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Biomedical subjects

J Dunne

Publications and source records attributed to J Dunne.

At least 37 records · Page 2Linked to original sources
PubMed2000

Serrate1-induced notch signalling regulates the decision between immunity and tolerance made by peripheral CD4(+) T cells.

Signals derived from antigen-presenting cells (APC) influence the functional differentiation of CD4(+) T cells. We report here that Serrate1 (Jagged1), a ligand for the Notch1 receptor, may contribute to the differentiation of peripheral CD4(+) T cells into either helper or regulatory cells. Our findings demonstrate that antigen presented by murine APC overexpressing human Serrate1 induces naive peripheral CD4(+) T cells to become regulatory cells. These cells can inhibit primary and secondary immune responses, and transfer antigen-specific tolerance to recipient mice. Our results show that Notch signalling may help explain 'linked' suppression in peripheral tolerance, whereby tolerance induced to one epitope encompasses all epitopes on that antigen during the course of an immune response.

Animals↗
PubMed1998

The role of learning in remembered duration.

In two experiments, the effects of learning on both the accuracy and bias of duration judgments were examined. In Experiment 1, subjects learned one of two tasks (i.e., using a computer software package, building a model car), containing a varying number of action steps, over a one-, three-, or five-trial period. Retrospective judgments of a task's total duration revealed that accuracy was high at intermediate stages of learning but was low at early stages due to an overestimation bias and low at later stages due to an underestimation bias. The number of action steps within a task influenced behavior only at early learning stages where more action steps led to significantly longer duration estimates. Experiment 2 acted as a converging operation in which novice and experienced pianists were asked to estimate, in advance, how long they thought it would take them to play melodies that varied in their degree of familiarity (i.e. recently learned, well learned, extremely well learned). When these estimates were compared with the melodies' actual playing times, results revealed a similar pattern of accuracy and bias as found in Experiment 1. These findings are discussed in terms of a "structural remembering model" that emphasizes the role of event predictability in time estimation behavior.

Analysis of Variance↗
PubMed1998

Nurses have rights too.

Nurses in their professional role are proud to serve others. But they have rights which should be respected.

Ethics, Nursing↗
PubMed1996

Pilot-controlled trial of the extracorporeal liver assist device in acute liver failure.

The objective of this pilot controlled study was to evaluate the extracorporeal liver assist device (ELAD) in patients with acute liver failure who were judged to still have a significant chance of survival (approximately 50%) and in those who had already fulfilled criteria for transplantation. Twenty-four patients were divided into two groups, 17 with a potentially recoverable lesion (group I) and 7 listed for transplantation (group II), and then randomly allocated to ELAD haemoperfusion or control. The median period of ELAD haemoperfusion was 72 hours (range 3-168 h). Biocompatibility of the device was good, with no acceleration in platelet consumption, and haemodynamic stability was maintained. Two patients were withdrawn from the study because of worsening of preexisting disseminated intravascular coagulation in one case and a hypersensitivity reaction in the other. Deterioration with respect to encephalopathy grade was more frequent in the control patients, 7 of 12 (58%), than in the ELAD-treated patients, 3 of 12 (25%). In group I where survival for the ELAD cases was 7 of 9 (78%), there was a higher than expected survival in the controls, 6 of 8 (75%). For group II cases, survival was 1 of 3 (33%) for the ELAD-treated patients, and 1 of 4 (25%) for the controls. Both of the survivors underwent transplantation. Assessment of additive function for the device revealed an improvement in galactose elimination capacity after 6 hours of haemoperfusion. Based on the results of this pilot-controlled trial, better indices of prognosis will be required, in addition to those used to select for transplantation, if patients at an earlier stage of clinical deterioration are to be included in future studies.

Adolescent↗
PubMed1996

Steroids for intubated croup masking airway haemangioma.

Recently, the beneficial role of steroids for acute laryngotracheobronchitis has been more clearly defined for both intubated and unintubated patients. However, corticosteroids also improve the clinical signs of airway haemangiomata. Two patients are described who illustrate how this can be a source of diagnostic confusion.

Airway Obstruction↗
PubMed1996

Beta-2-microglobulin, neopterin and monocyte Fc gamma receptors in opportunistic infections of HIV-positive patients.

The aim of this study was to examine serum and cellular markers of immune activation in HIV-positive (HIV+) patients with and without current opportunistic infections. Fc gamma receptor (Fc gamma R) expression on monocytes, serum neopterin and beta-2-microglobulin were studied. Thirty HIV+ patients (grouped according to Centers for Disease Control (CDC) classification) were studied and compared with 27 normal blood donor controls. HIV+ patients were further separated into three groups: 2 (CDC II), 3 (CDC III/IV without infections) and 4 (CDC III/IV with current infections). Eleven of the patients had current opportunistic infections. Results indicate that beta-microglobulin, neopterin, fc gamma RI, Fc gamma RII and Fc gamma III were significantly increased in HIV+ patients compared to controls. Further analysis of the data using Tukey-Kramer all pairwise comparison revealed that for beta-2-microglobulin the mean values for patients in groups 2, 3 and 4 were significantly different (P < 0.0001). Serum neopterin levels and the percentage of CD14+14+ monocytes expressing Fc gamma RIII showed significant differences in the mean values of group 2 and group 4; similarly, for CD4+ lymphocyte counts group 2 and group 4 were significantly different. These results indicated that beta-2-microglobulin, neopterin and CD14+ monocyte Fc gamma RIII are increased particularly in HIV+ patients with current opportunistic infections while CD4+ lymphocyte counts are reduced. The results suggest that these markers, particularly beta-2-microglobulin, could be useful indicators of the inflammatory process associated with opportunistic infection at later stages of disease where other laboratory markers may be atypical.

AIDS-Related Opportunistic Infections↗
PubMed1995

Molecular cloning and tissue expression of FAT, the human homologue of the Drosophila fat gene that is located on chromosome 4q34-q35 and encodes a putative adhesion molecule.

FAT, a new member of the human cadherin super-family, has been isolated from the T-leukemia cell line J6. The predicted protein closely resembles the Drosophila tumor suppressor fat, which is essential for controlling cell proliferation during Drosophila development. The gene has the potential to encode a large transmembrane protein of nearly 4600 residues with 34 tandem cadherin repeats, five EGF-like repeats, and a laminin A-G domain. The cytoplasmic sequence contains two domains with distant homology to the cadherin catenin-binding region. Northern blotting analysis of J6 mRNA demonstrated full-length, approximately 15-kb, FAT message in addition to several 5'-truncated transcripts. In addition to its presence in J6 cells, in situ hybridization revealed FAT mRNA expression in epithelia and in some mesenchymal compartments. Furthermore, higher levels of expression were observed in fetal, as opposed to adult, tissue, suggesting that its expression may be developmentally regulated in these tissues. FAT shows homologies with a number of proteins important in developmental decisions and cell:cell communication and is the first fat-like protein reported in vertebrates. The gene encoding FAT was located by in situ hybridization on chromosome 4q34-q35. We propose that this family of molecules is likely to be important in mammalian developmental processes and cell communication.

Amino Acid Sequence↗