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Biomedical subjects

R L Simons

Publications and source records attributed to R L Simons.

At least 19 recordsLinked to original sources
PubMed1998

Predicting risk for pregnancy by late adolescence: a social contextual perspective.

To evaluate a model of social contextual influences on risk for adolescent pregnancy, 368 target adolescents (52% female, 48% male) and their mothers, fathers, and closest age siblings were assessed 6 times over a 7-year period beginning when the target adolescents were in 7th grade. Two pathways were found to increase risk for involvement in a pregnancy by late adolescence. Middle adolescent risk-taking behavior mediated the influence of early adolescent parental warmth-involvement and deviant-peer affiliations on involvement in a pregnancy by 12th grade. Also, early adolescent academic competence mediated the relationship between parental warmth-involvement and involvement in a pregnancy by 12th grade. Theoretical and practical implications of the results are discussed.

Adolescent↗
PubMed1996

Parents and peer group as mediators of the effect of community structure on adolescent problem behavior.

Used a sample of 207 single-parent families residing in 104 small, Midwestern communities to test hypotheses regarding the link between community context and adolescent conduct problems and psychological distress. For boys, community disadvantage had a direct affect on psychological distress, while it indirectly boosted the probability of conduct problems by disrupting parenting and increasing affiliation with deviant peers. Community disadvantage was unrelated to the deviant behavior or emotional well-being of girls. Proportion of single-parent households in the community had a direct effect on girls' conduct problems. It also contributed indirectly to girls' conduct problems by increasing the probability of involvement with deviant peers. Possible explanations for these gender differences are provided.

Adolescent↗
PubMed1994

Economic stress, coercive family process, and developmental problems of adolescents.

We propose a model of family conflict and coercion that links economic stress in family life to adolescent symptoms of internalizing and externalizing emotions and behaviors. The 180 boys and 198 girls in the study were living in intact families in the rural Midwest, an area characterized by economic decline and uncertainty. Theoretical constructs in the model were measured using both trained observer and family member reports. These adolescents and their parents were interviewed each year for 3 years during the seventh, eighth, and ninth grades. Our theoretical model proposes that economic pressure experienced by parents increases parental dysphoria and marital conflict as well as conflicts between parents and children over money. High levels of spousal irritability, coupled with coercive exchanges over money matters, were expected to be associated with greater hostility in general by parents toward their children. These hostile/coercive exchanges were expected to increase the likelihood of adolescent emotional and behavioral problems. Overall, results were consistent with the proposed model. Moreover, the hypothesized processes applied equally well to the behavior of mothers and fathers, as well as sons and daughters.

Acting Out↗
PubMed1994

Parents' stressful life events and adolescent depressed mood.

The present study of 451 families living in the rural Midwest examines a mediational model of the relationship between the stressful life events experienced by parents and adolescent depressed mood. This model is intended to overcome two limitations in previous research on the relationship between parents' stressful events and adolescent depressed mood by 1) examining a mediating process involving parental mood and parenting behavior, and 2) using multiple informants to assess the theoretical constructs. Findings from the present study indicate that stressful life events experienced by parents are first related to parents' depressed mood which operates to disrupt skillful parenting practices. The disrupted parenting practices in turn place adolescents at increased risk for developing depressive symptoms. The results show that inclusion of these mediating processes represents a significant improvement over the bivariate model and that the hypothesized mediational model generalizes to four parent-adolescent dyads: fathers and sons, fathers and daughters, mothers and sons, and mothers and daughters. Moreover, parents' stressful life events are related directly to adolescent boys' depressed mood only when parents' reports are included in both theoretical constructs. When parents' reports are removed as an indicator for the adolescent depressed mood construct, the effects of parental stress on adolescent depressed mood are largely accounted for by stress-related parental depressed mood and harsh/inconsistent parenting.

Adolescent↗
PubMed1993

A comparison of adaptive strategies and patterns of victimization among homeless adolescents and adults.

One hundred and fifty-six homeless adolescents and 319 homeless adults interviewed directly on the streets and in shelters were compared for backgrounds of abuse, adaptations to life on the streets, and rates of criminal victimization when on the streets. Homeless adolescents were more likely to be from abusive family backgrounds, more likely to rely on deviant survival strategies, and more likely to be criminally victimized. A social learning model of adaptation and victimization on the streets was hypothesized. Although the model was supported for both homeless adults and adolescents, it was more strongly supported for adolescents than adults, and for males than females regardless of age.

Adaptation, Psychological↗
PubMed1993

Husband and wife differences in response to undesirable life events.

