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Sally Roberts

Publications and source records attributed to Sally Roberts.

47 records · Page 3Linked to original sources
PubMed2002

A reservoir for methicillin-resistant Staphylococcus aureus in the Auckland community?

AIM: To determine if there is a difference in methicillin-resistant Staphylococcus aureus (MRSA) colonisation rates between patients over the age of 60 years admitted to Auckland Hospital from either residential care facilities (RCF) or the community. METHODS: A prospective cohort study. The following information was collected: patient demographics; admission in the last 12 months; presence of risk factors for MRSA colonisation; any history of MRSA colonisation. Swabs from the nose, perineum and any infected wounds or skin lesions were collected. Urine was cultured if the patient had a urinary catheter in situ. RESULTS: 19 (9%) patients of 213 from RCF, and 6 (3%) patients of 201 from the community were positive for MRSA (p = 0.02). Patients admitted to hospital in the previous 12 months were three times more likely to be colonised with MRSA than others (p = 0.01). Excluding those patients already known to be MRSA positive, patients admitted from RCF were six times more likely to be newly found to be MRSA positive. Twenty four of the 25 MRSA isolates were EMRSA-15. CONCLUSIONS: Patients from RCF are statistically more likely to be colonised with MRSA compared with patients of similar age admitted from the community. Identification of such high-risk carriers allows targeted infection control activity to control MRSA within hospitals.

Aged↗
PubMed2002

Vancomycin-resistant enterococcal colonisation of hospitalised patients in Auckland.

AIM: To assess the prevalence of vancomycin-resistant enterococcal colonisation of hospitalised patients in five selected Auckland hospitals. METHODS: Faeces specimens submitted to the Microbiology Laboratories at Auckland and Middlemore Hospitals for Clostridium difficile toxin assay were screened for the presence of vancomycin-resistant enterococci (VRE). RESULTS: VRE were cultured from two of 686 patients, giving a colonisation rate of 0.3% in those patients who had a faeces sample submitted for C. difficile toxin assay (95% CI 0 to 0.7%). Both isolates were Enterococcus faecalis; susceptible to ampicillin, resistant to vancomycin and of the vanA genotype. CONCLUSIONS: This is the first screening study in New Zealand that has identified patients with VRE colonisation. While VRE are still rarely isolated in this country, rates of colonisation and infection may be increasing. Hospitals need to be aware of the likely emergence of VRE and be prepared to implement strategies to limit their spread.

Adolescent↗
PubMed2002

Increased nerve and blood vessel ingrowth associated with proteoglycan depletion in an ovine anular lesion model of experimental disc degeneration.

STUDY DESIGN: Nerves and blood vessel distribution in discs were localized immunohistochemically and correlated with the proteoglycan contents of normal and degenerate disc tissues. OBJECTIVE: The aim of the present study was to systematically evaluate whether nerve and blood vessel ingrowth was associated with depletion of disc proteoglycans and degenerative changes in an established experimental model of disc degeneration. SUMMARY OF BACKGROUND DATA: Animal models of disc degeneration, allowing longitudinal study of pathogenic mechanisms, are limited. The ovine model enables systematic monitoring of blood vessel and nerve ingrowth during the development of disc degeneration after injury to the anulus fibrosus. METHODS: Merino sheep received a controlled left anterolateral surgical defect in the outer anulus fibrosus of the L1-L2 and L3-L4 discs (lesion group); sham-operated controls received the retroperitoneal anterolateral approach only. Animals were killed 3, 6, 12, and 26 months postoperation, and the discs were collected for histology and compositional and morphologic analyses. Sagittal tissue sections were stained with toluidine blue and hematoxylin and eosin; Type IV collagen immunolocalization visualized blood vessel ingrowth, and nerves were immunolocalized using monoclonal antibodies to growth-associated protein (GAP-43), protein gene product 9.5, and glial fibrillary acidic protein. RESULTS: Compositional and histologic results demonstrated early focal depletion 3-12 months postoperation of glycosaminoglycan associated with lesion development, increased blood vessel and nerve ingrowth, and infiltration of cells from the outer anulus fibrosus along the plane of the original defect. Blood vessel numbers in the outer to mid third of the anulus fibrosus were elevated in the lesion discs 3-6 months postoperation reaching a maximum at 12 months postoperation; nerves immunoreactive with protein gene product 9.5 (also maximal at 12 months postoperation) were often found associated (but not exclusively) with blood vessels, and some nerves were also reactive with GAP-43 and glial fibrillary acidic protein, but only at 12 months postoperation. CONCLUSIONS: Nerve and blood vessel ingrowth into the anulus fibrosis were strongly associated with proteoglycan depletion. The ovine anular lesion model of disc degeneration is a useful experimental model for the systematic evaluation of nerve and blood vessel development after anular injury.

