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T Duffy

Publications and source records attributed to T Duffy.

At least 19 recordsLinked to original sources
PubMed2006

Differential detection of Blastocrithidia triatomae and Trypanosoma cruzi by amplification of 24salpha ribosomal RNA genes in faeces of sylvatic triatomine species from rural northwestern Argentina.

Flagellates indistinguishable from Trypanosoma cruzi were detected by microscopy in faecal samples of 2/110 Triatoma guasayana and 2/283 Triatoma garciabesi captured in a rural area of northwestern Argentina. Inoculation of faecal homogenates to mice followed by xenodiagnosis, haemoculture, histopathology and culture from cardiac homogenates, and PCR based on T. cruzi minicircle and nuclear sequences failed to detect T. cruzi infection, pointing to another trypanosomatidean. A PCR strategy targeted to the D7 domain of 24salpha ribosomal DNA genes amplified a 250 bp sequence from one T. guasayana and one T. garciabesi faecal lysate. Sequence analysis revealed 100% identity with 24salpha rDNA amplicons from Blastocrithidia triatomae obtained from faeces of reared Triatoma infestans bugs. Phylogenetic analysis clustered this sequence with C. fasciculata and L. major, separated from the Trypanosoma branch (bootstrap: 968/1000), in concordance with a Neighbour-joining dendrogram based on 18s rDNA sequences. This PCR procedure provides a rapid sensitive tool for differential diagnosis of morphologically similar trypanosomatids in field surveys of Chagas disease vectors and laboratory-reared triatomines used for xenodiagnosis.

Animals↗
PubMed2006

PCR-based screening and lineage identification of Trypanosoma cruzi directly from faecal samples of triatomine bugs from northwestern Argentina.

This study applied improved DNA extraction and polymerase chain reaction strategies for screening and identification of Trypanosoma cruzi lineages directly from faeces of triatomines collected in a well-defined rural area in northwestern Argentina. Amplification of the variable regions of the kinetoplastid minicircle genome (kDNA-PCR) was performed in faecal lysates from 33 microscope (MO)-positive and 93 MO-negative Triatoma infestans, 2 MO-positive and 38 MO-negative Triatoma guasayana and 2 MO-positive and 73 MO-negative Triatoma garciabesi. kDNA-PCR detected T. cruzi in 91% MO-positive and 7.5% MO-negative T. infestans, which were confirmed by amplification of the minicircle conserved region. In contrast, kDNA-PCR was negative in all faecal samples from the other triatomine species. A panel of PCR-based genomic markers (intergenic region of spliced-leader DNA, 24Salpha and 18S rRNA genes and A10 sequence) was implemented to identify the parasite lineages directly in DNA lysates from faeces and culture isolates from 28 infected specimens. Two were found to be infected with TCI, 24 with TCIIe, 1 with TCIId and 1 revealed a mixed TCI+TCII infection in the faecal sample whose corresponding culture only showed TCII, providing evidence of the advantages of direct typing of biological samples. This study provides an upgrade in the current diagnosis and lineage identification of T. cruzi in field-collected triatomines and shows T. cruziII strains as predominant in the region.

Animals↗
PubMed2005

The role of web-based environmental information in urban planning--the environmental information system for planners.

The Environmental Information System for Planners (EISP) is a proof of concept web-based system designed to support decision making within the UK planning framework by making information on environmental issues more widely accessible. It incorporates relevant outputs from the Natural Environment Research Council (NERC) Urban Regeneration and the Environment (URGENT) research programme and from research directly commissioned by the Office of the Deputy Prime Minister (ODPM). It supports three principal planning functions carried out by local authorities: pre-planning enquiries, development control decisions and strategic planning. Eleven environmental science themes are incorporated: Air quality, Shallow undermining, Landslide susceptibility, Groundwater protection, Flood risk, Drainage, Land contamination, Proximity to landfill, Biodiversity, Natural and Man-made heritage. Decision flow diagrams represent detailed analysis of workflow in each theme, taking account of best practice, regulatory responsibilities and planning guidance. Industry-standard web technologies integrate the flows and provide access to the system via secure web pages. Underpinning the system is an environmental geographical information system (GIS) containing up-to-date data, information and models relevant to each theme. The modular system design allows new legislation and local priorities and datasets to be easily incorporated. Web technology delivers information and research data that have hitherto been difficult for the non-specialist to access and have therefore been under-exploited. The study has demonstrated a successful application of the principles of e-Governance in an area where informed decisions commonly require specialist information. The system, if rolled out nationally, offers potential economic benefits and efficiency savings for both planners and developers.