In the present study of 451 married couples living in the rural midwest, gender differences were examined in reports of exposure and vulnerability to specific types of undesirable life events. Consistent with expectations derived from either a social structural or identity perspective, the results demonstrated that men are more likely than women to report exposure to and to be distressed by work and financial events. Women, on the other hand, are more strongly influenced by exposure to negative events within the family but not within their network of friends. Outcomes vary according to the type of emotional distress. Financial stress, for example, increases hostility among men more than among women, but wives are more likely than husbands to report somatic complaints in response to the same stressor. The findings demonstrate the need for future research that more directly investigates the intraindividual and social mechanisms which account for gender differences in a broad range of emotional and behavioral responses to varying types of significant life changes.

Adaptation, Psychological↗
PubMed1992

Intergenerational continuity of parental rejection and depressed affect.

Using survey and observational data from a sample of 451 intact families, this study used structural equation modeling to examine the intergenerational continuity of depressed mood and rejecting parenting. The model partially replicated the intergenerational model of Elder, Caspi, and Downey (1986) that indicates a cyclical transmission process by which parents' personality traits affect parent-child interaction, which, in turn, increases the propensity for developmental problems among offspring. The results indicated a pattern of intergenerational transmission of depressed mood through parental rejection of offspring. Multiple reporters and multiple indicators strengthen previous intergenerational findings by reducing some of the method variance biases that have been problematic in prior studies.

Adolescent↗
PubMed1992

A family process model of economic hardship and adjustment of early adolescent boys.

We propose a family process model that links economic stress in family life to prosocial and problematic adolescent adjustment. Employing a sample of 205 seventh-grade boys aged 12 to 14 years (M = 12.7) and living in intact families in the rural Midwest, the theoretical constructs in the model were measured using both trained observer and family member reports. In general, results were consistent with the proposed model. Objective economic conditions such as per capita income and unstable work were related to parents' emotional status and behaviors through their perceptions of increased economic pressures such as the inability to pay monthly bills. These pressures were associated with depression and demoralization for both parents, which was related to marital conflict and disruptions in skillful parenting. Disrupted parenting mediated the relations between the earlier steps in the stress process and adolescent adjustment. The emotions and behaviors of both mothers and fathers were almost equally affected by financial difficulties, and disruptions in each parent's child-rearing behaviors had adverse consequences for adolescent development.

Adaptation, Psychological↗
PubMed1992

Support from spouse as mediator and moderator of the disruptive influence of economic strain on parenting.

A model is presented regarding associations between economic strain, support from spouse, and quality of parenting. The model was tested using a sample of 451 2-parent families, each of which included a seventh grader (age 12-13). Parent and adolescent reports, as well as observational ratings, were used as indicators of constructs. Analysis using structural equation modeling procedures indicated that level of spouse support was positively related to supportive parenting, whereas economic strain operated to undermine parental involvement. As posited, economic strain produced its effect through a direct relation with parenting and indirectly through its association with spouse support. These findings held for mothers and fathers, regardless of the gender of the child. Spouse support moderated the impact of economic strain on supportive parenting for mothers but not fathers. Possible explanations for this gender difference are presented.

Adult↗
PubMed1991

The effects of early family relationships on contemporary relationships and assistance patterns between adult children and their parents.

We investigated the influence of early parent-child relationships on contemporary adult child-parent relationships and the effects of these relationships on the level of assistance between adult child and parent. A sample of 902 married men and women were questioned regarding their current relationships with their elderly parents, the level of assistance provided them, and the quality of their relationship with their parents when they were growing up. The findings indicated that early parent-child relationships and the characteristics of parents when adult children were growing up influenced contemporary adult child-parent relationships. In turn, the quality of the contemporary adult child-parent relationship was found to have a slight effect on assistance from adult children to their parents.

Activities of Daily Living↗
PubMed1989

Economic hardship, parenting, and distress in adolescence.

The relation between family economic hardship and adolescent distress among secondary school students in a small Midwestern community was investigated. According to prior results, family hardship has both direct and indirect effects on adolescent distress. The indirect effects come about through stress-induced changes in parental nurturance and parental discipline. The findings of this study showed that hardship effects varied according to type of distress. For females as well as males, economic hardship had both direct and indirect effects on a depression-loneliness distress factor. The indirect effects occurred through less parental nurturance and more inconsistent discipline. No direct effect of economic hardship was found for either males or females on a distress factor composed of delinquency and drug use items. For both females and males, however, an indirect effect of family economic hardship on the delinquency-drug use factor was found with inconsistent parental discipline as the mediating variable.

