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Biomedical subjects

R M Ryan

Publications and source records attributed to R M Ryan.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1997

Changes in surfactant protein gene expression in a neonatal rabbit model of hyperoxia-induced fibrosis.

Lung injuries, including bronchopulmonary dysplasia, alter the surfactant system. We developed a newborn rabbit model of acute, followed by chronic, hyperoxic injury to study surfactant protein (SP) gene expression. Initial litters were exposed to >95% O2 until 50% died (LD50; 7-11 days old). Subsequent litters were exposed to >95% O2 for 8 days, followed by 60% O2 until 22-36 days. Controls were exposed to room air. LD50 animals displayed acute pulmonary inflammation, edema, protein leak, and surfactant dysfunction. These changes resolved, and fibrosis developed by 22 days. Whole lung SP-A mRNA expression (measured by membrane hybridization) was twice control levels at 4 days of >95% O2, with specific elevations in terminal bronchioles and type II cells at 4 days and the LD50 by in situ hybridization. Whole lung SP-B and SP-C mRNA were unchanged from control throughout exposure. However, in situ hybridization showed elevations in SP-B and SP-C mRNA in type II cells in inflamed areas at the LD50. SP mRNA alterations resolved by 22-36 days. The surfactant system recovers from acute hyperoxic injury, despite continued 60% O2 exposure.

Acute Disease↗
PubMed1997

Hyperoxic injury decreases alveolar epithelial cell expression of vascular endothelial growth factor (VEGF) in neonatal rabbit lung.

Normal neonatal lung growth requires a substantial increase in microvascular endothelial cells. Oxygen injury to neonatal lung destroys endothelial cells and alters the normal process of alveolarization, including development of the microvasculature. The mechanisms that regulate lung alveolar capillary growth and development are not known. Vascular endothelial growth factor (VEGF) is a specific mitogen for endothelial cells that is often expressed by epithelial cells in close proximity to capillary beds. VEGF expression is induced by hypoxia and may be inhibited by hyperoxia. We examined the cell-specific expression of VEGF during normal postnatal lung development and the effects of hyperoxic lung injury on VEGF mRNA and protein in vivo. Normal newborn rabbits between 1 day and 5 wk of age had VEGF transcripts located mainly in alveolar epithelial cells, with little or no VEGF mRNA noted in smooth muscle or endothelial cells. A subpopulation of freshly isolated, normal type II cells, but not mesenchymal cells, expressed VEGF mRNA. Newborn rabbits exposed to 100% oxygen for 4 days had no change in VEGF mRNA abundance, transcript location, or immunostaining. Animals exposed to 100% oxygen for an average of 9 days had an 80% decrease in lung VEGF mRNA abundance, decreased alveolar epithelial cell VEGF expression, and decreased VEGF immunostaining. Recovery of VEGF expression to control levels occurred during a 5-day recovery period. We conclude that alveolar epithelial cells in postnatal lung express VEGF, suggesting epithelial regulation of alveolar capillary formation. Furthermore, hyperoxic injury decreases neonatal lung VEGF mRNA and protein, which may be a contributory mechanism of impaired postnatal microvascular development in oxygen injury.

Animals↗
PubMed1997

Multicenter controlled clinical trial of high-frequency jet ventilation in preterm infants with uncomplicated respiratory distress syndrome.

