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Biomedical subjects

N Rousseau

Publications and source records attributed to N Rousseau.

At least 19 recordsLinked to original sources
PubMed2005

Hybrid epitaxial-colloidal semiconductor nanostructures.

We present a growth technique which combines wet-chemical growth and molecular beam epitaxy (MBE) to create complex semiconductor nanostructures with nanocrystals as active optical material. The obtained results show that wet-chemically prepared semiconductor nanocrystals can be incorporated in an epitaxally grown crystalline cap layer. As an exemplary system we chose CdSe nanorods and CdSe(ZnS) core-shell nanocrystals in ZnSe and discuss the two limits of thin (d approximately 2R) and thick (d>2R) ZnSe cap layers of thickness d for CdSe nanorods and nanodots of radii R between 2 and 4 nm. In contrast to the strain-induced CdSe/ZnSe Stranski-Krastanow growth of a quantum dot layer in a semiconductor heterostructure, the technique proposed here does not rely on strain and thus results in additional degrees of freedom for choosing composition, concentration, shape, and size of the nanocrystals. Transmission electron microscopy and X-ray diffractometry show that the ZnSe cap layer is of high crystalline quality and provides all parameters for a consecutive growth of Bragg structures, waveguides, or diode structures for electrical injection.

Cadmium Compounds↗
PubMed2004

[Cerebral abscess: MRI, DWI and MRS features].

Although rare in non immunodeficient patients, the correct diagnosis of brain abscess is essential in order to initiate urgent medical and surgical treatment. We describe the imaging features including spectroscopy and diffusion MRI.

Brain Abscess↗
PubMed2001

Evidence-based guideline for the primary care management of stable angina.

This is an updated version of the first North of England Stable Angina Guideline (1,2) and summarizes the full guideline. (3) This paper presents all the recommendations within the guideline; and where these are new or substantially altered from the original version, it also presents a summary of the supporting evidence. The aims and methods of development (summarized in Box 1) of this guideline are unchanged from the original version, to which readers are directed for more detail. The research questions raised during the development of this guideline are shown in Box 2.

Angina Pectoris↗
PubMed2001

Evidence-based guideline on the primary care management of asthma.

This is an updated version of the first North of England Asthma Guideline (1,2) and summarizes the full guideline. (3) This paper presents all the recommendations within the guideline and, where these are new or substantially altered from the original version, it also presents a summary of the supporting evidence. The aims and methods of development (summarized in Box 1) of this guideline are unchanged from the original version, to which readers are directed for more detail. The research questions raised during the development of this guideline are shown in Box 2.

Asthma↗
PubMed2000

Guidelines in professions allied to medicine.

BACKGROUND: Clinical practice guidelines aim to reduce inappropriate variations in practice and to promote the delivery of evidence-based health care. OBJECTIVES: To identify and assess the effects of studies of the introduction of clinical practice guidelines in nursing (including health visiting), midwifery and other professions allied to medicine. SEARCH STRATEGY: We searched the Cochrane Effective Practice and Organisation of Care Group specialised register, MEDLINE (1975 to 1996), EMBASE, Cinahl and Sigle to 1996, the NHS Economic Evaluations Database (1994 to 1996), DHSS-Data (1983 to 1996), the Database of Abstracts of Reviews of Effectiveness (1994 to 1996) and reference lists of articles. We also hand searched the journal Quality in Health Care, made personal contact with content experts and contacted libraries identified by an expert panel. SELECTION CRITERIA: Randomised trials, controlled before-and-after studies and interrupted time series analyses of the introduction of interventions comparing 1. Clinical guidelines plus dissemination and/or implementation strategies versus no guidelines; 2. Guidelines plus dissemination and/or implementation strategies versus guidelines plus alternative dissemination and/or implementation strategies; and 3. (post hoc) Guidelines used by professions allied to medicine versus standard physician care. The participants were nurses, midwives and other professions allied to medicine. DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted data and assessed study quality. MAIN RESULTS: Eighteen studies were included involving more than 467 health care professionals. The reporting of study methods was inadequate for all studies. In all but one study, nurses were the targeted professional group; one study was aimed solely at dieticians. The various behaviours targeted included the management of hypertension, low back pain and hyperlipidaemia. Nine studies were identified for comparison 1. Three out of five studies observed improvements in at least some processes of care and six out of eight studies observed improvements in outcomes of care. Only one study included a formal economic evaluation, with equivocal findings. Three studies were identified for comparison 2 but it was difficult to draw firm conclusions because of poor methods. Six studies were identified for comparison 3 (post hoc). These studies generally supported the hypothesis that there was no difference between care given by nurses using clinical guidelines and standard physician care. REVIEWER'S CONCLUSIONS: There is some evidence that guideline-driven care is effective in changing the process and outcome of care provided by professions allied to medicine. However, caution is needed in generalising findings to other professions and settings.

