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Biomedical subjects

A Long

Publications and source records attributed to A Long.

At least 37 records · Page 2Linked to original sources
PubMed2003

[Lower limb arterial disease: Doppler sonography follow-up after revascularization].

Follow-up color duplex sonography after arterial surgery or angioplasty for lower limb arterial disease evaluates the outcome of the procedure and searches for lesions compromising patency. The various types of lesions are described. After surgical bypass, lesions include stenosis, anastomotic abnormality (enlargement, false-aneurysm), arterio-venous fistula, intrinsic bypass abnormalities, and collections. After endoluminal treatment, the main lesions include residual stenosis, restenosis, and in-stent hyperplasia. Local complications related to arterial puncture are described. The frequency and the type of lesions encountered depend on the interval between the date of the revascularization and the follow-up examination.

Aftercare↗
PubMed2002

Copper speciation and accumulation in the gill microenvironment of carp ( Cyprinus carpio) in the presence of kaolin particles.

Carp were exposed to copper adsorbed on kaolin particles at various concentrations (0-2.4 mg/L), and net accumulation due to elevated adsorbed copper in the surrounding water was observed. Copper speciation in the water and fish gill microenvironment was modeled in the presence and absence of kaolin using a chemical speciation program (MINTEQA2). The adsorption affinity constants of kaolin for copper at various pH values used in the speciation calculations were experimentally determined, and the quantitative relationship between the affinity constant and pH was modeled. Copper accumulations in fish gills exposed to kaolin-adsorbed copper was then observed. The results indicate that desorption occurred in the fish gill microenvironment due to both mucus competition of copper and slight increase in water pH. Furthermore, the available copper species increased as a result of desorption, causing a net accumulation of Cu by the gills.

Adsorption↗
PubMed2002

Reconciling voices.

There is a lack of nursing research in relation to how people with mental health problems make sense of their experiences of mental distress. Furthermore, few nursing related studies have conveyed service user's understandings and meanings for their experiences of mental 'disorder'. Narrative psychology claims that people make sense of the world and their lives by using narrative structures to organize diverse experiences. By sharing these stories with others, interpretations are negotiated and personal and cultural meanings are formed. This study used a tried and tested approach to narrative analysis to analyse the transcribed narrative of one man, Gary, who was experiencing mental health problems. The study explores Gary's process of meaning making as it appears in his narrative; the frameworks and metaphors that he uses to help him make sense of his experiences. The tensions between Gary's internal voices and beliefs and the external voices of surrounding culture and psychiatry are highlighted. Emphasis is placed on the importance of attending and responding to personal meanings embedded in narratives as a means of developing sensitive nursing care and enriching nursing research.

Adult↗
PubMed2002

Critical review of non- or minimally invasive methods (duplex ultrasonography, MR- and CT-angiography) for evaluating stenosis of the proximal internal carotid artery.

OBJECTIVE: to assess the performance of non- or minimally invasive methods (duplex ultrasonography, MR- and CT-angiography) in measuring stenosis of the proximal internal carotid prior to endarterectomy without preoperative intra-arterial digital subtraction angiography (DSA). METHODS: systematic review of the literature (five databases, 1990 to February 2001). The value of each imaging technique was studied through its reproducibility and its sensitivity/specificity compared to DSA. RESULTS: sensitivity exceeded 80% and specificity 90% in over two-thirds of the methodologically sound studies, regardless of technique, although direct comparisons between results had to be avoided since the findings originated from different populations. The main drawback of duplex ultrasonography is its levels of reproducibility. In contrast, only a few studies have addressed the reproducibility of MR- and CT-angiography. When the results of duplex and MR-angiography agree, the combination use of these two techniques provides a better diagnosis than either technique taken alone. CONCLUSIONS: all three techniques appear suitable for measuring stenosis of the proximal internal carotid when compared to DSA.

