Biomedical subjects

R M Ryan

Publications and source records attributed to R M Ryan.

At least 19 recordsLinked to original sources

PubMed2001

Narrative representations of caregivers and emotion dysregulation as predictors of maltreated children's rejection by peers.

This study examined whether maltreated children were more likely than nonmaltreated children to develop poor-quality representations of caregivers and whether these representations predicted children's rejection by peers. A narrative task assessing representations of mothers and fathers was administered to 76 maltreated and 45 nonmaltreated boys and girls (8-12 years old). Maltreated children's representations were more negative/constricted and less positive/coherent than those of nonmaltreated children. Maladaptive representations were associated with emotion dysregulation, aggression, and peer rejection, whereas positive/coherent representations were related to prosocial behavior and peer preference. Representations mediated maltreatment's effects on peer rejection in part by undermining emotion regulation. Findings suggest that representations of caregivers serve an important regulatory function in the peer relationships of at-risk children.

Caregivers↗

PubMed2001

On happiness and human potentials: a review of research on hedonic and eudaimonic well-being.

Well-being is a complex construct that concerns optimal experience and functioning. Current research on well-being has been derived from two general perspectives: the hedonic approach, which focuses on happiness and defines well-being in terms of pleasure attainment and pain avoidance; and the eudaimonic approach, which focuses on meaning and self-realization and defines well-being in terms of the degree to which a person is fully functioning. These two views have given rise to different research foci and a body of knowledge that is in some areas divergent and in others complementary. New methodological developments concerning multilevel modeling and construct comparisons are also allowing researchers to formulate new questions for the field. This review considers research from both perspectives concerning the nature of well-being, its antecedents, and its stability across time and culture.

Affect↗

PubMed2000

Self-determination theory and the facilitation of intrinsic motivation, social development, and well-being.

Human beings can be proactive and engaged or, alternatively, passive and alienated, largely as a function of the social conditions in which they develop and function. Accordingly, research guided by self-determination theory has focused on the social-contextual conditions that facilitate versus forestall the natural processes of self-motivation and healthy psychological development. Specifically, factors have been examined that enhance versus undermine intrinsic motivation, self-regulation, and well-being. The findings have led to the postulate of three innate psychological needs--competence, autonomy, and relatedness--which when satisfied yield enhanced self-motivation and mental health and when thwarted lead to diminished motivation and well-being. Also considered is the significance of these psychological needs and processes within domains such as health care, education, work, sport, religion, and psychotherapy.

Adaptation, Psychological↗

PubMed2000

Within-person variation in security of attachment: a self-determination theory perspective on attachment, need fulfillment, and well-being.

Attachment research has traditionally focused on individual differences in global patterns of attachment to important others. The current research instead focuses primarily on within-person variability in attachments across relational partners. It was predicted that within-person variability would be substantial, even among primary attachment figures of mother, father, romantic partner, and best friend. The prediction was supported in three studies. Furthermore, in line with self-determination theory, multilevel modeling and regression analyses showed that, at the relationship level, individuals' experience of fulfillment of the basic needs for autonomy, competence, and relatedness positively predicted overall attachment security, model of self, and model of other. Relations of both attachment and need satisfaction to well-being were also explored.

Adaptation, Psychological↗

PubMed2000

Early dexamethasone-attempting to prevent chronic lung disease.

