, dyspneic, and they had a rapid pulse rate. Only 4% of the control animals showed signs of anaphylaxis. Serum magnesium concentration, [Mg2+], fell from 1.32 +/- 0.07 mM in control guinea pigs to 0.56 +/- 0.04 mM in those fed an Mg(2+)-deficient diet. Cardiomyolysis (CM) developed in 19% of the anaphylactic animals and in 3% of the controls. We conclude that Mg(2+)-deficient animals continue to function, provided conditions are normal, but they are unable to withstand stress. The heart, however, appears to be better equipped to defend itself against Mg2+ deficiency and low serum [Mg2+], a supposition supported by the fact that heart [Mg2+] is not significantly reduced in hypomagnesemic guinea pigs (0.864 +/- 0.021 microgram/mg dry weight in control, and 0.834 +/- 0.062 microgram/mg dry weight in magnesium-deficient animals). The data indicate that hypomagnesemia heightens the intensity of the immune response, thereby exacerbating both anaphylactic shock (AS) and CM. A normal serum [Mg2+] would thus seem essential for protection against immune stress.
Explore the source record for details and available documents.
Explore the source record for details and available documents.