Biomedical subjects
Publications and source records attributed to R S John.
Three cases of transfusion-transmitted malaria in Canada are described. Although very rare, this diagnosis should be considered in transfusion recipients who have undiagnosed symptoms consistent with malaria. Thick and thin blood smears should be urgently examined to exclude this possibility.
The authors examined the relation between parents' hostility during conflict-focused discussions and child behavior problems. Parents engaged in 3 discussions: a dyadic marital discussion of marital disagreements, a dyadic marital discussion of child-related disagreements, and a triadic family discussion with the child about the child-related disagreements. Eighty-nine 2-parent community families with a child aged 9-13 years participated. A significant 3-way interaction between interparental hostility, parent-to-child hostility, and child sex accounted for variance in children's behavior problems. Among boys, higher levels of parent-to-child hostility during family discussions exacerbated the effects of interparental hostility on boys' adjustment. Thus, exposure to higher levels of both interparental and parent-to-child hostility may put boys at risk for developing internalizing and externalizing behavior problems.
Coparenting is examined as an explanatory link between marital conflict and parent-child relations in 2-parent families. Data were collected from 3 samples (pilot sample, n = 220 mothers; preadolescent sample, n = 75 couples; preschool sample, n = 172 couples) by using the Coparenting Questionnaire (G. Margolin, 1992b) to assess parents' perceptions of one another on 3 dimensions--cooperation, triangulation, and conflict. Main effects for child's age and for parents' gender were found for cooperation, and an interaction between parent and child gender was found for triangulation. Regression analyses were consistent with a model of coparenting mediating the relationship between marital conflict and parenting. Discussion addresses the theoretical and clinical importance of viewing coparenting as conceptually separate from other family processes.
Gender differences are evident in the etiology and maintenance of aggressive behavior (which is on the increase for both male and female youths), but the explanatory models that have been proposed, including social learning theory and information processing models, are more appropriate for boys than for girls. In an attempt to elucidate processes underlying aggression, particularly for girls, the authors explored locus of control as a cognitive variable possibly related to aggressive behavior. The relationships between teacher-reported aggression and 3 types of locus of control (internal, powerful other, and unknown) for success and failure experiences were investigated. For girls, aggressive behavior was positively related to internal and unknown locus of control. In contrast, boys' aggressive behavior was unrelated to internal locus of control beliefs and negatively related to external locus of control beliefs. Possible explanatory mechanisms for the relationship between locus of control beliefs and aggression are discussed. The present study contributes to the understanding of aggression in girls and points to different processes underlying girls' and boys' aggression.
The study examines whether the link between the marital relationship and sibling interaction is direct or mediated by the mother-child relationship. Seventy-three same-sex siblings pairs aged 3 years 6 months to 8 years 6 months were observed during free play. Mothers completed questionnaires assessing marital functioning and their relationship with their 2 children. Results indicated that older siblings' negative behavior is linked with negative dimensions of the marital and the mother-child relationship, whereas younger siblings' negative behavior is linked with the mother-child and the differential mother-child relationship. Siblings; positive behavior, although linked with spacing, is not linked with positive dimensions of family interaction. Most important, the linkage between negative marital relations and older siblings; negative behavior was found to be mediated by maternal power assertion, thereby supporting the indirect model of negative family interaction.
OBJECTIVE: To determine the nature and extent of cognitive deficits in early stage (asymptomatic) human immunodeficiency virus (HIV)-positive homosexual and bisexual men. DESIGN: A cross-sectional design was used to compare 27 HIV-positive, asymptomatic (Centers for Disease Control and Prevention stages 2 and 3) homosexual and bisexual men, who were designated as the seropositive group, with 29 seronegative homosexual and bisexual men, who were designated as the control group. METHODS: The participant groups were closely matched on a number of demographic and lifestyle variables. Participants were carefully and repeatedly screened for substance abuse, a history of psychiatric problems, use of psychoactive medications, and neurological problems. All participants completed an extensive neuropsychological battery and a computerized information processing battery to identify cognitive deficits. RESULTS: No significant between-group differences were found on either the neuropsychological assessments or the information processing tests. Additionally, we found no evidence of a subgroup of seropositive, asymptomatic individuals with general cognitive slowing. CONCLUSIONS: Educated, HIV-positive asymptomatic individuals may show little difference in cognitive performance compared with a group of matched controls when the groups are carefully screened and matched. Additionally, computerized tests may be no more sensitive than neuropsychological tests to cognitive decrements for these types of participants.
OBJECTIVE: To examine how children, aged 8 to 11 years, react to observing their parents' naturally occurring marital conflict in their own homes and to compare reactions among children raised in homes characterized by different types of marital conflict. METHOD: For 5 1/2 weeks, mothers and fathers of 110 children used daily home diaries to record independently their children's reactions to marital conflict. Logistic regression compared the likelihood of exhibiting specific reactions to conflict among children from marriages characterized by low conflict (LOWCON; n = 37), nonphysical conflict (NOPHYCON; n = 35), and physical conflict (PHYCON; n = 38). RESULTS: Mothers' and fathers' reports indicate that children from PHYCON homes were more likely than children from LOWCON and NOPHYCON homes to leave the room, misbehave or appear angry, and appear sad or frightened. CONCLUSIONS: These results support the notion that different histories of exposure to marital conflict may contribute to the way in which children react to their parents' marital conflict.
