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Biomedical subjects

L Salter

Publications and source records attributed to L Salter.

9 recordsLinked to original sources

UVA-induced apoptosis studied by the new apo/necro-Comet-assay which distinguishes viable, apoptotic and necrotic cells.

An adaptation of the Comet-assay was developed which enables the discrimination of viable, apoptotic and necrotic single cells by use of the common Annexin-V staining and a dye exclusion test on the cells already embedded in agarose gel on glass slides. Membrane integrity (Ethidium-Homodimer exclusion), cellular esterase activity (Calcein blue-AM) as well as translocation of phosphadidyl-serine (Annexin-V) were analysed using these stains. The advantage of the 'apo/necro-Comet-assay' is that the viability status of individual cells can be determined and correlated with the DNA fragmentation pattern (comet) formed by the same cells. Hence, DNA damage can be assessed and correlated with viable cells or cells undergoing early, mid- or late stage apoptosis or necrosis as identified by the staining pattern. The staining was verified using heat and etoposide-induced apoptosis. This technique, among others, was used to study whether apoptotic fragmentation interferes with repair kinetics measured with the comet assay following UVA exposure (doses up to 1,280 kJ/m(2)) in the cultured human keratinocytes (HaCaT). Therefore, a time course of apoptotic events (phosphatidyl translocation and TUNEL fragmentation) was established and correlated to the DNA fragmentation in the comet-assay. Apoptotic cells were detected more than 8 h later. The combined three-colour staining method with the comet assay showed that there was no significant interference of DNA repair by apoptotic fragmentation processes since DNA repair was almost completed before the onset of apoptotic fragmentation. The apo/necro-Comet-assay reduces the general problem of false-positive results in genotoxicity tests using the Comet-assay.

Annexin A5↗

Sun protection initiatives in Cornwall.

Recent evidence indicates that there are significant numbers of cases of malignant melanoma in the UK. In order to assess the current position with regard to sun awareness in Cornwall, a questionnaire survey of all state primary school heads (n = 123) and a survey of a random sample of GP practices (n = 9) was carried out. The data obtained were supported by visits to libraries and Tourist Information Centres at urban and rural centres--this enabled the identification of sun awareness literature. Key health professionals who worked within the field of health promotion were also contacted. The findings showed that in Cornwall public campaigns organized around the issue of sun protection took place only sporadically, although GP surgeries usually organize a display at the appropriate time of the year. None of the public places (e.g. Tourist Information Centres, libraries) surveyed had sun protection messages on display. It is concluded that insufficient sun awareness initiatives were being undertaken in Cornwall. Although most primary schools included sun awareness education in their curriculum in a form based on the Sun Awareness Guidelines produced by the Department of Health in 1995, few schools considered further measures to protect pupils on hot and sunny days. In particular the provision of shade, the scheduling of outdoor activities and the use of sunscreen and protective clothing were not standard.

Child↗

Photodynamic therapy using meta-tetrahydroxyphenylchlorin (Foscan) for the treatment of vulval intraepithelial neoplasia.

BACKGROUND: Photodynamic therapy (PDT) has unique properties which make it suitable for the local treatment of superficial epithelial disorders; it has been suggested as a useful treatment for carcinoma in situ of the vulva. OBJECTIVES: To evaluate the effect of the systemic photosensitizing agent meta-tetrahydroxyphenylchlorin (mTHPC or temoporfin; Foscan, Biolitec, Edinburgh, U.K.) in vulval intraepithelial neoplasia type III (VIN III). METHODS: PDT using mTHPC was performed in six patients with VIN III. A dose of 0.1 mg kg(-1) body weight mTHPC was injected intravenously and the area of VIN irradiated 96 h later with 652-nm light from a diode laser. Patients were reviewed 1 week, 6 months and 2 years following treatment. RESULTS: Patients experienced only minimal pain from the initial treatment but two patients subsequently developed severe pain at the treated site for up to 2 weeks following PDT. All patients developed oedema and slough formation at the treated site and one patient developed cellulitis. At 6 months two patients had developed small recurrences of VIN at the original site and one patient had an area of VIN at a new site. These were treated either with further PDT or with a small excision. At 2 years there was no recurrence of VIN at the original site in all patients reviewed. CONCLUSIONS: This small case series demonstrates that mTHPC-PDT is a useful initial treatment for VIN III. It is relatively selective, shows good cosmesis and conserves form and function. This is a major advantage over surgery. Repeat treatments are also possible, which is important in a condition such as VIN, which tends to be multifocal. Systemic mTHPC-PDT appears to have an advantage over topical 5-aminolaevulinic acid-PDT as the photosensitizer is distributed widely in areas of disease and consequently identifies foci which may not be apparent clinically but become evident when illuminated.