BACKGROUND: We previously demonstrated improved survival and early outcomes in a pilot trial of 2 doses of intravenous dexamethasone for infants with surfactant-treated respiratory distress syndrome. (1) A multicenter, randomized, double-blind trial was undertaken to confirm these results. METHODS: Infants <30 weeks' gestation were eligible if they had respiratory distress syndrome, required mechanical ventilation at 12 to 18 hours of age, and had received at least 1 dose of exogenous surfactant. Infants were excluded if sepsis or pneumonia was suspected or if congenital heart disease or chromosomal abnormalities were present. A total of 384 infants were enrolled-189 randomized to dexamethasone (.5mg/kg birth weight at 12-18 hours of age and a second dose 12 hours later) and 195 to an equal volume of saline placebo. RESULTS: No differences were found in the dexamethasone versus placebo groups, respectively, regarding the primary outcomes of survival (79% vs 83%), survival without oxygen at 36 weeks' corrected gestational age (CGA; both 59%), and survival without oxygen at 36 weeks' CGA and without late glucocorticoid therapy (46% vs 44%). No significant differences between the groups in estimates from Kaplan-Meier survival analyses were found for median days on oxygen (50 vs 56 days), ventilation (20 vs 27 days), days to regain birth weight (15.5 vs 14 days), or length of stay (LOS; 88 vs 89 days). Infants given early dexamethasone were less likely to receive later glucocorticoid therapy for bronchopulmonary dysplasia during their hospitalization (27% vs 35%). No clinically significant side effects were noted in the dexamethasone group, although there were transient elevations in blood glucose and blood pressure followed by a return to baseline by study day 10. Among infants who died (40 vs 33), there were no differences in the median days on oxygen, ventilation, nor LOS. However, in survivors (149 vs 162), the following were observed: median days on oxygen 37 versus 45 days, ventilation 14 versus 19 days, and LOS 79 versus 81 days, for the dexamethasone versus placebo groups, respectively. CONCLUSIONS: This dose of early intravenous dexamethasone did not reduce the requirement for oxygen at 36 weeks' CGA and survival was not improved. However, early dexamethasone reduced the use of later prolonged dexamethasone therapy, and among survivors, reduced the median days on oxygen and ventilation. We conclude that this course of early dexamethasone probably represents a near minimum dose for instituting a prophylactic regimen against bronchopulmonary dysplasia.

Bronchopulmonary Dysplasia↗

PubMed1999

A meta-analytic review of experiments examining the effects of extrinsic rewards on intrinsic motivation.

A meta-analysis of 128 studies examined the effects of extrinsic rewards on intrinsic motivation. As predicted, engagement-contingent, completion-contingent, and performance-contingent rewards significantly undermined free-choice intrinsic motivation (d = -0.40, -0.36, and -0.28, respectively), as did all rewards, all tangible rewards, and all expected rewards. Engagement-contingent and completion-contingent rewards also significantly undermined self-reported interest (d = -0.15, and -0.17), as did all tangible rewards and all expected rewards. Positive feedback enhanced both free-choice behavior (d = 0.33) and self-reported interest (d = 0.31). Tangible rewards tended to be more detrimental for children than college students, and verbal rewards tended to be less enhancing for children than college students. The authors review 4 previous meta-analyses of this literature and detail how this study's methods, analyses, and results differed from the previous ones.

Behavior Therapy↗

PubMed1999

The importance of self-determination theory for medical education.

While some theories of human motivation focus exclusively on levels of motivation, self-determination theory argues that different types of motivators, even when the resulting motivation is high, will lead to very different outcomes. This theory differentiates between two primary kinds of motivation, controlled and autonomous. Controlled motivation depends either on explicit or implicit rewards or punishment or on people's internalized beliefs about what is expected of them. Learning in controlled situations, in which students act under pressure and anxiety, is likely to be rote, short-lived, and poorly integrated into students' long-term values and skills. In contrast, autonomous motivation, as its name implies, is personally endorsed and reflects what people find interesting and important. While controlled motivation involves compliance with pressures, autonomous motivation involves behaving with a sense of volition, agency, and choice. Autonomously motivated learning leads to better educational outcomes. There is evidence that medical students who learn in autonomy-supportive environments act in more autonomy-supportive ways in their interactions with patients. Because the reliable implementation of practice guidelines and physicians' use of an autonomy-supportive style have been associated with more positive health outcomes (particularly in the behavior-related areas of smoking cessation, weight loss, etc.), more autonomy-supportive medical education may result in more effective health care delivery.

Achievement↗

PubMed1999

Hyperoxia increases keratinocyte growth factor mRNA expression in neonatal rabbit lung.