BACKGROUND: The effect of anti-retroviral medications on the cognitive functions important in flying has not been determined. HYPOTHESIS: Anti-retroviral medications have no effect on the cognitive performance of individuals at the CDC 4C2 (symptomatic HIV disease with no illness indicative of full-blown AIDS) stage of infection. METHODS: A two-group study using a cross-sectional design was used. The participants in each group represented a sample of convenience obtained from a larger, naturalistic study. Each group consisted of 10 HIV+ males at the CDC 4C2 stage of infection. The two groups were found to be comparable on age, education, pre-morbid intelligence, and ethnicity. All members of the anti-retroviral medication group had been receiving medications for at least 3 mo. Those in the control group (no anti-retroviral medication) had received no anti-retroviral medications for at least 6 mo. Cognitive functioning was assessed using a computerized information processing battery that included test similar to those under consideration for inclusion in military pilot selection batteries and a neuropsychological battery. As part of the larger study, the participants were carefully and repetitively screened on factors known to affect performance on neuropsychological instruments. RESULTS: The groups showed little difference in cognitive functioning. CONCLUSION: Although more research is needed, anti-retroviral medication does not impair, and may improve, the cognitive processes of individuals with symptomatic HIV infection who do not have AIDS.
We examined teachers' reports to determine early patterns of school behavior that identify children who were diagnosed schizophrenic in adulthood. High risk subjects (n = 207) in the Copenhagen High Risk for schizophrenia project were examined on a 25-item questionnaire completed by teachers. A likelihood ratio approach was used to create a classification index relating school report to DSM-IIIR diagnoses made 31 years later. A standard receiver operating characteristic (ROC) analysis was used to evaluate the efficacy of the classification indices for distinguishing preschizophrenics from children who later developed schizotypal disorder, other nonpsychotic disorders, and no mental illness. Different items predicted schizophrenia in males and females. To a significantly greater degree than their controls, preschizophrenic males were lonely and rejected, behaved inappropriately, were disciplinary problems, emotionally high strung, and were more likely to have repeated a grade; preschizophrenic females were nervous and passive. Both preschizophrenic males and females were judged by teachers to be vulnerable to future psychotic problems. These findings are consistent with our preliminary findings, as well as with other research. They highlight the ability of teachers to identify school behaviors that may be used to select future schizophrenics for early intervention.
Mothers, fathers, and 8- to 11-year-old children from 181 two-parent families independently reported on the occurrence of husband-to-wife physical aggression and wife-to-husband physical aggression; parents additionally indicated whether the child had been witness to the aggression. First this study examined interspousal agreement regarding whether parents have been physically aggressive toward one another and whether the child has witnessed interparental physical aggression. There was moderate agreement between parents as to the occurrence of physical aggression and only fair agreement as to whether the child saw or heard the aggression. Second, this study explored the diagnosticity of a joint parent report as an indicator of child exposure to marital aggression. Receiver operating characteristic (ROC) curves are presented separately for husbands' and wives' aggression, indicating the explicit trade-off between true positives (sensitivity) and false positives (one minus specificity) in using the joint parent report as a diagnostic indicator. Standard ROC analysis suggests that the joint parent report is equally diagnostic in predicting children's reports of exposure to husbands' and wives' aggression. Finally, decisions regarding how to use parent reports as an indicator of children's exposure to marital aggression are discussed as depending on the base rate of child reports of exposure and the objective sought in classifying children and/or families.
Sequential analysis was used to compare the conflictual marital interactions of physically aggressive (PA, n = 17), verbally aggressive (VA, n = 15), withdrawing (WI, n = 18), and nondistressed, low-conflict (ND, n = 15) couples to describe behavior patterns characteristic of couples who report different marital conflict styles. Videotapes of couples enacting typical conflicts in their own homes were coded with a system designed to capture the affective aspects of communication. PA couples were characterized by the reciprocity of hostile affect and by rigid, highly contingent behavior patterns that were both stronger and longer lasting than those of other conflictual, but nonviolent, couples. In a limited way, ND couples demonstrated some of the same negative behavior patterns as the conflictual couples, but they were able to exit these negative interaction cycles quickly, which underscores the importance of further research into the de-escalation of conflict.
This study examined cognitive and emotional reactions to family discussions as experienced by sons and mothers from homes with physically aggressive (PA), verbally aggressive (VA), and low-conflict (LC) marital relationships. Boys of PA couples demonstrated more self-interference, self-distraction, and arousal and less criticism than did other sons in reaction to stimulated parental conflict. Boys of LC parents were more optimistic about family conflict and articulated more ideas concerning family structure and how conflict "should" proceed than did other sons. PA mothers made more positive evaluations and offered more autocratic suggestions than did VA mothers. Also, LC mothers, compared with both conflictual groups, made more democratic statements in response to low-conflict situations. These results indicate that marital conflict experienced in the home may influence sons' and mothers' appraisals of family and marital interactions.
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