OBJECTIVE: To test the hypothesis that high-frequency jet ventilation (HFJV) will reduce the incidence and/or severity of bronchopulmonary dysplasia (BPD) and acute airleak in premature infants who, despite surfactant administration, require mechanical ventilation for respiratory distress syndrome. DESIGN: Multicenter, randomized, controlled clinical trial of HFJV and conventional ventilation (CV). Patients were to remain on assigned therapy for 14 days or until extubation, whichever came first. Crossover from CV to HFJV was allowed if bilateral pulmonary interstitial emphysema or bronchopleural fistula developed. Patients could cross over to the other ventilatory mode if failure criteria were met. The optimal lung volume strategy was mandated for HFJV by protocol to provide alveolar recruitment and optimize lung volume and ventilation/perfusion matching, while minimizing pressure amplitude and O2 requirements. CV management was not controlled by protocol. SETTING: Eight tertiary neonatal intensive care units. PATIENTS: Preterm infants with birth weights between 700 and 1500 g and gestational age <36 weeks who required mechanical ventilation with FIO2 >0.30 at 2 to 12 hours after surfactant administration, received surfactant by 8 hours of age, were <20 hours old, and had been ventilated for <12 hours. Outcome Measures. Primary outcome variables were BPD at 28 days and 36 weeks of postconceptional age. Secondary outcome variables were survival, gas exchange, airway pressures, airleak, intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), and other nonpulmonary complications. RESULTS: A total of 130 patients were included in the final analysis; 65 were randomized to HFJV and 65 to CV. The groups were of comparable birth weight, gestational age, severity of illness, postnatal age, and other demographics. The incidence of BPD at 36 weeks of postconceptional age was significantly lower in babies randomized to HFJV compared with CV (20.0% vs 40.4%). The need for home oxygen was also significantly lower in infants receiving HFJV compared with CV (5.5% vs 23.1%). Survival, incidence of BPD at 28 days, retinopathy of prematurity, airleak, pulmonary hemorrhage, grade I-II IVH, and other complications were similar. In retrospect, it was noted that the traditional HFJV strategy emphasizing low airway pressures (HF-LO) rather than the prescribed optimal volume strategy (HF-OPT) was used in 29/65 HFJV infants. This presented a unique opportunity to examine the effects of different HFJV strategies on gas exchange, airway pressures, and outcomes. HF-OPT was defined as increase in positive end-expiratory pressure (PEEP) by >/=1 cm H2O from pre-HFJV baseline and/or use of PEEP of >/=7 cm H2O. Severe neuroimaging abnormalities (PVL and/or grade III-IV IVH) were not different between the CV and HFJV infants. However, there was a significantly lower incidence of severe IVH/PVL in HFJV infants treated with HF-OPT compared with CV and HF-LO. Oxygenation was similar between CV and HFJV groups as a whole, but HF-OPT infants had better oxygenation compared with the other two groups. There were no differences in PaCO2 between CV and HFJV, but the PaCO2 was lower for HF-LO compared with the other two groups. The peak inspiratory pressure and DeltaP (peak inspiratory pressure-PEEP) were lower for HFJV infants compared with CV infants. CONCLUSIONS: HFJV reduces the incidence of BPD at 36 weeks and the need for home oxygen in premature infants with uncomplicated RDS, but does not reduce the risk of acute airleak. There is no increase in adverse outcomes compared with CV. HF-OPT improves oxygenation, decreases exposure to hypocarbia, and reduces the risk of grade III-IV IVH and/or PVL.

Bronchopulmonary Dysplasia↗
PubMed1997

Consultation-liaison psychiatric nursing in long-term care.

1. The psychiatric and mental health APRN is in an excellent position to use his or her training and expertise to integrate various models of care. 2. Clinical functions of the psychiatric and mental health APRN include patient-focused and staff-centered activities, administrative functions include consulting, performance improvement, and research. 3. The psychiatric and mental health APRN is well-equipped to adapt to developing changes and challenges in the future of long-term care.

Aged↗
PubMed1997

Detection of intrauterine illicit drug exposure by newborn drug testing. National Academy of Clinical Biochemistry.

Identification of intrauterine drug-exposed newborns with toxicological screening may have benefits including close follow-up of the infant by both medical and social services. Applying specific written guidelines to select newborns for drug testing decreases bias and protects the physicians and hospitals involved. All drugs reported as positive should be confirmed by an appropriate second test. Urine and meconium testing are the best current options for identifying drug-exposed neonates. Urine testing sensitivity is low because of problems encountered in urine collections and the high thresholds used in current urine assays. The disadvantage to meconium testing is the increased labor and time required to work with this material. Testing of newborn hair is unlikely to be widely used until technically less demanding assays become available. Testing of amniotic fluid or gastric lavage is still in the developmental stages. Adopting lower urine assay thresholds for newborn samples would increase sensitivity and would be an appropriate modification of current methodologies.

Female↗
PubMed1997

Generic nursing outcome objectives for use in long-term care facilities.

Twenty-two registered nurses employed in four long-term care facilities generated data for a study about nursing diagnoses in long-term care (N = 360). Generic outcome objectives were developed as an integral part of the project. The research team also specified exceptions to the outcomes: instances where meeting outcome objectives might not be possible. The outcome objectives and exceptions for the sample's 20 most frequently occurring nursing diagnoses are presented as working statements. The authors expect that these outcome objectives and exceptions will be revised by nurses who use them in practice, basic and continuing education, and research.