Animals↗
PubMed2002

Cells from different regions of the intervertebral disc: effect of culture system on matrix expression and cell phenotype.

STUDY DESIGN: This study examined how the culture system and region of cellular origin affect disc cell morphology and extracellular matrix production. OBJECTIVE: To determine the role of the cell populations in the different regions of the adult intervertebral disc in maintaining gradients in composition across the disc. SUMMARY OF BACKGROUND DATA: It is not known whether the steep profiles in composition across the intervertebral disc are maintained by distinct cell populations or whether differences in cell metabolism are determined by changes in the physical environment across the disc. Very little information exists on the matrix produced by cells from the mature, non-notochordal nucleus pulposus. METHODS: Cells were extracted from articular cartilage, nucleus pulposus, and the inner and outer anulus fibrosus of caudal discs from 18- to 24-month-old steers cultured in alginate or collagen gels or in monolayer. The effect of culture system and cell origin on cell morphology and matrix synthesis was measured using 35S-sulphate labeling and indirect immunolocalization. RESULTS: Distinct morphologic differences between cells from different regions cultured in monolayer were retained through two passages. The rate of sulfate incorporation varied with cell type. Immediately after isolation, it was two- to threefold greater for nucleus cells than for cells from the disc inner anulus or articular cartilage. The rate was lowest for outer anulus cells. It also varied with culture system. For all cell types, the incorporation rate was highest in alginate and lowest in monolayer. Immunolocalization showed that nucleus cells stained strongly for all proteoglycan epitopes, whereas outer anulus cells stained least and in monolayer produced little proteoglycan. CONCLUSIONS: The disc has at least three distinct cell populations, which differ in morphology and in amount and type of matrix they produce. Cells from mature nucleus pulposus produced sulfated glycosaminoglycans at a high rate in contrast to reported results for notochordal nucleus cells. Alginate, although an appropriate culture system for inner anulus and nucleus cells, may not be a suitable medium for outer anulus cells.

Animals↗
PubMed2002

Human intervertebral disc aggrecan inhibits nerve growth in vitro.

OBJECTIVE: To assess the effects of human intervertebral disc aggrecan on nerve growth and guidance, using in vitro techniques. METHODS: Aggrecan extracted from human lumbar intervertebral discs was incorporated into tissue culture substrata for the culture of the human neuronal cell line, SH-SY5Y, or explants of chick dorsal root ganglia. The effects on nerve growth of different concentrations of aggrecan extracted from the anulus fibrosus and nucleus pulposus, and of these aggrecan preparations following enzymic deglycosylation, were compared. RESULTS: Disc aggrecan inhibited the growth of neurites from SH-SY5Y cells and induced growth cone turning of chick sensory neurites in a concentration-dependent manner. Aggrecan isolated from the anulus fibrosus was more inhibitory than that isolated from the nucleus pulposus, but enzymic pretreatments to reduce the glycosylation of both types of disc aggrecan partially abrogated their inhibitory effects. CONCLUSION: Nerve growth into degenerate intervertebral discs has been linked with the development of low back pain, but little is known about factors affecting disc innervation. The finding that disc aggrecan inhibits nerve growth in vitro, and that this inhibitory activity depends on aggrecan glycosylation, has important implications for our understanding of mechanisms that may regulate disc innervation in health and disease.

Aggrecans↗
PubMed2002

Elastic fibre organization in the intervertebral discs of the bovine tail.