Angiography, Digital Subtraction↗
PubMed2002

Spatiotemporal analysis of epizootic raccoon rabies propagation in Connecticut, 1991-1995.

The quantitative analysis of pathogen transmission within its specific spatial context should improve our ability to predict and control the epizootic spread of that disease. We compared two methods for calibrating the effect of local, spatially distributed environmental heterogeneities on disease spread. Using the time-of-first-appearance of raccoon rabies across the 169 townships in Connecticut, we estimated local spatial variation in township-to-township transmission rate using Trend Surface Analysis (TSA) and then compared these estimates with those based on an earlier probabilistic simulation using the same data. Both the probabilistic simulation and the TSA reveal significant reduction in transmission when local spatial domains are separated by rivers. The probabilistic simulation suggested that township-to-township transmission was reduced sevenfold for townships separated by a river. The global effect of this sevenfold reduction is to increase the time-to-first-appearance in the eastern townships of Connecticut by approximately 29.7% (spread was from west to east). TSA revealed a similar effect of rivers with an overall reduction in rate of local propagation due to rivers of approximately 22%. The 7.7% difference in these two estimates reveals slightly different aspects of the spatial dynamics of this epizootic. Together, these two methods can be used to construct an overall picture of the combined effects of local spatial variation in township-to-township transmission on patterns of local rate of propagation at scales larger than the immediate nearest neighboring townships.

Animals↗
PubMed2002

Nondetection of the S antigen due to the presence of sodium hypochlorite.

Low concentrations of sodium hypochlorite (chlorine bleach) are known to destroy S antigen on intact fresh red blood cells (RBCs). Sodium hypochlorite is commonly used as a disinfectant. We report nondetection of the S antigen in tube and microplate saline indirect antiglobulin testing (SIAT) with a lot of commercial saline utilized in our donor screening and reference laboratories. Known S+s+ RBCs were found to be nonreactive with anti-S by SIAT in our reference laboratory. Our investigation demonstrated the presence of chlorine in the commercial saline. The saline lot was used for several days of donor screening and recall of FFP and platelet concentrates was initiated. Two lots of saline were recalled from blood banks across North America.

Journal Article↗
PubMed2001

Structural and oxo-transfer reactivity differences of hexacoordinate and pentacoordinate (nitro)(tetraphenylporphinato)cobalt(III) derivatives.

The oxo-transfer catalyst (nitro)(pyridyl)cobalt(III) tetraphenylporphyrin has been reinvestigated by substitution of the distal pyridine ligand with 4-N,N-dimethylaminopyridine and 3,5-dichloropyridine. Differences in their structures and in the reactivity of the compounds toward catalytic secondary oxo transfer were investigated by FT-IR and UV-visible spectroscopy, cyclic voltammetry, X-ray diffraction, semiempirical calculations, and reactions with alkenes in dichloromethane solution. Very modest differences in the hexacoordinate compounds' structures were predicted and observed, but the secondary oxo-transfer reactivity at the nitro ligand varies markedly with the basicity of the pyridine ligand and the position of the coordination equilibrium. Oxo transfer occurs rapidly through the pentacoordinate species (nitro)cobalt(III) tetraphenylporphyrin that is generated by dissociation of the pyridine ligand and therefore is strongly related to the Hammett parameters of these nitrogenous bases. The reactive pentacoordinate species CoTPP(NO(2)) can be generated in solution by addition of lithium perchlorate to (py)CoTPP(NO(2)) by Lewis acid-base interactions or more simply by using the weaker Lewis base Cl(2)py instead of py as the distal ligand. In contrast to pentacoordinate (nitro)iron porphyrins, disproportionation reactions of CoTPP(NO(2)) compound are not evident. This pentacoordinate derivative, CoTPP(NO(2)), is reactive enough to stoichiometrically oxidize allyl bromide in minutes. Preliminary catalytic oxidation reaction studies of alkenes also indicate the involvement of both radical and nonradical oxo-transfer steps in the mechanism, suggesting formation of a peroxynitro intermediate in the reaction of the reduced CoTPP(NO) with O(2).