Acute hyperoxic lung injury remains a major factor in the development of chronic lung disease in neonates. A critical step in the repair of acute lung injury is the proliferation of type II alveolar epithelial cells. Type II cell proliferation is stimulated by keratinocyte growth factor (KGF), an epithelial cell-specific mitogen. We sought to investigate KGF mRNA expression in relation to type II cell proliferation during hyperoxic lung injury. We studied a previously described newborn (NB) rabbit model of acute and chronic hyperoxic injury [C. T. D'Angio, J. N. Finkelstein, M. B. LoMonaco, A. Paxhia, S. A. Wright, R. B. Baggs, R. H. Notter, and R. M. Ryan. Am. J. Physiol. 272 (Lung Cell. Mol. Physiol. 16): L720-L730, 1997]. NB rabbits were placed in 100% O2 for 9 days and then recovered in 60% O2. RT-PCR was used to synthesize and amplify a 267-bp fragment of rabbit KGF cDNA from whole lung RNA. KGF mRNA expression was analyzed by ribonuclease protection assay, and mRNA abundance was quantified by phosphorimaging. Proliferating cell nuclear antigen immunohistochemistry was used on lung sections to identify proliferating cells. The rabbit partial cDNA sequenced was >95% homologous to human cDNA, and all amino acids were conserved. Whole lung KGF mRNA expression was increased 12-fold after 6 days of hyperoxia compared with control lungs, and remained increased throughout the 100% O2 exposure period. Proliferating cell nuclear antigen immunohistochemistry showed an increase in type II cell proliferation after 8-12 days of hyperoxia. NB rabbits exposed to hyperoxic injury exhibit increased whole lung KGF mRNA expression preceding type II cell proliferation. KGF may be an important mitogen in the regulation of alveolar epithelial repair after hyperoxic lung injury.

Amino Acid Sequence↗

PubMed1999

Differential expression of VEGF mRNA splice variants in newborn and adult hyperoxic lung injury.

Lung development and repair of hyperoxic injury require closely regulated growth and regeneration of alveolar capillaries. Vascular endothelial growth factor (VEGF), a mitogen for endothelial cells, is expressed by alveolar epithelial cells. Alternative splicing of VEGF mRNA results in isoforms of varying mitogenicity and solubility. We examined changes in the proportions of the VEGF splice variant mRNAs in rabbit lung development and in control, oxygen-injured, and recovering newborn and adult rabbit lungs. The proportion of the 189-amino acid VEGF mRNA, which codes for an isoform that binds to the extracellular matrix, increased fivefold during development (from 8% of total VEGF message at 22 days gestation to 40% in 10-day newborn lungs; P < 0.001). During neonatal oxygen injury, its expression declined from 38 to 8% of VEGF message (P < 0.002) and returned to the control value in recovery. A similar pattern was observed in adults. VEGF protein in lung lavage fluid increased slightly during hyperoxia, declined to barely detectable levels at the 50% lethal dose time point, and increased 10-fold (newborn) or up to 40-fold (adult) in recovering animals. We conclude that alternative splicing may have important roles in the regulation of VEGF activity in developing and injured lungs.

Aging↗

PubMed1999

Vascular endothelial growth factor in pulmonary lavage fluid from premature infants: effects of age and postnatal dexamethasone.

Corticosteroids are used to ameliorate bronchopulmonary dysplasia (BPD). They also affect normal development, including the expression of growth factors such as vascular endothelial growth factor (VEGF). Deep pulmonary lavage specimens were collected on days 1, 3, 7 and 28 of life in 40 infants of <34 weeks of gestation at birth during a randomized controlled trial of two doses of dexamethasone (DEX) at 12 and 24 h of age for BPD prophylaxis. VEGF was measured by enzyme-linked immunosorbent assay. The 18 DEX and 21 control subjects had similar gestations, birth weights and oxygen requirements at study entry. Lavage VEGF tripled between day 1 and 3 in both groups. The day 7 levels were higher in DEX subjects than in controls. DEX and control values were similar on day 28. Higher lavage VEGF levels on days 1 and 3 were also correlated with lower gestational age at birth. Lavage VEGF levels were not associated with the development of BPD. We speculate that these DEX- and age-associated changes in VEGF may affect pulmonary angiogenesis.

Age Factors↗

PubMed1999

Amnestic syndrome presenting as malingering in a man with developmental disability.

The authors report an unusual presentation of amnestic syndrome mislabeled as malingering in a man with mild developmental disability. The case highlights the challenges to medical personnel in treating persons who visit emergency rooms often, particularly individuals with mental retardation. Diagnostic overshadowing was a primary factor in the failure to diagnose amnestic syndrome. Overshadowing occurs when a patient's problematic behaviors are attributed to mental retardation, and no attempt is made to search for the root causes of the problem. The case also highlights the need for emergency room personnel to maintain links with agencies involved in the day-to-day care of persons with developmental disabilities.

Amnesia↗

PubMed1998

The impact of prenatal drug exposure on the neonate.