Elastic fibres have been revealed by both elastin immunostaining and conventional histological orcein-staining in the intervertebral discs of the bovine tail. These fibres are distributed in all regions of the disc but their organization varies from region to region. In the centre of the nucleus, long (> 150 microm) elastic fibres are orientated radially. In the transitional region between nucleus and annulus, the orientation of the elastic fibres changes, producing a criss-cross pattern. In the annulus itself, elastic fibres appear densely distributed in the region between the lamellae and also in 'bridges' across the lamellae, particularly in the adult. Elastic fibres are apparent within the lamellae, orientated parallel to the collagen fibres of each lamella, particularly in the young (12-day-old) discs. In the region between the disc and the cartilaginous endplate, elastic fibres appear to anchor into the plate and terminate there. The results of this study suggest that elastic fibres contribute to the mechanical functioning of the intervertebral disc. The varying organization of the elastic fibres in the different regions of the disc is likely to relate to the different regional loading patterns.

Animals↗
PubMed2002

Changes in expression of the human homologue of the Drosophila discs large tumour suppressor protein in high-grade premalignant cervical neoplasias.

The Drosophila tumour suppressor discs large (Dlg) is a cell-junction localized protein that is required for the maintenance of epithelial cyto-architecture and the negative control of cell proliferation. The mammalian homologue is likely to have a similar mode of action, and therefore functional perturbation of this protein may be linked to the development of epithelial-derived cancers. The finding that several unrelated viral oncoproteins, including the E6 protein of oncogenic human papillomaviruses, bind to the human homologue of Dlg (hDlg) supports this proposition. Employing immunohistochemistry, we show that in uterine cervical squamous epithelia, prominent localization of hDlg at sites of intercellular contact occurs in cells that have left the proliferating basal cell layers and begun maturation. The presence of hDlg at sites of cell:cell contact diminishes, whilst intracellular cytoplasmic levels increase significantly in high-grade, but not low-grade, cervical neoplasias. In invasive squamous cell carcinomas, total cellular hDlg levels are greatly reduced. Our data suggest that loss of hDlg at sites of intercellular contact may be an important step in the development of epithelial cancers.

Adaptor Proteins, Signal Transducing↗
PubMed2002

Detection of CD4(+)- and CD8(+)-T-cell responses to human papillomavirus type 1 antigens expressed at various stages of the virus life cycle by using an enzyme-linked immunospot assay of gamma interferon release.

Human papillomavirus (HPV) antigens are expressed in epithelial cells at different stages of differentiation, and this may affect how they are handled by the immune system. We assessed the relative immunogenicities of four different HPV type 1 proteins: E6 and E7, which are made early in basal or parabasal cells; E4, which is made suprabasally in differentiating cells; and L1, a late protein which appears in the highly differentiated upper spinous layers. Pools of 15-mer peptides covering the primary sequences of all four proteins were used to screen 15 normal donors in enzyme-linked immunospot assays of gamma interferon release for both CD4(+)- and CD8(+)-T-cell reactivities. CD8(+)-T-cell responses were detected to the L1 protein in 7 of the 15 samples examined. No responses to E6, E7, or E4 were detected. CD4(+)-T-cell reactivities were again detected in 7 of the 15 donors. A broader spectrum of responses to E6 (three of seven), E4 (six of seven), and L1 (three of seven) was apparent, but there was no reactivity to E7. The predominant CD4(+) response was to E4. Reactivities were seen in some cases to corresponding regions on other common HPV types but were probably due to a multiple infection rather than to a cross-reaction. Antibodies to HPV1 virus-like particles were detected in 12 of the 15 (80%) donors, but antibody status did not correlate with T-cell reactivity. The differences in the relative immunogenicities of the four proteins revealed in this study are discussed in relation to how they may be processed and presented to the immune system by differentiating epithelial cells.

Amino Acid Sequence↗
PubMedDate not supplied

Educational approaches for maximizing arousal in children with multiple and severe disability: new directions for research and practice in early childhood contexts.

This paper provides a review of several critical issues and directions for research and practice, centred on children with multiple and severe disability, with special attention to the recent study of individual behaviour states as a measure of arousal and involvement. It notes several areas for future research and discusses educational interventions designed to improve the engagement of children, focusing on the central role of early intervention and human ecologies in supporting the achievement of positive educational outcomes for this population.

Abnormalities, Multiple↗