Journal Article↗
PubMed2001

Cutting edge: protein kinase C beta expression is critical for export of Il-2 from T cells.

Protein kinase C (PKC) plays an integral part in T cell activation and IL-2 secretion. We investigated the role of a particular PKC isoform, PKCbeta, in IL-2 production and secretion. The T cell lymphoma line HuT 78 secretes IL-2 in response to the phorbol ester PMA. A PKCbeta-deficient clone of HuT 78, K-4, did not secrete IL-2 in response to PMA stimulation. As assessed by RT-PCR, K-4 expressed mRNA for IL-2 following PMA activation, and intracellular IL-2 protein was detected by immunofluorescence. An enhanced green fluorescent protein-linked PKCbeta construct was microinjected into K-4 cells, which were then stimulated with PMA; those cells that expressed PKCbeta could secrete IL-2, as determined by an in situ immunofluorescent assay. This study demonstrates that PKCbeta is not necessary for transcription of the IL-2 gene or translation of mRNA to protein, but that expression of this PKC isoform is critical to the export of IL-2 molecules from T cells.

Cells, Cultured↗
PubMed2001

Simulation of acid-base condition and copper speciation in the fish gill microenvironment.

pH, alkalinity, and mucus content in the fish gill microenvironment of carp (Cyprinus carpio) were measured by exposing fish to copper at various water pH levels using an apparatus which separates inspired and expired water. The relationship between pH levels inside and outside of the gill microenvironment, between pH and alkalinity, and between mucus secretion, pH, and copper exposure concentration were modeled. Copper speciation in the surrounding water and in the fish gill microenvironment was simulated using MINTEQA2 chemical equilibrium calculation software. The results of the modeling for pH, alkalinity, and mucus calculation were then adopted as inputs for purposes of parameter identification in the speciation modeling. The differences observed in the copper species distribution between that of the fish gill microenvironment and the surrounding water were based on the speciation modeling. The change in copper bioavailability for fish uptake was also examined. The results indicate the presence of an experimental pH balance point at 6.9, where the pH in the fish gill microenvironment is identical to that of the surrounding water. The observed deviation range in pH levels between that found at the gills and that of the surrounding water varied from -0.4 to 0.8 units. A sinusoidal model was developed for calculation of gill pH based on the pH of the surrounding water. Models calculating alkalinity either in the gill microenvironment or in the surrounding water and for estimating mucus secretion were also developed. The results of the chemical equilibrium calculations demonstrate that, within a pH range of 6-9, the dominant species of copper in bulk solution shifted from free ions to that of the hydroxo complex. With respect to the fish gill microenvironment, the dominant species found under acidic conditions were the mucus copper complex and free ions. Because of the influence of mucus complexation and pH change, bioavailable copper species in the fish gill microenvironment were significantly lower than that in the bulk solution, especially under acidic conditions.

Acid-Base Equilibrium↗
PubMed2001

Crucial importance of PKC-beta(I) in LFA-1-mediated locomotion of activated T cells.

Crawling T cell locomotion in which activated lymphocyte function-associated antigen 1 (LFA-1) integrins participate is associated with translocation of the protein kinase C-beta (PKC-beta) isoenzyme to the microtubule cytoskeleton. In normal T cells and T lymphoma cell lines, this type of motility is accompanied by PKC-beta-sensitive cytoskeletal rearrangements and the formation of trailing cell extensions, which are supported by microtubules. Expression of PKC-beta(I) and enhanced green fluorescent protein (EGFP) in nonmotile PKC-beta-deficient T cells restored their locomotory behavior in response to a triggering stimulus delivered via LFA-1 and correlated directly with the degree of cell polarization. We have also shown that PKC-beta(I) is a component of the tubulin-enriched LFA-1-cytoskeletal complex assembled upon LFA-1 cross-linking. These observations may have physiological equivalents at advanced (post-integrin activation) stages of lymphocyte extravasation.

