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Biomedical subjects

S Ryan

Publications and source records attributed to S Ryan.

At least 73 records · Page 4Linked to original sources
PubMed1997

Rural school-based clinics: are adolescents willing to use them and what services do they want?

Using a theoretical model of access, factors associated with rural adolescents' willingness to use primary care services through a school-based health center (SBHC) were examined. Standardized measures of health status and use were administered to 633 adolescents in grades 7-12 who resided in one rural western Maryland county. Although only 6.5% (n = 41) of the sample indicated a willingness to change their regular source of care to an SBHC, greater numbers of adolescents reported a willingness to use SBHC services, with 18%, 38%, 25%, and 16%, indicating interest in routine, acute medical, miscellaneous, and reproductive health care services, respectively. Logistic regression analysis found those adolescents who reported eligibility for free-reduced lunch and no regular source of care for illness were 3.3 and 5.4 times more likely, respectively, to use an SBHC as a primary care site than those unwilling to change their source of care. Data suggest that initially many rural adolescents appear unwilling to change their primary care site to an SBHC, but do express a willingness to use offered services.

Adolescent↗
PubMed1997

Randomised controlled trial of acetate in preterm neonates receiving parenteral nutrition.

AIMS: To determine whether by partly replacing chloride with acetate in parenteral nutrition, hyperchloraemia, metabolic acidosis, and the subsequent use of interventions such as colloid infusion, alkali treatment, increased assisted ventilation, would be reduced. METHODS: Fifty eight neonates of less than 32 weeks gestation, receiving parenteral nutrition from days 3 to 10, were given either standard parenteral nutrition or a novel formulation with replacement of any chloride dose > 3 mmol/kg/day as acetate. RESULTS: Acetate (0 to 14.2 mmol/kg/day) reduced the incidence of hyperchloraemia from 77% to 25%, and caused an increase in base excess from day 5 onwards (mean intergroup difference 3.6 to 9.9 mmol/l), an increased pH (day 8, 7.34 vs 7.26), with an increased pCO2 (1 kPa). The acetate group received less bicarbonate (median 0 mmol vs 4.8 mmol) and less colloid (41 ml/kg vs 204 ml/kg). There was no difference in any parameter of assisted ventilation. CONCLUSION: Acetate in neonatal parenteral nutrition reduces metabolic acidosis and hyperchloraemia.

Acidosis↗
PubMed1997

Randomised controlled trial of a synthetic triglyceride milk formula for preterm infants.

AIMS: To test whether use of infant formula containing synthetic structured triglycerides results in: (i) increased palmitate absorption; (ii) increased total fat absorption; (iii) reduction in calcium soap formation in the gut; and hence (iv) increased calcium absorption. METHODS: A randomised study was made of 24 infants comparing three formulas, one containing the synthetic fat Betapol with 74% of palmitate in the 2-position, which was substantially higher than in the two comparison diets (8.4% and 28%). The hypothesised outcomes were tested using balance studies, detailed chemical analysis of stool specimens and dual calcium isotope tracers (44calcium orally and 46calcium intravenously). RESULTS: Three of the four hypotheses were confirmed: use of a formula rich in 2-position palmitate (i) improved palmitate (16:0) and also (18:0) absorption; (ii) reduced the formation of insoluble calcium soaps in the stool; and (iii) improved calcium absorption, determined by the dual tracer technique from 42 (SE 3)% to 57 (7)%. CONCLUSION: Synthetic triglycerides that mimic the stereoisometric structure of those in breast milk may have a valuable role in the design of formulas used for preterm infants in neonatal intensive care units.

Animals↗
PubMed1996

Living with rheumatoid arthritis: a phenomenological exploration.

The objective of this research was to elicit the experience of living with rheumatoid arthritis (RA) from the patient's frame of reference and to understand the global impact that this chronic illness has on social, psychological and physical well-being. A phenomenological methodology incorporating Colaizzi's procedural steps (1978) was used. Five main themes emerged from the research which highlighted the enormous impact that RA has on a patient's life. Nurses need to adopt an holistic approach to care and ensure that they understand the illness from the patient's perspective.

Adaptation, Psychological↗
PubMed1996

Adenovirus E1A proteins regulate phosphoenolpyruvate carboxykinase gene transcription through multiple mechanisms.