City Planning↗
PubMed2005

[Rheumatological arthroscopy].

Arthroscopy is a useful tool for the clinical rheumatologist. It allows the clinician to examine the synovial tissue under direct vision for evidence of active inflammation. It permits tissue sampling. Biopsies taken at arthroscopy can be used for diagnosis, as in the case of infectious arthritis, and in the context of clinical research. Arthroscopy also has therapeutic benefits when performed in conjunction with lavage. It is a simple procedure to perform, after the appropriate training. The procedure can be carried out on an outpatient basis and is well tolerated by patients. In this article we will outline the practical concerns relating to rheumatological arthroscopy.

Arthritis, Rheumatoid↗
PubMed2001

Psoriasis predicts a poor short-term outcome in patients with spondylarthropathy.

OBJECTIVE: The outcome of patients with recent-onset spondylarthropathy (SpA) is unclear. Therefore, the objective of this study was to prospectively correlate clinical and laboratory features with functional and radiologic outcome in patients with psoriatic SpA (PsS), undifferentiated SpA (uSpA), and Reiter's syndrome/reactive arthritis (ReA). METHODS: Patients presenting to an early arthritis clinic with a spondylarthropathy pattern of peripheral arthritis were selected and prospectively followed. Clinical and laboratory features were recorded at baseline, 12 months, and 24 months. Radiographs of affected joints were taken at presentation and at followup. RESULTS: The cohort consisted of 157 patients: 82 PsS, 59 uSpA, and 16 ReA. Symptom duration at presentation was progressively shorter, and the erythrocyte sedimentation rate/C-reactive protein (ESR/CRP) incrementally higher in ReA, uSpA, and PsS, respectively. There was a higher swollen joint count (SJC) in PsS compared with uSpA. In PsS, strong positive correlations were observed between ESR/CRP and articular indices. Initially, functional impairment was greater in ReA compared with uSpA and PsS but resolved completely in ReA. Clinical remission rates at 2 years were ReA 61% and uSpA 63%, compared with PsS 14%. Remission at 2 years could be predicted in SpA by disease category and presentation SJC. Baseline erosions in PsS (28%) and uSpA (5%) increased to 45% and 25%, respectively, at 2 years. CONCLUSION: These observations suggest a spectrum within the spondylarthropathy subgroups where at presentation the acute phase markers in ReA and uSpA reflect a systemic process, whereas in PsS they reflect articular manifestations. Although the clinical presentations are indistinguishable, PsS has a more aggressive clinical course with a poorer functional and radiologic outcome.

Adult↗
PubMed2001

Changing patterns of cell surface mono (ADP-ribosyl) transferase antigen ART2.2 on resting versus cytopathically-activated T cells in NOD/Lt mice.

AIMS/HYPOTHESIS: ART2.2 is a mouse T-cell surface ectoenzyme [mono (ADP-ribosyl) transferase] shed upon strong activation. We analysed temporal changes in ART2.2 expression in unmanipulated and cyclophosphamide-treated NOD/Lt mice compared with diabetes-resistant control strains. We used NAD, the ART2.2 substrate, to test whether ART-mediated ADP-ribosylation could retard diabetogenic activation of islet-reactive T cells in vitro. METHODS: ART2.2 and CD38, another NAD-utilizing enzyme, were measured by flow cytometry. ADP-ribosylation from ethano-NAD was followed by flow cytometry using a reagent specific for etheno-ADP ribose. RESULTS: Although mature NOD CD4 + and C D8 + T cells expressed ART2.2, this expression was delayed in young NOD mice when compared with control strains. This ontological delay at 3 weeks of age correlated with an early burst of CD25 expression unique to NOD splenic T cells. This pattern was reproduced in cyclophosphamide-accelerated diabetes in young NOD/Lt males, wherein a retarded repopulation of ART2.2 T cells in spleen and islets correlated with development of heavy insulitis and diabetes. NAD inhibited anti-CD3 induced activation of splenic T cells in vitro and also retarded killing of beta-cell targets by NOD islet-reactive CD8 effectors in vitro at concentrations equal to or greater than 1 micromol/l. Evidence suggested that CD38 on B lymphocytes competes with ART2.2 for substrate needed by B lymphocytes for ADP ribosylation. CONCLUSIONS: ART2.2 on T cells may not simply mark the resting state, but could also contribute to it via ADP-ribosylation.

ADP Ribose Transferases↗
PubMed2000

Metalloprotease-mediated shedding of enzymatically active mouse ecto-ADP-ribosyltransferase ART2.2 upon T cell activation.