Cell Line↗
PubMed2001

Critical incident stress debriefing following traumatic life experiences.

This study was designed to explore the use of critical incident stress debriefing as a therapeutic intervention following traumatic life events. A case study approach was used to allow the researchers to adopt a more flexible and overtly involved stance. Initial contact took place 24 h following the traumatic life experiences of three women. Critical incident stress debriefing was provided and data were collected and recorded within an ethical framework. Six months following the traumatic life experiences the women were interviewed again to explore their perceptions of the intervention that was provided. The results demonstrated positive outcomes. The women concluded that the debriefing intervention provided a safe forum for them to explore their needs, process their experiences and create constructive narratives. A carefully constructed critical incident stress debriefing intervention was used within the context of its objectives and acknowledged limitations. The study was small and generalizations cannot be made to other individuals who experience similar tragedies. Nevertheless, evidence from previous research coupled with the findings from this study suggests that mental health nurses might benefit from being educated and trained in critical incident stress debriefing. Further research needs to be carried out to explore the use of different models of stress debriefing applied to special circumstances. The goal of such interventions should be to alleviate symptoms and to prevent the development of a full-blown post-traumatic stress disorder.

Crisis Intervention↗
PubMed2001

The effectiveness of parenting programmes facilitated by health visitors.

AIM OF THE STUDY: This study was designed to evaluate the effectiveness of parenting programmes that are facilitated by health visitors and offer practical and emotional support to parents in the Down Lisburn Trust, Northern Ireland. METHODS: All parents (n=78) taking part were given a self-administered questionnaire both before and after attending a 'Positive Parenting' programme. The questionnaire contained items gathering demographic information, standardized measures of clinical anxiety/depression, personality states and coping styles and participants' experience of being a parent and what they wanted from the parenting group. Two items adapted from the Parent Stress Index looked at participants' ratings of themselves as parents, and if they enjoyed this role. STATISTICAL ANALYSIS: All statistics were computed using the SPSS for Windows (version 7) statistical package. The parametric paired-samples t-test was used with the ratio data generated by the Hospital Anxiety and Depression Scale (HADS) questionnaire. It is used to test the difference between the means of the pre and postsets of scores for significance. The nonparametric Wilcoxon test was used to find if there was a significant difference between the pre and postprogramme related samples by ranking the means. The Wilcoxon was chosen firstly because the data were ordinal in nature, hence it cannot be assumed that the findings follow the normal curve of distribution and secondly because it cannot be assumed that the data have homogeneity of variance. FINDINGS: At the end of the 8-week parenting programme, findings demonstrated significant statistically reduced levels of clinical anxiety and depression. Parents demonstrated an increase in more positive ratings of personality states such as not shouting at their children and being more calm and energetic at the end of the programme. Adaptive problem focused coping strategies were reported as being used more often subsequent to the programme, although some of the less adaptive emotion focused strategies had also increased in use. However, no change was evident in their ratings of how good a parent they were or if they enjoyed being a parent. CONCLUSIONS: Health visitors have the skills and are in the position to be preventative agents of inadequate parenting, and advocates of positive parenting. Factors relevant to the realm of positive parenting are highlighted as possible avenues for future research.

Adaptation, Psychological↗
PubMed2001

Functionalism and holism: community nurses' perceptions of health.