Allied Health Personnel↗
PubMed2000

Local information for primary care: the St Albans WAX Project (STAPCIS).

The St. Albans Primary Care Information Service (STAPCIS) is a database of locally focused information designed to be of use for GPs and the Primary Care team as a whole in a particular area. It is currently being used by practices in the St. Albans, Dacorum and Watford & Three Rivers Primary Care Groups. STAPCIS developed from a project initiated in late 1997 to pilot the use of the WAX software to improve access to directory-type and full-text material needed for easy access by primary care staff and traditionally difficult to manage. The database is updated centrally by the STAPCIS Librarian who distributes the new editions to the practices. The WAX software itself was developed by the Cambridge Centre for Clinical Informatics. STAPCIS contains locally and nationally produced relevant information from a variety of sources, including full-text clinical guidelines and directories of Trusts. Decisions on new content are made by a Steering Group and the GPs and Primary Care teams are particularly encouraged to make suggestions regarding new content. The service is financially supported by the three primary care groups. The STAPCIS Librarian is project-managed by the Library & Information Development Unit (North Thames ), which also provides additional equipment and expertise. A new software company, WaX Info Ltd ( ), will soon be releasing a new version of the software, WaX. WaX consists of a WaX client and WaX ActiveLibrary server software. With the new version, the 'books' of information will still be stored on the user's PC, retaining the speed of access, but the server will enable users to 'borrow' books from remote locations and will provide automatic updates of all books. The new software will improve the management and distribution processes of STAPCIS once all of the practices have Internet connectivity.

Community Health Services↗
PubMed2000

Predicting place of discharge from hospital for patients with a stroke or hip fracture on admission.

OBJECTIVES: To determine the predictive power of patient and service characteristics on place of discharge following hospital admission for an acute stroke and for hip fracture. METHODS: Prospective cohort of 440 acute stroke and 572 hip fracture patients aged 65 years or over admitted from home to six district general hospitals and associated community hospitals, three in the North and three in the South of England. RESULTS: Age, marital status, living arrangements, mental health status at admission, pre-admission self-rated disability, pre-admission use of home-care services, post-admission staff assessments of functional dependency as measured by Barthel Index and of confusion as measured by the modified Crichton Royal Behavioural Rating Scale and nursing staffs' expectation of place of discharge are all significantly related to place of discharge for stroke and hip fracture participants. Logistic regression correctly predicted discharge destination for 87% of stroke patients from data available at time of admission and 83% of hip fracture patients. Of the 30% of stroke patients discharged to an institution, the model correctly predicted 73%. However, of the 19% of hip fracture patients discharged to an institution, only 28% were correctly predicted. CONCLUSIONS: Data about older patients admitted to hospital with an acute condition should be routinely collected by hospital staff to inform clinical management and to permit risk-adjusted audit.

Aftercare↗
PubMed1999

Switch recombination in a transfected plasmid occurs preferentially in a B cell line that undergoes switch recombination of its chromosomal Ig heavy chain genes.

Ab class switching is induced upon B cell activation in vivo by immunization or infection or in vitro by treatment with mitogens, e. g. LPS, and results in the expression of different heavy chain constant region (CH) genes without a change in the Ab variable region. This DNA recombination event allows Abs to alter their biological activity while maintaining their antigenic specificity. Little is known about the molecular mechanism of switch recombination. To attempt to develop an assay for enzymes, DNA binding proteins, and DNA sequences that mediate switch recombination, we have constructed a plasmid DNA substrate that will undergo switch recombination upon stable transfection into the surface IgM+ B cell line (I.29 mu), a cell line capable of undergoing switch recombination of its endogenous genes. We demonstrate that recombination occurs between the two switch regions of the plasmid, as assayed by PCRs across the integrated plasmid switch regions, followed by Southern blot hybridization. Nucleotide sequence analysis of the PCR products confirmed the occurrence of S mu-S alpha recombination in the plasmid. Recombination of the plasmid in I.29 mu cells does not require treatment with inducers of switch recombination, suggesting that recombinase activity is constitutive in I.29 mu cells. Recombination does not require high levels of transcription across the switch regions of the plasmid. Fewer recombination events are detected in four different B and T cell lines that do not undergo switch recombination of their endogenous genes.

Animals↗
PubMed1999

Clinical guidelines in nursing, midwifery and the therapies: a systematic review.

