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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
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↗
PubMed1996

Behavior and injury in urban and rural adolescents.

OBJECTIVES: This study investigates the consistency of factors associated with adolescent injury in separate urban and rural samples. SAMPLES: Adolescents, 11-17 years old, in public schools in urban and rural Maryland (n = 2,712). METHODS: Separate bivariate and logistic regression analyses were conducted for each sample to determine individual and environmental factors associated with major and minor injuries experienced in the previous year. RESULTS: Multivariate analyses revealed that, for both samples, the probability of a major injury was highest for boys and, among both boys and girls, for those who played several team sports. Among rural youth, other significant covariates of both major and minor injuries were a tendency to engage in risky behavior and to use alcohol. For urban youth, being white, carrying a weapon for protection, attending an unsafe school, and working for pay were also significant covariates. Interactions were important and complex. CONCLUSIONS: The consistency of predictive factors, such as multiple sports team participation and risky and aggressive behaviors in completely different physical environments, underscores the need to address the contexts of heightened injury risk that some adolescents create wherever they live by playing sports and/or behaving in an antisocial, aggressive manner. Moreover, the perception of lack of safety in schools and neighborhoods is associated with increased injury rates, suggesting the need for policy interventions to target social environments as well as behavior.

Adolescent↗
PubMed1996

Balance abilities of professional dancers on select balance tests.

Documentation that dancers have better balance abilities than nondancers is important because of the number of dancers who sustain injury and then are referred to physical therapists for treatment. The purpose of this study was to compare balance abilities of professional dancers with nondancers on selected balance conditions. Fifteen dancers and 15 age- and gender-matched nondancers maintained one-legged stance under six combinations of visual and support surface conditions (Foam and Dome Test modified from two feet to one foot). Each condition was maintained for 30 seconds. A composite balance score was obtained for each subject by summing the number of seconds the individual maintained balance for each test condition. There was a significant difference in the mean composite balance score (across the six balance conditions) for the dance group compared with the control group (731 seconds and 563 seconds, respectively). Under sensory challenged conditions, it appeared that dancers were better able to maintain their postures upright against gravity. The balance strategies and techniques learned by professional dancers should be carefully analyzed to determine if they could be incorporated into treatment programs for nondancers who have balance instability and dancers who are injured.

Adult↗
PubMed1995

Uniform prehospital data elements and definitions: a report from the uniform prehospital emergency medical services data conference.

One of the district and universal aspects of emergency medical service (EMS) is the belief that before its implementation many people were dying or being killed by ill-equipped, poorly trained "hearse drivers" and that this tragic state of affairs has been rectified by the advances in the prehospital phase of care. Except for cases of nontraumatic, out-of-hospital cardiac arrest there is almost no convincing scientific evidence to prove that prehospital care has had an impact on morbidity or mortality. At the very foundation of this problem is the lack of a set of broad-based, well-conceived, accurate, reliable, uniform EMS data. Many attempts have been made to develop a uniform EMS data set, but without a national consensus these have not achieved wide distribution. In 1992, with the assistance of the National Highway Traffic Safety Administration, the national consensus process began with a series of meetings involving many EMS agencies and organizations. This culminated in August 1994 with the development of an 81-item uniform EMS data set. We detail the prior attempts at data set development and outline the process leading to the this uniform, national EMS data set.

Data Collection↗
PubMed1995

Oncogenicity of human papillomavirus- or adenovirus-transformed cells correlates with resistance to lysis by natural killer cells.

The reasons for the dissimilar oncogenicities of human adenoviruses and human papillomaviruses (HPV) in humans are unknown but may relate to differences in the capacities of the E1A and E7 proteins to target cells for rejection by the host natural killer (NK) cell response. As one test of this hypothesis, we compared the abilities of E1A- and E7-expressing human fibroblastic or keratinocyte-derived human cells to be selectively killed by either unstimulated or interferon (IFN)-activated NK cells. Cells expressing the E1A oncoprotein were selectively killed by unstimulated NK cells, while the same parental cells but expressing the HPV type 16 (HPV-16) or HPV-18 E7 oncoprotein were resistant to NK cell lysis. The ability of IFN-activated NK cells to selectively kill virally transformed cells depends on IFN's ability to induce resistance to NK cell lysis in normal (i.e., non-viral oncogene-expressing) but not virally transformed cells. E1A blocked IFN's induction of cytolytic resistance, resulting in the selective lysis of adenovirus-transformed cells by IFN-activated NK cells. The extent of IFN-induced NK cell killing of E1A-expressing cells was proportional to the level of E1A expression and correlated with the ability of E1A to block IFN-stimulated gene expression in target cells. In contrast, E7 blocked neither IFN-stimulated gene expression nor IFN's induction of cytolytic resistance, thereby precluding the selective lysis of HPV-transformed cells by IFN-activated NK cells. In conclusion, E1A expression marks cells for destruction by the host NK cell response, whereas the E7 oncoprotein lacks this activity.

Adenovirus E1A Proteins↗
PubMed1995

Telling parents their child has severe congenital anomalies.

A large number of potential malformations exist, but the key skills in communicating with the parents of a malformed baby are the same. Dissatisfaction is common in this situation and has prompted a national initiative in improving standards of disclosure of disability and malformation--the Right from the start strategy (see appendix). Key skills include keeping the family together, ie, not removing the baby unnecessarily, knowing how parents like to be informed, listening, checking that parents have understood, being nonderogatory and, most importantly, emphasizing the positive side of their newborn child.

Communication↗
PubMed1995

A quantitative approach to quality improvement and resource allocation.

This report illustrates ways in which routinely collected hospital morbidity data can be used to inform and improve decisions about resource allocation, priorities for services and opportunities for improvement. All hospitals, public and private, Australia-wide collect these data at enormous expense. The resources allocated to processing, analysing and utilizing the data are minimal by comparison. Used appropriately these data can provide valuable information to managers and clinicians alike.

Australia↗
PubMed1994

Posttraumatic stress disorder in a clinical sample of adults sexually abused as children.

Forty-seven help-seeking, adult survivors of childhood sexual abuse (CSA) were assessed to examine the relationship between the level of CSA exposure and the subsequent development of posttraumatic stress disorder. CSA exposure was operationalized to include the overall level of exposure, frequency and duration of the abuse, age of onset, use of force, perceived life threat, and the occurrence of penetration. Participants were administered standardized measures of PTSD, including the Structured Clinical Interview of DSM-III-R (SCID). On the SCID, 69% of the survivors met full DSM-III-R criteria for PTSD. Significant correlations were found between several overall exposure measures and PTSD diagnostic status and the intensity of PTSD symptomatology. Similar relationships were identified with the duration and frequency of the abuse, the age of onset, and the use of force. This study is important in that it utilized standardized measures of PTSD and found a significant incidence of PTSD among adult CSA survivors.

Adolescent↗
PubMed1994

Systemic embolism in thyrotoxicosis without cardiac arrhythmia.

A 39-year-old woman presented with an acute left hemisphere stroke and was found to have severe hyperthyroidism. She developed an acute right brachial artery occlusion while under continuous cardiac monitoring, and at no time exhibited atrial fibrillation. This case, and a review of the literature, suggests that thromboembolism occurs in thyrotoxicosis without atrial fibrillation.

Adult↗