T cells proteolytically shed the ectodomains of several cell surface proteins and, thereby, can alter their responsiveness and can release soluble intercellular regulators. ART2.2 is a GPI-anchored ecto-ADP-ribosyltransferase (ART) related to ADP-ribosylating bacterial toxins. ART2.2 is expressed exclusively by mature T cells. Here we show that ART2.2 is shed from the cell surface in enzymatically active form upon activation of T cells. Shedding of ART2.2 resembles that of L-selectin (CD62L) in dose response, kinetics of release, and sensitivity to the metalloprotease inhibitor Immunex Compound 3, suggesting that ART2.2, like CD62L, is cleaved by TNF-alpha-converting enzyme or by another metalloprotease. ART2.2 shed from activated T cells migrates slightly faster in SDS-PAGE analyses than does ART2.2 released upon cleavage of the GPI anchor. This indicates that shedding of ART2.2 is mediated by proteolytic cleavage close to its membrane anchor. Shed ART2.2 is enzymatically active and ADP-ribosylates several substrates in vitro. Thus, shedding of ART2.2 releases a potential intercellular regulator. Finally, using a new FACS assay for monitoring ADP-ribosylation of cell surface proteins, we demonstrate that shedding of ART2.2 correlates with a reduced sensitivity of T cell surface proteins to ADP-ribosylation. Our findings suggest that by shedding ART2.2 the activated T cell not only releases a potential intercellular regulator but also may alter its responsiveness to immune regulation by ART2.2-mediated ADP-ribosylation of cell surface proteins.

ADP Ribose Transferases↗
PubMed2000

Health visitors' knowledge and attitudes relating to HIV and AIDS.

Infection with human immunodeficiency virus (HIV) is increasing in the heterosexual community and people already affected by HIV are living longer. As a result, health visitors will be more involved in caring for people with HIV and acquired immune deficiency syndrome (AIDS). The aim of this study was to assess the knowledge level of health visitors about HIV infection and AIDS, and to identify some of the attitudes held by them concerning AIDS and the variety of symptoms that can occur in HIV positive individuals (AIDS related complex) before they have actually developed AIDS. The influence of AIDS-related education and the experience of caring for affected patients on health visitors' knowledge of the disease was assessed. The attitudes of carers towards these patients were also ascertained. All heath visitors (n = 88) working in the Merton and Sutton Community Healthcare Trust were invited to participate in a questionnaire survey. Fifty-five health visitors participated. Knowledge relating to HIV and AIDS was good, but the majority of respondents felt they did not have all the information they needed about HIV and AIDS. Almost one-quarter of respondents had cared for a client who was either HIV positive or had AIDS. Overall, the findings were quite encouraging. However, further education, training, and support were identified as necessary. These shortfalls need to be addressed in order to fully assist health visitors in their role of caring for clients and families affected by HIV and AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1999

A new monoclonal antibody detects a developmentally regulated mouse ecto-ADP-ribosyltransferase on T cells: subset distribution, inbred strain variation, and modulation upon T cell activation.

ADP-ribosylation of membrane proteins on mouse T cells by ecto-ADP-ribosyltransferase(s) (ARTs) can down-regulate proliferation and function. The lack of mAbs against mouse ARTs has heretofore prevented analysis of ART expression on T cell subsets. Using gene gun technology, we immunized a Wistar rat with an Art2b expression vector and produced a novel mAb, Nika102, specific for ART2.2, the Art2b gene product. We show that ART2.2 is expressed as a GPI-anchored protein on the surface of mature T cells. Inbred strain-dependent differences in ART2.2 expression levels were observed. C57BL/6J and C57BLKS/J express the Ag at high level, with up to 70% of CD4+ and up to 95% of CD8+ peripheral T cells expressing ART2.2. CBA/J and DBA/2J represent strains with lowest expression levels. T cell-deficient mice and NZW/LacJ mice with a defective structural gene for this enzyme were ART2.2 negative. In the thymus, ART2.2 expression is restricted to subpopulations of mature cells. During postnatal ontogeny, increasing percentages of T cells express ART2.2, reaching a peak at 6-8 wk of age. Interestingly, ART2.2 and CD25 are reciprocally expressed: activation-induced up-regulation of CD25 is accompanied by loss of ART2.2 from the cell surface. Nika102 thus defines a new differentiation/activation marker of thymic and postthymic T cells in the mouse and should be useful for further elucidating the function of the ART2.2 cell surface enzyme.

ADP Ribose Transferases↗
PubMed1996

Somatic c-KIT activating mutation in urticaria pigmentosa and aggressive mastocytosis: establishment of clonality in a human mast cell neoplasm.