Adult↗

N-acetyl-L-cysteine prevents DNA damage induced by UVA, UVB and visible radiation in human fibroblasts.

The thiol N-acetyl-L-cysteine (NAC) is a source of cysteine for the synthesis of the endogenous antioxidant glutathione (GSH) which is depleted by ultraviolet radiation. It is also associated with the scavenging of reactive oxygen species (ROS). In this study the effects of NAC were examined in cultured human fibroblasts during prolonged exposure to ultraviolet B (UVB), ultraviolet A (UVA) and visible irradiation (280-700 nm), delivered by a 150 W xenon-arc lamp. The alkaline comet assay was used to assess the DNA damage in individual cells. It was found that incubating skin and lung fibroblasts at 37 degrees C for 1 h with an optimal 6 mM NAC supplement prior to light exposure, significantly reduced the level of DNA damage in both cell types, however, the skin fibroblasts were less sensitive to xenon-arc lamp irradiation than lung fibroblasts. NAC incubation resulted in an initial delay in DNA damage when the cells were irradiated. There was also a significant reduction in the overall levels of DNA damage observed with continued irradiation. NAC significantly reduced the DNA damage produced in lung fibroblasts depleted of normal GSH protection by the glutamylcysteinyl synthetase inhibitor, L-buthionine-[S,R]-sulfoximine. Although the specific mechanism of NAC protection has not yet been elucidated, these results support the hypothesis that NAC may protect the cells directly, by scavenging ROS induced by UVA and visible radiation, and indirectly by donating cysteine for GSH synthesis.

Acetylcysteine↗

A preliminary investigation of the effects of arsenate on irradiation-induced DNA damage in cultured human lung fibroblasts.

Single-cell gel electrophoresis (the comet assay) was used to assess single-strand breaks (SSBs) produced in cultured lung human fibroblasts by xenon lamp irradiation alone, various concentrations of arsenate [As(V)], alone or various combinations of the two. It was found that significantly higher levels of SSBs were observed in the irradiated cells than the nonirradiated cells and that elevating levels of arsenate enhanced the level of damage detected in both irradiated and nonirradiated cells in a concentration-dependent manner; that is, incubating cells with arsenate alone produced marked DNA damage without an irradiation insult being necessary. The results of this study indicate that arsenate is acting as a cogenotoxin with irradiation in this cell line. This additive effect may also be cocarcinogenic, and as a result it is possible that less solar irradiation may be required to induce skin cancer in arsenic-exposed populations.

Arsenates↗

Pathways for continence care: development of the pathways.

This article is the second in a series of three covering a project into the use of care pathways for continence care undertaken by the authors. Loddon NHS Trust, Wiltshire and Swindon Healthcare NHS Trust and Salisbury Healthcare NHS Trust collaborated and supported their continence advisers in moving from financially driven assessment data to writing evidence-based care pathways and supporting patient information. The first article (Vol 9(9): 590-6) described the issues facing the continence advisers and the background to their decision to use full evidence-based care pathways. It also gave the results of an audit demonstrating that high quality equitable continence care was not reaching each patient. This article covers the literature search and the problems encountered in the setting up of a database and the development of a generic pathway, a symptom profile and specific pathways. It describes how each pathway evolved and was underpinned with the relevant evidence. It further describes the supporting information and design problems. Finally, it gives information on piloting the care pathways.

Critical Pathways↗

Pathways for continence care: background and audit.

This article is the first in a series of three covering the use of care pathways for continence care. Trusts in Basingstoke, Swindon and Salisbury have collaborated in supporting their continence advisers in moving from finance-driven assessment data to evidence-based care pathways and the provision of patient information. This article identifies the background and approach to care pathways and addresses the quality issues. It details the issues facing continence advisers and how care pathways may help to address them. Furthermore, it describes a baseline audit which was carried out to ensure that facts rather than beliefs were being used and this demonstrated that little advice or treatment was actually reaching the patient.

Aged↗

Pathways for continence care: the validation process.

This article is the third in a series of three describing a collaborative project between continence advisers in Loddon NHS Trust, Basingstoke, East Wiltshire Healthcare Trust, Swindon, and Salisbury Healthcare Trust to develop and implement care pathways to improve continence care provided to patients. The first article described the issues facing the continence advisers and the background to the decision to develop evidence-based care pathways (Vol 9(9): 590-6). The second covered the literature search and described how each pathway evolved (Vol (17): 1165-72). This article outlines the mechanisms by which the care pathways were subjected to a process of content validation.

Attitude of Health Personnel↗