Several social or recreational drugs singly or together have demonstrated effects on the fetus and neonate, with those effects extending into adulthood. The use of recreational drugs during pregnancy remains a major health problem, with adverse effects including higher rates of fetal distress and demise, lower Apgar scores, growth retardation, and adverse neurodevelopmental outcome. Ethanol has the most profound effects, with physical stigmata of the drug seen in one third of exposed infants. In children without the affected physical appearance, profound neurodevelopmental sequelae have been demonstrated. Other drugs, such as cocaine, heroin, amphetamines, and nicotine, have been associated with impaired fetal growth and acute withdrawal during the neonatal period. Subsequently, these infants and children have an increased risk for altered neurodevelopment and long-term health status. Long-term follow-up and assessment are essential. The risk of neonatal withdrawal or abstinence syndrome is greatest with narcotic drugs but has been found to occur in neonates following exposure to cocaine, nicotine, and amphetamines. Early treatment with tincture of opium, paregoric, or phenobarbital is crucial. Assessment of the overall health status of the infant should include growth parameters, signs and symptoms of infection (especially hepatitis, syphilis, and immunodeficiency viruses), and neurobehavioral function. Such assessments should not be limited to the newborn period, as neurodevelopmental sequelae may not be manifest until later in infancy and childhood. In addition, evaluation of the social milieu is warranted because of the increased risk for neglect and abuse of drug-exposed infants and children. Early intervention, maternal drug rehabilitation treatment, and parenting classes are frequently prescribed, but their efficacy is variable. Further investigations should study the potential benefits of these recommendations.

Developmental Disabilities↗

PubMed1998

Autonomous regulation and long-term medication adherence in adult outpatients.

Self-determination theory was applied to explore the motivational basis of adherence to long-term medication prescriptions. Adult outpatients with various diagnoses who had been on a medication for at least 1 month and expected to continue (a) completed questionnaires that assessed their autonomous regulation, other motivation variables, and perceptions of their physicians' support of their autonomy by hearing their concerns and offering choice; (b) provided subjective ratings of their adherence and a 2-day retrospective pill count during an interview with a clinical psychologist; and (c) provided a 14-day prospective pill count during a subsequent, brief telephone survey. LISREL analyses supported the self-determination model for adherence by confirming that patients' autonomous motivation for adherence did mediate the relation between patients' perceptions of their physicians' autonomy support and their own medication adherence.

Adult↗

PubMed1998

Absidia corymbifera infections in neonates.

We report the first two documented cases of neonatal zygomycosis caused by Absidia corymbifera. A premature infant developed disseminated disease from a cutaneous site with pulmonary, gastrointestinal, and cerebral involvement. The infant died despite amphotericin B therapy and surgical debridement. The second case occurred in a full-term infant with congenital heart disease and fungal pneumonitis. Zygomycosis was not suspected because of underlying cardiac disease and a complicated postoperative course, and this infant also died. Absidia joins a growing list of opportunistic fungal pathogens of the compromised neonate.

Fatal Outcome↗

PubMed1998

Comparison of two strategies for surfactant prophylaxis in very premature infants: a multicenter randomized trial.

INTRODUCTION: Previous trials of surfactant therapy in premature infants have demonstrated a survival advantage associated with prophylactic therapy as an immediate bolus, compared with the rescue treatment of established respiratory distress syndrome. The optimal strategy for prophylactic therapy, however, remains controversial. When administered as an endotracheal bolus immediately after delivery, surfactant mixes with the absorbing fetal lung fluid and may reach the alveoli before the onset of lung injury. This approach, however, causes a brief delay in the initiation of standard neonatal resuscitation, including positive pressure ventilation, and is associated with a risk for surfactant delivery into the right main stem bronchus or esophagus. As an alternative approach, surfactant prophylaxis may be administered in small aliquots soon after resuscitation and confirmation of endotracheal tube position. Although this strategy has substantial logistical advantages in clinical practice, its efficacy has not been established. OBJECTIVE: The purpose of this study was to determine whether the established benefits of the immediate bolus strategy for surfactant prophylaxis could still be achieved using a postventilatory aliquot strategy after initial standard resuscitation and stabilization. DESIGN: Multicenter randomized clinical trial with patients randomized before delivery to immediate bolus or postventilatory aliquot therapy. PARTICIPANTS: Inborn premature infants delivered to mothers at an estimated gestational age of 24[0/7] to 28[6/7] weeks. INTERVENTIONS: Those infants who were randomized to the immediate bolus strategy were intubated as rapidly as possible after birth, and a 3-mL intratracheal bolus of calf lung surfactant extract (Infasurf) was administered before the initiation of positive pressure ventilation. Those infants who were randomized to the postventilatory aliquot strategy received standard resuscitation measures with intubation by 5 minutes of age, if not required earlier. At 10 minutes after birth, 3 mL of surfactant was administered in 4 divided aliquots of 0.75 mL each. Patients in both groups were eligible to receive up to three additional doses of surfactant as rescue therapy in the neonatal intensive care unit, if needed. OUTCOME MEASURES: The primary outcome variable was survival to discharge to home. Secondary variables included neonatal complications and requirement for oxygen therapy at 36 weeks' postmenstrual age. RESULTS: Among three centers, 651 infants were enrolled and randomized before delivery. Survival to discharge to home was similar for the two strategies for surfactant therapy as prophylaxis: 76% for the immediate bolus group and 80% for the postventilatory aliquot group. In a secondary analysis, the rate of supplemental oxygen administration at 36 weeks' postmenstrual age was 18% for the immediate bolus group and 13% for the postventilatory aliquot group. CONCLUSIONS: Survival to discharge to home was similar with immediate bolus and postventilatory aliquot strategies for surfactant prophylaxis. Because of its logistical advantages in the delivery room and its beneficial effects on prolonged oxygen requirements, we recommend the postventilatory aliquot strategy for surfactant prophylaxis of premature infants delivered before 29 weeks' gestation.