Adaptation, Psychological↗
PubMed1988

Influenza virus infection of tracheal gland cells in culture.

Influenza virus-induced tracheobronchitis causes limited epithelial deciliation but markedly decreased mucociliary transport. This suggests that virus-induced alterations in airway mucus play a role in decreased mucociliary transport. Airway submucosal glands are a primary source of mucus. Therefore, we examined virus-gland cell interactions by exposing primary cultures of isolated feline tracheal gland cells to influenza A/Scotland/840/74 H3N2 virus for 1 h at a multiplicity of infection of 0.1. Virus production and release into the culture medium first occurred between 8 and 12 h postinfection and eventually reached a steady state that continued for at least 8 days. Virus which was produced and released by infected cells infected other monolayers, resulting in viral production similar to that after infection with stock virus. Hemadsorption assays conducted 24 h after infection demonstrated that most of the cells in a monolayer became infected. The infection was nonlytic according to cell morphology, trypan blue dye exclusion, and release of lactate dehydrogenase. Because lysis of a cell subpopulation could have been masked by subsequent cell division, we compared the uptake of [3H]thymidine by infected and control monolayers. There was no increase in uptake by infected monolayers. These results demonstrate that feline tracheal gland cells in primary culture undergo productive and nonlytic infection with influenza A virus. This model provides a unique system for the study of virus-gland interactions isolated from the influence of other tissues.

Animals↗
PubMed1987

Vertical dome division in rhinoplasty.

Vertical dome division in nasal tip surgery allows for repositioning of tissue with minimal excision. In difficult situations, these techniques will often enable the surgeon to maintain good tip position and appearance without the use of grafts. It is a technique worth the attention and understanding of the conservative rhinoplasty surgeon.

Cartilage↗
PubMed1985

Hemadsorption focus assay for growth of influenza and parainfluenza viruses in human dermal fibroblasts.

An assay for virus-induced hemadsorption foci in cultures of human dermal fibroblasts is described. The assay allows determination of activity of species-specific as well as nonspecific antiviral agents or biological factors, such as interferons. The assay may be used for abortive (e.g., influenza virus) and productive (e.g., parainfluenza virus) infections of human fibroblasts.

Fibroblasts↗
PubMed1981

Interferon production by human mononuclear leukocytes: differences between respiratory syncytial virus and influenza viruses.

The ability of respiratory syncytial virus (RSV) to induce interferon production by human mononuclear leukocytes was compared with that of influenza viruses. Cell culture fluids were assayed for interferon activity 1, 3 and 7 days after exposure to RSV or to one of two subtypes of influenza A virus (H0N1 and H3N2). RSV induced interferon production inconsistently and in low titers. Varying the multiplicity of infection did not improve the ability of RSV to induce interferon production. In contrast, influenza viruses were effective inducers of interferon production. Seropositivity to the influenza virus strains was not associated with increased interferon titers. Interferon produced after exposure to RSV or to the influenza viruses was resistant to low pH treatment. The data suggest that interferon production may not be a major component of human immunological defense against RSV infection.

Adult↗
PubMed1981

Interferon production in adults with respiratory syncytial viral infection.

Respiratory syncytial virus may cause repeated infections and appreciable illness in adults as well as children. Factors associated with immunity and recovery are poorly understood. We studied 37 adults with natural respiratory syncytial viral illness and eight experimentally infected volunteers for nasal interferon production. Their response was compared to that of 25 adults with influenza. Interferon was detected in only six of those with natural respiratory syncytial virus and in none of those with experimental infection. The quantities of interferon were low (geometric mean, 6 U/mL) and did not appear to affect viral shedding. In contrast, 24 of influenza patients produced interferon and in greater quantities (geometric mean, 116 U/mL). This suggests that interferon is not involved in recovery from respiratory syncytial viral infection and might indicate a lack of a local cell-mediated response that could relate to the often prolonged course and shedding observed with respiratory syncytial virus.

Adult↗
PubMed1980

Mitogen responses and interferon production after exposure of human macrophages to infectious and inactivated influenza viruses.

Human macrophages were exposed to two influenza A viruses representing different subtypes. The donors were likely to have been exposed to one subtype (H3N2) but not to the other (H0N 1). Similar effects upon the macrophages were observed for both subtypes: macrophage enhancement of mitogen-stimulated lymphocyte transformation responses was depressed, and the macrophages produced interferon. In contrast, macrophages exposed to inactivated virus exhibited normal enhancement of lymphocyte transformation response, yet produced interferon, although in lower titers than did macrophages exposed to infectious virus.

Hot Temperature↗