Humans↗
PubMed1997

Complication data collection: a prospective, standardised, coded system for otolaryngology or other branches of surgery.

This system for interdepartmental collection of data on surgical complications should, though designed for otolaryngology, be applicable to any surgical specialty. The system under which data are collected prospectively on a coded proforma has been shown to document considerably higher complication rates than retrospective, uncoded data collection and, as consultants are unlikely to report non-existent complications, we assume that the higher rates are more valid. The system also provides a list of factors which must be standardised before data on complication rates from different units can usefully be pooled or comparisons made between them.

Clinical Competence↗
PubMed1996

Motivational predictors of weight loss and weight-loss maintenance.

Self-determination theory proposes that behavior change will occur and persist if it is autonomously motivated. Autonomous motivation for a behavior is theorized to be a function both of individual differences in the autonomy orientation from the General Causality Orientations Scale and of the degree of autonomy supportiveness of relevant social contexts. We tested the theory with 128 patients in a 6-month, very-low-calorie weight-loss program with a 23-month follow-up. Analyses confirmed the predictions that (a) participants whose motivation for weight loss was more autonomous would attend the program more regularly, lose more weight during the program, and evidence greater maintained weight loss at follow-up, and (b) participants' autonomous motivation for weight loss would be predicted both by their autonomy orientation and by the perceived autonomy supportiveness of the interpersonal climate created by the health-care staff.

Adult↗
PubMed1996

Minimal follow-up after functional endoscopic sinus surgery. Does it affect outcome?

One disadvantage of functional endoscopic sinus surgery is the frequent post-operative cavity toilet considered necessary by most surgeons, which is not only costly but also very unwelcome to patients. In the Royal Berkshire Hospital in Reading, we have reviewed a series of 120 patients who underwent FESS over an 18-month period with minimal post-operative follow-up (first visit for cavity toilet at 2 weeks and, if possible, only one further visit) in order to assess outcome. The percentage of patients whose presenting symptom had significantly improved or was cured was 78%, and the mean number of follow-up visits was 2.8. We conclude that our policy of minimal post-operative follow-up following FESS allows results comparable with other series, and this policy should be further evaluated.

Endoscopy↗
PubMed1995

Interstitial deletion of 8q21-->22 associated with minor anomalies, congenital heart defect, and Dandy-Walker variant.

We describe an infant with a deletion of 8q21-->22 who had distinct clinical manifestations including minor facial anomalies, a congenital heart defect, a Dandy-Walker variant, and mild to moderate developmental delay. Her facial characteristics included small, wide-spaced eyes, asymmetric bilateral epicanthal folds, a broad nasal bridge, a "carp-shaped" mouth, micrognathia, and prominent, apparently low-set ears. Three other reports describe children with larger proximal deletions of 8q that include 8q21 and q22. These four children all have similar facial appearance. Of the others reported, one had a congenital heart defect and one had craniosynostosis. This case, in addition to the previously noted three cases, helps in delineating a recognizable syndrome.

Abnormalities, Multiple↗
PubMed1995

KTP-532 laser tonsillectomy--a potential day-case procedure?

We report the results of a prospective pilot study of 54 adult patients undergoing tonsillectomy using the KTP-532 laser, designed to assess whether the technique would facilitate day-case adult tonsillectomy. Subjective and objective assessment at six hours post-operatively showed that only 43 per cent could, in our judgement, have been discharged at this interval. Furthermore, the overall complication rate was 31 per cent with a secondary haemorrhage rate of 19 per cent. We conclude that KTP-532 laser tonsillectomy as performed in this pilot study compares unfavourably with dissection tonsillectomy and we discuss possible reasons for this.

Adolescent↗
PubMed1995

Giant cell reparative granuloma of the concha bullosa.

Giant cell reparative granuloma is a benign lesion occurring most commonly in the bones of the jaw and rarely in the paranasal sinuses. We present an unusual case of giant cell reparative granuloma arising within a concha bullosa. Complete excision was achieved using an endoscopic transnasal approach.

Female↗
PubMed1995

Psychological needs and the facilitation of integrative processes.