Drug Administration Schedule↗

PubMed1998

Cell-specific gene expression reveals changes in epithelial cell populations after bleomycin treatment.

Epithelial repair following acute lung injury involves proliferation and differentiation of existing Clara cells and type II cells. Other mechanisms of epithelial repair may be involved in particularly severe cases. We used epithelial cell-specific markers to examine changes in the mouse lung epithelium 28 days after bleomycin treatment. The spatial distribution of surfactant proteins A, B, C (SPA, SPB, SPC), and Clara cell-specific protein (CC10) mRNA was compared by in situ hybridization in serial lung sections. CC10 mRNA-containing airway cells were replaced in many areas by SPB mRNA-expressing, ciliated cells that did not contain CC10 mRNA. In distal airway regions, we observed a subpopulation of epithelial cells that appeared to express SPA, SPB, SPC, and CC10 mRNA, and speculated that they may represent a multipotential stem cell population. These cells were found in focal clusters, which suggests that they expanded from a common cell. CC10 mRNA-containing cells were seen in alveolar-like structures thought to be the result of Clara cell migration or outpocketing. Our data suggest that there are repair mechanisms involved in epithelial repair after severe injury that have not previously been described.

Animals↗

PubMed1997

Nature and autonomy: an organizational view of social and neurobiological aspects of self-regulation in behavior and development.

The concepts of self-regulation and autonomy are examined within an organizational framework. We begin by retracing the historical origins of the organizational viewpoint in early debates within the field of biology between vitalists and reductionists, from which the construct of self-regulation emerged. We then consider human autonomy as an evolved behavioral, developmental, and experiential phenomenon that operates at both neurobiological and psychological levels and requires very specific supports within higher order social organizations. We contrast autonomy or true self-regulation with controlling regulation (a nonautonomous form of intentional behavior) in phenomenological and functional terms, and we relate the forms of regulation to the developmental processes of intrinsic motivation and internalization. Subsequently, we describe how self-regulation versus control may be characterized by distinct neurobiological underpinnings, and we speculate about some of the adaptive advantages that may underlie the evolution of autonomy. Throughout, we argue that disturbances of autonomy, which have both biological and psychological etiologies, are central to many forms of psychopathology and social alienation.

Behavior↗

PubMed1997

On energy, personality, and health: subjective vitality as a dynamic reflection of well-being.

In this article, we examine subjective vitality, a positive feeling of aliveness and energy, in six studies. Subjective vitality is hypothesized to reflect organismic well-being and thus should covary with both psychological and somatic factors that impact the energy available to the self. Associations are shown between subjective vitality and several indexes of psychological well-being; somatic factors such as physical symptoms and perceived body functioning; and basic personality traits and affective dispositions. Subsequently, vitality is shown to be lower in people with chronic pain compared to matched controls, especially those who perceive their pain to be disabling or frightening. Subjective vitality is further associated with self-motivation and maintained weight loss among patients treated for obesity. Finally, subjective vitality is assessed in a diary study for its covariation with physical symptoms. Discussion focuses on the phenomenological salience of personal energy and its relations to physical and psychological well-being.

Adult↗