Mastocytosis is characterized by accumulations of mast cells in various organs (1). Most cases are indolent and confined to the skin, where discrete mast cell infiltrates are associated increased epidermal melanin, a clinical picture known as urticaria pigmentosa (UP). Other forms of mastocytosis combine UP with aggressive involvement of other organs or with haemotologic abnormalities (1-4). It is not known whether all forms of mastocytosis are true neoplasms or whether some might represent reactive hyperplasias (5-7). The c-KIT proto-oncogene encodes a type III receptor tyrosine kinase (KIT) that is critical to the development and survival of mast cells and melanocytes (8-11). The ligand for KIT (KL) can stimulate mast cell development, proliferation, and mediator release (9,12-17), as well as melanocyte proliferation and pigment production (18-20). To determine the role of c-KIT in the pathogenesis of mastocytosis, we examined tissue and cells isolated from a patient with UP and aggressive systemic mastocytosis with massive splenic involvement. We found a mutation that results in constitutive activation and expression of c-KIT in mast cells of both skin and spleen. This is the first in situ demonstration of an activation c-KIT mutation in neoplastic cells. It also demonstrates the clonal and neoplastic nature of this form of mastocytes.

Adult↗
PubMed1996

Radiographic interpretation by nurse practitioners in a minor injuries unit.

OBJECTIVE: To compare nurse practitioners with senior house officers (SHOs) for their ability to request and interpret correctly a limited range of x ray views of patients attending a minor injuries unit. DESIGN: Retrospective analysis of case records. METHODS: 150 accident and emergency (A&E) records with x ray requests were randomly selected from the SHOs' first, second, and third 2-month period of their 6-month appointments; 150 record cards were randomly selected from a nearby minor injuries unit over the same period. Copies of the records were reviewed blind and a decision made as to whether x ray requests were appropriate; x ray interpretation was compared with that of a consultant radiologist. RESULTS: 106 x rays were taken on the MIU patients (71%) and 124 on the A&E patients (83%). There was no statistically significant differences in the ability of the nurse practitioners and the SHOs to request and interpret appropriate x rays. In both groups the decision to carry out an x ray was considered appropriate in 70% of patients; x rays were positive in about one third. The sensitivity of radiological interpretation was 93% in both groups, and there were 2% missed positives. CONCLUSIONS: Appropriately trained nursae practitioners are at least as good as SHOs in recognising the need for an x ray and are as competent in their interpretation.

Adolescent↗
PubMed1993

Intratumor gene expression after adoptive immunotherapy in a murine tumor model. Regulation of messenger RNA levels associated with the differential expansion of tumor-infiltrating lymphocytes.

The aim of this paper was to show that the adoptive immunotherapy (AIT) of established tumors resulted in the activation of defined lymphocyte-associated genes at the site of rejection. C57BL/6J mice bearing the moderately immunogenic syngeneic MCA/76-9 sarcoma received combination therapy 10 days after tumor cell implantation. This consisted of a single i.p. injection of cyclophosphamide (CY) followed by the i.v. injection of tumor-sensitized T cells (CY/AIT). The previously observed in situ differential expansion of tumor-infiltrating lymphocytes (TIL) was associated with a parallel modulation of CD4 (L3T4) and CD8 Ag expression. Flow cytometric analysis indicated that the CD8+ TIL appeared to contain two subpopulations during the reported proliferative phase, but by day 8 after CY/AIT the cells were composed of a single bright population. The CD4+ TIL similarly appeared to show two subpopulations, but in contrast to the CD8+ TIL there was a shift to a predominantly less bright single population by day 8. The expression of lymphocyte genes (Ly-2 and Ly-4 encoding the CD8 and CD4 Ag, respectively, IL-2, IL-2R, IFN-gamma, and IL-6) was analyzed by Northern hybridization using RNA extracted from whole tumor tissue. Progressing tumors expressed only low and relatively constant levels of mRNA for all of the genes except Ly-2 over a 19-day period. In contrast, there were considerable temporal fluctuations in mRNA levels depending on whether the mice had received CY or CY/AIT, but it was apparent that CY/AIT induced the more dramatic changes as far as Ly-2, Ly-4, IL-2, and IFN-gamma mRNA levels were concerned. A preliminary survey of cytokine bioactivity released by tumor-associated cells isolated 9 days after CY/AIT indicated that both IFN-gamma and IL-6 activities were released by the cells, but not IL-2, despite the relatively high levels of IL-2 mRNA. These data provide evidence that the differential expansion of TIL after CY/AIT is accompanied by well defined changes in the levels of mRNA-encoding TIL membrane Ag and lymphokine genes and are concordant with the view that amplified anti-tumor immune responses occur after AIT.