The assumption that there are innate integrative or actualizing tendencies underlying personality and social development is reexamined. Rather than viewing such processes as either nonexistent or as automatic, I argue that they are dynamic and dependent upon social-contextual supports pertaining to basic human psychological needs. To develop this viewpoint, I conceptually link the notion of integrative tendencies to specific developmental processes, namely intrinsic motivation; internalization; and emotional integration. These processes are then shown to be facilitated by conditions that fulfill psychological needs for autonomy, competence, and relatedness, and forestalled within contexts that frustrate these needs. Interactions between psychological needs and contextual supports account, in part, for the domain and situational specificity of motivation, experience, and relative integration. The meaning of psychological needs (vs. wants) is directly considered, as are the relations between concepts of integration and autonomy and those of independence, individualism, efficacy, and cognitive models of "multiple selves."

Emotions↗
PubMed1995

Secretion of transforming growth factor-alpha (TGF alpha) by postnatal rabbit alveolar macrophages.

Transforming growth factor-alpha (TGF alpha) is a cytokine secreted by stimulated alveolar macrophages (AM) in vitro and after in vivo particulate or hyperoxia exposure and has been implicated in the processes of postnatal lung development. It is unknown if AM TGF alpha secretion changes during normal postnatal lung development. After sacrifice of New Zealand white rabbits on postnatal d 0-2, 5-7, 9-10, 14, 21, and 28 and > 4 mo (adult), AM were isolated by discontinuous density centrifugation and placed in culture in the presence or absence of concanavalin A (ConA) for 24 h. Media were collected, and the concentration and isoforms of TGF alpha in AM media samples were determined by an epidermal growth factor/TGF alpha radioreceptor assay and Western immunodetection, respectively. TGF alpha was present in media of AM from the 1.06 and 1.08 g/dL Percoll densities, but not in the 1.10 g/dL density. Statistically significant differences in TGF alpha secretion by unstimulated and ConA-stimulated AM at the various ages were not detected until d 14 (p < 0.02). Western blot analysis of unstimulated AM media samples from d 0-7 rabbits demonstrated the presence of TGF alpha isoforms at 46, 30, and 14.3 kD. At later postnatal ages (> or = d 9), a single 14.3-kD isoform was present. In contrast, analysis of ConA-stimulated AM media samples showed TGF alpha isoforms at 46, 30, and 14.3 kD for all ages; however, the 6-kD mature isoform was present only in juvenile (d 28) and adult media.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1994

Amnioinfusion during labor complicated by particulate meconium-stained amniotic fluid decreases neonatal morbidity.

OBJECTIVE: Our purpose was to evaluate the efficacy of prophylactic amnioinfusion in decreasing neonatal morbidity associated with labor complicated by particulate meconium-stained amniotic fluid and to assess potential complications of this procedure. STUDY DESIGN: One hundred five laboring pregnant women with particulate (moderate or thick) meconium by subjective clinical analysis were randomly assigned to receive amnioinfusion or to receive standard obstetric care without amnioinfusion. Patients with any antepartum complications, other than the presence of meconium, were excluded from the study. Statistical analyses consisted of the two-tailed and paired Student t tests, Pearson chi 2 test, and Wilcoxon nonparametric test. Significance was set at p < 0.05. RESULTS: The study included 47 patients in the study group and 58 patients in the control group. A significantly greater proportion of study patients demonstrated decreased meconium concentration between rupture of membranes and delivery (46 of 46 vs 15 of 58, p < 0.001). The relative dilution of meconium consistency by objective analysis was significantly different between the study group and the control group (77.1% decrease vs 9.3% increase, p < 0.001). The proportion of neonates with meconium below the vocal cords was reduced in the study group (two of 47 vs 36 of 58, p < 0.001). Umbilical artery pH was increased in the study group neonates (7.29 +/- 0.01 vs 7.25 +/- 0.009, p < 0.05). The rate of neonatal acidemia was reduced in the study group (4 of 45 vs 12 of 50, p < 0.05). The rate of meconium aspiration syndrome was reduced in the study group (1 of 47 vs 8 of 58, p < 0.05). Maternal and neonatal morbidity rates were similar. CONCLUSION: Prophylactic amnioinfusion should be considered a possible addition to the intrapartum management of patients with particulate meconium-stained amniotic fluid.

Acidosis↗