This paper reports the results of a study that was designed to explore and examine the perceptions of two groups of newly qualified community nurses about the factors they considered to be embedded within the concepts of health, health-enhancing behaviours at individual, family and community levels and their 'innermost self'. The research was exploratory in nature, and included two sample groups: group 1 comprised 16 newly qualified health visitors; group 2 comprised 16 newly qualified community mental health nurses. Purposive sampling was used and data were collected using semi-structured interviews. The group of health visitors perceived health in terms of physical fitness and functional states. At a global level they perceived the need to provide education on health matters. They gave generously to 'charities' and perceived the 'inner self' as 'that part that matters'. The group of community mental health nurses perceived health in terms of holism and being states. Their concept of health was related to listening to each individual's perception of what is 'right' and 'health-enhancing' for them. At a global level they considered the protection of the ozone layer and the promotion of a just and equitable society which focused on the reduction of poverty, to be key health-enhancing activities. They perceived their 'innermost self' to be 'that part of me that makes life worth living', and the soul. The findings have implications for developing new and creative approaches for teaching the holistic concept of health and healing. Educational activities could be designed which strive to ensure that nurses themselves have safe and health embracing opportunities for exploring all the elements that are embedded within the topic of health. Their role in facilitating holistic health promoting activities for all clients also needs to be addressed.

Attitude of Health Personnel↗
PubMed2001

A survey of community mental health nurses' perceptions of clinical supervision in Northern Ireland.

Since the early 1990s, clinical supervision has been the subject of debate by nurse academics and practitioners. This debate has encouraged the adoption of clinical supervision by the profession throughout the United Kingdom. Search of the literature demonstrates that there has been little published research regarding clinical supervision in Northern Ireland. This study is designed to redress this information deficit. The current position of clinical supervision in relation to community psychiatric nursing in Northern Ireland is explored and evaluated. A survey approach was adopted, collecting data from community psychiatric nurses (CPNs) in Health and Social Services Trusts in Northern Ireland. Data was obtained relating to the practice of clinical supervision and to attitudes of CPNs, their managers and supervisors. Results indicate that there is support for clinical supervision and that it is being implemented within community psychiatric nursing in Northern Ireland, although not in all cases. However, the findings indicate that serious education and training deficits exist, and the importance of the interface between managerial and clinical supervision is emphasized. The issues of providing effective education and training in supervision skills, and the uncertainty that was highlighted regarding fundamental concepts underpinning clinical supervision, have implications for nursing practice, education and management. In addition, based on findings of this study, the difference between management-led supervision and clinical supervision as envisaged by the UKCC, which promotes the personal and professional development of nurses, requires further exploration.

Adult↗
PubMed2001

[Computer simulation of HA influence on copper bioavailability to the fish gills].

Copper speciation in the gill microenvironment of neon terris (Paracheirodon innesi) and the influence of humic acid and pH on copper bioavailability were investigated using exposure experiment and chemical equilibrium calculation. It was found that the copper speciation was changed because of the influence of the humic acid. With the existence of humic acid, the dominant species of copper in the bulk solution was humic acid complexed copper. However, humic acid complexed copper along with mucus complexed copper dominated the fish gill microenvironment. Consequently, the bioavailable copper species both in the bulk solution and in the fish gill microenvironment were significantly reduced by humic acid. The result of the modeling also indicated that the influence of pH was more significant under alkaline condition.

Animals↗
PubMed2000

Cross-linking of LFA-1 induces secretion of macrophage inflammatory protein (MIP)-lalpha and MIP-1beta with consequent directed migration of activated lymphocytes.

Cross-linking of LFA-1 induces an active locomotory phenotype in T cells. In this study we demonstrate that cross-linking of LFA-1 using a monoclonal antibody results in the secretion of MIP-1alpha and MIP-1beta. Similar results were seen with anti-CD44 but not with anti-transferrin receptor or anti-MHC class 1. We examined the ability of activated lymphocytes to migrate onto a substrate consisting of large protein G-Sepharose beads coated with anti-LFA-1 and anti-CD44. In this system a signal is provided by cells at the point of contact with the beads. Cells migrated to cover the bead surface within 24 h. This contact was shown to be inhibited by the introduction of neutralizing antibodies to MIP-1alpha and MIP-1beta. Hence cross-linking of LFA-1 or CD44 induce chemokine secretion which may be of relevance in directional migration of lymphocytes.

Antibodies, Monoclonal↗