Animals↗
PubMed1992

Effect of inhibiting enkephalin catabolism in the VTA on motor activity and extracellular dopamine.

The mixed inhibitor of enkephalin catabolism, kelatorphan, was microinjected into the ventral tegmental area (VTA) of rats to determine if endogenous enkephalins can modulate dopamine transmission in the mesoaccumbens projection. The concentration of extracellular dopamine content in the nucleus accumbens was monitored using in vivo microdialysis simultaneously with measuring motor behavior. Kelatorphan microinjection into the VTA produced a dose-related increase in motor activity and extracellular dopamine in the nucleus accumbens. While the change in extracellular dopamine was modest as compared to exogenous stimulation by a mu agonist such as DAMGO, there was a marked increase in the extracellular content of dopamine and serotonin metabolites. This suggests that mesoaccumbens dopamine transmission is under tonic control of endogenous enkephalins at the ventral tegmental area level.

Amino Acid Sequence↗
PubMed1991

A heterologous hormone response element enhances expression of rat beta-casein promoter-driven chloramphenicol acetyltransferase fusion genes in the mammary gland of transgenic mice.

Previous studies have demonstrated that the entire rat beta-casein (R beta C) gene and a -524/+490 R beta C fragment-chloramphenicol acetyltransferase (CAT) fusion gene are expressed preferentially in the mammary gland of transgenic mice in a developmentally regulated fashion. However, transgene expression was infrequent, less than 1% of that observed for the endogenous gene, and varied as much as 500-fold, presumably due to the site of chromosomal integration. To determine whether a heterologous hormone-responsive enhancer could be used to increase both the level and frequency of expression in the mammary gland, a fragment derived from the mouse mammary tumor virus long terminal repeat containing four hormone response elements (HREs) was inserted into the R beta C promoter at a site not known to contain transcriptional regulatory elements. Transgenic mice generated which carried HRE-enhanced R beta C-CAT fusion genes expressed CAT activity in the mammary glands of all founder lines examined at levels that were on average 13-fold greater than for lines generated with similar constructs not carrying HREs. In the highest expressing line, the level of HRE-enhanced transgene expression was found to be developmentally regulated, increasing 14-fold in the mammary gland from virgin to day 10 of lactation. In this line, expression was also observed in the thymus and spleen; however, the level of CAT activity was 4-fold lower than in the mammary gland and was not developmentally regulated. In adrenalectomized mice, the administration of dexamethasone stimulated CAT expression in the mammary gland but not in the thymus and spleen. These studies demonstrate that in the context of the R beta C promoter, the HRE functions in the mammary gland to increase both the frequency and level of transgene expression.

Animals↗
PubMed1990

Within-mouth correlations for indicators of the host response in gingival crevicular fluid.

Gingival crevicular fluid was collected from multiple sites in patients with chronic adult periodontitis, and analysed for the lysosomal enzymes beta-glucuronidase and arylsulphatase, the cytoplasmic enzyme lactate dehydrogenase, total IgA, IgG and IgM and the protease inhibitor alpha 2-macroglobulin. The within-mouth (intraclass) correlation coefficients were calculated to describe the relationship between samples collected from individual patients. Data collected at baseline and 3 months after root planing and scaling were analysed, as was the change between examinations. Volume of crevicular fluid demonstrated the smallest intraclass correlation coefficient (0.16 at baseline, 0.12 at 3 months; 0.11 change), while probing depth and enzyme activity had moderate intraclass correlations (i.e. 0.36, 0.36, 0.26 for beta-glucuronidase). Immunoglobulin and alpha 2-macroglobulin activity in the fluid had the strongest correlations (i.e. 0.64, 0.57, 0.65 for IgG). The correlations for anatomically related teeth within a quadrant (molar, non-molar) were equivalent to or greater than the correlation for all samples within a mouth. Examined by tooth type, the intraclass correlations for volume of crevicular fluid, probing depth, beta-glucuronidase, arylsulphatase and lactate dehydrogenase were higher for non-molar teeth. In contrast, intraclass correlations for IgA, IgG, IgM and alpha 2-macroglobulin in samples from molar teeth were either equivalent to or greater than the correlations for non-molar samples. Calculation of intraclass correlation coefficients for such data can (1) indicate the degree of variability present in multiple samples of crevicular fluid collected from individual patients, (2) provide information about the source of host mediators in the fluid, and (3) help identify appropriate sampling strategies for the fluid.

Adult↗