BACKGROUND: While nursing, midwifery and professions allied to medicine (PAMs) are increasingly using clinical guidelines to reduce inappropriate variations in practice and ensure higher quality care, there have been no rigorous overviews of their effectiveness in relation to these professions. We identified 18 evaluations of guidelines which met established quality for evaluations of interventions aimed at changing professional practice. This paper describes characteristics of guidelines evaluated and the effectiveness of different dissemination and implementation strategies used. METHODS: Guideline evaluations conducted since 1975 which used a randomized controlled trial, controlled before-and-after, or interrupted time-series design, were identified using a combination of database and hand searching. FINDINGS: It is mostly impossible to tell whether the guidelines evaluated were based on evidence. The most common method of guideline dissemination was the distribution of printed educational materials. Three studies compared different dissemination and/or implementation strategies: findings suggest educational interventions may be of value in the dissemination of guidelines and confer a benefit over passive dissemination.

Allied Health Occupations↗
PubMed1998

Outcomes following acute hospital care for stroke or hip fracture: how useful is an assessment of anxiety or depression for older people?

OBJECTIVE: To investigate the association between severe life events and mental health outcomes following acute hospital care for older patients with acute stroke or fractured neck of femur. DESIGN: Prospective longitudinal survey of stroke and hip fracture patients admitted to hospital from admission to 6-month follow-up. SETTING: Six district general hospitals, three in the North and three in the South of England. PARTICIPANTS: 642 patients admitted to hospital with an acute stroke (268) or hip fracture (374) resident in a private household at 6 months follow-up. MAIN OUTCOME MEASURES: Hospital Anxiety and Depression Scale, cognitive items of the Survey Psychiatric Assessment Scale, Clackmannan Disability Scale, Severe Life Events Inventory, Wenger Social Support Network Typology. RESULTS: 47% of 6-month survivors of stroke or hip fracture resident in private households had a possible psychiatric illness: dementia (13%), anxiety or depression (41%). 57% had severe or very severe disability and 48% experienced additional life events (17% two or more) after hospital admission. Severe disability was strongly associated with a higher prevalence of anxiety (p < 0.0005) or depression (p < 0.0001). Social contact was associated with a lower prevalence of anxiety (p < 0.01) or depression (p < 0.0001) and social support network type was strongly associated with depression (p < 0.001) but not anxiety (p = 0.096). Number of severe life events was associated with anxiety (p < 0.001) but not depression (p = 0.058). CONCLUSION: Disability is probably a more robust outcome measure than assessments of mental health for older people in uncontrolled studies.

Aged↗
PubMed1998

Effect of aging on growth hormone-induced insulin-like growth factor-I secretion from cultured rat chondrocytes.

The physiological roles of growth hormone (GH) and insulin-like growth factor-I (IGF-I) in adult other than their effects on tissue growth is to maintain the integrity of the organism. It has been proposed that reduced availability of both hormones in late adulthood may contribute to the initiation of the major alterations and senescent changes in body composition that characterize normal human aging. Since accumulated evidence points to a direct interplay of GH with chondrocytes in cartilage, we determined in the present study the effect of aging on both basal and GH-stimulated IGF-I production from rat cultured chondrocytes. Namely, we investigated the effect of 0, 10 and 100 ng/ml of growth hormone on IGF-I levels during 1, 2, 4 and 8 days in monolayer cultured costal chondrocytes from 2-, 6-, 14- and 18-month-old rats. Measurement of IGF-I levels was done by a radioimmunoassay following a validated formic acid-heating-acetone extraction procedure. In 6- and 14-month-old rat chondrocytes, basal IGF-I secretion was higher than that of the 2-month-old control rats. In 18-month-old rat chondrocytes, basal IGF-I secretion was lower than in any other age group. Whereas in 2-, 6- and 14-month-old rat chondrocytes, GH induced a dose-related IGF-I response which was highly significant on day 8, the 18-month-old rat chondrocytes no longer responded to GH treatments. Our results suggest that the decrease in IGF-I production from cultured rat chondrocytes could be related to the blunted GH secretion in the course of aging. Therefore, GH availability in the course of aging appears to be a determinant factor in tissue responsiveness and underscores the hypothesis that GH replacement could present a therapeutic potential against the aging senescent changes.

Aging↗
PubMed1998

Effect of clinical guidelines in nursing, midwifery, and the therapies: a systematic review of evaluations.