Recently, Kalvakolanu et al. (Kalvakolanu, D. V. R., Liu, J., Hanson, R. W., Harter, M. L., and Sen, G. C. (1992) J. Biol. Chem. 267, 2530-2536) showed that E1A inhibited the basal and cAMP-stimulated transcription of the gene for phosphoenolpyruvate carboxykinase (PEPCK). This inhibition was mediated by the conserved region 1 (CR1) domain of E1A, which has been shown by other laboratories to bind to the cellular transcriptional adaptor proteins, p300 and cAMP response element binding protein (CREB)-binding protein (CBP). The PEPCK gene promoter contains a functional cAMP-response element, through which CREB and, therefore, CBP modulate transcription, and a consensus p300 DNA binding sequence is also present in a distal protein binding site of the promoter. We hypothesized that E1A might inhibit PEPCK gene transcription by binding to p300 and/or CBP. Surprisingly, we found that E1A consistently stimulated basal transcription from the PEPCK promoter in transfection assays in adenovirus (Ad)-infected HepG2 hepatoma cells or E1A-expressing, stably transfected 3T3 fibroblasts and nuclear run-on assays in Ad-infected H4IIE hepatoma cells. E1A also enhanced the stimulation of PEPCK gene transcription by Bt2cAMP. In transfection assays, wild type Ad5 expressing both 243R and 289R forms of E1A or a mutant virus expressing the 289R form alone stimulated transcription from the PEPCK promoter by approximately 5-fold 20 h postinfection. However, no stimulation was observed in cells infected with a virus expressing either the 243R protein alone or a 289R protein from which conserved region 3 (CR3) was mutated. Mutation or deletion of CR1 of E1A had no significant effect on transcription from the PEPCK promoter. Mutations within conserved region 2 (CR2) of E1A that inhibit the binding of E1A to the retinoblastoma gene product (pRb) further enhanced the stimulation of transcription from the PEPCK promoter by 2 3-fold compared with wild type E1A. These findings suggested that the normal function of pRb is to stimulate PEPCK gene transcription, and that this process is inhibited by the binding of E1A to pRb. This hypothesis was confirmed by overexpressing pRb in HepG2 cells, which stimulated transcription from the PEPCK promoter. Our findings indicate that Ad E1A regulates PEPCK gene transcription through a stimulatory mechanism involving CR3, and by attenuating a stimulatory effect of pRb through CR2.

Adenovirus E1A Proteins↗
PubMed1996

Inhibition of IFN-stimulated gene expression and IFN induction of cytolytic resistance to natural killer cell lysis correlate with E1A-p300 binding.

Treatment of target cells with IFN induces resistance to NK cell lysis. This process is blocked by expression of E1A gene products in adenovirus (Ad)-infected and Ad-transformed cells. We compared the ability of adenovirus serotype 5 (Ad5) E1A exon 1 mutants to inhibit the induction of cytolytic resistance by IFN and block IFN-stimulated gene expression with their capacity to bind the cellular proteins p105 (retinoblastoma gene product), p107, and p300. E1A mutants that did not express conserved region 3 (CR3; residues 138-184) or contained deletions in the nonconserved regions between residues 26-35 or 86-120, bound p105, p107, and p300 and were not impaired in their capacity to block IFN-stimulated gene expression or IFN's induction of cytolytic resistance. E1A mutants with deletions in CR2 (residues 121-138) could not bind p105 or p107, but blocked IFN-stimulated gene expression and IFN's induction of cytolytic resistance. In contrast, mutants in CR1 or the N-terminal nonconserved region (residues 2, 4-25, and 48-60), which define E1A's binding site for p300, were unable to block either IFN-stimulated gene expression or IFN's induction of cytolytic resistance. We conclude that E1A's capacity to block both IFN-stimulated gene expression and IFN's induction of cytolytic resistance appears to be transduced through a pathway that involves E1A-p300 binding. The capacity of E1A to block IFN's induction of cytolytic resistance is probably secondary to E1A's more general ability to inhibit IFN-stimulated gene expression.

Cytotoxicity, Immunologic↗
PubMed1996

Deletion variants within the NF-kappa B activation domain of the LMP1 oncogene prevail in acquired immunodeficiency syndrome-related large cell lymphomas and human immunodeficiency virus-negative atypical lymphoproliferations.

This sequencing study of 17 acquired immunodeficiency syndrome-related lymphomas (9 primary brain, 8 systemic) and 8 human immunodeficiency virus-negative atypical lymphoproliferations expressing large amounts of the latent membrane protein 1 (LMP1) of Epstein-Barr virus was performed to characterize the carboxy terminal NF-kappa B activation domain of LMP1 at the molecular level in an immunocompromised host. In-frame deletions within the NF-kappa B activation domain were identified in all but 2 primary brain lymphomas, 4 systemic lymphomas, and 4 atypical lymphoproliferations, ie, in 60% of cases. In addition, non silent point mutations (range 1 to 5, mean 3.3) were detected in all cases. Although all changes occurred within the first 100 nucleotides of the carboxy terminal NF-kappa B activation domain--a critical sequence for the protein half-life--not a single point mutation was found in the remaining 62 nucleotides, necessary for malignant transformation. Such a clustering of nonrandom sequence variations, associated with a high oncoprotein expression in immunocompromised hosts, suggests that this part of the LMP1 oncogene behaves as a hypervariable region with natural selection of growth-promoting variants through prolongation of the protein half-life.

Amino Acid Sequence↗
PubMed1996

Family process and child anxiety and aggression: an observational analysis.

Barrett, Rapee, Dadds, and Ryan (1996) described a phenomenon whereby family discussions magnified the style of children's problem solving in a way characteristic of their particular clinical diagnosis. That is, anxious children became more avoidant, aggressive children more aggressive, and nonclinic children more prosocial, after discussing ambiguous hypothetical situations with their parents. This study examined specific sequences of communications exchanged between parents and children hypothesized to underlie this family exacerbation of child cognitive style. Family discussions were videotaped and categorized for groups of anxious, aggressive, and nonclinic children and their parents. Results revealed differences between groups of parents in frequency of agreeing with and listening to their child and the frequency of pointing out positive consequences. Conditional probability analyses showed that parents of anxious children were more likely to reciprocate avoidance, while parents of nonclinic children were more likely to agree with and listen to prosocial plans from their child. Differences in parent behaviors observed during the family discussions were reliably associated with the child's response to the ambiguous situation proposed after the family discussion. Results support a model of developmental anxiety and aggression that emphasizes the interaction of family processes and social-cognitive development in the child.

Adolescent↗
PubMed1996

The influence of evoking stimulus level on the neural suppression of transient evoked otoacoustic emissions.

This study concerns the suppression of transient evoked otoacoustic emissions (TEOAEs) by contralateral noise. The suppression is interpreted as neurally induced changes in cochlear mechanics. The magnitude of TEOAE suppression is explored in response to a single level of contralateral noise, in 20 normal subjects, and as a function of TEOAE evoking stimulus power in 6 subjects. TEOAE were found to be relatively more susceptible to contralateral suppression when the TEOAE evoking stimulus was low. This suggests that saturation of the TEOAE generator by the evoking stimulus reduces the susceptibility of the generator to neural suppression. However, this relation did not hold between ears. Those ears in which the TEOAE seemed easier to saturate were easier to suppress by contralateral noise. We have concluded that TEOAE generators can differ in their susceptibility to neural suppression. Ears in which the TEOAE generating mechanism is less dependent on the ipsilateral evoking stimuli power level, are also naturally more susceptible to efferent suppression.

Acoustic Stimulation↗
PubMed1996

Breaking the boundaries between nursing and sociology: a critical realist ethnography of the theory-practice gap.

This paper is a response to the challenges laid down by Hannah Cooke in a paper in the Journal of Advanced Nursing entitled "Boundary work in the nursing curriculum: the case of sociology' (Cooke 1993a). In her paper, Cooke noted that the outlook of nursing and sociology are inimicable because nursing's concentration on individuals is at variance with sociology's concern with wider social issues. We argue that it is possible for nursing research to give due attention to social structures without losing its focus on individuals. One methodology that could facilitate this broadening of nursing's epistemological boundaries is critical realist ethnography, which works under the assumption that the relationship between social structures and individual actors involves a two-way process, in that while the enablements and constraints imposed by structures influence individual actions, those actions in turn either maintain or transform social structures. To demonstrate how such a methodology could be applied in nursing research, we work through a case study concerning the theory-practice gap, arguing that the gap is neither the result of clinicians' ignorance of nor antipathy to theory, but is largely generated by the lack of resources enjoyed by nurses, which in turn is a reflection of the social structure of capitalism within which nurses operate.