BACKGROUND: Although nursing, midwifery, and professions allied to medicine are increasingly using clinical guidelines to reduce inappropriate variations in practice and ensure higher quality care, there have been no rigorous overviews of their effectiveness, 18 evaluations of guidelines were identified that meet Cochrane criteria for scientific rigor. METHODS: Guideline evaluations conducted since 1975 which used a randomised controlled trial, controlled before and after, or interrupted time series design were identified through a combination of database and hand searching. RESULTS: 18 studies met the inclusion criteria. Three studies evaluated guideline dissemination or implementation strategies, nine compared use of a guideline with a no guideline state; six studies examined skill substitution: performance of nurses operating according to a guideline were compared with standard care, generally provided by a physician. Significant changes in the process of care were found in six out of eight studies measuring process and in which guidelines were expected to have a positive impact on performance. In seven of the nine studies measuring outcomes of care, significant differences in favour of the intervention group were found. Skill substitution studies generally supported the hypothesis of no difference between protocol driven by nurses and care by a physician. Only one study included a formal economic evaluation, with equivocal findings. CONCLUSIONS: Findings from the review provide some evidence that care driven by a guideline can be effective in changing the process and outcome of care. However, many studies fell short of the criteria of the Cochrane Effective Practice and Organisation of Care Group (EPOC) for methodological quality.

Allied Health Occupations↗
PubMed1997

Issues of recruitment and maintaining high response rates in a longitudinal study of older hospital patients in England--pathways through care study.

STUDY OBJECTIVES: To describe and discuss the methods used to recruit and maintain an unbiased sample of older discharged hospital patients in a study of the process and outcomes of hospital care. DESIGN: Prospective longitudinal interview study of consecutive patients admitted to hospital over a 12 month period and followed up for six months. Interviews took place in hospital five days after admission, at home 10 days after discharge, and six months after admission. SETTING: Six hospital locations: three in the north of England and three in the south. PARTICIPANTS: People aged 65 and over admitted to hospital with a new stroke or fractured neck of femur, their significant other, and nursing staff caring for them. MAIN RESULTS: Of 3105 patients referred to the study, 2111 were eligible and 1671 (79%) were recruited. Recruited stroke patients were younger than those not recruited and rates differed between locations for both stroke and fractured neck of femur. By six months after admission 25% had died. Outcome data were obtained for 85% of the surviving patients. Patients who died were older and frailer before admission. Among survivors, outcome data for stroke patients were less likely to be obtained for men, those more able initially, and those who were married. Response rates to each interview differed according to respondent types. Interviews were more likely to be obtained with significant others than patients. Patients who were not able to be interviewed were older and frailer; significant others were less likely to be interviewed if the patients were younger and more able. CONCLUSIONS: High response rates can be achieved with very frail older people if strategies are adopted to maintain their interest and if self reported data are supplemented by interviewing significant others.

Age Factors↗
PubMed1997

[From vocation to discipline].

This article looks at the history of nursing care in relation to modern-day nurse theorists' concepts of a professional nursing identity. In her discussion of the history of female caregivers and the nursing profession, the author attempts to show that by shifting nursing care from the concept of a vocation to a so-called scientific concept, nurses have failed to resolve their identity problem. The author maintains that the reason for this failure stems from the early days of the profession when line managers ignored the tradition of caregiving, rather than using it as the basic rationale of the nursing profession. This former tradition had caregivers using medicinal herbs, preparing home remedies, performing minor surgery, helping women during childbirth (midwifery), accompanying the dying and helping the poor. The author concludes that nurses would benefit from greater awareness of their profession's historical roots. This would in turn give them a clearer understanding of the type of services they are capable of delivering to the public.

Canada↗
PubMed1995

Increased insulin-like growth factor 1 production by human osteoarthritic chondrocytes is not dependent on growth hormone action.

OBJECTIVE: To investigate insulin-like growth factor 1 (IGF-1) production in normal and osteoarthritis (OA) chondrocytes and to further examine the role of growth hormone (GH) in adult human cartilage and, in particular, in diseased tissue. METHODS: IGF-1 production was measured with a radioimmunoassay. Binding assay, Northern blot, and reverse transcriptase polymerase chain reaction (RT-PCR) techniques were used for GH receptor (GHR) detection. The biological response to GH was estimated via IGF-1 production. RESULTS: We observed that basal levels of IGF-1 production were significantly higher in OA chondrocytes than in normal cells (P < 0.005). Adult human chondrocytes, however, were unresponsive to GH stimulation with regard to IGF-1 production, as shown in dose-response (0-1,000 ng/ml) and time-course (days 1-8) studies. In addition, no specific 125I-GH binding was detected in either cell type. Northern blot analysis revealed a 5.5-kb GHR messenger RNA (mRNA) species, but semiquantitative RT-PCR revealed no difference in GHR mRNA expression by normal and OA chondrocytes. CONCLUSION: This study indicates that the elevated synthesis of IGF-1 by adult human OA chondrocytes occurs through a GH/GHR-independent mechanism, suggesting that other factors are capable of controlling local IGF-1 production in these cells.

Aged↗