Anthropology, Cultural↗
PubMed1996

School-based health services.

Children, particularly adolescents, have unique health care needs and experience frequent barriers to receiving needed medical care. The expansion of school-based health services since the early 1970s is one recent development in the area of health services delivery that is a specific response to facilitate meeting the medical needs of youth. Limited resources, shrinking budgets, demographic and behavioral changes among our nation's youth, and recent trends toward managed care all demand innovative strategies by school-based health services if they are to ensure their viability in providing adequate health care to children and adolescents. This article reviews the recently published literature regarding the role of school-based health centers as sites providing primary care services to children and adolescents. In addition, it addresses recent efforts to develop strategies that school-based health centers may need to consider in order to adapt and survive within the environment of health care reform and managed care.

Adolescent↗
PubMed1996

Comparative effects of platelet-derived growth factor-BB and insulin-like growth factor-I, individually and in combination, on periodontal regeneration in Macaca fascicularis.

Platelet-derived growth factor (PDGF) and insulin-like growth factor I (IGF-I) in combination have previously been shown to enhance periodontal regeneration. The objective of this study was to further characterize the biological effects of this combination of growth factors in non-human primates and compare the effects to those of each growth factor individually. Ligature-induced periodontitis was initiated in 10 cynomolgus monkeys. After periodontal lesions were established, surgery was performed, and either a methylcellulose gel vehicle or vehicle containing 10 micrograms each of either PDGF-BB, IGF-I or both PDGF-BB and IGF-I was applied to exposed root surfaces. Biopsies were taken 4 and 12 wk after treatment and the extent of periodontal regeneration was assessed by histomorphometry. At both 4 and 12 wk vehicle-treated lesions generally revealed minimal osseous defect fill (ODF) (8.5 +/- 2.1% and 14.5 +/- 5.7%, respectively) and new attachment (NA) (34.1 +/- 5.2% and 26.6 +/- 10.5%, respectively). IGF-I treatment did not significantly alter healing compared to vehicle in any parameter at both 4 and 12 wk. PDGF-BB-treated sites exhibited significant (p < 0.05) regeneration of NA (69.6 + 12.0%) at 12 wk; trends for PDGF-BB treatment effect were also observed in other parameters at 4 and 12 wk, although these increases were not statistically significant. Treatment with PDGF-BB/IGF-I resulted in 21.6 +/- 5.1% and 42.5 +/- 8.3% ODF at 4 and 12 wk, respectively, and 64.1 +/- 7.7% and 74.6 +/- 7.4% NA at 4 and 12 wk, respectively (all significantly greater than vehicle, p < 0.05). The results from this study demonstrated that: 1) IGF-I alone at the dose tested did not significantly alter periodontal wound healing; 2) PDGF-BB alone significantly stimulated NA, with trends of effect on other parameters; and 3) the PDGF-BB/IGF-I combination resulted in significant increases in NA and ODF above vehicle at both 4 and 12 wk.

Alveolar Process↗
PubMed1996

Sequence of the bchG gene from Chloroflexus aurantiacus: relationship between chlorophyll synthase and other polyprenyltransferases.

The sequence of the Chloroflexus aurantiacus open reading frame thought to be the C. aurantiacus homolog of the Rhodobacter capsulatus bchG gene is reported. The BchG gene product catalyzes esterification of bacteriochlorophyllide a by geranylgeraniol-PPi during bacteriochlorophyll a biosynthesis. Homologs from Arabidopsis thaliana, Synechocystis sp. strain PCC6803, and C. aurantiacus were identified in database searches. Profile analysis identified three related polyprenyltransferase enzymes which attach an aliphatic alcohol PPi to an aromatic substrate. This suggests a broader relationship between chlorophyll synthases and other polyprenyltransferases.

Amino Acid Sequence↗